:root {
  --ink: #2c241f;
  --ink-soft: #57463b;
  --paper: #eadfbf;
  --paper-deep: #d5b883;
  --teal: #315f5b;
  --red: #b04438;
  --shell: #181411;
  --line: rgba(44, 36, 31, 0.2);
  --column-width: 58px;
  --column-line: rgba(173, 62, 50, 0.38);
  --inner-line: rgba(173, 62, 50, 0.62);
  --hand-font: "Qiaopi MaShan";
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  font-family:
    "Microsoft YaHei",
    "PingFang SC",
    "Hiragino Sans GB",
    system-ui,
    sans-serif;
  color: #f4ead8;
  background: #16120f;
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  border: 1px solid rgba(244, 234, 216, 0.22);
  border-radius: 6px;
  color: #f4ead8;
  background: rgba(255, 255, 255, 0.08);
  cursor: pointer;
  transition:
    background 150ms ease,
    border-color 150ms ease,
    transform 150ms ease;
}

select {
  width: 100%;
  min-height: 40px;
  padding: 0 10px;
  border: 1px solid rgba(244, 234, 216, 0.2);
  border-radius: 6px;
  color: #f4ead8;
  background: rgba(255, 255, 255, 0.08);
}

button:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(244, 234, 216, 0.4);
}

button:active {
  transform: translateY(1px);
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid #d6a85b;
  outline-offset: 2px;
}

.app-shell {
  min-height: 100svh;
  padding: 18px;
  background-image: var(--scene-image);
  background-position: center;
  background-size: cover;
}

.app-shell::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  content: "";
  background:
    linear-gradient(180deg, rgba(16, 12, 9, 0.4), rgba(16, 12, 9, 0.7)),
    linear-gradient(90deg, rgba(16, 12, 9, 0.84), rgba(16, 12, 9, 0.42) 48%, rgba(16, 12, 9, 0.7));
}

.workspace {
  display: grid;
  grid-template-columns: minmax(280px, 380px) minmax(0, 1fr);
  gap: 18px;
  min-height: calc(100svh - 36px);
}

.composer {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 18px;
  border: 1px solid rgba(244, 234, 216, 0.2);
  border-radius: 8px;
  background: rgba(24, 20, 17, 0.78);
  backdrop-filter: blur(14px);
}

.brand {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 12px;
  align-items: center;
}

.brand-mark {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  border: 2px solid rgba(188, 72, 56, 0.75);
  color: #ffc7b8;
  font-family: KaiTi, STKaiti, serif;
  font-size: 24px;
}

h1 {
  margin: 0 0 4px;
  font-size: 22px;
  font-weight: 700;
}

p {
  margin: 0;
}

.brand p,
.hint {
  color: rgba(244, 234, 216, 0.72);
  font-size: 13px;
  line-height: 1.6;
}

.field {
  display: grid;
  gap: 8px;
}

.field span {
  color: rgba(244, 234, 216, 0.78);
  font-size: 13px;
}

textarea,
input {
  width: 100%;
  border: 1px solid rgba(244, 234, 216, 0.22);
  border-radius: 6px;
  color: #fff8eb;
  background: rgba(0, 0, 0, 0.26);
}

textarea {
  min-height: 44px;
  resize: vertical;
  padding: 9px 10px;
  line-height: 1.45;
}

input {
  height: 42px;
  padding: 0 11px;
}

.quick-prompts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.quick-prompts button,
.share-actions button,
.actions button,
.segmented button {
  min-height: 40px;
  padding: 0 12px;
}

.controls-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  padding: 4px;
  border: 1px solid rgba(244, 234, 216, 0.18);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.18);
}

.relation-segmented {
  grid-template-columns: repeat(4, 1fr);
}

.segmented button {
  position: relative;
  z-index: 1;
  border-color: transparent;
  background: transparent;
}

.segmented button.active {
  color: #211912;
  background: #dfb76f;
}

.actions,
.share-actions {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.share-actions {
  grid-template-columns: repeat(2, 1fr);
}

.package-actions {
  display: grid;
}

.package-actions button {
  min-height: 48px;
  border-color: rgba(236, 192, 92, 0.86);
  color: #24180e;
  background:
    linear-gradient(180deg, rgba(255, 231, 150, 0.96), rgba(218, 164, 62, 0.96));
  box-shadow:
    inset 0 1px 0 rgba(255, 250, 222, 0.72),
    0 10px 24px rgba(0, 0, 0, 0.22);
  font-size: 16px;
  font-weight: 800;
}

.package-actions button:hover {
  border-color: rgba(255, 219, 126, 0.96);
  background:
    linear-gradient(180deg, rgba(255, 238, 169, 0.98), rgba(230, 178, 75, 0.98));
}

.monetize-panel {
  display: grid;
  gap: 10px;
  padding: 12px;
  border: 1px solid rgba(223, 183, 111, 0.32);
  border-radius: 8px;
  background: rgba(28, 22, 16, 0.48);
}

.monetize-panel strong {
  display: block;
  color: #ffe6a6;
  font-size: 15px;
}

.monetize-panel span {
  display: block;
  margin-top: 3px;
  color: rgba(244, 234, 216, 0.7);
  font-size: 12px;
  line-height: 1.5;
}

.monetize-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.monetize-actions button {
  min-height: 36px;
  border-radius: 6px;
}

#buyoutBtn {
  border-color: rgba(236, 192, 92, 0.78);
  color: #25190e;
  background: #dfb76f;
  font-weight: 800;
}

#buyoutBtn:disabled {
  cursor: default;
  opacity: 0.72;
}

.payment-dialog,
.share-dialog {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(10, 8, 6, 0.72);
  backdrop-filter: blur(10px);
}

.payment-dialog[hidden],
.share-dialog[hidden] {
  display: none;
}

.payment-card,
.share-card {
  position: relative;
  display: grid;
  gap: 12px;
  width: min(360px, 100%);
  padding: 18px;
  border: 1px solid rgba(244, 234, 216, 0.22);
  border-radius: 8px;
  color: #f8edd9;
  background: rgba(29, 23, 18, 0.96);
  box-shadow: 0 22px 70px rgba(0, 0, 0, 0.46);
}

.payment-card h2,
.share-card h2 {
  margin: 0;
  font-size: 20px;
}

.payment-card p,
.payment-card small,
.share-card p,
.share-card small {
  color: rgba(248, 237, 217, 0.72);
  font-size: 13px;
  line-height: 1.55;
}

.payment-card img,
.share-card img {
  width: min(240px, 72vw);
  margin: 0 auto;
  border-radius: 8px;
  background: #fff;
}

.payment-close,
.share-close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 30px;
  height: 30px;
  padding: 0;
}

.payment-code-field input {
  text-align: center;
  letter-spacing: 0.08em;
}

#shareLinkInput {
  height: 38px;
  padding: 0 10px;
  color: #fff8eb;
  font-size: 12px;
}

.share-dialog-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.share-dialog-actions button {
  min-height: 38px;
}

.payment-contact {
  padding: 9px 10px;
  border: 1px solid rgba(223, 183, 111, 0.36);
  border-radius: 6px;
  color: #ffe6a6 !important;
  background: rgba(223, 183, 111, 0.12);
}

.primary {
  color: #211912;
  border-color: #e6be78;
  background: #dfb76f;
  font-weight: 700;
}

.primary:hover {
  background: #edc882;
}

.preview-stage {
  position: relative;
  display: grid;
  min-height: 640px;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(244, 234, 216, 0.18);
  border-radius: 8px;
}

.background-credit {
  position: absolute;
  right: 14px;
  bottom: 12px;
  color: rgba(244, 234, 216, 0.62);
  font-size: 12px;
}

.paper-maximize {
  position: absolute;
  right: 14px;
  top: 14px;
  z-index: 6;
  display: none;
  min-height: 34px;
  padding: 0 12px;
  border-color: rgba(223, 183, 111, 0.54);
  color: #25190e;
  background: #dfb76f;
  font-size: 13px;
  font-weight: 700;
}

.letter {
  position: relative;
  width: min(520px, calc(100vw - 500px));
  aspect-ratio: 0.62;
  min-height: 720px;
  padding: 46px 42px 46px;
  color: var(--ink);
  border: 12px solid var(--paper-edge, #f1ead4);
  box-shadow:
    0 22px 70px rgba(0, 0, 0, 0.46),
    inset 0 0 0 3px var(--inner-line),
    inset 0 0 0 7px rgba(176, 68, 56, 0.14);
  background-color: var(--paper);
  isolation: isolate;
  overflow: hidden;
  transition:
    opacity 360ms ease,
    transform 420ms cubic-bezier(0.2, 0.7, 0.2, 1),
    filter 360ms ease;
}

.letter.mail-hidden {
  opacity: 0;
  filter: blur(4px);
  transform: translateY(18px) scale(0.92) rotateX(8deg);
  pointer-events: none;
}

.preview-stage:has(.mail-stage:not([hidden])) .page-nav {
  opacity: 0;
  pointer-events: none;
}

.letter.paper-tea {
  --paper: #ead7a7;
  --paper-edge: #f1e2bd;
  --column-line: rgba(157, 58, 45, 0.32);
  --inner-line: rgba(151, 57, 45, 0.62);
  background-color: #ead7a7;
}

.letter.paper-faded {
  --paper: #dfc69c;
  --paper-edge: #ede0c1;
  --column-line: rgba(164, 54, 46, 0.31);
  --inner-line: rgba(164, 54, 46, 0.58);
  background-color: #dfc69c;
}

.letter.paper-mottle {
  --paper: #d8c192;
  --paper-edge: #ead8ae;
  --column-line: rgba(142, 55, 42, 0.29);
  --inner-line: rgba(139, 50, 42, 0.55);
  background-color: #d8c192;
}

