/* ==========================================================================
   欧博娱乐 · 共享样式表 /assets/site.css
   深靛墨底层 + 暖沙纸阅读画板 + 索引卡组件 + 编号等宽排版
   ========================================================================== */

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

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd { margin: 0; }

ul, ol { padding: 0; }
ul[class], ol[class] { list-style: none; }

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

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

a { color: inherit; text-decoration: none; }

[hidden] { display: none !important; }

/* ---------- 变量：色彩面积与字体阶梯 ---------- */
:root {
  --ink: #0E1B3D;
  --ink-mid: #16295C;
  --ink-deep: #0A1330;
  --paper: #F3E9D7;
  --paper-light: #FBF6EC;
  --gold: #C89A4B;
  --gold-bright: #E8B85C;
  --clay: #C4552F;
  --teal: #2E8C86;
  --slate: #6B7A99;
  --hairline: #B9C4D6;

  --ink-40: rgba(14, 27, 61, .40);
  --ink-66: rgba(14, 27, 61, .66);
  --ink-78: rgba(14, 27, 61, .78);
  --line-soft: rgba(14, 27, 61, .14);
  --line-line: rgba(185, 196, 214, .72);
  --line-dark: rgba(243, 233, 215, .16);
  --text-on-dark: rgba(243, 233, 215, .82);
  --text-on-dark-dim: rgba(243, 233, 215, .56);

  --shadow-panel: 0 20px 44px -30px rgba(10, 19, 48, .75);
  --shadow-raise: 16px 18px 0 -4px rgba(22, 41, 92, .10), 0 18px 34px -28px rgba(10, 19, 48, .70);

  --font-display: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "SimSun", serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, "SFMono-Regular", "Courier New", monospace;

  --shell-max: 1200px;
  --gutter: clamp(18px, 4vw, 48px);
  --radius-soft: 14px;
}

/* ---------- 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--paper);
  background-image:
    radial-gradient(circle at 8% -8%, rgba(200, 154, 75, .18), transparent 52%),
    radial-gradient(circle at 96% 2%, rgba(46, 140, 134, .10), transparent 46%),
    repeating-linear-gradient(0deg, rgba(14, 27, 61, .022) 0 1px, transparent 1px 5px);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: .01em;
}

::selection {
  background: rgba(232, 184, 92, .55);
  color: var(--ink-deep);
}

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

.site-footer :focus-visible,
.site-header :focus-visible { outline-color: var(--gold-bright); }

#main-content:focus { outline: none; }

/* ---------- 布局基础 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.page-main { padding-block: clamp(28px, 5vw, 60px); }

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--slate);
}

.rule-hair {
  border: 0;
  border-top: 1px solid var(--line-soft);
  margin-block: clamp(20px, 3vw, 34px);
}

/* ---------- 跳转链 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 10px 18px;
  background: var(--gold-bright);
  color: var(--ink-deep);
  border: 2px solid var(--ink);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  transition: transform .2s ease;
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 页头：工具条 ---------- */
.site-header {
  position: relative;
  z-index: 30;
  isolation: isolate;
  background: var(--ink);
  color: var(--paper-light);
}

.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, rgba(251, 246, 236, .045) 0 1px, transparent 1px 84px);
}

.scroll-meter {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 90;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--gold-bright), var(--clay));
  pointer-events: none;
  transition: transform .12s linear;
}

.header-utility {
  position: relative;
  z-index: 1;
  background: rgba(22, 41, 92, .62);
  border-bottom: 1px solid var(--line-dark);
}

.utility-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  min-height: 40px;
  padding-block: 8px;
}

.utility-brand {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .10em;
  color: var(--text-on-dark-dim);
}

.utility-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
}

.utility-link {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-on-dark);
  transition: color .2s ease, border-color .2s ease;
}

.utility-link:hover,
.utility-link:focus-visible {
  color: var(--gold-bright);
  border-bottom-color: var(--gold-bright);
}

/* ---------- 页头：居中刊头 ---------- */
.masthead {
  position: relative;
  z-index: 1;
  padding-block: clamp(22px, 3.6vw, 40px) clamp(18px, 2.8vw, 30px);
  text-align: center;
}

.masthead-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.masthead-kicker {
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .28em;
  color: var(--gold);
}

.masthead-kicker::before,
.masthead-kicker::after {
  content: "";
  width: clamp(28px, 8vw, 92px);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(200, 154, 75, .8));
}

.masthead-kicker::after {
  background: linear-gradient(270deg, transparent, rgba(200, 154, 75, .8));
}

.masthead-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(38px, 7vw, 68px);
  line-height: .98;
  letter-spacing: .16em;
  text-indent: .16em;
  color: var(--paper-light);
  text-shadow: 0 2px 0 rgba(10, 19, 48, .55);
  transition: color .2s ease;
}

