/* ============================================================
   竞博电竞官网 · /assets/site.css
   共享层：重置 / 变量 / 中文排版 / 框景头部 / 页脚 / 通用组件
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar-h, 76px) + 24px);
}

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

/* ---------- 设计令牌 ---------- */
:root {
  /* 色彩 */
  --ink: #1A0A10;
  --deep-vermilion: #45121A;
  --vermilion: #C0272D;
  --gold: #E0A93B;
  --gold-hi: #FFDE8A;
  --neon: #38E1D4;
  --glass-white: #F6F0E7;
  --gray-gold: #9C8A66;
  --copper: #6E4A21;
  --neon-mist: rgba(56, 225, 212, 0.15);

  --line: rgba(224, 169, 59, 0.30);
  --line-soft: rgba(110, 74, 33, 0.55);
  --glass-1: rgba(246, 240, 231, 0.09);
  --glass-2: rgba(246, 240, 231, 0.035);
  --shade: rgba(26, 10, 16, 0.78);

  /* 字体 */
  --font-display: "Alibaba PuHuiTi 3.0 Heavy", "Noto Sans SC", "Source Han Sans SC",
                  "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei",
               system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular,
               Consolas, "Courier New", monospace;

  /* 字号阶梯 */
  --fs-14: 0.875rem;
  --fs-16: 1rem;
  --fs-18: 1.125rem;
  --fs-22: 1.375rem;
  --fs-30: 1.875rem;
  --fs-44: 2.75rem;
  --fs-68: 4.25rem;

  /* 骨架尺寸 */
  --topbar-h: 76px;
  --rail-w: 232px;
  --radius: 2px;
  --cut: 14px;
}

/* ---------- 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--topbar-h);
  padding-left: var(--rail-w);
  background-color: var(--ink);
  background-image:
    radial-gradient(900px 520px at 88% -10%, rgba(192, 39, 45, 0.22), transparent 62%),
    radial-gradient(760px 460px at 6% 12%, rgba(69, 18, 26, 0.75), transparent 68%),
    radial-gradient(520px 380px at 50% 118%, rgba(56, 225, 212, 0.07), transparent 70%);
  background-attachment: fixed;
  color: var(--glass-white);
  font-family: var(--font-body);
  font-size: var(--fs-18);
  font-weight: 400;
  line-height: 1.9;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

body[data-nav-open] { overflow: hidden; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--glass-white);
  font-style: normal;
}

p { margin-bottom: 0; }

a { color: var(--gold-hi); text-decoration: none; }
a:hover { color: var(--neon); }

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

::selection { background: rgba(192, 39, 45, 0.72); color: var(--gold-hi); }

#main-content { display: block; scroll-margin-top: calc(var(--topbar-h) + 24px); }

/* ---------- 通用工具 ---------- */
.wrap {
  width: min(1240px, 100%);
  margin-inline: auto;
  padding-inline: clamp(18px, 3.6vw, 56px);
}

.page { padding-block: clamp(26px, 4vw, 54px) 0; }

.cut {
  clip-path: polygon(var(--cut) 0, 100% 0, 100% calc(100% - var(--cut)),
                     calc(100% - var(--cut)) 100%, 0 100%, 0 var(--cut));
}

.cut-title {
  display: inline-block;
  padding: 0.14em 0.5em 0.2em 0.44em;
  background: linear-gradient(100deg, var(--vermilion) 0%, #8d1d24 72%, #6b151b 100%);
  color: var(--glass-white);
  box-shadow: inset 0 0 0 1px rgba(255, 222, 138, 0.35);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% calc(100% - var(--cut)),
                     calc(100% - var(--cut)) 100%, 0 100%, 0 var(--cut));
}

.page-title {
  font-family: var(--font-display);
  font-size: clamp(var(--fs-30), 5vw, var(--fs-44));
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-block: 0 0.5em;
}

.sec-head { margin-bottom: clamp(24px, 3vw, 44px); }

.sec-title {
  font-size: clamp(var(--fs-22), 3.4vw, var(--fs-30));
  letter-spacing: -0.02em;
  margin: 0;
}

.sec-kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gray-gold);
  margin-bottom: 0.55em;
}

