/* =========================================================
   猫 · 首页样式
   结构顺序：基础变量 → 艺术背景 → 导航 → 主内容 → 页脚 → 响应式
   ========================================================= */

:root {
  --night-950: #041126;
  --night-900: #081b3d;
  --night-700: #174a83;
  --moon: #f7dc8a;
  --day: #fff8d8;
  --ink: #081328;
  --white: #ffffff;
  --glass-dark: rgba(5, 17, 39, 0.62);
  --glass-light: rgba(255, 255, 255, 0.13);
  --glass-border: rgba(255, 255, 255, 0.30);
  --shadow: 0 24px 70px rgba(2, 9, 23, 0.28);
  --radius-lg: 28px;
  --radius-md: 20px;
  --ease: cubic-bezier(.22, .8, .24, 1);
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--night-950);
  color-scheme: dark;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  color: var(--white);
  font-family: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
  font: inherit;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--moon);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 50%;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--white);
  color: var(--ink);
  transform: translate(-50%, -180%);
  transition: transform .2s ease;
}

.skip-link:focus {
  transform: translate(-50%, 0);
}

/* ---------- 全屏艺术背景与动态光影 ---------- */

.art-stage {
  position: fixed;
  z-index: -1;
  inset: 0;
  overflow: hidden;
  background: var(--night-900);
  isolation: isolate;
}

.art-stage__image {
  position: absolute;
  inset: -2%;
  background-image:
    linear-gradient(90deg, rgba(1, 8, 22, .22), transparent 36%, transparent 74%, rgba(255, 242, 188, .06)),
    url("day-night-art-v3.webp");
  background-position: center;
  background-size: cover;
  filter: saturate(1.04) contrast(1.02);
  transform: none;
}

/* 月光使用冷色、柔和的椭圆扩散；运动幅度很小，避免喧宾夺主。 */
.light--moon {
  position: absolute;
  inset: -16% 35% 30% -18%;
  background:
    radial-gradient(circle at 24% 24%, rgba(255, 239, 173, .28), transparent 17%),
    radial-gradient(ellipse at 42% 40%, rgba(112, 170, 255, .22), transparent 58%);
  mix-blend-mode: screen;
  filter: blur(12px);
  animation: moon-drift 11s ease-in-out infinite alternate;
}

/* 日光更温暖、范围更大，和右下方白昼风景呼应。 */
.light--sun {
  position: absolute;
  inset: 14% -18% -24% 38%;
  background:
    radial-gradient(circle at 78% 24%, rgba(255, 248, 205, .42), transparent 21%),
    radial-gradient(ellipse at 65% 66%, rgba(255, 205, 107, .23), transparent 64%);
  mix-blend-mode: screen;
  filter: blur(14px);
  animation: sun-pulse 9s ease-in-out infinite alternate;
}

/* 整幅画表面的“玻璃扫光”：只是一层光带，不包含场景内容。 */
.glass-sheen {
  position: absolute;
  inset: -55%;
  width: 42%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, .18), rgba(255, 249, 211, .28), transparent);
  filter: blur(20px);
  mix-blend-mode: screen;
  transform: rotate(25deg) translateX(-80vw);
  animation: glass-sweep 13s linear infinite;
}

.grain {
  position: absolute;
  inset: 0;
  opacity: .15;
  background-image:
    repeating-linear-gradient(118deg, rgba(255,255,255,.025) 0 1px, transparent 1px 5px),
    repeating-linear-gradient(28deg, rgba(0,0,0,.022) 0 1px, transparent 1px 6px);
  pointer-events: none;
}

@keyframes slow-breathe {
  from { transform: scale(1.02); }
  to { transform: scale(1.055); }
}

@keyframes moon-drift {
  from { transform: translate3d(-1.5%, -1%, 0) rotate(-2deg); opacity: .76; }
  to { transform: translate3d(3%, 2%, 0) rotate(2deg); opacity: 1; }
}

@keyframes sun-pulse {
  from { transform: translate3d(1%, -1%, 0) scale(.98); opacity: .72; }
  to { transform: translate3d(-2%, 2%, 0) scale(1.06); opacity: 1; }
}

