/* ============================================================
   皇家国际站 · 共享样式 /assets/site.css
   皇家档案长卷：深蓝连续底、鎏金细线、等宽索引、纸白间歇
   ============================================================ */

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

html { -webkit-text-size-adjust: 100%; }

body, h1, h2, h3, h4, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg { max-width: 100%; }
button { font: inherit; }

:root {
  /* 色板 */
  --royal-900: #0A1A2A;
  --royal-850: #0D2135;
  --royal-800: #10283D;
  --royal-700: #17364E;
  --royal-600: #1F4460;
  --mist: #9FB3C4;
  --paper: #F3EFE6;
  --paper-dim: rgba(243, 239, 230, 0.74);
  --gold: #C9A227;
  --gold-soft: #E8CF7A;
  --lake: #2F7F8C;
  --clay: #A6533F;
  --line: rgba(201, 162, 39, 0.30);
  --line-soft: rgba(159, 179, 196, 0.18);
  --ink-on-paper: #0A1A2A;
  --amber-ink: #8A6A12;

  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 1.25 模块化阶梯 */
  --step--1: 0.8125rem;
  --step-0: 1rem;
  --step-1: 1.25rem;
  --step-2: 1.5625rem;
  --step-3: 1.9531rem;
  --step-4: 2.4414rem;
  --step-5: clamp(2.35rem, 5.4vw, 3.9rem);

  /* 结构 */
  --shell: 1240px;
  --gutter: clamp(18px, 5vw, 64px);
  --ease: cubic-bezier(0.22, 0.68, 0.26, 1);
  --progress: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

body {
  background: var(--royal-900);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--gold); color: var(--royal-900); }

:focus-visible {
  outline: 2px solid var(--gold-soft);
  outline-offset: 3px;
  border-radius: 2px;
}

a {
  color: var(--gold-soft);
  text-decoration: none;
  transition: color 0.25s var(--ease);
}
a:hover { color: var(--gold); }

/* ---------------- 排版 ---------------- */

.display-1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--step-5);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-wrap: balance;
}

.display-2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.7rem, 3.4vw, 2.6rem);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--paper);
  text-wrap: balance;
}

.heading-3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  line-height: 1.34;
  color: var(--paper);
}

.lede {
  font-size: clamp(1.02rem, 1.4vw, 1.18rem);
  line-height: 1.85;
  color: rgba(243, 239, 230, 0.84);
  max-width: 62ch;
}

.body-text {
  font-size: var(--step-0);
  line-height: 1.85;
  color: rgba(243, 239, 230, 0.78);
  max-width: 70ch;
}

.note {
  font-size: 0.86rem;
  line-height: 1.72;
  color: var(--mist);
  border-left: 2px solid var(--line);
  padding-left: 14px;
  max-width: 48ch;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}
.kicker::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
  opacity: 0.9;
  flex: 0 0 auto;
}

.chapter-no {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--gold);
}

/* ---------------- 按钮 ---------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.28s var(--ease), color 0.28s var(--ease),
    border-color 0.28s var(--ease);
}

.btn--gold {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--royal-900);
}
.btn--gold:hover {
  background: var(--gold-soft);
  border-color: var(--gold-soft);
  color: var(--royal-900);
}

.btn--line {
  background: transparent;
  border-color: var(--line);
  color: var(--gold-soft);
}
.btn--line:hover {
  border-color: var(--gold);
  background: rgba(201, 162, 39, 0.10);
  color: var(--gold-soft);
}

.btn--paper {
  background: transparent;
  border-color: rgba(138, 106, 18, 0.45);
  color: var(--amber-ink);
}
.btn--paper:hover {
  background: var(--amber-ink);
  border-color: var(--amber-ink);
  color: var(--paper);
}

/* ---------------- 布局骨架 ---------------- */

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(46px, 7.5vw, 100px); }

.band {
  position: relative;
  border-top: 1px solid var(--line-soft);
}
.band--night { background: var(--royal-900); }
.band--deep { background: var(--royal-800); }
.band--panel { background: var(--royal-700); }
.band--paper {
  background: var(--paper);
  color: var(--ink-on-paper);
  border-top-color: rgba(10, 26, 42, 0.14);
}
.band--paper .display-1,
.band--paper .display-2,
.band--paper .heading-3 { color: var(--ink-on-paper); }
.band--paper .lede { color: #3B4C5A; }
.band--paper .body-text { color: #3F4F5C; }
.band--paper .note { color: #5B6B78; border-left-color: var(--gold); }
.band--paper .kicker,
.band--paper .chapter-no { color: var(--amber-ink); }
.band--paper a { color: var(--amber-ink); }
.band--paper a:hover { color: #6B4F08; }
.band--paper .btn--gold { color: var(--royal-900); }
.band--paper .btn--line {
  color: var(--ink-on-paper);
  border-color: rgba(10, 26, 42, 0.32);
}
.band--paper .btn--line:hover {
  background: rgba(10, 26, 42, 0.06);
  border-color: var(--ink-on-paper);
  color: var(--ink-on-paper);
}

