@font-face {
  font-family: "HanShaoJieXingKai";
  src: url("./HanShaoJieXingKaiJianTi/M006-HanShaoJieXingKaiJianTi-2.ttf") format("truetype");
  font-display: swap;
}

:root {
  --ink: #6f4633;
  --link-ink: #9b563a;
  --paper-w: min(92vw, calc(88svh * 1086 / 1448));
  --env-w: min(90vw, calc(72svh * 1122 / 1402));
  color-scheme: only light;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
  overflow: hidden;
}

body {
  color: var(--ink);
  font-family: "HanShaoJieXingKai", "KaiTi", "STKaiti", serif;
  background: #f2d8ad url("./图片素材/背景图.png") center / cover no-repeat fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

button {
  font: inherit;
  -webkit-tap-highlight-color: transparent;
}

.scene {
  position: relative;
  display: grid;
  width: 100vw;
  height: 100svh;
  place-items: center;
  padding: max(14px, env(safe-area-inset-top)) max(14px, env(safe-area-inset-right)) max(18px, env(safe-area-inset-bottom)) max(14px, env(safe-area-inset-left));
  isolation: isolate;
}

.scene::before {
  position: absolute;
  inset: 0;
  z-index: -1;
  content: "";
  background: linear-gradient(180deg, rgba(255, 246, 229, 0.1), rgba(86, 52, 27, 0.18));
}

.envelope-stage,
.letter-stage {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: inherit;
}

.envelope-stage {
  transition: opacity 420ms ease, transform 520ms cubic-bezier(0.2, 0.78, 0.25, 1);
}

.envelope-stage.hidden {
  pointer-events: none;
  opacity: 0;
  transform: translateY(8svh) scale(0.86);
}

.envelope-button {
  position: relative;
  width: var(--env-w);
  aspect-ratio: 1122 / 1402;
  padding: 0;
  border: 0;
  cursor: pointer;
  background: transparent;
  filter: drop-shadow(0 18px 24px rgba(75, 43, 19, 0.26));
  transition: transform 420ms cubic-bezier(0.2, 0.78, 0.25, 1), filter 420ms ease;
}

.envelope-button:active {
  transform: scale(0.985);
}

.envelope-button.opening {
  transform: scale(1.05) translateY(-1.8svh);
  filter: drop-shadow(0 24px 32px rgba(75, 43, 19, 0.3));
}

.envelope-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  user-select: none;
  pointer-events: none;
  transition: opacity 360ms ease, transform 520ms cubic-bezier(0.2, 0.78, 0.25, 1);
}

.envelope-open {
  opacity: 0;
  transform: translateY(1.5svh) scale(0.98);
}

.envelope-stage[data-state="openEnvelope"] .envelope-closed {
  opacity: 0;
  transform: scale(1.02);
}

.envelope-stage[data-state="openEnvelope"] .envelope-open {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.letter-stage {
  pointer-events: none;
  opacity: 0;
  transform: translateY(10svh) scale(0.74);
  transition: opacity 440ms ease, transform 720ms cubic-bezier(0.19, 1, 0.22, 1);
}

.letter-stage.visible {
  pointer-events: auto;
  opacity: 1;
  transform: translateY(0) scale(1);
}

.letter-card {
  position: relative;
  width: var(--paper-w);
  aspect-ratio: 1086 / 1448;
  cursor: pointer;
  filter: drop-shadow(0 18px 26px rgba(77, 44, 18, 0.24));
  transition: opacity 260ms ease, transform 320ms ease;
}

.letter-stage[data-page-role="ending"] .letter-card {
  cursor: default;
}

.letter-card.turning-next {
  opacity: 0;
  transform: translateX(-5vw) rotate(-1deg);
}

.letter-card.turning-prev {
  opacity: 0;
  transform: translateX(5vw) rotate(1deg);
}

.letter-paper {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  user-select: none;
  pointer-events: none;
}

.letter-text {
  position: absolute;
  overflow: hidden;
  color: var(--ink) !important;
  -webkit-text-fill-color: var(--ink) !important;
  font-size: clamp(17px, 4.6vw, 25px);
  line-height: 1.72;
  letter-spacing: 0;
  text-align: left;
  text-shadow: 0 1px 0 rgba(255, 247, 231, 0.48);
  white-space: pre-wrap;
}

.letter-text p {
  margin: 0;
  text-indent: 2em;
}

.letter-text .letter-date {
  margin-top: 1.72em;
  text-align: right;
  text-indent: 0;
}

