/* =========================================================
   阿紫与阿虎 — 雾中绘本
   气质：水墨夜岚 + 灯笼暖金 + 编辑式留白
   ========================================================= */

:root {
  --ink: #1a1520;
  --ink-soft: #3d3448;
  --mist: #ebe4f0;
  --paper: #f7f1e8;
  --paper-dim: rgba(247, 241, 232, 0.72);
  --plum: #5c3d6e;
  --plum-deep: #2b1a36;
  --gold: #c9a06a;
  --gold-soft: #e8d2ad;
  --ember: #d4785a;
  --line: rgba(92, 61, 110, 0.18);
  --shadow: 0 24px 60px rgba(26, 21, 32, 0.28);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --font-display: "ZCOOL XiaoWei", "Songti SC", serif;
  --font-body: "Noto Serif SC", "Songti SC", serif;
  --font-ui: "DM Sans", "PingFang SC", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--plum-deep);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

img {
  display: block;
  max-width: 100%;
}

/* ---------- ambient background ---------- */
.sky {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  transition: background 1.2s var(--ease);
  background:
    radial-gradient(ellipse 80% 50% at 20% 10%, rgba(201, 160, 106, 0.18), transparent 55%),
    radial-gradient(ellipse 70% 60% at 90% 80%, rgba(92, 61, 110, 0.45), transparent 50%),
    linear-gradient(165deg, #1a1024 0%, #2b1a36 40%, #1a1520 100%);
}

.sky::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.45'/%3E%3C/svg%3E");
  mix-blend-mode: soft-light;
}

.sky[data-tone="mist"] {
  background:
    radial-gradient(ellipse 90% 60% at 50% 30%, rgba(180, 190, 220, 0.22), transparent 60%),
    linear-gradient(180deg, #1e2438 0%, #2a2238 100%);
}
.sky[data-tone="dawn"],
.sky[data-tone="spring"] {
  background:
    radial-gradient(ellipse 70% 50% at 70% 20%, rgba(255, 210, 170, 0.25), transparent 55%),
    linear-gradient(160deg, #2a2230 0%, #3a2e3a 100%);
}
.sky[data-tone="autumn"],
.sky[data-tone="sunset"],
.sky[data-tone="home"] {
  background:
    radial-gradient(ellipse 80% 50% at 80% 30%, rgba(255, 150, 80, 0.28), transparent 55%),
    linear-gradient(165deg, #2a1a18 0%, #3a2420 50%, #1a1520 100%);
}
.sky[data-tone="night-market"] {
  background:
    radial-gradient(ellipse 50% 40% at 50% 70%, rgba(255, 120, 60, 0.3), transparent 60%),
    linear-gradient(180deg, #120c18 0%, #2a1820 100%);
}
.sky[data-tone="summer"] {
  background:
    radial-gradient(ellipse 70% 50% at 40% 20%, rgba(255, 180, 200, 0.22), transparent 55%),
    linear-gradient(165deg, #2a2030 0%, #3a2840 100%);
}
.sky[data-tone="starry"] {
  background:
    radial-gradient(ellipse 60% 40% at 30% 20%, rgba(120, 140, 220, 0.2), transparent 55%),
    linear-gradient(180deg, #0a0c18 0%, #1a1430 100%);
}
.sky[data-tone="rain"] {
  background:
    radial-gradient(ellipse 70% 50% at 50% 40%, rgba(80, 100, 140, 0.2), transparent 60%),
    linear-gradient(180deg, #121820 0%, #1c1828 100%);
}

/* floating particles */
.motes {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  overflow: hidden;
}
.mote {
  position: absolute;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--gold-soft);
  opacity: 0;
  animation: float-mote linear infinite;
}
@keyframes float-mote {
  0% { transform: translateY(110vh) scale(0.6); opacity: 0; }
  10% { opacity: 0.55; }
  90% { opacity: 0.25; }
  100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}

/* ---------- app shell ---------- */
.app {
  position: relative;
  z-index: 2;
  height: 100vh;
  height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

/* ---------- top bar ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.5rem 0.5rem;
  opacity: 0;
  transform: translateY(-8px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.app.is-reading .topbar {
  opacity: 1;
  transform: none;
}

.brand {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.12em;
  color: var(--paper);
}