.prose { max-width: 42em; font-size: var(--fs-18); }
.prose p { margin-bottom: 1.4em; color: rgba(246, 240, 231, 0.92); }
.prose p:last-child { margin-bottom: 0; }
.prose h2, .prose h3 { margin-block: 1.9em 0.7em; }
.prose h2 { font-size: var(--fs-22); }
.prose h3 { font-size: var(--fs-18); color: var(--gold-hi); }
.prose ul { margin: 0 0 1.4em; padding-left: 1.1em; }
.prose ul li {
  position: relative;
  padding-left: 0.9em;
  margin-bottom: 0.45em;
  color: rgba(246, 240, 231, 0.9);
}
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.82em;
  width: 0.5em;
  height: 2px;
  background: var(--neon);
}
.prose strong { color: var(--gold-hi); font-weight: 700; }

.section { padding-block: clamp(48px, 8vw, 108px); position: relative; }
.section--deep {
  background: linear-gradient(180deg, rgba(69, 18, 26, 0.9), rgba(26, 10, 16, 0.2));
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}
.section--pause { padding-block: clamp(56px, 10vw, 132px); }

.rule-ticks {
  height: 10px;
  border-top: 1px solid var(--line);
  background-image: repeating-linear-gradient(90deg, var(--gold) 0 1px, transparent 1px 22px);
  background-size: auto 6px;
  background-repeat: repeat-x;
  opacity: 0.55;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.62em 1.25em;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: var(--fs-16);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease, color 0.18s ease,
              background-color 0.18s ease, border-color 0.18s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--gold {
  background: linear-gradient(150deg, var(--gold-hi), var(--gold) 58%, #a8761f);
  color: #1A0A10;
  border-color: rgba(255, 222, 138, 0.8);
  box-shadow: 0 8px 22px -14px rgba(255, 222, 138, 0.9);
}
.btn--gold:hover { color: #1A0A10; box-shadow: 0 10px 26px -12px rgba(56, 225, 212, 0.55); }

.btn--ghost {
  background: rgba(246, 240, 231, 0.05);
  color: var(--gold-hi);
  border-color: var(--line);
}
.btn--ghost:hover { color: var(--neon); border-color: var(--neon); background: var(--neon-mist); }

.btn--quiet {
  background: transparent;
  color: var(--gray-gold);
  border-color: var(--line-soft);
  font-size: var(--fs-14);
  padding: 0.45em 0.9em;
}
.btn--quiet:hover { color: var(--gold-hi); border-color: var(--gold); }
.btn[data-copied] { color: var(--neon); border-color: var(--neon); }

/* ---------- 跳转链 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 50%;
  z-index: 140;
  transform: translate(-50%, -180%);
  padding: 0.6em 1.3em;
  background: var(--gold-hi);
  color: #1A0A10;
  font-size: var(--fs-14);
  font-weight: 800;
  border-radius: var(--radius);
  box-shadow: 0 8px 20px -10px rgba(0, 0, 0, 0.8);
  transition: transform 0.2s ease;
}
.skip-link:focus { transform: translate(-50%, 0); color: #1A0A10; }

/* ============================================================
   头部：顶部压边条 + 左侧栏目轨道 + 阅读进度
   ============================================================ */
.site-header { position: relative; z-index: 70; }

.frame-top {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 90;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.8vw, 26px);
  padding-inline: clamp(14px, 2.2vw, 28px);
  background: linear-gradient(180deg, rgba(69, 18, 26, 0.95), rgba(26, 10, 16, 0.93));
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7em;
  min-width: 0;
  flex: none;
  color: inherit;
  text-decoration: none;
}

.brand__mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  font-family: var(--font-display);
  font-size: var(--fs-22);
  font-weight: 900;
  color: #1A0A10;
  background: linear-gradient(150deg, var(--gold-hi), var(--gold) 56%, #8a5f16);
  clip-path: polygon(7px 0, 100% 0, 100% calc(100% - 7px), calc(100% - 7px) 100%, 0 100%, 0 7px);
}

.brand__text { display: flex; flex-direction: column; line-height: 1.15; min-width: 0; }
.brand__name {
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--glass-white);
}
.brand__line {
  font-size: var(--fs-14);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--gray-gold);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand:hover .brand__name { color: var(--gold-hi); }

