/* =============================================
   AB官方总站 — 全站共享基础样式
   ============================================= */

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

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-text);
}

p { margin: 0; }

a {
  color: var(--c-gold);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover { color: var(--c-gold-light); }

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

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

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

address { font-style: normal; }

main { display: block; flex: 1; }

hr {
  border: none;
  border-top: 1px solid var(--c-grid);
  margin: var(--sp-5) 0;
}

/* ---------- CSS 变量 ---------- */
:root {
  /* 色彩 */
  --c-bg: #0B1D3A;
  --c-bg-alt: #0F3B3F;
  --c-bg-wine: #5E1D2C;
  --c-bg-indigo: #2D2352;
  --c-gold: #D4AF37;
  --c-gold-light: #E8D5A8;
  --c-text: #F5F8FC;
  --c-muted: #7A9BC2;
  --c-grid: #334155;
  --c-green: #6F8C5E;

  /* 字体 */
  --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', SFMono-Regular, Consolas, 'Liberation Mono', monospace;

  /* 字号 */
  --fs-display: clamp(32px, 4.5vw, 44px);
  --fs-h1: clamp(24px, 3vw, 32px);
  --fs-h2: clamp(20px, 2.4vw, 24px);
  --fs-h3: 18px;
  --fs-body: 16px;
  --fs-caption: 13px;

  /* 布局 */
  --container-w: 1280px;
  --gutter: clamp(16px, 3vw, 48px);
  --header-h: 64px;

  /* 间距 */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 16px;
  --sp-4: 24px;
  --sp-5: 32px;
  --sp-6: 48px;
  --sp-7: 64px;
  --sp-8: 96px;

  /* 动效 */
  --dur: 0.3s;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 通用排版 ---------- */
h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

.display {
  font-size: var(--fs-display);
  line-height: 1.18;
}

.caption {
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  color: var(--c-muted);
  letter-spacing: 0.06em;
}

.lead {
  font-size: 18px;
  line-height: 1.8;
  color: var(--c-muted);
  max-width: 60ch;
}

.text-gold { color: var(--c-gold); }
.text-muted { color: var(--c-muted); }
.text-green { color: var(--c-green); }

/* ---------- 焦点与选中 ---------- */
:focus-visible {
  outline: 2px solid var(--c-gold);
  outline-offset: 2px;
}

::selection {
  background: rgba(212, 175, 55, 0.3);
  color: var(--c-text);
}

[id] {
  scroll-margin-top: calc(var(--header-h) + 20px);
}

/* ---------- 布局容器 ---------- */
.site-container {
  width: 100%;
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container-narrow {
  max-width: 760px;
  margin-inline: auto;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(16px, 2.5vw, 32px);
}

.col-span-3 { grid-column: span 3; }
.col-span-4 { grid-column: span 4; }
.col-span-6 { grid-column: span 6; }
.col-span-8 { grid-column: span 8; }
.col-span-12 { grid-column: span 12; }

@media (max-width: 1023px) {
  .col-span-3,
  .col-span-4,
  .col-span-6,
  .col-span-8 {
    grid-column: span 6;
  }
}

@media (max-width: 767px) {
  .grid-12 { gap: var(--sp-3); }

  .col-span-3,
  .col-span-4,
  .col-span-6,
  .col-span-8,
  .col-span-12 {
    grid-column: span 12;
  }
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: fixed;
  top: -100%;
  left: 16px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--c-gold);
  color: var(--c-bg);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  transition: top 0.2s var(--ease);
}

.skip-link:focus {
  top: 16px;
}

/* ---------- 头部命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(8, 21, 41, 0.96);
  border-bottom: 1px solid var(--c-grid);
}

.header-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

.header-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1100;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--c-gold), var(--c-gold-light));
  box-shadow: 0 0 6px rgba(212, 175, 55, 0.4);
}

/* ---------- 品牌 ---------- */
.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  text-decoration: none;
  color: var(--c-text);
}

.brand-link:hover { color: var(--c-text); }

.brand-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--c-gold);
  background: rgba(212, 175, 55, 0.08);
  color: var(--c-gold);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
}

.brand-meta {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.04em;
}

.brand-tagline {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-muted);
}

/* ---------- 主导航 ---------- */
.header-nav {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 10px;
  font-size: 14px;
  text-decoration: none;
  color: var(--c-text);
  border: 1px solid transparent;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.nav-link::before {
  content: attr(data-index);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  color: var(--c-muted);
  transition: color var(--dur) var(--ease);
}

.nav-link::after {
  display: none;
}

.nav-link:hover {
  color: var(--c-gold-light);
  background: rgba(212, 175, 55, 0.05);
  border-color: var(--c-grid);
}

.nav-link:hover::before {
  color: var(--c-gold);
}

.nav-link[aria-current="page"] {
  color: var(--c-gold-light);
  background: rgba(212, 175, 55, 0.07);
  border-color: rgba(212, 175, 55, 0.35);
}