.letter.paper-ash {
  --paper: #d6d1b6;
  --paper-edge: #e8e3ca;
  --column-line: rgba(128, 67, 54, 0.28);
  --inner-line: rgba(132, 58, 49, 0.52);
  background-color: #d6d1b6;
}

.letter.paper-tide {
  --paper: #d7c7a2;
  --paper-edge: #eadfc3;
  --column-line: rgba(134, 64, 50, 0.3);
  --inner-line: rgba(139, 57, 48, 0.58);
  background-color: #d7c7a2;
}

.letter.exporting {
  box-shadow: none;
}

.letter.exporting::before {
  opacity: 0.12;
}

.letter::before,
.letter::after {
  position: absolute;
  inset: 0;
  z-index: -1;
  content: "";
}

.letter::before {
  opacity: 0.48;
  background-image:
    linear-gradient(90deg, transparent 0 49%, rgba(91, 57, 29, 0.1) 50%, transparent 51%),
    linear-gradient(0deg, transparent 0 47%, rgba(91, 57, 29, 0.07) 48%, transparent 50%),
    repeating-linear-gradient(83deg, rgba(88, 55, 24, 0.06) 0 1px, transparent 1px 8px),
    repeating-linear-gradient(4deg, rgba(255, 255, 255, 0.1) 0 1px, transparent 1px 11px),
    radial-gradient(circle at 16% 42%, rgba(67, 43, 24, 0.13), transparent 9%),
    radial-gradient(circle at 86% 52%, rgba(67, 43, 24, 0.11), transparent 11%),
    radial-gradient(circle at 44% 84%, rgba(107, 69, 31, 0.1), transparent 12%);
}

.letter.paper-mottle::before {
  opacity: 0.64;
  background-image:
    radial-gradient(ellipse at 18% 22%, rgba(92, 52, 24, 0.22), transparent 18%),
    radial-gradient(ellipse at 75% 72%, rgba(83, 48, 29, 0.2), transparent 22%),
    repeating-linear-gradient(92deg, rgba(82, 53, 31, 0.08) 0 1px, transparent 1px 7px),
    repeating-linear-gradient(4deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 12px);
}

.letter.paper-ash::before {
  opacity: 0.58;
  background-image:
    linear-gradient(90deg, rgba(70, 72, 60, 0.12), transparent 24%, rgba(255, 255, 255, 0.1) 58%, transparent),
    radial-gradient(circle at 28% 38%, rgba(67, 68, 58, 0.16), transparent 20%),
    repeating-linear-gradient(87deg, rgba(66, 68, 55, 0.06) 0 1px, transparent 1px 9px);
}

.letter.paper-tide::before {
  opacity: 0.66;
  background-image:
    linear-gradient(110deg, transparent 0 18%, rgba(98, 66, 43, 0.16) 24%, transparent 34%),
    radial-gradient(ellipse at 80% 18%, rgba(78, 49, 31, 0.19), transparent 20%),
    radial-gradient(ellipse at 12% 88%, rgba(98, 66, 43, 0.2), transparent 24%),
    repeating-linear-gradient(2deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 10px);
}

.letter::after {
  border: 1px solid var(--inner-line);
  inset: 20px;
  pointer-events: none;
}

.letter-head,
.letter-foot {
  position: absolute;
  z-index: 2;
  color: rgba(44, 36, 31, 0.8);
  font-family:
    var(--hand-font),
    "Qiaopi MaShan",
    KaiTi,
    STKaiti,
    cursive;
  font-size: 18px;
  line-height: 1.55;
  writing-mode: vertical-rl;
  text-orientation: upright;
  letter-spacing: 0;
}

.letter-head {
  left: 30px;
  bottom: 42px;
  display: flex;
  gap: 26px;
  align-items: flex-start;
}

.letter-foot {
  left: 38px;
  right: auto;
  bottom: 58px;
  top: auto;
  display: flex;
  gap: 14px;
  align-items: flex-end;
  font-size: 20px;
  opacity: 0.9;
}

.letter:not(.is-final-page) .letter-foot {
  display: none;
}

.letter-head {
  display: none !important;
}

.letter-foot span + span {
  display: block;
  font-size: 17px;
  opacity: 0.82;
}

.letter-body {
  position: absolute;
  inset: 64px 20px 64px 20px;
  z-index: 2;
  overflow: hidden;
  transform: none;
}

.rule-lines {
  position: absolute;
  inset: 20px;
  z-index: 1;
  pointer-events: none;
}

.rule-lines span {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--column-line);
}

.handwriting {
  font-family:
    var(--hand-font),
    "Qiaopi MaShan",
    KaiTi,
    STKaiti,
    cursive;
  font-size: var(--hand-size, 25px);
  line-height: var(--render-column-width, var(--column-width, 58px));
  font-weight: var(--hand-weight, 400);
  color: rgba(35, 31, 27, 0.9);
}

.letter-column {
  position: absolute;
  top: 0;
  bottom: 0;
  width: var(--render-column-width, var(--column-width, 58px));
  display: flex;
  align-items: center;
  writing-mode: vertical-rl;
  text-orientation: upright;
  white-space: normal;
  overflow: hidden;
}

.hand-char {
  display: inline-block;
  margin-block: var(--hand-spread, 0);
  transform: translateX(var(--dy)) rotate(calc(var(--rot) + var(--hand-slant, 0deg)));
}

.stamp {
  position: absolute;
  right: 26px;
  bottom: 26px;
  width: 158px;
  height: 158px;
  display: grid;
  place-items: center;
  border: 8px double rgba(154, 52, 41, 0.72);
  color: rgba(154, 52, 41, 0.76);
  font-family:
    var(--hand-font),
    "Qiaopi MaShan",
    KaiTi,
    STKaiti,
    cursive;
  font-size: 64px;
  line-height: 1;
  transform: rotate(-5deg);
}

.stamp-tilt {
  width: 168px;
  height: 136px;
  border-style: solid;
  font-size: 62px;
  transform: rotate(-9deg);
}

.stamp-round {
  width: 150px;
  height: 150px;
  border-radius: 999px;
  border-style: double;
  font-size: 78px;
  transform: rotate(7deg);
}

.stamp-signet {
  width: 154px;
  height: 124px;
  border: 7px solid rgba(154, 52, 41, 0.7);
  font-size: 56px;
  transform: rotate(-4deg);
}

.page-nav {
  position: absolute;
  left: 50%;
  bottom: 14px;
  z-index: 3;
  display: grid;
  grid-template-columns: auto auto auto;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border: 1px solid rgba(244, 234, 216, 0.18);
  border-radius: 6px;
  color: #f4ead8;
  background: rgba(24, 20, 17, 0.72);
  transform: translateX(-50%);
}

.page-nav[hidden] {
  display: none;
}

.page-nav button {
  min-height: 28px;
  padding: 0 10px;
  border-radius: 4px;
}

.page-nav button:disabled {
  cursor: default;
  opacity: 0.45;
}

.reader-continue {
  position: absolute;
  right: 18px;
  bottom: 18px;
  z-index: 8;
  min-height: 42px;
  padding: 0 18px;
  border-color: rgba(236, 192, 92, 0.86);
  color: #24180e;
  background: linear-gradient(180deg, rgba(255, 231, 150, 0.96), rgba(218, 164, 62, 0.96));
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.28);
  font-weight: 800;
}

.reader-continue[hidden] {
  display: none;
}

body.shared-reading .workspace {
  grid-template-columns: 1fr;
}

body.shared-reading .composer {
  display: none;
}

body.shared-reading .preview-stage {
  min-height: calc(100svh - 36px);
}

.mail-stage {
  position: absolute;
  inset: 0;
  z-index: 6;
  display: grid;
  place-items: center;
  perspective: 1200px;
  background:
    radial-gradient(circle at 50% 38%, rgba(235, 215, 174, 0.22), transparent 30%),
    rgba(24, 20, 17, 0.58);
}

.mail-stage[hidden] {
  display: none;
}

.folded-paper {
  position: absolute;
  width: min(500px, 80vw);
  aspect-ratio: 0.62;
  min-height: 680px;
  transform-origin: center;
  transform-style: preserve-3d;
}

.folded-paper::after {
  position: absolute;
  left: 12%;
  right: 12%;
  bottom: -34px;
  height: 46px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.28);
  content: "";
  filter: blur(16px);
  transform: translateZ(-50px);
}

.fold-sheet {
  position: absolute;
  inset: 0;
  overflow: hidden;
  border: 10px solid rgba(246, 237, 210, 0.9);
  background-color: #e6d4aa;
  background-position: center;
  background-size: 100% 100%;
  box-shadow:
    inset 0 0 0 2px rgba(154, 52, 41, 0.28),
    inset 0 0 42px rgba(96, 61, 30, 0.12),
    0 30px 76px rgba(0, 0, 0, 0.34);
  transform-style: preserve-3d;
  backface-visibility: hidden;
}

.fold-sheet::before,
.fold-sheet::after {
  position: absolute;
  inset: 0;
  pointer-events: none;
  content: "";
}

.fold-sheet::before {
  background:
    linear-gradient(90deg, transparent 0 48%, rgba(255, 255, 255, 0.22) 50%, transparent 53%),
    linear-gradient(180deg, transparent 0 48%, rgba(50, 35, 22, 0.12) 50%, transparent 53%);
  opacity: 0;
  mix-blend-mode: multiply;
}

.fold-sheet::after {
  background:
    radial-gradient(ellipse at 35% 48%, rgba(255, 255, 255, 0.22), transparent 28%),
    linear-gradient(120deg, transparent 0 42%, rgba(50, 35, 22, 0.18) 50%, transparent 58%);
  opacity: 0;
}

.fold-sheet-fallback {
  background:
    linear-gradient(90deg, rgba(154, 52, 41, 0.26) 0 1px, transparent 1px 100%),
    repeating-linear-gradient(90deg, transparent 0 22px, rgba(154, 52, 41, 0.18) 22px 23px, transparent 23px 54px),
    repeating-linear-gradient(0deg, rgba(60, 45, 30, 0.045) 0 1px, transparent 1px 7px),
    linear-gradient(120deg, rgba(255, 247, 219, 0.24), rgba(132, 91, 48, 0.12)),
    #e6d4aa;
}