.frame-tagline {
  flex: 1 1 auto;
  min-width: 0;
  text-align: center;
  font-size: var(--fs-14);
  letter-spacing: 0.14em;
  color: var(--gray-gold);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.frame-tagline::before,
.frame-tagline::after {
  content: "";
  display: inline-block;
  width: 26px;
  height: 1px;
  margin-inline: 0.9em;
  vertical-align: middle;
  background: var(--line);
}

.frame-actions { display: flex; align-items: center; gap: 0.55em; flex: none; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55em;
  flex: none;
  padding: 0.5em 0.85em;
  background: rgba(246, 240, 231, 0.06);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--gold-hi);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: 0.08em;
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--gold-hi);
  transition: background-color 0.2s ease;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: inherit;
  transition: transform 0.22s ease, top 0.22s ease;
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: var(--neon); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

/* 左侧栏目轨道 */
.frame-rail {
  position: fixed;
  left: 0;
  top: var(--topbar-h);
  bottom: 0;
  z-index: 88;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  padding: 26px 16px 22px 20px;
  background: linear-gradient(180deg, rgba(69, 18, 26, 0.72), rgba(26, 10, 16, 0.94) 62%);
  border-right: 1px solid var(--line);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  overflow-y: auto;
  overscroll-behavior: contain;
}
.frame-rail::after {
  content: "";
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 9px;
  background-image: repeating-linear-gradient(180deg, var(--gold) 0 1px, transparent 1px 20px);
  opacity: 0.3;
  pointer-events: none;
}

.rail-list { display: flex; flex-direction: column; gap: 2px; }

.rail-list a {
  display: flex;
  align-items: baseline;
  gap: 0.7em;
  padding: 0.52em 0.6em 0.52em 0.82em;
  border-left: 2px solid transparent;
  color: var(--gray-gold);
  font-size: var(--fs-18);
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}
.rail-list a:hover { color: var(--gold-hi); background: rgba(224, 169, 59, 0.08); }

.rail-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--copper);
}
.rail-name { line-height: 1.4; }

.rail-list a[aria-current="page"] {
  color: var(--gold-hi);
  border-left-color: var(--neon);
  background: linear-gradient(90deg, var(--neon-mist), rgba(56, 225, 212, 0) 88%);
}
.rail-list a[aria-current="page"] .rail-num { color: var(--neon); }
.rail-list a[aria-current="page"] .rail-name { font-weight: 900; }

.rail-note {
  margin-top: auto;
  padding-top: 22px;
  font-size: 0.72rem;
  line-height: 1.8;
  letter-spacing: 0.06em;
  color: var(--copper);
}

/* 阅读进度 */
.read-progress {
  position: fixed;
  left: 0;
  right: 0;
  top: calc(var(--topbar-h) - 2px);
  height: 2px;
  z-index: 92;
  background: rgba(224, 169, 59, 0.14);
  pointer-events: none;
}
.read-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  position: relative;
  background: linear-gradient(90deg, var(--gold), var(--gold-hi));
  transition: width 0.1s linear;
}
.read-progress__bar::after {
  content: "";
  position: absolute;
  right: -3px;
  top: -3px;
  width: 8px;
  height: 8px;
  background: var(--neon);
  box-shadow: 0 0 10px var(--neon);
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  margin-top: clamp(52px, 8vw, 120px);
  background: linear-gradient(180deg, var(--deep-vermilion) 0%, #2a0c13 55%, var(--ink) 100%);
  border-top: 1px solid var(--line);
  padding-top: clamp(38px, 5vw, 66px);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background-image: repeating-linear-gradient(90deg, var(--gold) 0 14px, transparent 14px 30px);
  opacity: 0.32;
}

.footer-deck {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) minmax(0, 2.15fr);
  gap: clamp(26px, 4vw, 62px);
  padding-bottom: clamp(28px, 3.5vw, 46px);
}

.footer-brand__mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  margin-bottom: 0.7em;
  font-family: var(--font-display);
  font-size: var(--fs-22);
  font-weight: 900;
  color: #1A0A10;
  background: linear-gradient(150deg, var(--gold-hi), var(--gold) 58%, #8a5f16);
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}
.footer-brand__name {
  font-family: var(--font-display);
  font-size: var(--fs-22);
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--glass-white);
  margin-bottom: 0.25em;
}
.footer-brand__line {
  font-size: var(--fs-14);
  letter-spacing: 0.04em;
  color: var(--gray-gold);
  max-width: 24em;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(18px, 2.4vw, 34px);
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 0.55em;
  margin-bottom: 0.85em;
  font-family: var(--font-body);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--gold);
  text-transform: none;
}
.footer-col__title::before {
  content: "";
  width: 2px;
  height: 0.95em;
  background: var(--neon);
  flex: none;
}