.masthead-brand:hover .brand-name,
.masthead-brand:focus-visible .brand-name { color: var(--gold-bright); }

.brand-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .38em;
  text-indent: .38em;
  color: rgba(243, 233, 215, .52);
}

.masthead-tagline {
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: .20em;
  text-indent: .20em;
  color: var(--text-on-dark);
}

/* ---------- 页头：导航条 ---------- */
.nav-bar {
  position: relative;
  z-index: 2;
  background: var(--paper);
  border-top: 2px solid var(--gold);
  border-bottom: 1px solid var(--line-soft);
  box-shadow: 0 -12px 24px -20px rgba(10, 19, 48, .9);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 12px;
}

.site-nav { flex: 1 1 auto; min-width: 0; }

.nav-list {
  display: flex;
  justify-content: center;
  gap: clamp(4px, 1.6vw, 24px);
  overflow-x: auto;
  scrollbar-width: thin;
}

.nav-list::-webkit-scrollbar { height: 3px; }
.nav-list::-webkit-scrollbar-thumb { background: var(--hairline); }

.nav-list { counter-reset: navidx; }

.nav-link {
  display: inline-block;
  padding: 15px 8px 13px;
  border-bottom: 3px solid transparent;
  font-family: var(--font-sans);
  font-size: 15px;
  letter-spacing: .06em;
  white-space: nowrap;
  color: var(--ink-78);
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}

.nav-link::before {
  counter-increment: navidx;
  content: counter(navidx, decimal-leading-zero);
  margin-right: 7px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--slate);
  vertical-align: 2px;
}

.nav-link:hover {
  color: var(--clay);
  border-bottom-color: rgba(196, 85, 47, .45);
}

.nav-link[aria-current="page"] {
  color: var(--clay);
  font-weight: 700;
  border-bottom-color: var(--clay);
}

.nav-link[aria-current="page"]::before { color: var(--clay); }

/* ---------- 页头：移动目录按钮 ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-block: 10px;
  padding: 9px 14px;
  border: 1px solid var(--ink);
  background: var(--paper-light);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
}

.nav-toggle-glyph {
  display: block;
  width: 16px;
  height: 11px;
  border-top: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  position: relative;
}

.nav-toggle-glyph::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 2px;
  margin-top: -1px;
  background: currentColor;
}

.nav-toggle[aria-expanded="true"] {
  background: var(--ink);
  color: var(--paper-light);
  border-color: var(--ink);
}

.nav-toggle-text { line-height: 1; }

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  position: relative;
  margin-top: clamp(40px, 6vw, 80px);
  padding-top: clamp(40px, 5.5vw, 68px);
  background: var(--ink);
  color: var(--text-on-dark);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(251, 246, 236, .04) 0 1px, transparent 1px 72px),
    radial-gradient(circle at 88% -6%, rgba(46, 140, 134, .22), transparent 52%),
    radial-gradient(circle at 4% 4%, rgba(196, 85, 47, .16), transparent 46%);
}

.footer-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.4fr;
  gap: clamp(22px, 3vw, 44px);
  padding-bottom: clamp(30px, 4vw, 46px);
}

.footer-col { min-width: 0; }

.footer-col--brand { max-width: 34ch; }

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: .20em;
  color: var(--paper-light);
}

.footer-desc {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--text-on-dark-dim);
}

.footer-note {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px dashed rgba(200, 154, 75, .48);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .10em;
  color: var(--gold);
}

.footer-heading {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .26em;
  color: var(--gold);
}

.footer-list { display: block; }

.footer-list li + li { margin-top: 9px; }

.footer-link {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-on-dark);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--gold-bright);
  border-bottom-color: rgba(232, 184, 92, .6);
}

.footer-contact { display: flex; flex-direction: column; gap: 11px; }

.contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
}

.contact-key {
  flex: 0 0 auto;
  min-width: 36px;
  font-family: var(--font-sans);
  font-size: 12px;
  letter-spacing: .16em;
  color: rgba(185, 196, 214, .82);
}

.contact-value {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .02em;
  line-height: 1.6;
  color: rgba(251, 246, 236, .92);
  word-break: break-word;
}

.copy-btn {
  min-width: 54px;
  padding: 3px 8px;
  border: 1px solid rgba(200, 154, 75, .6);
  background: transparent;
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  text-align: center;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}

.copy-btn:hover,
.copy-btn:focus-visible {
  background: rgba(200, 154, 75, .18);
  color: var(--gold-bright);
  border-color: var(--gold-bright);
}

.copy-btn[data-copied="true"] {
  background: var(--teal);
  border-color: var(--teal);
  color: var(--paper-light);
}

.footer-legal {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 26px;
  padding-block: 18px 28px;
  border-top: 1px solid var(--line-dark);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: rgba(243, 233, 215, .55);
}