.fold-sheet-fallback::after {
  opacity: 0.38;
}

.boat-fold,
.boat-keel {
  position: absolute;
  z-index: 4;
  pointer-events: none;
  opacity: 0;
  background:
    linear-gradient(135deg, rgba(255, 249, 226, 0.46), rgba(118, 76, 41, 0.12)),
    rgba(232, 212, 166, 0.82);
  box-shadow: 0 10px 22px rgba(60, 38, 23, 0.18);
}

.boat-fold-0,
.boat-fold-1 {
  top: 0;
  width: 50%;
  height: 50%;
}

.boat-fold-2,
.boat-fold-3 {
  bottom: 0;
  width: 50%;
  height: 50%;
}

.boat-fold-0 {
  left: 0;
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  transform-origin: right bottom;
}

.boat-fold-1 {
  right: 0;
  clip-path: polygon(0 0, 100% 0, 0 100%);
  transform-origin: left bottom;
}

.boat-fold-2 {
  left: 0;
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  transform-origin: right top;
}

.boat-fold-3 {
  right: 0;
  clip-path: polygon(0 0, 100% 100%, 0 100%);
  transform-origin: left top;
}

.boat-keel {
  left: 18%;
  right: 18%;
  top: 47%;
  height: 9%;
  border-radius: 999px 999px 26px 26px;
  transform-origin: center;
}

.fold-crease {
  position: absolute;
  z-index: 2;
  opacity: 0;
  background: rgba(71, 46, 28, 0.28);
  box-shadow:
    0 0 12px rgba(255, 248, 224, 0.28),
    0 0 18px rgba(60, 38, 23, 0.16);
  transform-origin: center;
}

.fold-crease::after {
  position: absolute;
  inset: 0;
  background: rgba(255, 249, 228, 0.32);
  content: "";
  transform: translateX(2px);
}

.crease-0,
.crease-1,
.crease-2,
.crease-3 {
  top: 0;
  bottom: 0;
  width: 2px;
}

.crease-0 { left: 50%; }
.crease-1 { left: 33.333%; }
.crease-2 { left: 66.666%; }
.crease-3 { left: 20%; }

.crease-4,
.crease-5 {
  left: 0;
  right: 0;
  height: 2px;
}

.crease-4 { top: 50%; }
.crease-5 { top: 33.333%; }

.packaging .fold-sheet::before,
.packaging .fold-sheet::after,
.opening .fold-sheet::before,
.opening .fold-sheet::after {
  animation: foldLightSweep 2.4s forwards ease-in-out;
}

.packaging .fold-crease,
.opening .fold-crease {
  animation: creaseWake 2.35s forwards ease-in-out;
}

.fold-half .crease-1,
.fold-half .crease-2,
.fold-half .crease-3,
.fold-half .crease-4,
.fold-half .crease-5,
.fold-trifold .crease-0,
.fold-trifold .crease-3,
.fold-trifold .crease-4,
.fold-trifold .crease-5,
.fold-gate .crease-3,
.fold-gate .crease-4,
.fold-gate .crease-5,
.fold-accordion .crease-4,
.fold-accordion .crease-5,
.fold-cross .crease-1,
.fold-cross .crease-2,
.fold-cross .crease-3,
.fold-pocket .crease-0,
.fold-pocket .crease-3,
.fold-pocket .crease-5,
.fold-mountain .crease-4,
.fold-mountain .crease-5,
.fold-reverse .crease-3,
.fold-reverse .crease-5,
.fold-rabbit .crease-1,
.fold-rabbit .crease-2,
.fold-boat .crease-1,
.fold-boat .crease-2,
.fold-boat .crease-3 {
  display: none;
}

.fold-rabbit .crease-0,
.fold-rabbit .crease-3,
.fold-boat .crease-0,
.fold-boat .crease-3 {
  display: block;
  top: -8%;
  bottom: -8%;
  height: auto;
  width: 2px;
}

.fold-rabbit .crease-0 {
  left: 38%;
  transform: rotate(22deg);
}

.fold-rabbit .crease-3 {
  left: 62%;
  transform: rotate(-22deg);
}

.fold-boat .crease-0 {
  left: 32%;
  transform: rotate(31deg);
}

.fold-boat .crease-3 {
  left: 68%;
  transform: rotate(-31deg);
}

.fold-letter-clone {
  position: absolute;
  left: calc(var(--col) * -100%);
  top: calc(var(--row) * -100%);
  width: calc(var(--cols) * 100%) !important;
  height: calc(var(--rows) * 100%) !important;
  min-height: 100% !important;
  margin: 0 auto;
  box-shadow: 0 26px 70px rgba(0, 0, 0, 0.42);
  transform: none;
  pointer-events: none;
}

.fold-model {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
}

.fold-panel {
  position: absolute;
  left: calc(var(--col) * 100% / var(--cols));
  top: calc(var(--row) * 100% / var(--rows));
  width: calc(100% / var(--cols));
  height: calc(100% / var(--rows));
  overflow: hidden;
  background: rgba(234, 219, 180, 0.92);
  box-shadow:
    inset 0 0 0 1px rgba(154, 52, 41, 0.18),
    0 16px 36px rgba(0, 0, 0, 0.18);
  transform: translateZ(calc(var(--col) * 0.3px + var(--row) * 0.4px));
  transform-style: preserve-3d;
  backface-visibility: hidden;
}

.fold-panel-face {
  position: absolute;
  inset: 0;
  background-repeat: no-repeat;
  background-color: rgba(234, 219, 180, 0.96);
  transform: translateZ(0.2px);
}

.fold-panel-fallback {
  background:
    linear-gradient(90deg, rgba(154, 52, 41, 0.24) 0 1px, transparent 1px 100%),
    repeating-linear-gradient(90deg, transparent 0 18px, rgba(154, 52, 41, 0.18) 18px 19px, transparent 19px 48px),
    repeating-linear-gradient(0deg, rgba(60, 45, 30, 0.05) 0 1px, transparent 1px 7px),
    linear-gradient(120deg, rgba(255, 247, 219, 0.2), rgba(132, 91, 48, 0.11)),
    #e6d4aa;
}

.fold-panel-fallback::after {
  position: absolute;
  inset: 12% 18% 14% 28%;
  opacity: 0.36;
  background:
    repeating-linear-gradient(90deg, rgba(29, 25, 20, 0.32) 0 2px, transparent 2px 26px),
    repeating-linear-gradient(0deg, transparent 0 18px, rgba(29, 25, 20, 0.18) 18px 19px, transparent 19px 34px);
  content: "";
  filter: blur(0.2px);
}

.fold-letter-clone .page-nav {
  display: none;
}

.folded-paper > span {
  position: absolute;
  inset: 0;
  border-left: 1px solid rgba(154, 52, 41, 0.24);
  transform-origin: center;
}

.folded-paper > span:nth-child(1) {
  transform: translateX(-28%);
}

.folded-paper > span:nth-child(2) {
  transform: translateX(28%);
}

.folded-paper > span:nth-child(3) {
  border-top: 1px solid rgba(154, 52, 41, 0.2);
  transform: translateY(24%);
}

.qiaopi-envelope {
  position: relative;
  width: min(390px, 70vw);
  aspect-ratio: 1.62;
  padding: 0;
  overflow: hidden;
  border: 2px solid rgba(127, 75, 42, 0.45);
  border-radius: 2px;
  color: rgba(49, 38, 29, 0.88);
  background:
    linear-gradient(18deg, transparent 49.4%, rgba(120, 75, 45, 0.16) 50%, transparent 50.6%),
    linear-gradient(-18deg, transparent 49.4%, rgba(120, 75, 45, 0.16) 50%, transparent 50.6%),
    repeating-linear-gradient(92deg, rgba(111, 75, 40, 0.06) 0 1px, transparent 1px 9px),
    #e7d6b1;
  box-shadow: 0 22px 60px rgba(0, 0, 0, 0.42);
  transform: translateY(38px) scale(0.82);
  opacity: 0;
}

.qiaopi-envelope:disabled {
  cursor: default;
}

.envelope-flap {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(150deg, transparent 51%, rgba(122, 76, 42, 0.18) 52%, transparent 54%),
    linear-gradient(30deg, transparent 51%, rgba(122, 76, 42, 0.18) 52%, transparent 54%);
  pointer-events: none;
}

.envelope-red-strip {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 34%;
  width: 32%;
  background: rgba(180, 55, 45, 0.28);
  border-inline: 1px solid rgba(154, 52, 41, 0.32);
}

.envelope-recipient,
.envelope-sender {
  position: absolute;
  z-index: 1;
  writing-mode: vertical-rl;
  font-family: var(--hand-font), "Qiaopi MaShan", KaiTi, STKaiti, cursive;
}

.envelope-recipient {
  top: 30px;
  left: 48%;
  font-size: 24px;
  transform: translateX(-50%);
}

.envelope-sender {
  left: 22px;
  bottom: 24px;
  font-size: 17px;
  opacity: 0.82;
}

.postmark {
  position: absolute;
  right: 24px;
  top: 22px;
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  border: 3px solid rgba(154, 52, 41, 0.72);
  border-radius: 50%;
  color: rgba(154, 52, 41, 0.78);
  font-family: var(--hand-font), "Qiaopi MaShan", KaiTi, STKaiti, cursive;
  font-size: 16px;
  line-height: 1.05;
  opacity: 0;
  transform: rotate(-12deg) scale(1.45);
}

.envelope-hint {
  position: absolute;
  right: 22px;
  bottom: 18px;
  z-index: 1;
  color: rgba(75, 55, 40, 0.72);
  font-size: 13px;
  opacity: 0;
}