@keyframes glass-sweep {
  0%, 12% { transform: rotate(25deg) translateX(-90vw); opacity: 0; }
  25% { opacity: .85; }
  55%, 100% { transform: rotate(25deg) translateX(235vw); opacity: 0; }
}

/* ---------- 左侧可收纳菜单 ---------- */

.nav-dock {
  position: fixed;
  z-index: 20;
  top: 50%;
  left: 22px;
  width: 288px;
  transform: translateY(-50%);
  transition: width .55s var(--ease), left .55s var(--ease);
}

.nav-panel,
.reveal-button,
.feature-panel,
.site-footer {
  border: 1px solid var(--glass-border);
  background:
    linear-gradient(140deg, rgba(255,255,255,.17), rgba(255,255,255,.04) 38%, rgba(5,17,39,.18)),
    var(--glass-dark);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.25), var(--shadow);
  backdrop-filter: blur(24px) saturate(1.25);
  -webkit-backdrop-filter: blur(24px) saturate(1.25);
}

.nav-panel {
  width: 288px;
  padding: 22px;
  overflow: hidden;
  border-radius: var(--radius-lg);
  transform: translateX(0);
  opacity: 1;
  transition: transform .55s var(--ease), opacity .35s ease;
}

.nav-panel::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(115deg, transparent 20%, rgba(255,255,255,.09) 42%, transparent 58%);
  transform: translateX(-120%);
  animation: panel-polish 9s ease-in-out infinite;
  pointer-events: none;
}

@keyframes panel-polish {
  0%, 40% { transform: translateX(-120%); }
  68%, 100% { transform: translateX(120%); }
}

.nav-panel__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 2px 18px;
  border-bottom: 1px solid rgba(255,255,255,.15);
}

.cat-mark {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  border: 1px solid rgba(255,255,255,.28);
  border-radius: 15px;
  background: linear-gradient(145deg, rgba(247,220,138,.24), rgba(255,255,255,.06));
}

.cat-mark svg {
  width: 33px;
  fill: var(--moon);
}

.cat-mark circle {
  fill: var(--night-950);
}

.cat-mark .cat-mark__mouth {
  fill: none;
  stroke: var(--night-950);
  stroke-linecap: round;
  stroke-width: 1.8;
}

.nav-panel__brand strong,
.nav-panel__brand small {
  display: block;
}

.nav-panel__brand strong {
  font-family: "Noto Serif SC", "Songti SC", STSong, serif;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: .12em;
}

.nav-panel__brand small {
  margin-top: 3px;
  color: rgba(255,255,255,.6);
  font-size: .72rem;
  letter-spacing: .17em;
}

.primary-nav {
  display: grid;
  gap: 9px;
  margin-top: 17px;
}

.nav-item {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 42px 1fr 22px;
  gap: 11px;
  align-items: center;
  width: 100%;
  min-height: 68px;
  padding: 9px 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  background: transparent;
  text-align: left;
  cursor: pointer;
  transition: transform .25s var(--ease), background .25s ease, border-color .25s ease;
}

.nav-item:hover,
.nav-item.is-active {
  border-color: rgba(255,255,255,.22);
  background: linear-gradient(110deg, rgba(255,255,255,.15), rgba(255,255,255,.06));
  transform: translateX(4px);
}

.nav-item__icon {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 14px;
  background: rgba(3, 14, 34, .28);
}

.nav-item__icon svg {
  width: 22px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.55;
}

.nav-item__copy strong,
.nav-item__copy small {
  display: block;
}

.nav-item__copy strong {
  font-size: 1rem;
  font-weight: 650;
  letter-spacing: .08em;
}

.nav-item__copy small {
  margin-top: 4px;
  color: rgba(255,255,255,.58);
  font-size: .78rem;
}

.nav-item__arrow {
  color: var(--moon);
  font-size: 1.1rem;
  transition: transform .25s ease;
}

.nav-item:hover .nav-item__arrow,
.nav-item.is-active .nav-item__arrow {
  transform: translateX(3px);
}