.letter-image-link {
  position: relative;
  z-index: 2;
  display: inline-block;
  padding: 0 0.08em;
  color: var(--link-ink) !important;
  -webkit-text-fill-color: var(--link-ink) !important;
  cursor: pointer;
  pointer-events: auto;
  text-decoration: underline;
  text-decoration-color: var(--link-ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

.letter-card[data-page-kind="cover"] .letter-text {
  inset: 15% 15% 14%;
}

.letter-card[data-page-kind="middle"] .letter-text {
  inset: 8% 11%;
  transform: none;
}

.letter-card[data-page-kind="ending"] .letter-text {
  inset: 16% 14% 25%;
}

.letter-actions {
  position: absolute;
  left: 50%;
  bottom: max(14px, env(safe-area-inset-bottom));
  display: flex;
  width: min(90vw, 420px);
  justify-content: center;
  gap: 10px;
  transform: translateX(-50%);
  pointer-events: none;
}

.letter-action {
  display: none;
  min-width: 76px;
  min-height: 42px;
  padding: 9px 15px 8px;
  border: 1px solid rgba(117, 77, 44, 0.25);
  border-radius: 999px;
  color: #74472f;
  cursor: pointer;
  background: rgba(255, 243, 218, 0.78);
  box-shadow: 0 8px 18px rgba(91, 54, 25, 0.14);
  backdrop-filter: blur(8px);
  transition: transform 180ms ease, background-color 180ms ease;
  pointer-events: auto;
}

.letter-action:active {
  transform: translateY(1px) scale(0.98);
}

.image-modal {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: grid;
  place-items: center;
  padding: max(18px, env(safe-area-inset-top)) max(18px, env(safe-area-inset-right)) max(18px, env(safe-area-inset-bottom)) max(18px, env(safe-area-inset-left));
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease;
}

.image-modal.open {
  opacity: 1;
  pointer-events: auto;
}

.image-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(49, 31, 18, 0.55);
  backdrop-filter: blur(5px);
}

.image-modal-panel {
  position: relative;
  width: min(88vw, 430px);
  max-height: 84svh;
  margin: 0;
  padding: 14px;
  border-radius: 8px;
  background: rgba(255, 241, 213, 0.95);
  box-shadow: 0 22px 46px rgba(46, 27, 12, 0.34);
  transform: translateY(12px) scale(0.96);
  transition: transform 220ms ease;
}

.image-modal.open .image-modal-panel {
  transform: translateY(0) scale(1);
}

.image-modal-close {
  position: absolute;
  top: 10px;
  right: 10px;
  min-width: 54px;
  min-height: 34px;
  border: 1px solid rgba(117, 77, 44, 0.22);
  border-radius: 999px;
  color: #74472f;
  background: rgba(255, 246, 229, 0.9);
  box-shadow: 0 8px 16px rgba(91, 54, 25, 0.12);
}

.image-modal-picture {
  display: block;
  width: 100%;
  max-height: calc(84svh - 28px);
  object-fit: contain;
  border-radius: 4px;
}

.letter-stage[data-page-role="cover"] .next,
.letter-stage[data-page-role="middle"] .previous,
.letter-stage[data-page-role="middle"] .next,
.letter-stage[data-page-role="ending"] .previous,
.letter-stage[data-page-role="ending"] .close {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

@media (max-height: 700px) {
  :root {
    --paper-w: min(88vw, calc(84svh * 1086 / 1448));
    --env-w: min(86vw, calc(68svh * 1122 / 1402));
  }

  .letter-text {
    font-size: clamp(15px, 4.25vw, 21px);
    line-height: 1.62;
  }

  .letter-actions {
    gap: 8px;
  }

  .letter-action {
    min-width: 68px;
    min-height: 38px;
    padding: 7px 12px 6px;
  }
}

@media (min-width: 600px) {
  :root {
    --paper-w: min(520px, calc(88svh * 1086 / 1448));
    --env-w: min(470px, calc(72svh * 1122 / 1402));
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #6f4633;
    --link-ink: #9b563a;
    color-scheme: only light;
  }

  html,
  body,
  .scene,
  .letter-card,
  .letter-text,
  .letter-text p {
    color: var(--ink) !important;
    -webkit-text-fill-color: var(--ink) !important;
  }

  .letter-image-link {
    color: var(--link-ink) !important;
    -webkit-text-fill-color: var(--link-ink) !important;
    text-decoration-color: var(--link-ink) !important;
  }
}

@media (prefers-reduced-motion: reduce) {

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}