.btn-one-step {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 10px;
  padding: 8px 14px;
  border: 1px solid var(--c-gold);
  background: var(--c-gold);
  color: var(--c-bg);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.btn-one-step::before {
  content: "\2197";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
}

.btn-one-step:hover {
  background: var(--c-gold-light);
  border-color: var(--c-gold-light);
  color: var(--c-bg);
}

/* ---------- 移动导航按钮 ---------- */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 9px;
  border: 1px solid var(--c-grid);
  background: transparent;
}

.toggle-bar {
  display: block;
  width: 100%;
  height: 1px;
  background: var(--c-text);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), background var(--dur) var(--ease);
}

.nav-toggle:hover .toggle-bar {
  background: var(--c-gold);
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- 移动端导航 ---------- */
@media (max-width: 1023px) {
  .nav-toggle {
    display: inline-flex;
  }

  .header-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px var(--gutter) 20px;
    background: rgba(8, 21, 41, 0.98);
    border-bottom: 1px solid var(--c-grid);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
  }

  .header-nav[data-open] {
    display: flex;
  }

  .nav-link {
    justify-content: flex-start;
    padding: 13px 10px;
    border-bottom: 1px solid var(--c-grid);
    font-size: 15px;
  }

  .nav-link::after {
    display: block;
    content: "\2192";
    margin-left: auto;
    font-family: var(--font-mono);
    font-size: 14px;
    color: var(--c-muted);
  }

  .btn-one-step {
    margin: 14px 0 0;
    justify-content: center;
    padding: 12px 14px;
  }
}

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: var(--sp-8);
  background: linear-gradient(180deg, #081523 0%, #0A1B36 100%);
  border-top: 1px solid var(--c-grid);
  color: var(--c-text);
}

.site-footer::before {
  content: "";
  display: block;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, rgba(212, 175, 55, 0.55) 30%, rgba(212, 175, 55, 0.55) 70%, transparent 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.2fr;
  gap: var(--sp-6);
  padding-block: clamp(40px, 6vw, 72px);
}

.footer-brand,
.footer-nav,
.footer-support {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer-kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-muted);
  margin-bottom: 10px;
}

.footer-brand-name {
  display: block;
  font-size: 26px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--c-text);
}

.footer-brand-sub {
  display: block;
  margin-top: 2px;
  font-size: 14px;
  color: var(--c-muted);
}

.footer-tagline {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gold);
}

.footer-icp {
  margin-top: var(--sp-3);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
}

.footer-heading {
  margin-bottom: 14px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.footer-nav {
  gap: 8px;
}

.footer-link {
  font-size: 14px;
  color: var(--c-muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.footer-link:hover {
  color: var(--c-gold-light);
  padding-left: 6px;
}

.footer-link[aria-current="page"] {
  color: var(--c-gold);
}

.footer-support {
  gap: 12px;
}

.footer-info {
  font-size: 13px;
  color: var(--c-muted);
  line-height: 1.6;
}

.footer-value {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-text);
  overflow-wrap: anywhere;
}

.footer-note {
  margin-block: var(--sp-4);
  padding: 14px 18px;
  border-left: 2px solid var(--c-gold);
  background: rgba(212, 175, 55, 0.04);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-muted);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  padding-block: var(--sp-4);
  border-top: 1px solid var(--c-grid);
}

.footer-copy {
  font-size: 13px;
  color: var(--c-muted);
}

.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
}

.footer-legal-links a {
  font-size: 13px;
  color: var(--c-muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.footer-legal-links a:hover {
  color: var(--c-gold-light);
}

.footer-legal-links a[aria-current="page"] {
  color: var(--c-gold);
}

/* ---------- 浮动操作层 ---------- */
.fab-step {
  position: fixed;
  right: 20px;
  bottom: 76px;
  z-index: 700;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid var(--c-gold);
  background: var(--c-gold);
  color: var(--c-bg);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  box-shadow: 0 6px 20px rgba(212, 175, 55, 0.28);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.fab-step::before {
  content: "\2197";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
}

.fab-step:hover {
  background: var(--c-gold-light);
  border-color: var(--c-gold-light);
  color: var(--c-bg);
  box-shadow: 0 8px 30px rgba(212, 175, 55, 0.4);
  transform: translateY(-2px);
}

.goto-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--c-grid);
  background: rgba(11, 29, 58, 0.9);
  color: var(--c-gold);
  font-family: var(--font-mono);
  font-size: 18px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.goto-top[data-visible] {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.goto-top:hover {
  background: var(--c-gold);
  border-color: var(--c-gold);
  color: var(--c-bg);
}

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid var(--c-gold);
  border-radius: 0;
  background: transparent;
  color: var(--c-gold);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.btn:hover {
  background: rgba(212, 175, 55, 0.08);
  color: var(--c-gold-light);
  border-color: var(--c-gold-light);
}

.btn-gold {
  background: var(--c-gold);
  border-color: var(--c-gold);
  color: var(--c-bg);
}