.nav-panel__note {
  margin: 16px 4px 12px;
  color: rgba(255,255,255,.5);
  font-family: "Noto Serif SC", "Songti SC", STSong, serif;
  font-size: .78rem;
}

.collapse-button {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  width: 100%;
  min-height: 42px;
  border: 1px solid rgba(255,255,255,.16);
  border-radius: 14px;
  background: rgba(3, 14, 34, .23);
  color: rgba(255,255,255,.72);
  cursor: pointer;
  transition: background .2s ease, color .2s ease;
}

.collapse-button:hover {
  background: rgba(255,255,255,.12);
  color: var(--white);
}

.collapse-button svg,
.reveal-button svg {
  width: 19px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.8;
}

.reveal-button {
  position: absolute;
  top: 50%;
  left: 8px;
  display: grid;
  width: 45px;
  min-height: 120px;
  padding: 14px 0;
  place-items: center;
  border-radius: 0 18px 18px 0;
  color: var(--white);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translate(-110%, -50%);
  transition: transform .45s var(--ease), opacity .25s ease, background .2s ease;
}

.reveal-button:hover {
  background: rgba(255,255,255,.16);
}

.reveal-button span {
  font-size: .75rem;
  letter-spacing: .25em;
  line-height: 1;
  writing-mode: vertical-rl;
}

/* 折叠状态由 JavaScript 给 nav-dock 添加 is-collapsed 类。 */
.nav-dock.is-collapsed {
  left: 0;
  width: 45px;
}

.nav-dock.is-collapsed .nav-panel {
  opacity: 0;
  pointer-events: none;
  transform: translateX(calc(-100% - 35px));
}

.nav-dock.is-collapsed .reveal-button {
  opacity: 1;
  pointer-events: auto;
  transform: translate(0, -50%);
}

/* ---------- 中央首页内容 ---------- */

.page {
  position: relative;
  z-index: 2;
  min-height: 100vh;
}

.hero {
  position: absolute;
  top: 50%;
  left: 50%;
  width: min(560px, 42vw);
  padding: 26px 30px 29px;
  border: 1px solid rgba(255,255,255,.21);
  border-radius: 32px;
  background: linear-gradient(135deg, rgba(6,18,40,.38), rgba(255,255,255,.08));
  box-shadow: inset 0 1px rgba(255,255,255,.24), 0 24px 80px rgba(2,9,23,.18);
  backdrop-filter: blur(10px) saturate(1.1);
  -webkit-backdrop-filter: blur(10px) saturate(1.1);
  transform: translate(-50%, -50%);
  transition: opacity .35s ease, transform .45s var(--ease);
}

.hero.is-muted {
  opacity: .18;
  transform: translate(-50%, -50%) scale(.96);
}

.hero__eyebrow {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 10px;
  color: rgba(255,255,255,.78);
  font-size: .78rem;
  font-weight: 650;
  letter-spacing: .18em;
}

.hero__eyebrow span,
.feature-panel__status span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--moon);
  box-shadow: 0 0 0 5px rgba(247,220,138,.13), 0 0 18px var(--moon);
}

.hero h1 {
  margin: 0;
  font-family: "Noto Serif SC", "Songti SC", STSong, serif;
  font-size: clamp(5.2rem, 11vw, 9.5rem);
  font-weight: 700;
  letter-spacing: .04em;
  line-height: .96;
  text-shadow: 0 7px 25px rgba(3,11,27,.38);
}

.hero__intro {
  max-width: 430px;
  margin: 18px 0 25px;
  color: rgba(255,255,255,.88);
  font-family: "Noto Serif SC", "Songti SC", STSong, serif;
  font-size: clamp(1rem, 1.4vw, 1.2rem);
  line-height: 1.85;
  letter-spacing: .06em;
}

.hero__explore {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid rgba(255,255,255,.3);
  border-radius: 999px;
  background: rgba(255,255,255,.11);
  color: var(--white);
  cursor: pointer;
  transition: gap .25s ease, background .25s ease, transform .25s ease;
}