.progress {
  display: flex;
  gap: 0.4rem;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.progress button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1px solid rgba(247, 241, 232, 0.35);
  background: transparent;
  transition: transform 0.25s var(--ease), background 0.25s, border-color 0.25s;
}
.progress button:hover {
  transform: scale(1.35);
  border-color: var(--gold);
}
.progress button.is-done {
  background: rgba(201, 160, 106, 0.55);
  border-color: transparent;
}
.progress button.is-current {
  background: var(--gold);
  border-color: var(--gold);
  box-shadow: 0 0 0 4px rgba(201, 160, 106, 0.22);
  transform: scale(1.25);
}

/* ---------- stage ---------- */
.stage {
  position: relative;
  min-height: 0;
  display: grid;
  place-items: center;
  padding: 0.5rem 1.25rem 0.75rem;
}

/* ---------- prologue ---------- */
.prologue {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 2rem;
  text-align: center;
  color: var(--paper);
  transition: opacity 0.7s var(--ease), visibility 0.7s;
}
.prologue.is-gone {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.prologue-card {
  max-width: 34rem;
  padding: 2.5rem 2rem;
  border: 1px solid rgba(247, 241, 232, 0.14);
  background: rgba(26, 21, 32, 0.35);
  backdrop-filter: blur(14px);
  border-radius: 2px;
  box-shadow: var(--shadow);
}

.prologue-kicker {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--gold-soft);
  margin-bottom: 1.25rem;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.1s forwards;
}

.prologue h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 7vw, 3.6rem);
  font-weight: 400;
  letter-spacing: 0.18em;
  margin-bottom: 0.75rem;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.25s forwards;
}

.prologue-sub {
  font-size: 0.98rem;
  letter-spacing: 0.18em;
  color: rgba(247, 241, 232, 0.72);
  margin-bottom: 2rem;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.4s forwards;
}

.prologue-lines {
  list-style: none;
  display: grid;
  gap: 0.65rem;
  margin-bottom: 2.25rem;
  min-height: 6.5rem;
}

.prologue-lines li {
  font-size: 0.98rem;
  line-height: 1.75;
  letter-spacing: 0.06em;
  color: rgba(247, 241, 232, 0.88);
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.prologue-lines li.is-shown {
  opacity: 1;
  transform: none;
}

.btn-enter {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.85rem 1.6rem;
  border: 1px solid rgba(201, 160, 106, 0.55);
  color: var(--gold-soft);
  font-family: var(--font-ui);
  font-size: 0.82rem;
  letter-spacing: 0.22em;
  border-radius: 999px;
  transition: background 0.3s, color 0.3s, transform 0.3s var(--ease);
  opacity: 0;
  animation: rise 0.9s var(--ease) 1.8s forwards;
}
.btn-enter:hover {
  background: rgba(201, 160, 106, 0.18);
  color: var(--paper);
  transform: translateY(-2px);
}
.btn-enter .arrow {
  transition: transform 0.3s var(--ease);
}
.btn-enter:hover .arrow {
  transform: translateX(4px);
}

@keyframes rise {
  to { opacity: 1; transform: none; }
}

/* ---------- chapter view ---------- */
.chapter {
  width: min(1080px, 100%);
  height: 100%;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(1rem, 3vw, 2.5rem);
  align-items: center;
  opacity: 0;
  transform: translateY(18px) scale(0.985);
  pointer-events: none;
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.chapter.is-active {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.frame {
  position: relative;
  border-radius: 4px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: #0d0a12;
  aspect-ratio: 4 / 3;
  cursor: zoom-in;
}
.frame::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(247, 241, 232, 0.12);
  border-radius: inherit;
  z-index: 2;
  pointer-events: none;
}
.frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.04);
  transition: transform 1.4s var(--ease), opacity 0.8s var(--ease);
  opacity: 0;
}
.chapter.is-active .frame img {
  opacity: 1;
  transform: scale(1);
}
.frame:hover img {
  transform: scale(1.03);
}

.frame-meta {
  position: absolute;
  left: 0.9rem;
  bottom: 0.85rem;
  z-index: 3;
  padding: 0.35rem 0.7rem;
  font-family: var(--font-ui);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  color: var(--paper);
  background: rgba(26, 21, 32, 0.45);
  backdrop-filter: blur(8px);
  border-radius: 999px;
}

.panel {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 0;
  color: var(--paper);
  padding: 0.25rem 0.2rem;
}

.chapter-no {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  letter-spacing: 0.32em;
  color: var(--gold);
  margin-bottom: 0.7rem;
  opacity: 0;
  transform: translateY(8px);
  transition: 0.5s var(--ease) 0.1s;
}
.chapter.is-active .chapter-no {
  opacity: 1;
  transform: none;
}