.envelope-western .envelope-red-strip {
  left: auto;
  right: 24px;
  width: 10px;
  background: rgba(180, 55, 45, 0.42);
}

.envelope-bureau .qiaopi-envelope {
  background:
    radial-gradient(circle at 18% 22%, rgba(154, 52, 41, 0.13), transparent 16%),
    linear-gradient(90deg, rgba(180, 55, 45, 0.24) 0 18%, transparent 18% 100%),
    repeating-linear-gradient(92deg, rgba(111, 75, 40, 0.06) 0 1px, transparent 1px 9px),
    #e3cf9f;
}

.envelope-postal .qiaopi-envelope {
  border-color: rgba(70, 97, 88, 0.38);
  background:
    linear-gradient(90deg, rgba(49, 95, 91, 0.18), transparent 18% 82%, rgba(180, 55, 45, 0.16)),
    repeating-linear-gradient(0deg, rgba(111, 75, 40, 0.05) 0 1px, transparent 1px 11px),
    #d9dac4;
}

.packaging .folded-paper {
  animation-duration: 3.25s;
  animation-fill-mode: forwards;
  animation-timing-function: cubic-bezier(0.36, 0, 0.14, 1);
}

.packaging .fold-panel,
.opening .fold-panel {
  animation-duration: 1.78s;
  animation-fill-mode: forwards;
  animation-timing-function: cubic-bezier(0.42, 0, 0.18, 1);
}

.opening .folded-paper {
  animation-duration: 1.9s;
  animation-fill-mode: forwards;
  animation-timing-function: cubic-bezier(0.18, 0.7, 0.18, 1);
}

.opening .fold-panel {
  animation-direction: reverse;
}

.packaging .qiaopi-envelope {
  animation: envelopeReceive 1.9s 0.82s forwards cubic-bezier(0.42, 0, 0.18, 1);
}

.packaging .postmark {
  animation: postmarkDrop 0.42s 2.36s forwards ease-out;
}

.packaging .envelope-hint,
.sealed .envelope-hint {
  opacity: 1;
}

.sealed .folded-paper {
  display: none;
}

.sealed .qiaopi-envelope {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.sealed .postmark {
  opacity: 1;
  transform: rotate(-12deg) scale(1);
}

.sealed.fold-half .qiaopi-envelope {
  transform: translateY(0) scale(1) rotate(-0.4deg);
}

.sealed.fold-trifold .qiaopi-envelope {
  transform: translateY(0) scale(1) rotate(0.5deg);
}

.sealed.fold-gate .qiaopi-envelope .envelope-flap {
  background:
    linear-gradient(90deg, transparent 47%, rgba(122, 76, 42, 0.2) 48%, transparent 51%),
    linear-gradient(150deg, transparent 51%, rgba(122, 76, 42, 0.18) 52%, transparent 54%),
    linear-gradient(30deg, transparent 51%, rgba(122, 76, 42, 0.18) 52%, transparent 54%);
}

.sealed.fold-accordion .qiaopi-envelope::after,
.sealed.fold-mountain .qiaopi-envelope::after,
.sealed.fold-rabbit .qiaopi-envelope::after,
.sealed.fold-boat .qiaopi-envelope::after {
  position: absolute;
  left: 16%;
  right: 16%;
  bottom: 17px;
  height: 8px;
  border-top: 1px solid rgba(122, 76, 42, 0.24);
  border-bottom: 1px solid rgba(122, 76, 42, 0.14);
  content: "";
}

.sealed.fold-accordion .qiaopi-envelope::after {
  background: repeating-linear-gradient(90deg, rgba(122, 76, 42, 0.16) 0 1px, transparent 1px 18px);
}

.sealed.fold-mountain .qiaopi-envelope::after {
  height: 12px;
  clip-path: polygon(0 60%, 18% 12%, 36% 62%, 54% 12%, 72% 62%, 90% 14%, 100% 58%, 100% 100%, 0 100%);
  background: rgba(122, 76, 42, 0.13);
}

.sealed.fold-rabbit .qiaopi-envelope::after {
  left: 32%;
  right: 32%;
  height: 18px;
  clip-path: polygon(0 100%, 24% 12%, 50% 72%, 76% 12%, 100% 100%);
  background: rgba(122, 76, 42, 0.13);
}

.sealed.fold-boat .qiaopi-envelope::after {
  left: 25%;
  right: 25%;
  height: 18px;
  clip-path: polygon(0 70%, 50% 8%, 100% 70%, 82% 100%, 18% 100%);
  background: rgba(122, 76, 42, 0.13);
}

.fold-trifold .folded-paper {
  animation-name: foldTrifold;
}

.fold-half .folded-paper {
  animation-name: foldHalf;
}

.fold-gate .folded-paper {
  animation-name: foldGate;
}

.fold-accordion .folded-paper {
  animation-name: foldAccordion;
}

.fold-cross .folded-paper {
  animation-name: foldCross;
}

.fold-roll .folded-paper {
  animation-name: foldRoll;
}

.fold-mountain .folded-paper {
  animation-name: foldMountain;
}

.fold-pocket .folded-paper {
  animation-name: foldPocket;
}

.fold-reverse .folded-paper {
  animation-name: foldReverse;
}

.fold-rabbit .folded-paper {
  animation-name: foldRabbit;
}

.fold-boat .folded-paper {
  animation-name: foldBoat;
}

.fold-half .panel-0,
.unfold-half .panel-0 { transform-origin: right center; animation-name: panelFoldLeft; }
.fold-half .panel-1,
.unfold-half .panel-1 { transform-origin: left center; animation-name: panelFoldRight; }

.fold-trifold .panel-0,
.unfold-trifold .panel-0 { transform-origin: right center; animation-name: panelFoldLeft; }
.fold-trifold .panel-2,
.unfold-trifold .panel-2 { transform-origin: left center; animation-name: panelFoldRight; }

.fold-gate .panel-0,
.unfold-gate .panel-0 { transform-origin: right center; animation-name: panelGateLeft; }
.fold-gate .panel-3,
.unfold-gate .panel-3 { transform-origin: left center; animation-name: panelGateRight; }
.fold-gate .panel-1,
.unfold-gate .panel-1 { transform-origin: right center; animation-name: panelSoftLeft; }
.fold-gate .panel-2,
.unfold-gate .panel-2 { transform-origin: left center; animation-name: panelSoftRight; }

.fold-accordion .panel-0,
.unfold-accordion .panel-0,
.fold-accordion .panel-2,
.unfold-accordion .panel-2,
.fold-accordion .panel-4,
.unfold-accordion .panel-4 { transform-origin: right center; animation-name: panelAccordionA; }
.fold-accordion .panel-1,
.unfold-accordion .panel-1,
.fold-accordion .panel-3,
.unfold-accordion .panel-3 { transform-origin: left center; animation-name: panelAccordionB; }

.fold-cross .panel-0,
.unfold-cross .panel-0 { transform-origin: right bottom; animation-name: panelCrossA; }
.fold-cross .panel-1,
.unfold-cross .panel-1 { transform-origin: left bottom; animation-name: panelCrossB; }
.fold-cross .panel-2,
.unfold-cross .panel-2 { transform-origin: right top; animation-name: panelCrossC; }
.fold-cross .panel-3,
.unfold-cross .panel-3 { transform-origin: left top; animation-name: panelCrossD; }

.fold-pocket .panel-0,
.unfold-pocket .panel-0 { transform-origin: right center; animation-name: panelPocketLeft; }
.fold-pocket .panel-2,
.unfold-pocket .panel-2 { transform-origin: left center; animation-name: panelPocketRight; }

.fold-mountain .panel-0,
.unfold-mountain .panel-0,
.fold-mountain .panel-2,
.unfold-mountain .panel-2 { transform-origin: right center; animation-name: panelMountainA; }
.fold-mountain .panel-1,
.unfold-mountain .panel-1,
.fold-mountain .panel-3,
.unfold-mountain .panel-3 { transform-origin: left center; animation-name: panelMountainB; }

.fold-reverse .panel-0,
.unfold-reverse .panel-0,
.fold-reverse .panel-3,
.unfold-reverse .panel-3 { transform-origin: right center; animation-name: panelReverseA; }
.fold-reverse .panel-2,
.unfold-reverse .panel-2,
.fold-reverse .panel-5,
.unfold-reverse .panel-5 { transform-origin: left center; animation-name: panelReverseB; }
.fold-reverse .panel-1,
.unfold-reverse .panel-1,
.fold-reverse .panel-4,
.unfold-reverse .panel-4 { transform-origin: center center; animation-name: panelReverseCenter; }

.fold-rabbit .panel-0,
.unfold-rabbit .panel-0,
.fold-rabbit .panel-3,
.unfold-rabbit .panel-3 { transform-origin: right bottom; animation-name: panelRabbitLeft; }
.fold-rabbit .panel-2,
.unfold-rabbit .panel-2,
.fold-rabbit .panel-5,
.unfold-rabbit .panel-5 { transform-origin: left bottom; animation-name: panelRabbitRight; }
.fold-rabbit .panel-1,
.unfold-rabbit .panel-1,
.fold-rabbit .panel-4,
.unfold-rabbit .panel-4 { transform-origin: center top; animation-name: panelRabbitEar; }

.fold-boat .panel-0,
.unfold-boat .panel-0 { transform-origin: right bottom; animation-name: panelBoatLeftTop; }
.fold-boat .panel-1,
.unfold-boat .panel-1 { transform-origin: left bottom; animation-name: panelBoatRightTop; }
.fold-boat .panel-2,
.unfold-boat .panel-2 { transform-origin: right top; animation-name: panelBoatLeftBottom; }
.fold-boat .panel-3,
.unfold-boat .panel-3 { transform-origin: left top; animation-name: panelBoatRightBottom; }

.opening .qiaopi-envelope {
  opacity: 1;
  animation: envelopeOpen 1.1s forwards cubic-bezier(0.18, 0.7, 0.18, 1);
}