.hero__explore:hover {
  gap: 17px;
  background: rgba(255,255,255,.19);
  transform: translateY(-2px);
}

.hero__explore svg {
  width: 21px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

/* ---------- 点击菜单后出现的功能说明 ---------- */

.feature-panel {
  position: fixed;
  z-index: 10;
  top: 50%;
  right: clamp(28px, 7vw, 118px);
  width: min(420px, calc(100vw - 380px));
  padding: 30px;
  border-radius: var(--radius-lg);
  transform: translateY(-45%) scale(.96);
  opacity: 0;
  transition: opacity .35s ease, transform .45s var(--ease);
}

.feature-panel[hidden] {
  display: block;
  visibility: hidden;
  pointer-events: none;
}

.feature-panel.is-visible {
  visibility: visible;
  opacity: 1;
  transform: translateY(-50%) scale(1);
}

.feature-panel__close {
  position: absolute;
  top: 16px;
  right: 16px;
  display: grid;
  width: 38px;
  height: 38px;
  padding: 0;
  place-items: center;
  border: 1px solid rgba(255,255,255,.16);
  border-radius: 50%;
  background: rgba(255,255,255,.08);
  cursor: pointer;
}

.feature-panel__close:hover {
  background: rgba(255,255,255,.16);
}

.feature-panel__close svg {
  width: 18px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-width: 1.7;
}

.feature-panel__index {
  margin: 0 0 12px;
  color: var(--moon);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
}

.feature-panel h2 {
  margin: 0;
  font-family: "Noto Serif SC", "Songti SC", STSong, serif;
  font-size: clamp(2.4rem, 5vw, 4rem);
  line-height: 1.2;
}

.feature-panel__description {
  margin: 13px 0 20px;
  color: rgba(255,255,255,.75);
  font-size: 1rem;
  line-height: 1.8;
}

.feature-panel__list {
  display: grid;
  gap: 9px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-panel__list li {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 14px;
  border: 1px solid rgba(255,255,255,.13);
  border-radius: 14px;
  background: rgba(255,255,255,.065);
}

.feature-panel__list li::before {
  content: "";
  width: 5px;
  height: 5px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--moon);
  box-shadow: 0 0 10px rgba(247,220,138,.9);
}

.feature-panel__status {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 22px 0 0;
  color: rgba(255,255,255,.56);
  font-size: .8rem;
}

/* ---------- 页脚备案 ---------- */

.site-footer {
  position: fixed;
  z-index: 12;
  right: 22px;
  bottom: 18px;
  display: flex;
  align-items: center;
  gap: 11px;
  min-height: 38px;
  padding: 8px 14px;
  border-radius: 999px;
  color: rgba(255,255,255,.68);
  font-size: .76rem;
}

.site-footer a {
  color: rgba(255,255,255,.86);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--white);
  text-decoration: none;
  text-underline-offset: 3px;
}

.site-footer__divider {
  width: 1px;
  height: 13px;
  background: rgba(255,255,255,.24);
}

.site-footer__date {
  color: rgba(255,255,255,.5);
}

.noscript-message {
  position: fixed;
  z-index: 50;
  top: 12px;
  left: 50%;
  margin: 0;
  padding: 10px 15px;
  border-radius: 10px;
  background: #fff5d2;
  color: #16213a;
  transform: translateX(-50%);
}

/* ---------- 平板和手机适配 ---------- */

@media (max-width: 900px) {
  .nav-dock {
    left: 14px;
  }

  .hero {
    left: 50%;
    width: min(500px, 52vw);
  }

  .feature-panel {
    right: 24px;
    width: calc(100vw - 356px);
  }

  .site-footer__date {
    display: none;
  }
}

@media (max-width: 680px) {
  .art-stage__image {
    inset: -1%;
    background-position: 56% center;
  }

  .nav-dock {
    top: 14px;
    left: 12px;
    width: min(288px, calc(100vw - 24px));
    transform: none;
  }