.btn-gold:hover {
  background: var(--c-gold-light);
  border-color: var(--c-gold-light);
  color: var(--c-bg);
}

.btn-block {
  display: flex;
  width: 100%;
}

/* ---------- 面包屑 ---------- */
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--c-grid);
}

.breadcrumb a {
  color: var(--c-gold);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--c-gold-light);
}

.breadcrumb [aria-current="page"] {
  color: var(--c-muted);
}

/* ---------- 章节画板 ---------- */
.chapter {
  padding-block: clamp(40px, 6vw, 80px);
}

.chapter + .chapter {
  border-top: 1px solid var(--c-grid);
}

.chapter-head {
  margin-bottom: var(--sp-5);
}

.chapter-no {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-gold);
  opacity: 0.9;
}

.chapter-title {
  margin-top: var(--sp-2);
  font-size: var(--fs-h2);
}

.chapter-lead {
  margin-top: var(--sp-2);
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ---------- 旁注索引条 ---------- */
.section-index {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-left: 14px;
  border-left: 2px solid var(--c-gold);
  font-family: var(--font-mono);
  font-size: 13px;
}

.section-index a {
  color: var(--c-muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.section-index a:hover {
  color: var(--c-gold-light);
}

.section-index a[aria-current="true"],
.section-index a[aria-current="page"] {
  color: var(--c-gold);
}

/* ---------- 珠宝色分区面板 ---------- */
.panel {
  padding: clamp(20px, 3vw, 40px);
  border: 1px solid var(--c-grid);
  background: rgba(245, 248, 252, 0.02);
}

.panel-secondary {
  background: var(--c-bg-alt);
  border-color: rgba(245, 248, 252, 0.14);
}

.panel-wine {
  background: var(--c-bg-wine);
  border-color: rgba(245, 248, 252, 0.14);
}

.panel-indigo {
  background: var(--c-bg-indigo);
  border-color: rgba(245, 248, 252, 0.14);
}

/* ---------- 信息卡片 ---------- */
.card {
  border: 1px solid var(--c-grid);
  background: rgba(245, 248, 252, 0.02);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.card:hover {
  border-color: var(--c-gold);
  background: rgba(212, 175, 55, 0.04);
}

.card-body {
  padding: var(--sp-4);
}

.card-title {
  margin-bottom: var(--sp-2);
  font-size: 18px;
  font-weight: 700;
}

.card-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-muted);
}

.card-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
}

/* ---------- 等宽标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--c-muted);
  border: 1px solid var(--c-grid);
  background: rgba(245, 248, 252, 0.02);
}

.tag-gold {
  color: var(--c-gold);
  border-color: rgba(212, 175, 55, 0.45);
}

.tag-green {
  color: var(--c-green);
  border-color: rgba(111, 140, 94, 0.6);
}

/* ---------- 数据对照表 ---------- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  line-height: 1.6;
}

.data-table th {
  padding: 12px 14px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--c-gold);
  border-bottom: 1px solid var(--c-gold);
  white-space: nowrap;
}

.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--c-grid);
  color: var(--c-text);
}

.data-table tbody tr:hover td {
  background: rgba(212, 175, 55, 0.05);
}

/* ---------- 图片容器 ---------- */
.media-container {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--c-grid);
  background-color: var(--c-bg-indigo);
  background-image:
    linear-gradient(90deg, rgba(212, 175, 55, 0.06) 1px, transparent 1px),
    linear-gradient(rgba(212, 175, 55, 0.06) 1px, transparent 1px);
  background-size: 28px 28px;
}

.media-container img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-portrait { aspect-ratio: 3 / 4; }
.media-wide { aspect-ratio: 21 / 9; }

.media-caption {
  padding: 8px 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
  border-bottom: 1px solid var(--c-grid);
}

/* ---------- 文章正文 ---------- */
.prose {
  max-width: 72ch;
  font-size: 16px;
  line-height: 1.9;
}

.prose p {
  margin-bottom: var(--sp-4);
}

.prose h2 {
  margin-top: var(--sp-6);
  margin-bottom: var(--sp-3);
}

.prose h3 {
  margin-top: var(--sp-5);
  margin-bottom: var(--sp-3);
}

.prose a {
  color: var(--c-gold);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--c-gold-light);
}

.prose ul,
.prose ol {
  margin: var(--sp-3) 0 var(--sp-4);
  padding-left: var(--sp-4);
  list-style: disc;
}

/* ---------- 响应式细节 ---------- */
@media (max-width: 767px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--sp-5);
  }

  .footer-legal {
    flex-direction: column;
    align-items: flex-start;
  }

  .fab-step {
    right: 14px;
    bottom: 68px;
    padding: 8px 12px;
  }

  .goto-top {
    right: 14px;
    bottom: 20px;
    width: 38px;
    height: 38px;
  }
}

@media (max-width: 480px) {
  .brand-tagline {
    display: none;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}