.opening .folded-paper {
  animation-duration: 1.12s;
  animation-fill-mode: forwards;
  animation-timing-function: cubic-bezier(0.18, 0.7, 0.18, 1);
}

.unfold-trifold .folded-paper {
  animation-name: unfoldTrifold;
}

.unfold-half .folded-paper {
  animation-name: unfoldHalf;
}

.unfold-gate .folded-paper {
  animation-name: unfoldGate;
}

.unfold-accordion .folded-paper {
  animation-name: unfoldAccordion;
}

.unfold-cross .folded-paper {
  animation-name: unfoldCross;
}

.unfold-roll .folded-paper {
  animation-name: unfoldRoll;
}

.unfold-mountain .folded-paper {
  animation-name: unfoldMountain;
}

.unfold-pocket .folded-paper {
  animation-name: unfoldPocket;
}

.unfold-reverse .folded-paper {
  animation-name: unfoldReverse;
}

.unfold-rabbit .folded-paper {
  animation-name: unfoldRabbit;
}

.unfold-boat .folded-paper {
  animation-name: unfoldBoat;
}

@keyframes foldTrifold {
  0% { transform: translateY(34px) rotateX(0) scale(0.42); opacity: 0; }
  18% { transform: translateY(-26px) rotateX(0) scale(1.08); opacity: 1; }
  38% { transform: translateY(-18px) rotateY(0) scale(1); }
  58% { transform: translateY(-10px) rotateY(64deg) scaleX(0.58); }
  82% { transform: translateY(78px) rotateX(72deg) rotateZ(-3deg) scale(0.48, 0.4); opacity: 1; }
  100% { transform: translateY(118px) rotateZ(-1deg) scale(0.34, 0.2); opacity: 0; }
}

@keyframes foldCarryToEnvelope {
  0% { transform: translateY(26px) scale(0.54); opacity: 0; }
  16% { transform: translateY(-24px) scale(1.04); opacity: 1; }
  66% { transform: translateY(-8px) scale(0.92); opacity: 1; }
  88% { transform: translateY(82px) scale(0.45); opacity: 1; }
  100% { transform: translateY(122px) scale(0.24); opacity: 0; }
}

@keyframes unfoldCarryFromEnvelope {
  0% { transform: translateY(104px) scale(0.24); opacity: 0; }
  24% { transform: translateY(62px) scale(0.46); opacity: 1; }
  72% { transform: translateY(-12px) scale(0.98); opacity: 1; }
  100% { transform: translateY(-18px) scale(1); opacity: 1; }
}

@keyframes panelFoldLeft {
  0%, 24% { transform: rotateY(0) translateZ(0); }
  62% { transform: rotateY(-86deg) translateZ(14px); }
  100% { transform: rotateY(-176deg) translateZ(28px); }
}

@keyframes panelFoldRight {
  0%, 28% { transform: rotateY(0) translateZ(0); }
  66% { transform: rotateY(86deg) translateZ(14px); }
  100% { transform: rotateY(176deg) translateZ(28px); }
}

@keyframes panelGateLeft {
  0%, 20% { transform: rotateY(0); }
  58% { transform: rotateY(-78deg) translateZ(16px); }
  100% { transform: rotateY(-162deg) translateZ(30px); }
}

@keyframes panelGateRight {
  0%, 20% { transform: rotateY(0); }
  58% { transform: rotateY(78deg) translateZ(16px); }
  100% { transform: rotateY(162deg) translateZ(30px); }
}

@keyframes panelSoftLeft {
  0%, 42% { transform: rotateY(0); }
  100% { transform: rotateY(-42deg) translateZ(10px); }
}

@keyframes panelSoftRight {
  0%, 42% { transform: rotateY(0); }
  100% { transform: rotateY(42deg) translateZ(10px); }
}

@keyframes panelAccordionA {
  0%, 18% { transform: rotateY(0); }
  44% { transform: rotateY(-62deg) translateZ(12px); }
  72% { transform: rotateY(58deg) translateZ(20px); }
  100% { transform: rotateY(-146deg) translateZ(28px); }
}

@keyframes panelAccordionB {
  0%, 18% { transform: rotateY(0); }
  44% { transform: rotateY(62deg) translateZ(12px); }
  72% { transform: rotateY(-58deg) translateZ(20px); }
  100% { transform: rotateY(146deg) translateZ(28px); }
}

@keyframes panelCrossA {
  0%, 22% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(68deg) rotateY(-42deg) translateZ(16px); }
  100% { transform: rotateX(156deg) rotateY(-86deg) translateZ(30px); }
}

@keyframes panelCrossB {
  0%, 22% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(68deg) rotateY(42deg) translateZ(16px); }
  100% { transform: rotateX(156deg) rotateY(86deg) translateZ(30px); }
}

@keyframes panelCrossC {
  0%, 22% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(-68deg) rotateY(-42deg) translateZ(16px); }
  100% { transform: rotateX(-156deg) rotateY(-86deg) translateZ(30px); }
}

@keyframes panelCrossD {
  0%, 22% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(-68deg) rotateY(42deg) translateZ(16px); }
  100% { transform: rotateX(-156deg) rotateY(86deg) translateZ(30px); }
}

@keyframes panelPocketLeft {
  0%, 24% { transform: rotateY(0); }
  64% { transform: rotateY(-98deg) translateZ(18px); }
  100% { transform: rotateY(-178deg) translateZ(30px) scaleX(0.86); }
}

@keyframes panelPocketRight {
  0%, 24% { transform: rotateY(0); }
  64% { transform: rotateY(98deg) translateZ(18px); }
  100% { transform: rotateY(178deg) translateZ(30px) scaleX(0.86); }
}

@keyframes panelMountainA {
  0%, 18% { transform: rotateY(0); }
  54% { transform: rotateY(-72deg) translateZ(18px); }
  100% { transform: rotateY(-150deg) translateZ(36px); }
}

@keyframes panelMountainB {
  0%, 18% { transform: rotateY(0); }
  54% { transform: rotateY(72deg) translateZ(18px); }
  100% { transform: rotateY(150deg) translateZ(36px); }
}

@keyframes panelReverseA {
  0%, 20% { transform: rotateY(0) rotateX(0); }
  52% { transform: rotateY(-74deg) rotateX(18deg) translateZ(16px); }
  100% { transform: rotateY(154deg) rotateX(-28deg) translateZ(34px); }
}

@keyframes panelReverseB {
  0%, 20% { transform: rotateY(0) rotateX(0); }
  52% { transform: rotateY(74deg) rotateX(-18deg) translateZ(16px); }
  100% { transform: rotateY(-154deg) rotateX(28deg) translateZ(34px); }
}

@keyframes panelReverseCenter {
  0%, 38% { transform: rotateX(0) scale(1); }
  100% { transform: rotateX(58deg) scale(0.86); }
}

@keyframes panelRabbitLeft {
  0%, 18% { transform: rotateY(0) rotateZ(0); }
  54% { transform: rotateY(-68deg) rotateZ(-18deg) translateZ(20px); }
  100% { transform: rotateY(-148deg) rotateZ(-32deg) translateZ(34px); }
}

@keyframes panelRabbitRight {
  0%, 18% { transform: rotateY(0) rotateZ(0); }
  54% { transform: rotateY(68deg) rotateZ(18deg) translateZ(20px); }
  100% { transform: rotateY(148deg) rotateZ(32deg) translateZ(34px); }
}

@keyframes panelRabbitEar {
  0%, 36% { transform: rotateX(0) scale(1); }
  72% { transform: rotateX(48deg) scale(0.82); }
  100% { transform: rotateX(72deg) scale(0.68); }
}

@keyframes panelBoatLeftTop {
  0%, 20% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(62deg) rotateY(-52deg) rotateZ(-8deg) translateZ(18px); }
  100% { transform: rotateX(142deg) rotateY(-82deg) rotateZ(-22deg) translateZ(36px); }
}

@keyframes panelBoatRightTop {
  0%, 20% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(62deg) rotateY(52deg) rotateZ(8deg) translateZ(18px); }
  100% { transform: rotateX(142deg) rotateY(82deg) rotateZ(22deg) translateZ(36px); }
}

@keyframes panelBoatLeftBottom {
  0%, 20% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(-62deg) rotateY(-52deg) rotateZ(8deg) translateZ(18px); }
  100% { transform: rotateX(-142deg) rotateY(-82deg) rotateZ(22deg) translateZ(36px); }
}

@keyframes panelBoatRightBottom {
  0%, 20% { transform: rotateX(0) rotateY(0); }
  58% { transform: rotateX(-62deg) rotateY(52deg) rotateZ(-8deg) translateZ(18px); }
  100% { transform: rotateX(-142deg) rotateY(82deg) rotateZ(-22deg) translateZ(36px); }
}

@keyframes foldHalf {
  0% { transform: translateY(24px) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) scale(1.05); opacity: 1; }
  42% { transform: translateY(-18px) rotateY(0) scale(1); }
  66% { transform: translateY(18px) rotateY(82deg) scaleX(0.5); }
  86% { transform: translateY(86px) rotateY(88deg) scale(0.42, 0.46); opacity: 1; }
  100% { transform: translateY(122px) rotateY(90deg) scale(0.3, 0.24); opacity: 0; }
}

@keyframes foldGate {
  0% { transform: translateY(34px) scale(0.44); opacity: 0; }
  18% { transform: translateY(-24px) scale(1.1); opacity: 1; }
  42% { transform: translateY(-16px) rotateZ(2deg) scale(1); }
  60% { transform: translateY(-8px) rotateY(-78deg) scaleX(0.5); }
  82% { transform: translateY(78px) rotateX(58deg) rotateZ(4deg) scale(0.44, 0.34); opacity: 1; }
  100% { transform: translateY(118px) scale(0.34, 0.2); opacity: 0; }
}