  .nav-panel {
    width: min(288px, calc(100vw - 24px));
    max-height: calc(100vh - 28px);
    overflow-y: auto;
  }

  .nav-dock.is-collapsed {
    top: 22%;
    left: 0;
    width: 43px;
  }

  .reveal-button {
    left: 0;
    min-height: 106px;
    border-radius: 0 16px 16px 0;
  }

  .hero {
    top: 45%;
    left: 50%;
    width: calc(100vw - 44px);
    max-width: 480px;
    padding: 22px 24px 25px;
  }

  .hero h1 {
    font-size: clamp(5rem, 28vw, 7.6rem);
  }

  .feature-panel {
    top: 50%;
    right: 18px;
    left: 18px;
    width: auto;
    padding: 26px;
  }

  .site-footer {
    right: 12px;
    bottom: 10px;
    left: 12px;
    justify-content: center;
  }

  .site-footer__date {
    display: none;
  }
}

@media (max-height: 620px) and (min-width: 681px) {
  .nav-panel {
    max-height: calc(100vh - 30px);
    padding: 16px;
    overflow-y: auto;
  }

  .nav-item {
    min-height: 56px;
  }

  .nav-panel__note {
    display: none;
  }

  .hero {
    padding-block: 20px;
  }

  .hero h1 {
    font-size: 5rem;
  }
}

/* 第二版：收纳按钮独立固定定位，避免继承面板高度或负偏移导致裁切。 */
.reveal-button { position: fixed; left: 8px; top: 50%; width: 44px; min-height: 108px; border-radius: 17px; background: rgba(13,25,43,.22); backdrop-filter: blur(7px); }
.nav-dock.is-collapsed { top: 50%; left: 0; height: 0; }
.nav-dock.is-collapsed .nav-panel { visibility: hidden; }
.nav-panel { background: linear-gradient(140deg,rgba(255,255,255,.12),rgba(4,16,37,.30)); backdrop-filter: blur(12px); text-shadow: 0 1px 5px #07152c; }
.cat-mark { background: rgba(255,255,255,.48); border-radius: 50%; }
.cat-mark svg { fill: #0b0c10; width: 39px; }
.cat-mark circle { fill: #f5eee0; }
.cat-mark .cat-mark__mouth { stroke: #d6d3cf; }
.nav-dock.is-collapsed .reveal-button { visibility: visible; }
.site-footer { left: 12px; right: 12px; bottom: 14px; justify-content: center; flex-wrap: wrap; border: 0; border-radius: 0; background: none; box-shadow: none; backdrop-filter: none; -webkit-backdrop-filter: none; color: white; text-shadow: 0 1px 4px #151b26; }
.site-footer a { color: white; }
#waveCanvas { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; filter: drop-shadow(12px 16px 12px rgba(0,0,0,.8)); }
.art-stage.wave-ready #waveCanvas { opacity: 1; }
.art-stage.wave-ready .art-stage__image { visibility: hidden; }
/* 波峰光照由 Canvas 投影同步计算，避免画布与扫光相互脱节。 */
.glass-sheen { display: none; }
@media (pointer: fine) { body, button, a { cursor: url("paw.svg") 3 3, auto; } }
.hero { text-align: center; }
.hero__eyebrow { justify-content: center; }
.hero__intro { margin-left: auto; margin-right: auto; }
.art-stage { background: repeating-linear-gradient(0deg,transparent 0 2px,#ffffff06 2px 3px),repeating-linear-gradient(90deg,#08090b 0 2px,#191a1d 2px 3px); }
.art-stage.wave-ready .light, .art-stage.wave-ready .grain { display: none; }
@media (max-width: 680px) { .nav-dock.is-collapsed { top: 22%; } .reveal-button { left: 8px; } }

/* 用户选择“减少动态效果”时，关闭持续动画但保留完整视觉。 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}

/* 不支持 backdrop-filter 的旧浏览器使用更实的背景保证可读性。 */
@supports not (backdrop-filter: blur(10px)) {
  .nav-panel,
  .reveal-button,
  .feature-panel {
    background: rgba(6, 20, 46, .92);
  }
}