.legal-item { line-height: 1.6; }

/* ==========================================================================
   通用组件
   ========================================================================== */

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1.5px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: .06em;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.btn:hover { background: var(--ink); color: var(--paper-light); }

.btn--solid {
  background: var(--ink);
  color: var(--paper-light);
  border-color: var(--ink);
}

.btn--solid:hover { background: var(--ink-mid); border-color: var(--ink-mid); }

.btn--clay {
  background: var(--clay);
  border-color: var(--clay);
  color: var(--paper-light);
}

.btn--clay:hover { background: #a8441f; border-color: #a8441f; color: var(--paper-light); }

.btn--ghost {
  border-color: var(--line-soft);
  color: var(--ink-78);
  background: var(--paper-light);
}

.btn--ghost:hover { background: var(--paper-light); color: var(--clay); border-color: var(--gold); }

.btn--on-dark {
  border-color: rgba(243, 233, 215, .55);
  color: var(--paper-light);
}

.btn--on-dark:hover {
  background: var(--paper-light);
  border-color: var(--paper-light);
  color: var(--ink);
}

.btn--sm { padding: 7px 13px; font-size: 12.5px; }

/* 面包屑 */
.breadcrumb {
  padding-block: 14px;
  border-bottom: 1px solid var(--line-soft);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--slate);
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-inline: 9px;
  color: var(--hairline);
}

.breadcrumb-link { color: var(--ink-66); border-bottom: 1px solid transparent; }
.breadcrumb-link:hover { color: var(--clay); border-bottom-color: rgba(196, 85, 47, .5); }
.breadcrumb-current { color: var(--ink); }

/* 章节抬头 */
.section-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 32px);
}

.section-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .24em;
  color: var(--clay);
}

.section-kicker::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--clay);
}

.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1.24;
}

.section-desc {
  max-width: 38em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-66);
}

/* 面板 */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 34px);
  background: var(--paper-light);
  border: 1px solid var(--line-soft);
  box-shadow: var(--shadow-panel);
}

.panel--paper { background: var(--paper); }

.panel--dark {
  background: var(--ink);
  border-color: rgba(243, 233, 215, .14);
  color: var(--paper);
  background-image:
    repeating-linear-gradient(90deg, rgba(251, 246, 236, .05) 0 1px, transparent 1px 76px),
    radial-gradient(circle at 92% 0%, rgba(46, 140, 134, .22), transparent 55%);
}

.panel--dark .section-title { color: var(--paper-light); }
.panel--dark .section-desc { color: var(--text-on-dark); }
.panel--dark .section-kicker { color: var(--gold-bright); }
.panel--dark .section-kicker::before { background: var(--gold-bright); }

.panel--raise { box-shadow: var(--shadow-raise); }

/* 索引卡 */
.index-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 22px 22px 24px;
  background: var(--paper-light);
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
  transition: border-color .2s ease, box-shadow .2s ease, background-color .2s ease;
}

.index-card:hover {
  border-color: var(--gold);
  background: #fffdf8;
  box-shadow: 0 16px 30px -26px rgba(10, 19, 48, .8);
}

.index-card__no {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--clay);
}

.index-card__title {
  margin-top: 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.42;
}

.index-card__meta {
  margin-top: 9px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--slate);
}

.index-card__body {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-66);
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .10em;
  line-height: 1.6;
  color: var(--slate);
  background: rgba(251, 246, 236, .7);
}

.tag--gold {
  color: var(--ink);
  background: rgba(200, 154, 75, .22);
  border-color: rgba(200, 154, 75, .58);
}

.tag--teal {
  color: #1F635F;
  background: rgba(46, 140, 134, .13);
  border-color: rgba(46, 140, 134, .46);
}

.tag--clay {
  color: var(--clay);
  background: rgba(196, 85, 47, .10);
  border-color: rgba(196, 85, 47, .42);
}

/* 栅格 */
.grid { display: grid; gap: clamp(14px, 2vw, 22px); }

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

.grid--stagger {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(14px, 2vw, 24px);
}

.grid--stagger > *:nth-child(4n+1) { grid-column: span 7; }
.grid--stagger > *:nth-child(4n+2) { grid-column: span 5; }
.grid--stagger > *:nth-child(4n+3) { grid-column: span 5; }
.grid--stagger > *:nth-child(4n+4) { grid-column: span 7; }

/* 非对称双栏 + 粘性侧栏 */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 288px;
  gap: clamp(20px, 3vw, 40px);
  align-items: start;
}

.split--reverse { grid-template-columns: 288px minmax(0, 1fr); }

.split__rail {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

@media (min-width: 901px) {
  .split__rail { position: sticky; top: 20px; }
}

/* 筛选条 */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-block: 12px;
  margin-bottom: 20px;
  border-block: 1px solid var(--line-soft);
}