.chapter-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 2.8rem);
  font-weight: 400;
  letter-spacing: 0.16em;
  margin-bottom: 0.45rem;
  opacity: 0;
  transform: translateY(10px);
  transition: 0.55s var(--ease) 0.18s;
}
.chapter.is-active .chapter-title {
  opacity: 1;
  transform: none;
}

.chapter-mood {
  font-size: 0.88rem;
  letter-spacing: 0.14em;
  color: rgba(247, 241, 232, 0.55);
  margin-bottom: 1.1rem;
  opacity: 0;
  transition: 0.55s var(--ease) 0.28s;
}
.chapter.is-active .chapter-mood {
  opacity: 1;
}

.reveal-area {
  min-height: 0;
  margin-top: 0.85rem;
  margin-bottom: 0;
  /* 正文在按钮下方展开，不预先占位，避免误以为页面“空了一截” */
}

.lines {
  list-style: none;
  display: grid;
  gap: 0.7rem;
}

.lines li {
  position: relative;
  padding-left: 0.9rem;
  font-size: clamp(0.95rem, 1.6vw, 1.05rem);
  line-height: 1.85;
  letter-spacing: 0.04em;
  color: rgba(247, 241, 232, 0.9);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
}
.lines li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--gold);
  opacity: 0.7;
}
.lines li.is-shown {
  opacity: 1;
  transform: none;
}

.hint {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: rgba(247, 241, 232, 0.42);
  margin-bottom: 0;
  min-height: 1.2em;
  transition: opacity 0.4s;
}
.hint.is-hidden {
  opacity: 0;
  height: 0;
  min-height: 0;
  overflow: hidden;
  margin: 0;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  align-items: center;
  margin-bottom: 0.65rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 2.6rem;
  padding: 0.55rem 1.15rem;
  border-radius: 999px;
  font-family: var(--font-ui);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  transition: transform 0.25s var(--ease), background 0.25s, border-color 0.25s, color 0.25s;
}
.btn:hover {
  transform: translateY(-1px);
}
.btn:active {
  transform: translateY(0);
}
.btn-primary {
  background: linear-gradient(135deg, rgba(201, 160, 106, 0.95), rgba(212, 120, 90, 0.9));
  color: #1a1220;
  border: 1px solid transparent;
}
.btn-primary:hover {
  filter: brightness(1.05);
}
.btn-ghost {
  border: 1px solid rgba(247, 241, 232, 0.22);
  color: rgba(247, 241, 232, 0.85);
}
.btn-ghost:hover {
  border-color: rgba(201, 160, 106, 0.55);
  color: var(--gold-soft);
}
.btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none;
}

/* ---------- bottom nav ---------- */
.bottombar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.4rem 1.5rem 1.1rem;
  color: rgba(247, 241, 232, 0.45);
  font-family: var(--font-ui);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  opacity: 0;
  transition: opacity 0.5s;
}
.app.is-reading .bottombar {
  opacity: 1;
}

/* ---------- lightbox ---------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  background: rgba(10, 8, 14, 0.88);
  backdrop-filter: blur(10px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.35s, visibility 0.35s;
  padding: 1.5rem;
  cursor: zoom-out;
}
.lightbox.is-open {
  opacity: 1;
  visibility: visible;
}
.lightbox img {
  max-width: min(1200px, 96vw);
  max-height: 90vh;
  border-radius: 4px;
  box-shadow: var(--shadow);
  transform: scale(0.96);
  transition: transform 0.4s var(--ease);
}
.lightbox.is-open img {
  transform: scale(1);
}

/* ---------- ending toast ---------- */
.end-note {
  position: fixed;
  left: 50%;
  bottom: 2rem;
  transform: translateX(-50%) translateY(20px);
  z-index: 40;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  background: rgba(247, 241, 232, 0.92);
  color: var(--ink);
  font-family: var(--font-display);
  letter-spacing: 0.14em;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s, transform 0.5s var(--ease);
}
.end-note.is-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  body { overflow: auto; }
  .app {
    height: auto;
    min-height: 100vh;
    min-height: 100dvh;
  }
  .stage {
    padding: 0.5rem 1rem 1rem;
  }
  .chapter {
    grid-template-columns: 1fr;
    gap: 1.1rem;
    align-content: start;
  }
  .frame {
    max-height: 48vh;
  }
  .panel {
    padding-bottom: 0.5rem;
  }
  .reveal-area {
    min-height: 0;
  }
  .topbar {
    padding: 0.85rem 1rem 0.35rem;
  }
  .bottombar {
    padding: 0.2rem 1rem 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}