.footer-col__list li { margin-bottom: 0.42em; }
.footer-col__list a {
  position: relative;
  display: inline-block;
  font-size: var(--fs-14);
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
  color: rgba(246, 240, 231, 0.78);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}
.footer-col__list a:hover {
  color: var(--neon);
  border-bottom-color: var(--neon);
  transform: translateX(3px);
}

.footer-contact {
  grid-column: 1 / -1;
  padding-top: clamp(22px, 2.6vw, 34px);
  border-top: 1px solid var(--line-soft);
}
.footer-contact__title {
  margin-bottom: 0.9em;
  font-family: var(--font-body);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--gold);
}
.footer-contact__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: clamp(16px, 2vw, 30px);
}
.contact-item__label {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--copper);
  color: var(--gray-gold);
  margin-bottom: 0.25em;
}
.contact-item__value {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--glass-white);
  word-break: break-word;
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.6em 1.6em;
  padding-block: 18px 24px;
  border-top: 1px solid var(--line-soft);
}
.footer-base__meta {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--gray-gold);
}

/* ============================================================
   通用内容组件
   ============================================================ */
.glass {
  background: linear-gradient(160deg, var(--glass-1), var(--glass-2));
  border: 1px solid var(--line);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.slab {
  background: linear-gradient(165deg, rgba(69, 18, 26, 0.92), rgba(26, 10, 16, 0.92));
  border: 1px solid var(--line-soft);
}

.panel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(16px, 2vw, 26px);
}

.index-list { display: flex; flex-direction: column; }
.index-list a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1em;
  padding: 0.7em 0.4em;
  border-bottom: 1px solid var(--line-soft);
  color: rgba(246, 240, 231, 0.86);
  font-size: var(--fs-16);
  text-decoration: none;
  transition: color 0.18s ease, padding-left 0.18s ease, background-color 0.18s ease;
}
.index-list a:hover { color: var(--gold-hi); padding-left: 0.9em; }
.index-list a[aria-current="true"] {
  color: var(--gold-hi);
  background: linear-gradient(90deg, var(--neon-mist), transparent 70%);
  box-shadow: inset 2px 0 0 var(--neon);
}

.metric-box {
  display: inline-flex;
  flex-direction: column;
  gap: 0.2em;
  padding: 0.45em 0.7em 0.55em;
  border: 1px solid var(--gold-hi);
  background: rgba(255, 222, 138, 0.07);
  box-shadow: 0 0 0 4px rgba(255, 222, 138, 0.06);
}
.metric {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(var(--fs-44), 8vw, var(--fs-68));
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold-hi);
}
.metric-label {
  font-size: var(--fs-14);
  letter-spacing: 0.12em;
  color: var(--gray-gold);
}

.step-list {
  display: grid;
  gap: clamp(14px, 1.8vw, 22px);
  position: relative;
}
.step-list > li {
  position: relative;
  padding-left: 2.4em;
}
.step-list > li::before {
  content: "";
  position: absolute;
  left: 0.62em;
  top: 0.9em;
  bottom: -1.4em;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), rgba(224, 169, 59, 0.12));
}
.step-list > li:last-child::before { display: none; }
.step-list > li::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0.86em;
  width: 1.25em;
  height: 1.25em;
  border: 1px solid var(--gold);
  background: var(--ink);
  transform: rotate(45deg);
}
.step-list > li:nth-child(2n)::after { border-color: var(--neon); }
.step-list__title {
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 900;
  color: var(--glass-white);
}
.step-list__desc { font-size: var(--fs-16); color: rgba(246, 240, 231, 0.82); }