.grid {
  display: grid;
  gap: clamp(18px, 2.6vw, 36px);
}
.grid--split { grid-template-columns: 7fr 5fr; }
.grid--split-rev { grid-template-columns: 5fr 7fr; }
.grid--third { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--chess { grid-template-columns: repeat(12, minmax(0, 1fr)); }

/* ---------------- 面板 / 标签 / 分隔 ---------------- */

.panel {
  position: relative;
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--royal-700);
  border: 1px solid var(--line-soft);
}
.panel--quiet { background: rgba(23, 54, 78, 0.48); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  line-height: 1.4;
  text-transform: uppercase;
  white-space: nowrap;
}
.tag--gold { color: var(--gold-soft); }
.tag--lake { color: #82C3CE; border-color: rgba(47, 127, 140, 0.72); }
.tag--clay { color: #D89179; border-color: rgba(166, 83, 63, 0.72); }

.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 39, 0));
}

/* ---------------- 图片容器（页面阶段放占位图） ---------------- */

.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line-soft);
  background:
    linear-gradient(135deg, rgba(47, 127, 140, 0.26), transparent 58%),
    linear-gradient(315deg, rgba(201, 162, 39, 0.18), transparent 62%),
    var(--royal-800);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(45deg, rgba(159, 179, 196, 0.07) 0 1px, transparent 1px 14px),
    radial-gradient(circle at 78% 20%, rgba(201, 162, 39, 0.16), transparent 46%);
}
.media__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 4 / 5; }
.media--square { aspect-ratio: 1 / 1; }
.media__tag {
  position: absolute;
  left: 14px;
  top: 14px;
  z-index: 2;
}
.media__caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  color: var(--mist);
}

/* ---------------- 面包屑 ---------------- */

.breadcrumb {
  padding-block: 18px;
  border-bottom: 1px solid var(--line-soft);
}
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--mist);
}
.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--gold);
  opacity: 0.6;
}
.breadcrumb__link { color: var(--mist); }
.breadcrumb__link:hover { color: var(--gold-soft); }
.breadcrumb__current { color: var(--paper); }

/* ============================================================
   页头
   ============================================================ */

.skip-link {
  position: absolute;
  left: clamp(12px, 3vw, 40px);
  top: -70px;
  z-index: 300;
  padding: 10px 20px;
  background: var(--gold);
  color: var(--royal-900);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-decoration: none;
  transition: top 0.22s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible {
  top: 14px;
  color: var(--royal-900);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: rgba(10, 26, 42, 0.88);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-soft);
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease),
    box-shadow 0.35s var(--ease);
}
.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--gold-soft) 45%, var(--lake));
  transform: scaleX(var(--progress));
  transform-origin: 0 50%;
  will-change: transform;
}
.site-header[data-scrolled] {
  background: rgba(10, 26, 42, 0.97);
  border-bottom-color: var(--line);
  box-shadow: 0 20px 44px -34px #000;
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 3vw, 40px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(13px, 1.8vw, 22px) var(--gutter);
  transition: padding 0.35s var(--ease);
}
.site-header[data-scrolled] .site-header__inner {
  padding-block: clamp(8px, 1.1vw, 12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  color: var(--paper);
  text-decoration: none;
}
.brand__mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  color: var(--gold);
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: radial-gradient(circle at 30% 18%, rgba(201, 162, 39, 0.20), transparent 72%);
}
.brand__mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: 1px solid rgba(201, 162, 39, 0.24);
  pointer-events: none;
}
.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}
.brand__name {
  font-family: var(--font-display);
  font-size: 1.06rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--paper);
}
.brand__code {
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  color: var(--mist);
}
.brand:hover .brand__name { color: var(--gold-soft); }

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.8vw, 26px);
  margin-left: auto;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.5vw, 24px);
}
.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 0;
  color: rgba(243, 239, 230, 0.76);
  font-size: 0.88rem;
  letter-spacing: 0.03em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.25s var(--ease);
}
.site-nav__index {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--mist);
  opacity: 0.78;
  transition: color 0.25s var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--gold-soft);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.35s var(--ease);
}
.site-nav__link:hover { color: var(--gold-soft); }
.site-nav__link:hover::after { transform: scaleX(1); }
.site-nav__link:hover .site-nav__index { color: var(--gold); }
.site-nav__link[aria-current="page"] { color: var(--gold-soft); }
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] .site-nav__index { color: var(--gold); opacity: 1; }