@keyframes foldAccordion {
  0% { transform: translateY(24px) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) scale(1.06); opacity: 1; }
  36% { transform: translateY(-12px) skewX(0) scale(1); }
  52% { transform: translateY(2px) skewX(-18deg) scale(0.82, 0.72); }
  68% { transform: translateY(36px) skewX(18deg) scale(0.62, 0.48); }
  86% { transform: translateY(86px) skewX(-8deg) scale(0.42, 0.28); opacity: 1; }
  100% { transform: translateY(122px) scale(0.32, 0.18); opacity: 0; }
}

@keyframes foldCross {
  0% { transform: translateY(24px) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) scale(1.06); opacity: 1; }
  38% { transform: translateY(-16px) rotateX(0) rotateY(0) scale(1); }
  56% { transform: translateY(6px) rotateX(78deg) scale(0.66, 0.5); }
  74% { transform: translateY(52px) rotateX(78deg) rotateY(70deg) scale(0.46, 0.34); }
  100% { transform: translateY(122px) rotateX(82deg) rotateY(78deg) scale(0.28, 0.2); opacity: 0; }
}

@keyframes foldRoll {
  0% { transform: translateY(34px) rotate(-4deg) scale(0.44); opacity: 0; }
  18% { transform: translateY(-24px) rotate(2deg) scale(1.12); opacity: 1; }
  42% { transform: translateY(-8px) rotate(10deg) scale(0.82, 0.46); }
  64% { transform: translateY(26px) rotate(18deg) scale(0.68, 0.24); }
  84% { transform: translateY(84px) rotate(8deg) scale(0.48, 0.18); opacity: 1; }
  100% { transform: translateY(118px) scale(0.34, 0.14); opacity: 0; }
}

@keyframes foldMountain {
  0% { transform: translateY(34px) rotate(0) scale(0.42); opacity: 0; }
  18% { transform: translateY(-24px) rotate(0) scale(1.1); opacity: 1; }
  44% { transform: translateY(-12px) rotate(-36deg) skewY(-10deg) scale(0.72); }
  68% { transform: translateY(30px) rotate(22deg) skewY(8deg) scale(0.56, 0.42); }
  84% { transform: translateY(82px) rotate(-12deg) scale(0.42, 0.32); opacity: 1; }
  100% { transform: translateY(118px) rotate(0) scale(0.32, 0.18); opacity: 0; }
}

@keyframes foldReverse {
  0% { transform: translateY(24px) rotate(0) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) rotate(0) scale(1.08); opacity: 1; }
  40% { transform: translateY(-12px) rotateY(-36deg) rotateX(0) scale(0.9); }
  58% { transform: translateY(18px) rotateY(58deg) rotateX(-48deg) scale(0.62); }
  80% { transform: translateY(78px) rotateY(-24deg) rotateX(70deg) scale(0.42, 0.34); opacity: 1; }
  100% { transform: translateY(122px) rotateY(0) rotateX(82deg) scale(0.3, 0.2); opacity: 0; }
}

@keyframes foldRabbit {
  0% { transform: translateY(24px) rotate(0) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) scale(1.08); opacity: 1; }
  38% { transform: translateY(-18px) rotate(-8deg) skewX(0) scale(0.92); }
  58% { transform: translateY(8px) rotate(18deg) skewX(-26deg) scale(0.58, 0.66); }
  76% { transform: translateY(70px) rotate(-18deg) skewX(18deg) scale(0.38, 0.46); opacity: 1; }
  100% { transform: translateY(122px) rotate(0) skewX(0) scale(0.26, 0.2); opacity: 0; }
}

@keyframes foldBoat {
  0% { transform: translateY(24px) rotate(0) scale(0.48); opacity: 0; }
  16% { transform: translateY(-28px) rotate(0) scale(1.08); opacity: 1; }
  36% { transform: translateY(-10px) rotateX(68deg) scale(0.8, 0.58); }
  58% { transform: translateY(18px) rotateX(68deg) rotateZ(9deg) skewX(20deg) scale(0.58, 0.36); }
  82% { transform: translateY(82px) rotateX(74deg) rotateZ(-7deg) scale(0.42, 0.24); opacity: 1; }
  100% { transform: translateY(122px) rotateX(80deg) scale(0.3, 0.16); opacity: 0; }
}

@keyframes foldPocket {
  0% { transform: translateY(34px) scale(0.44); opacity: 0; }
  18% { transform: translateY(-24px) scale(1.1); opacity: 1; }
  40% { transform: translateY(-10px) rotateX(76deg) scale(0.74, 0.56); }
  64% { transform: translateY(34px) rotateX(18deg) rotateZ(-6deg) scale(0.54, 0.38); }
  84% { transform: translateY(82px) rotateX(28deg) scale(0.46, 0.32); opacity: 1; }
  100% { transform: translateY(118px) scale(0.34, 0.2); opacity: 0; }
}

@keyframes envelopeReceive {
  0% { opacity: 0; transform: translateY(52px) scale(0.82); }
  48% { opacity: 1; transform: translateY(30px) scale(0.96); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes postmarkDrop {
  0% { opacity: 0; transform: rotate(-12deg) scale(1.55); }
  72% { opacity: 1; transform: rotate(-12deg) scale(0.92); }
  100% { opacity: 1; transform: rotate(-12deg) scale(1); }
}

@keyframes envelopeOpen {
  0% { transform: translateY(0) scale(1); opacity: 1; }
  64% { transform: translateY(28px) rotateX(18deg) scale(0.95); opacity: 0.85; }
  100% { transform: translateY(82px) scale(0.82); opacity: 0; }
}

@keyframes unfoldTrifold {
  0% { transform: translateY(86px) scale(0.34, 0.2); opacity: 0; }
  36% { transform: translateY(38px) rotateX(54deg) scale(0.5, 0.42); opacity: 1; }
  100% { transform: translateY(-18px) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldHalf {
  0% { transform: translateY(100px) rotateY(90deg) scale(0.3, 0.24); opacity: 0; }
  42% { transform: translateY(42px) rotateY(84deg) scale(0.48, 0.48); opacity: 1; }
  72% { transform: translateY(-8px) rotateY(12deg) scale(0.9); }
  100% { transform: translateY(-18px) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldGate {
  0% { transform: translateY(86px) scale(0.34, 0.2); opacity: 0; }
  44% { transform: translateY(30px) rotateY(-60deg) scaleX(0.54); opacity: 1; }
  100% { transform: translateY(-18px) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldAccordion {
  0% { transform: translateY(100px) scale(0.32, 0.18); opacity: 0; }
  34% { transform: translateY(44px) skewX(-18deg) scale(0.52, 0.34); opacity: 1; }
  66% { transform: translateY(8px) skewX(16deg) scale(0.82, 0.72); }
  100% { transform: translateY(-18px) skewX(0) scale(1); opacity: 1; }
}

@keyframes unfoldCross {
  0% { transform: translateY(100px) rotateX(82deg) rotateY(78deg) scale(0.28, 0.2); opacity: 0; }
  38% { transform: translateY(48px) rotateX(78deg) rotateY(60deg) scale(0.44, 0.34); opacity: 1; }
  70% { transform: translateY(4px) rotateX(24deg) rotateY(0) scale(0.76); }
  100% { transform: translateY(-18px) rotateX(0) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldRoll {
  0% { transform: translateY(86px) scale(0.34, 0.14); opacity: 0; }
  50% { transform: translateY(28px) rotate(8deg) scale(0.78, 0.32); opacity: 1; }
  100% { transform: translateY(-18px) rotate(0) scale(1); opacity: 1; }
}

@keyframes unfoldMountain {
  0% { transform: translateY(86px) rotate(-10deg) scale(0.32, 0.18); opacity: 0; }
  46% { transform: translateY(26px) rotate(-30deg) skewY(-10deg) scale(0.7); opacity: 1; }
  100% { transform: translateY(-18px) rotate(0) scale(1); opacity: 1; }
}

@keyframes unfoldReverse {
  0% { transform: translateY(100px) rotateX(82deg) scale(0.3, 0.2); opacity: 0; }
  36% { transform: translateY(46px) rotateY(-24deg) rotateX(70deg) scale(0.42, 0.34); opacity: 1; }
  66% { transform: translateY(12px) rotateY(50deg) rotateX(-32deg) scale(0.68); }
  100% { transform: translateY(-18px) rotateY(0) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldRabbit {
  0% { transform: translateY(100px) scale(0.26, 0.2); opacity: 0; }
  36% { transform: translateY(48px) rotate(-18deg) skewX(18deg) scale(0.38, 0.46); opacity: 1; }
  66% { transform: translateY(6px) rotate(16deg) skewX(-22deg) scale(0.62, 0.66); }
  100% { transform: translateY(-18px) rotate(0) skewX(0) scale(1); opacity: 1; }
}

@keyframes unfoldBoat {
  0% { transform: translateY(100px) rotateX(80deg) scale(0.3, 0.16); opacity: 0; }
  38% { transform: translateY(48px) rotateX(74deg) rotateZ(-7deg) scale(0.42, 0.24); opacity: 1; }
  68% { transform: translateY(8px) rotateX(48deg) rotateZ(7deg) skewX(14deg) scale(0.68, 0.5); }
  100% { transform: translateY(-18px) rotateX(0) rotateZ(0) skewX(0) scale(1); opacity: 1; }
}

@keyframes unfoldPocket {
  0% { transform: translateY(86px) scale(0.34, 0.2); opacity: 0; }
  44% { transform: translateY(26px) rotateX(64deg) scale(0.72, 0.58); opacity: 1; }
  100% { transform: translateY(-18px) rotateX(0) scale(1); opacity: 1; }
}

@keyframes foldLightSweep {
  0%, 16% { opacity: 0; transform: translateX(-12%) scale(1); }
  34% { opacity: 0.28; transform: translateX(0) scale(1.02); }
  58% { opacity: 0.46; transform: translateX(8%) scale(0.98); }
  86%, 100% { opacity: 0.18; transform: translateX(0) scale(0.96); }
}