.filter-btn {
  padding: 7px 13px;
  border: 1px solid var(--line-soft);
  background: var(--paper-light);
  color: var(--ink-66);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}

.filter-btn:hover { border-color: var(--gold); color: var(--ink); }

.filter-btn[aria-pressed="true"] {
  background: var(--clay);
  border-color: var(--clay);
  color: var(--paper-light);
}

.filter-count {
  margin-left: 6px;
  font-size: 10.5px;
  opacity: .72;
}

.filter-empty {
  margin-top: 18px;
  padding: 24px;
  border: 1px dashed var(--hairline);
  background: var(--paper-light);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-66);
  text-align: center;
}

/* 锚点条 */
.anchor-bar {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-block: 10px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--line-soft);
}

.anchor-link {
  padding: 6px 11px;
  border-bottom: 2px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ink-66);
  white-space: nowrap;
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}

.anchor-link:hover { color: var(--clay); }

.anchor-link[aria-current="true"] {
  color: var(--ink);
  border-bottom-color: var(--clay);
  background: rgba(196, 85, 47, .08);
}

/* 表格 */
.table-scroll { overflow-x: auto; }

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-sans);
  font-size: 13.5px;
  line-height: 1.7;
}

.data-table th {
  padding: 10px 12px;
  background: var(--ink-mid);
  color: var(--paper-light);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .08em;
  text-align: left;
  white-space: nowrap;
}

.data-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line-soft);
  vertical-align: top;
  color: var(--ink-78);
}

.data-table tbody tr:nth-child(even) { background: rgba(14, 27, 61, .035); }

/* 时间轴 */
.timeline {
  position: relative;
  padding-left: 72px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 31px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold), rgba(200, 154, 75, .18));
}

.timeline__item {
  position: relative;
  padding-bottom: clamp(18px, 2.6vw, 30px);
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: -46px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--clay);
  box-shadow: 0 0 0 4px rgba(196, 85, 47, .16);
}

.timeline__stamp {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .10em;
  color: var(--slate);
}

/* 图片容器基础规则 */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background:
    radial-gradient(circle at 78% 12%, rgba(200, 154, 75, .28), transparent 52%),
    linear-gradient(142deg, var(--ink-mid), var(--ink) 58%, var(--ink-deep));
  border: 1px solid var(--line-soft);
}

.media-frame[data-empty="true"]::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(158deg, rgba(200, 154, 75, .30) 0 1px, transparent 1px 13px),
    repeating-linear-gradient(158deg, rgba(46, 140, 134, .18) 0 1px, transparent 1px 39px);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-frame__caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--slate);
}

/* 提示块 */
.callout {
  padding: 16px 18px;
  border-left: 3px solid var(--gold);
  background: rgba(200, 154, 75, .10);
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-78);
}

.callout--teal {
  border-left-color: var(--teal);
  background: rgba(46, 140, 134, .10);
}

/* 滚动显现 */
html.js [data-reveal] { opacity: 0; transform: translateY(14px); }

html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
  transition: opacity .24s ease, transform .24s ease;
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1080px) {
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-col--contact { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .split,
  .split--reverse { grid-template-columns: minmax(0, 1fr); }

  .grid--stagger { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--stagger > *:nth-child(n) { grid-column: span 1; }

  .brand-name { letter-spacing: .12em; text-indent: .12em; }
}

@media (max-width: 719px) {
  .nav-inner { flex-wrap: wrap; justify-content: flex-start; }

  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    flex: 1 0 100%;
    width: 100%;
    padding-bottom: 8px;
    border-top: 1px dashed var(--line-soft);
  }

  .site-nav[data-open="true"] { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    overflow: visible;
  }

  .nav-link {
    display: block;
    padding: 13px 6px;
    border-bottom: 1px solid var(--line-soft);
    border-left: 3px solid transparent;
  }

  .nav-link[aria-current="page"] {
    border-bottom-color: var(--line-soft);
    border-left-color: var(--clay);
    background: rgba(196, 85, 47, .07);
  }

  .grid--two { grid-template-columns: minmax(0, 1fr); }

  .timeline { padding-left: 48px; }
  .timeline::before { left: 19px; }
  .timeline__item::before { left: -34px; }

  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .footer-col--contact { grid-column: auto; }
  .footer-col--brand { max-width: none; }

  .footer-legal { flex-direction: column; }
}

@media (max-width: 420px) {
  .utility-brand { font-size: 11px; letter-spacing: .06em; }
  .utility-list { gap: 4px 12px; }
  .utility-link { font-size: 11px; }
  .contact-value { font-size: 12px; }
  .grid--stagger { grid-template-columns: minmax(0, 1fr); }
}

/* ==========================================================================
   动效降级
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  html.js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .scroll-meter { transition: none; }
}