.site-header__cta {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 18px;
  border: 1px solid var(--gold);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.3s var(--ease), color 0.3s var(--ease),
    border-color 0.3s var(--ease);
}
.site-header__cta::before {
  content: "";
  width: 16px;
  height: 1px;
  background: currentColor;
  opacity: 0.8;
  flex: 0 0 auto;
}
.site-header__cta:hover {
  background: var(--gold);
  border-color: var(--gold-soft);
  color: var(--royal-900);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 10px 15px;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  cursor: pointer;
  transition: border-color 0.28s var(--ease), color 0.28s var(--ease);
}
.nav-toggle:hover { border-color: var(--gold); color: var(--gold); }
.nav-toggle__bars {
  display: grid;
  gap: 5px;
  width: 18px;
}
.nav-toggle__bars span {
  display: block;
  height: 1px;
  background: currentColor;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}
.nav-toggle__label { line-height: 1; }

body.nav-open { overflow: hidden; }

/* ============================================================
   页脚
   ============================================================ */

.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--royal-850), var(--royal-900) 58%);
  color: var(--paper-dim);
}
.site-footer__rule {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  opacity: 0.6;
}
.site-footer__inner {
  display: grid;
  grid-template-columns: 1.5fr 0.9fr 1.15fr 0.9fr;
  gap: clamp(26px, 4vw, 48px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(38px, 6vw, 70px) var(--gutter) clamp(28px, 4vw, 46px);
}
.site-footer__brand {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 34ch;
}
.site-footer__name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--paper);
}
.site-footer__desc {
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--paper-dim);
}
.site-footer__code {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  color: var(--mist);
  text-transform: uppercase;
}
.site-footer__col { min-width: 0; }
.site-footer__title {
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
}
.footer-list {
  display: grid;
  gap: 12px;
}
.footer-list__link {
  display: inline-block;
  font-size: 0.9rem;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color 0.25s var(--ease);
}
.footer-list__link:hover { color: var(--gold-soft); }
.footer-list__label {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}
.footer-list__value {
  display: block;
  font-size: 0.88rem;
  line-height: 1.62;
  color: var(--paper);
  word-break: break-word;
}
.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 24px;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 18px var(--gutter) clamp(26px, 4vw, 40px);
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--mist);
}
.site-footer__copy,
.site-footer__meta { margin: 0; }

/* ============================================================
   滚动显现（仅在 JS 可用时启用）
   ============================================================ */

[data-js] [data-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
[data-js] [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ============================================================
   响应式
   ============================================================ */

@media (max-width: 1180px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: auto;
    width: min(360px, 88vw);
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin: 0;
    padding: 92px clamp(20px, 6vw, 32px) 32px;
    background: linear-gradient(180deg, var(--royal-800), var(--royal-900) 62%);
    border-left: 1px solid var(--line);
    box-shadow: -30px 0 64px -42px #000;
    transform: translateX(101%);
    visibility: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    transition: transform 0.42s var(--ease), visibility 0.42s var(--ease);
    z-index: 130;
  }
  .site-nav[data-open] {
    transform: translateX(0);
    visibility: visible;
  }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }
  .site-nav__list li { border-bottom: 1px solid var(--line-soft); }
  .site-nav__link {
    padding: 15px 2px;
    font-size: 1rem;
    width: 100%;
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] {
    color: var(--gold-soft);
    border-left: 2px solid var(--gold);
    padding-left: 12px;
  }
  .site-header__cta {
    margin-top: 26px;
    justify-content: center;
    padding: 13px 18px;
    font-size: 0.74rem;
  }
}

@media (max-width: 1080px) {
  .grid--split,
  .grid--split-rev { grid-template-columns: 1fr; }
  .grid--third { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--chess { grid-template-columns: repeat(6, minmax(0, 1fr)); }

  .site-footer__inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 680px) {
  .brand__code { display: none; }
  .brand__name { font-size: 1rem; letter-spacing: 0.1em; }
  .brand__mark { width: 38px; height: 38px; font-size: 0.95rem; }

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

  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .site-footer__base {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  .media--wide { aspect-ratio: 16 / 10; }
}

@media (max-width: 420px) {
  .nav-toggle__label { display: none; }
}

/* ============================================================
   降低动效
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .site-nav { transition: none; }
  .site-header::after { transition: none; }

  [data-js] [data-reveal] {
    opacity: 1;
    transform: none;
  }
}