/* 术语词典 */
.term {
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--neon);
  background: linear-gradient(150deg, rgba(246, 240, 231, 0.055), rgba(246, 240, 231, 0.015));
  margin-bottom: 12px;
}
.term__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1em;
  width: 100%;
  padding: 0.85em 1em;
  background: none;
  border: 0;
  color: var(--gold-hi);
  font-family: var(--font-mono);
  font-size: var(--fs-16);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: left;
  cursor: pointer;
}
.term__head::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--gray-gold);
}
.term[data-open] .term__head::after { content: "–"; color: var(--neon); }
.term__body {
  display: none;
  padding: 0 1em 1.1em;
  font-size: var(--fs-16);
  line-height: 1.9;
  color: rgba(246, 240, 231, 0.88);
}
.term[data-open] .term__body { display: block; }

/* 标签切换 */
.tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.tabs__btn {
  padding: 0.5em 1.05em;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: rgba(246, 240, 231, 0.04);
  color: var(--gray-gold);
  font-size: var(--fs-16);
  font-weight: 700;
  cursor: pointer;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}
.tabs__btn[aria-selected="true"] {
  color: #1A0A10;
  background: linear-gradient(150deg, var(--gold-hi), var(--gold));
  border-color: var(--gold-hi);
}
.tabs__panel[hidden] { display: none; }

/* 面包屑 */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55em;
  margin-bottom: clamp(16px, 2vw, 26px);
  font-size: var(--fs-14);
  letter-spacing: 0.04em;
  color: var(--gray-gold);
}
.crumbs a { color: var(--gold); border-bottom: 1px solid rgba(224, 169, 59, 0.4); }
.crumbs a:hover { color: var(--neon); border-bottom-color: var(--neon); }
.crumbs span[aria-hidden="true"] { color: var(--copper); }

/* 图片容器 */
.img-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  background: linear-gradient(150deg, #2a0f16, var(--deep-vermilion));
}
.img-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.img-frame--16x9 { aspect-ratio: 16 / 9; }
.img-frame--4x3 { aspect-ratio: 4 / 3; }
.img-frame--1x1 { aspect-ratio: 1 / 1; }
.img-frame--slash {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
}
.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  box-shadow: inset 0 0 0 1px rgba(255, 222, 138, 0.14);
}
.img-frame__cap {
  margin-top: 0.7em;
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  color: var(--gray-gold);
}

/* 显现动效协议 */
html.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(14px) scale(0.985);
  transition: opacity 0.5s ease, transform 0.5s cubic-bezier(0.2, 0.7, 0.3, 1);
}
html.reveal-ready [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1180px) {
  :root { --rail-w: 208px; }
  .footer-deck { grid-template-columns: minmax(200px, 1fr) minmax(0, 2fr); }
}

@media (max-width: 1080px) {
  :root { --topbar-h: 68px; }
  body { padding-left: 0; }

  .nav-toggle { display: inline-flex; }
  .frame-tagline { display: none; }
  .frame-actions { margin-left: auto; }

  .frame-rail {
    width: min(320px, 82vw);
    transform: translateX(-104%);
    transition: transform 0.28s cubic-bezier(0.22, 0.68, 0.3, 1);
    box-shadow: 0 0 40px -10px rgba(0, 0, 0, 0.9);
    z-index: 96;
  }
  .frame-rail[data-open] { transform: translateX(0); }

  body[data-nav-open]::after {
    content: "";
    position: fixed;
    inset: var(--topbar-h) 0 0 0;
    background: rgba(10, 4, 7, 0.62);
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
    z-index: 94;
  }

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

@media (max-width: 720px) {
  body { font-size: var(--fs-16); }
  .frame-actions .btn--ghost { display: none; }
  .brand__line { display: none; }
  .brand__mark { width: 34px; height: 34px; font-size: var(--fs-18); }
  .footer-cols { grid-template-columns: 1fr 1fr; gap: 20px 16px; }
  .footer-base { justify-content: flex-start; }
}

@media (max-width: 620px) {
  :root { --topbar-h: 60px; --cut: 11px; }
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 0.5em 0.7em; }
  .frame-top { gap: 10px; }
  .footer-contact__grid { grid-template-columns: 1fr; }
  .step-list > li { padding-left: 2em; }
}

@media (max-width: 420px) {
  .brand__name { font-size: var(--fs-16); }
  .frame-actions .btn { padding: 0.55em 0.9em; font-size: 0.875rem; }
}

@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;
  }
  html.reveal-ready [data-reveal] { opacity: 1; transform: none; }
}