@keyframes creaseWake {
  0%, 14% { opacity: 0; filter: blur(2px); }
  32% { opacity: 0.68; filter: blur(0.2px); }
  72% { opacity: 0.48; filter: blur(0.5px); }
  100% { opacity: 0.18; filter: blur(0.8px); }
}

@keyframes foldTrifold {
  0% { transform: translateY(28px) rotateX(0) rotateZ(-1deg) scale(0.5); opacity: 0; }
  14% { transform: translateY(-30px) rotateX(0) rotateZ(0) scale(1.04); opacity: 1; }
  32% { transform: translateY(-24px) rotateX(8deg) scale(1); }
  52% { transform: translateY(-18px) rotateY(-42deg) scale(0.78, 0.98); }
  70% { transform: translateY(26px) rotateY(34deg) rotateX(40deg) scale(0.54, 0.58); }
  88% { transform: translateY(96px) rotateX(72deg) rotateZ(-2deg) scale(0.42, 0.28); opacity: 1; }
  100% { transform: translateY(132px) rotateX(76deg) scale(0.3, 0.18); opacity: 0; }
}

@keyframes foldHalf {
  0% { transform: translateY(26px) rotateY(0) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) rotateY(0) scale(1.05); opacity: 1; }
  36% { transform: translateY(-18px) rotateY(0) scale(1); }
  58% { transform: translateY(10px) rotateY(54deg) scale(0.68, 0.98); }
  78% { transform: translateY(78px) rotateY(84deg) rotateZ(2deg) scale(0.44, 0.44); opacity: 1; }
  100% { transform: translateY(132px) rotateY(88deg) scale(0.28, 0.2); opacity: 0; }
}

@keyframes foldGate {
  0% { transform: translateY(30px) scale(0.48); opacity: 0; }
  14% { transform: translateY(-30px) scale(1.06); opacity: 1; }
  34% { transform: translateY(-18px) rotateX(4deg) scale(1); }
  54% { transform: translateY(0) rotateY(-34deg) scale(0.66, 0.96); }
  76% { transform: translateY(70px) rotateX(58deg) rotateZ(3deg) scale(0.46, 0.36); opacity: 1; }
  100% { transform: translateY(132px) rotateX(70deg) scale(0.3, 0.18); opacity: 0; }
}

@keyframes foldAccordion {
  0% { transform: translateY(26px) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) scale(1.05); opacity: 1; }
  30% { transform: translateY(-20px) skewX(0) scale(1); }
  46% { transform: translateY(-4px) skewX(-13deg) scale(0.76, 0.88); }
  62% { transform: translateY(28px) skewX(13deg) scale(0.58, 0.58); }
  82% { transform: translateY(88px) skewX(-6deg) rotateX(62deg) scale(0.42, 0.3); opacity: 1; }
  100% { transform: translateY(132px) rotateX(74deg) scale(0.3, 0.16); opacity: 0; }
}

@keyframes foldCross {
  0% { transform: translateY(26px) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) scale(1.05); opacity: 1; }
  36% { transform: translateY(-18px) rotateX(0) rotateY(0) scale(1); }
  56% { transform: translateY(12px) rotateX(54deg) scale(0.72, 0.62); }
  76% { transform: translateY(74px) rotateX(72deg) rotateY(42deg) scale(0.44, 0.34); opacity: 1; }
  100% { transform: translateY(132px) rotateX(78deg) rotateY(52deg) scale(0.28, 0.18); opacity: 0; }
}

@keyframes foldMountain {
  0% { transform: translateY(30px) rotate(0) scale(0.48); opacity: 0; }
  14% { transform: translateY(-30px) rotate(0) scale(1.06); opacity: 1; }
  36% { transform: translateY(-18px) rotate(-3deg) scale(1); }
  56% { transform: translateY(4px) rotate(-18deg) skewY(-6deg) scale(0.66, 0.72); }
  78% { transform: translateY(78px) rotate(12deg) rotateX(62deg) scale(0.44, 0.32); opacity: 1; }
  100% { transform: translateY(132px) rotate(0) rotateX(72deg) scale(0.28, 0.17); opacity: 0; }
}

@keyframes foldPocket {
  0% { transform: translateY(30px) scale(0.48); opacity: 0; }
  14% { transform: translateY(-30px) scale(1.06); opacity: 1; }
  36% { transform: translateY(-18px) rotateX(0) scale(1); }
  56% { transform: translateY(8px) rotateX(58deg) rotateZ(-4deg) scale(0.64, 0.54); }
  78% { transform: translateY(80px) rotateX(28deg) scale(0.48, 0.34); opacity: 1; }
  100% { transform: translateY(132px) scale(0.3, 0.18); opacity: 0; }
}

@keyframes foldReverse {
  0% { transform: translateY(26px) rotate(0) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) rotate(0) scale(1.06); opacity: 1; }
  34% { transform: translateY(-18px) rotateY(-20deg) scale(0.96); }
  54% { transform: translateY(8px) rotateY(46deg) rotateX(-38deg) scale(0.64); }
  78% { transform: translateY(78px) rotateY(-18deg) rotateX(66deg) scale(0.42, 0.32); opacity: 1; }
  100% { transform: translateY(132px) rotateY(0) rotateX(76deg) scale(0.28, 0.18); opacity: 0; }
}

@keyframes foldRabbit {
  0% { transform: translateY(26px) rotate(0) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) scale(1.06); opacity: 1; }
  36% { transform: translateY(-18px) rotate(-5deg) scale(0.96); }
  58% { transform: translateY(8px) rotate(14deg) skewX(-18deg) scale(0.58, 0.66); }
  78% { transform: translateY(78px) rotate(-12deg) skewX(12deg) scale(0.38, 0.42); opacity: 1; }
  100% { transform: translateY(132px) rotate(0) skewX(0) scale(0.26, 0.18); opacity: 0; }
}

@keyframes foldBoat {
  0% { transform: translateY(26px) rotate(0) scale(0.5); opacity: 0; }
  14% { transform: translateY(-32px) rotate(0) scale(1.06); opacity: 1; }
  36% { transform: translateY(-14px) rotateX(32deg) scale(0.88, 0.72); }
  58% { transform: translateY(16px) rotateX(58deg) rotateZ(7deg) skewX(15deg) scale(0.58, 0.4); }
  80% { transform: translateY(84px) rotateX(70deg) rotateZ(-5deg) scale(0.42, 0.25); opacity: 1; }
  100% { transform: translateY(132px) rotateX(78deg) scale(0.28, 0.16); opacity: 0; }
}

@keyframes unfoldTrifold {
  0% { transform: translateY(112px) rotateX(76deg) scale(0.3, 0.18); opacity: 0; }
  28% { transform: translateY(64px) rotateX(66deg) scale(0.42, 0.28); opacity: 1; }
  58% { transform: translateY(8px) rotateY(-26deg) scale(0.72, 0.76); }
  100% { transform: translateY(-18px) rotateX(0) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldHalf {
  0% { transform: translateY(112px) rotateY(88deg) scale(0.28, 0.2); opacity: 0; }
  36% { transform: translateY(52px) rotateY(76deg) scale(0.44, 0.44); opacity: 1; }
  72% { transform: translateY(-8px) rotateY(12deg) scale(0.9); }
  100% { transform: translateY(-18px) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldGate {
  0% { transform: translateY(112px) rotateX(70deg) scale(0.3, 0.18); opacity: 0; }
  36% { transform: translateY(46px) rotateY(-48deg) scale(0.5, 0.42); opacity: 1; }
  100% { transform: translateY(-18px) rotateY(0) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldAccordion {
  0% { transform: translateY(112px) rotateX(74deg) scale(0.3, 0.16); opacity: 0; }
  34% { transform: translateY(52px) skewX(-12deg) scale(0.52, 0.34); opacity: 1; }
  66% { transform: translateY(8px) skewX(12deg) scale(0.82, 0.72); }
  100% { transform: translateY(-18px) skewX(0) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldCross {
  0% { transform: translateY(112px) rotateX(78deg) rotateY(52deg) scale(0.28, 0.18); opacity: 0; }
  36% { transform: translateY(48px) rotateX(68deg) rotateY(36deg) scale(0.44, 0.34); opacity: 1; }
  72% { transform: translateY(2px) rotateX(18deg) rotateY(0) scale(0.8); }
  100% { transform: translateY(-18px) rotateX(0) rotateY(0) scale(1); opacity: 1; }
}

@keyframes unfoldMountain {
  0% { transform: translateY(112px) rotateX(72deg) scale(0.28, 0.17); opacity: 0; }
  42% { transform: translateY(42px) rotate(14deg) rotateX(54deg) scale(0.46, 0.34); opacity: 1; }
  100% { transform: translateY(-18px) rotate(0) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldPocket {
  0% { transform: translateY(112px) scale(0.3, 0.18); opacity: 0; }
  42% { transform: translateY(36px) rotateX(46deg) scale(0.62, 0.48); opacity: 1; }
  100% { transform: translateY(-18px) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldReverse {
  0% { transform: translateY(112px) rotateY(0) rotateX(76deg) scale(0.28, 0.18); opacity: 0; }
  40% { transform: translateY(48px) rotateY(-20deg) rotateX(60deg) scale(0.44, 0.34); opacity: 1; }
  74% { transform: translateY(4px) rotateY(28deg) rotateX(10deg) scale(0.78); }
  100% { transform: translateY(-18px) rotateY(0) rotateX(0) scale(1); opacity: 1; }
}

@keyframes unfoldRabbit {
  0% { transform: translateY(112px) rotate(0) skewX(0) scale(0.26, 0.18); opacity: 0; }
  40% { transform: translateY(48px) rotate(-12deg) skewX(12deg) scale(0.42, 0.38); opacity: 1; }
  100% { transform: translateY(-18px) rotate(0) skewX(0) scale(1); opacity: 1; }
}

@keyframes unfoldBoat {
  0% { transform: translateY(112px) rotateX(78deg) scale(0.28, 0.16); opacity: 0; }
  36% { transform: translateY(50px) rotateX(68deg) rotateZ(-5deg) scale(0.42, 0.28); opacity: 1; }
  70% { transform: translateY(4px) rotateX(22deg) rotateZ(3deg) scale(0.82, 0.66); }
  100% { transform: translateY(-18px) rotateX(0) rotateZ(0) scale(1); opacity: 1; }
}

.fold-boat .fold-sheet {
  animation: foldSheetToBoat 1.62s forwards cubic-bezier(0.28, 0, 0.16, 1);
}

.fold-boat .boat-fold-0 {
  animation: boatCornerLeftTop 1.16s 0.14s forwards cubic-bezier(0.22, 0.72, 0.2, 1);
}

.fold-boat .boat-fold-1 {
  animation: boatCornerRightTop 1.16s 0.2s forwards cubic-bezier(0.22, 0.72, 0.2, 1);
}

.fold-boat .boat-fold-2 {
  animation: boatCornerLeftBottom 1.1s 0.42s forwards cubic-bezier(0.22, 0.72, 0.2, 1);
}

.fold-boat .boat-fold-3 {
  animation: boatCornerRightBottom 1.1s 0.48s forwards cubic-bezier(0.22, 0.72, 0.2, 1);
}

.fold-boat .boat-keel {
  animation: boatKeelRise 1.28s 0.72s forwards cubic-bezier(0.22, 0.72, 0.2, 1);
}

.fold-boat .folded-paper {
  animation-name: foldBoatToEnvelope;
  animation-duration: 2.15s;
  animation-timing-function: cubic-bezier(0.34, 0, 0.12, 1);
}

.packaging.fold-boat .qiaopi-envelope {
  animation: envelopeReceive 1.35s 0.86s forwards cubic-bezier(0.42, 0, 0.18, 1);
}

.packaging.fold-boat .postmark {
  animation: postmarkDrop 0.36s 1.84s forwards ease-out;
}

@keyframes foldSheetToBoat {
  0% {
    border-radius: 0;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    filter: none;
  }
  35% {
    clip-path: polygon(7% 5%, 93% 5%, 88% 94%, 12% 94%);
    filter: drop-shadow(0 8px 14px rgba(60, 38, 23, 0.16));
  }
  68% {
    border-radius: 3px 3px 18px 18px;
    clip-path: polygon(8% 54%, 25% 25%, 50% 10%, 75% 25%, 92% 54%, 82% 78%, 18% 78%);
  }
  100% {
    border-radius: 4px 4px 18px 18px;
    clip-path: polygon(4% 60%, 25% 26%, 50% 6%, 75% 26%, 96% 60%, 82% 84%, 18% 84%);
    filter: drop-shadow(0 14px 22px rgba(0, 0, 0, 0.22));
  }
}

@keyframes boatCornerLeftTop {
  0% { opacity: 0; transform: rotateY(0) rotateZ(0); }
  18% { opacity: 0.88; }
  100% { opacity: 0.92; transform: rotateY(-128deg) rotateZ(-7deg); }
}

@keyframes boatCornerRightTop {
  0% { opacity: 0; transform: rotateY(0) rotateZ(0); }
  18% { opacity: 0.88; }
  100% { opacity: 0.92; transform: rotateY(128deg) rotateZ(7deg); }
}

@keyframes boatCornerLeftBottom {
  0% { opacity: 0; transform: rotateX(0) rotateZ(0); }
  16% { opacity: 0.85; }
  100% { opacity: 0.88; transform: rotateX(122deg) rotateZ(5deg); }
}

@keyframes boatCornerRightBottom {
  0% { opacity: 0; transform: rotateX(0) rotateZ(0); }
  16% { opacity: 0.85; }
  100% { opacity: 0.88; transform: rotateX(122deg) rotateZ(-5deg); }
}

@keyframes boatKeelRise {
  0% { opacity: 0; transform: translateY(26px) rotateX(64deg) scale(0.42, 0.3); }
  48% { opacity: 0.84; }
  100% { opacity: 0.92; transform: translateY(0) rotateX(0) scale(1); }
}

@keyframes foldBoatToEnvelope {
  0% { transform: translateY(24px) rotateZ(0) scale(0.5); opacity: 0; }
  10% { transform: translateY(-30px) rotateZ(0) scale(1.04); opacity: 1; }
  42% { transform: translateY(-16px) rotateX(0) rotateZ(0) scale(0.86); opacity: 1; }
  68% { transform: translateY(24px) rotateX(18deg) rotateZ(-5deg) scale(0.52, 0.34); opacity: 1; }
  86% { transform: translateY(96px) rotateX(42deg) rotateZ(2deg) scale(0.36, 0.2); opacity: 0.94; }
  100% { transform: translateY(132px) rotateX(58deg) scale(0.2, 0.12); opacity: 0; }
}

@media (max-width: 960px) {
  .app-shell {
    padding: 10px;
  }

  .workspace {
    grid-template-columns: 1fr;
  }

  .composer {
    order: 2;
  }

  .preview-stage {
    min-height: auto;
    padding: 18px 0;
  }

  .letter {
    width: min(94vw, 520px);
    min-height: 620px;
    padding: 40px 28px 34px;
  }

  .handwriting {
    font-size: var(--hand-size, 22px);
    line-height: 2.05;
  }

}

@media (max-width: 520px) {
  .app-shell {
    padding: 6px;
  }

  .workspace {
    gap: 8px;
  }

  .preview-stage {
    position: sticky;
    top: 0;
    z-index: 12;
    min-height: 43svh;
    height: 43svh;
    padding: 8px 0;
    border-color: rgba(244, 234, 216, 0.24);
    background: rgba(17, 13, 10, 0.78);
    backdrop-filter: blur(10px);
  }

  .preview-stage .background-credit {
    display: none;
  }

  .paper-maximize {
    display: block;
  }

  body.paper-fullscreen {
    overflow: hidden;
  }

  body.paper-fullscreen .preview-stage {
    position: fixed;
    inset: 0;
    z-index: 60;
    width: 100vw;
    height: 100svh;
    min-height: 100svh;
    padding: 42px 0 24px;
    border-radius: 0;
    border-width: 0;
    background: rgba(17, 13, 10, 0.94);
  }

  body.paper-fullscreen .letter {
    width: min(96vw, 64svh);
    padding: 22px 12px 24px;
    border-width: 10px;
  }

  body.paper-fullscreen .letter-body {
    inset: 28px 12px 38px 12px;
  }

  body.paper-fullscreen .stamp {
    right: 18px;
    bottom: 20px;
    width: 100px;
    height: 100px;
    border-width: 6px;
    font-size: 42px;
  }

  body.paper-fullscreen .page-nav {
    bottom: 14px;
  }

  .composer {
    gap: 10px;
    padding: 12px;
  }

  .brand {
    grid-template-columns: 34px 1fr;
    gap: 10px;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
    font-size: 18px;
  }

  h1 {
    font-size: 18px;
  }

  .brand p,
  .hint {
    font-size: 12px;
    line-height: 1.45;
  }

  .field {
    gap: 6px;
  }

  textarea {
    min-height: 32px;
    max-height: 56px;
    padding: 7px 9px;
    line-height: 1.35;
  }

  .quick-prompts button,
  .share-actions button,
  .actions button,
  .segmented button {
    min-height: 36px;
    padding: 0 10px;
  }

  .quick-prompts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .letter {
    width: min(66vw, 250px);
    min-height: 0;
    padding: 14px 8px 14px;
    border-width: 8px;
    box-shadow:
      0 14px 36px rgba(0, 0, 0, 0.36),
      inset 0 0 0 2px var(--inner-line),
      inset 0 0 0 5px rgba(176, 68, 56, 0.12);
  }

  .letter-body {
    inset: 22px 8px 28px 8px;
    transform: none;
  }

  .letter-head {
    left: 22px;
    bottom: 34px;
  }

  .letter-foot {
    left: 18px;
    bottom: 32px;
    top: auto;
    font-size: 15px;
  }

  .letter-foot span + span {
    font-size: 13px;
  }

  .stamp {
    right: 10px;
    bottom: 12px;
    width: 66px;
    height: 66px;
    border-width: 4px;
    font-size: 28px;
  }

  .stamp-tilt {
    width: 76px;
    height: 62px;
    font-size: 28px;
  }

  .stamp-round {
    width: 66px;
    height: 66px;
    font-size: 34px;
  }

  .stamp-signet {
    width: 74px;
    height: 58px;
    border-width: 4px;
    font-size: 24px;
  }

  .page-nav {
    bottom: 8px;
    min-height: 30px;
    padding: 4px;
    gap: 6px;
  }

  .page-nav button {
    min-height: 28px;
    padding: 0 8px;
    font-size: 12px;
  }

  .reader-continue {
    right: 10px;
    bottom: 10px;
    min-height: 36px;
    padding: 0 12px;
    font-size: 13px;
  }

  body.shared-reading .preview-stage {
    position: relative;
    height: calc(100svh - 12px);
    min-height: calc(100svh - 12px);
    padding: 10px 0 48px;
  }

  body.shared-reading .letter {
    width: min(92vw, 390px);
    padding: 22px 12px 26px;
  }

  .qiaopi-envelope {
    width: min(330px, 82vw);
  }

  .folded-paper {
    width: min(330px, 76vw);
    min-height: 500px;
  }

  .fold-letter-clone {
    min-height: 500px;
  }

  .envelope-recipient {
    font-size: 21px;
  }

  .postmark {
    right: 18px;
    top: 18px;
    width: 60px;
    height: 60px;
    font-size: 14px;
  }
}