/* ==========================================================================
   亿兆体育 Site CSS — 共享样式基础
   ========================================================================== */

/* ---------- 1. CSS 变量 ---------- */
:root {
  --color-deep: #0A0F1E;
  --color-deep-alt: #070C17;
  --color-indigo: #3D2C5C;
  --color-teal: #0B4C4F;
  --color-wine: #5E1A2A;
  --color-orange: #FF6B35;
  --color-blue: #00D4FF;
  --color-text: #E8E8E8;
  --color-muted: #A0A0A0;
  --color-positive: #00FFAA;
  --color-negative: #FF4D9D;

  --font-heading: "Rajdhani", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Microsoft YaHei", sans-serif;

  --header-huge: clamp(34px, 6vw, 56px);
  --header-large: clamp(26px, 4vw, 40px);
  --header-medium: clamp(20px, 3vw, 28px);

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;

  --max-width: 1280px;
  --rad-sm: 4px;
  --rad-md: 6px;
  --ease: 0.25s ease;
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 70px;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-deep);
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: 0.04em;
  color: var(--color-text);
}

h1 { font-size: var(--header-huge); }
h2 { font-size: var(--header-large); }
h3 { font-size: var(--header-medium); }
h4 { font-size: 18px; }

p { margin-bottom: 1em; }

a {
  color: var(--color-blue);
  text-decoration: none;
  transition: color var(--ease);
}

a:hover { color: var(--color-orange); }

ul, ol { list-style: none; }

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

button {
  font-family: inherit;
  font-size: inherit;
  border: none;
  background: none;
  color: inherit;
  cursor: pointer;
}

::selection {
  background: rgba(255, 107, 53, 0.35);
  color: var(--color-text);
}

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

#main-content {
  scroll-margin-top: 60px;
}

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

/* ---------- 3. 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section {
  position: relative;
  padding: 56px 0;
}

.section--indigo { background-color: var(--color-indigo); }
.section--teal { background-color: var(--color-teal); }
.section--wine { background-color: var(--color-wine); }
.section--slate { background-color: #121A2E; }

@media (min-width: 769px) {
  .section { padding: 88px 0; }
}

@media (max-width: 600px) {
  .wrap {
    padding-left: 16px;
    padding-right: 16px;
  }
}

/* ---------- 4. 网格 ---------- */
.grid {
  display: grid;
  gap: 24px;
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--aside { grid-template-columns: 1fr 320px; }

@media (max-width: 960px) {
  .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .grid--aside { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
}

/* ---------- 5. 正文排版 ---------- */
.prose {
  font-size: 16px;
  line-height: 1.75;
}

.prose p { margin-bottom: 1.1em; }
.prose h2, .prose h3 { margin-top: 1.8em; margin-bottom: 0.6em; }
.prose ul, .prose ol { padding-left: 1.5em; margin-bottom: 1.1em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li { margin-bottom: 0.4em; }

/* ---------- 6. 标题与面包屑 ---------- */
.section-title {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
  font-size: var(--header-large);
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--color-text);
  margin-bottom: 16px;
}

.section-title::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--color-orange);
  transform: rotate(45deg);
  box-shadow: 0 0 10px rgba(255, 107, 53, 0.45);
  flex-shrink: 0;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 16px 0;
  font-size: 13px;
  color: var(--color-muted);
}

.breadcrumb a { color: var(--color-muted); transition: color 0.2s ease; }
.breadcrumb a:hover { color: var(--color-blue); }
.breadcrumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: rgba(255, 255, 255, 0.25);
}
.breadcrumb li[aria-current="page"] {
  color: var(--color-orange);
  font-weight: 500;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: var(--rad-sm);
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  border: 1px solid transparent;
  text-decoration: none;
  line-height: 1.4;
  transition: background-color var(--ease), color var(--ease),
              border-color var(--ease), box-shadow var(--ease), transform var(--ease);
}

.btn--primary {
  background: var(--color-orange);
  color: var(--color-deep);
  border-color: var(--color-orange);
  box-shadow: 0 2px 12px rgba(255, 107, 53, 0.25);
}

.btn--primary:hover {
  background: #ff8552;
  border-color: #ff8552;
  box-shadow: 0 2px 18px rgba(255, 107, 53, 0.4);
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--color-blue);
  border-color: rgba(0, 212, 255, 0.4);
}

.btn--ghost:hover {
  background: rgba(0, 212, 255, 0.08);
  border-color: var(--color-blue);
  box-shadow: 0 0 12px rgba(0, 212, 255, 0.25);
}

/* ---------- 8. 卡片 ---------- */
.card {
  position: relative;
  padding: 24px;
  background:
    linear-gradient(150deg, rgba(61, 44, 92, 0.18) 0%, transparent 40%),
    rgba(10, 15, 30, 0.45);
  border: 1px solid rgba(0, 212, 255, 0.12);
  border-radius: var(--rad-md);
  box-shadow:
    4px 4px 0 rgba(0, 0, 0, 0.25),
    0 0 0 1px rgba(0, 212, 255, 0.06),
    0 4px 16px rgba(0, 0, 0, 0.18);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.035);
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px) translateX(-2px);
  border-color: rgba(0, 212, 255, 0.3);
  box-shadow:
    6px 6px 0 rgba(0, 0, 0, 0.22),
    0 0 0 1px rgba(0, 212, 255, 0.1),
    0 12px 28px rgba(0, 0, 0, 0.3);
}

.card--emph {
  background:
    linear-gradient(135deg, rgba(61, 44, 92, 0.5) 0%, transparent 50%),
    linear-gradient(315deg, rgba(11, 76, 79, 0.35) 0%, transparent 60%),
    rgba(10, 15, 30, 0.55);
  box-shadow:
    5px 5px 0 rgba(0, 0, 0, 0.28),
    0 0 0 1px rgba(0, 212, 255, 0.08),
    0 6px 20px rgba(0, 0, 0, 0.25);
}

/* ---------- 9. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  border-radius: 2px;
  background: rgba(0, 212, 255, 0.1);
  color: var(--color-blue);
  border: 1px solid rgba(0, 212, 255, 0.25);
}

.tag--orange {
  background: rgba(255, 107, 53, 0.12);
  color: var(--color-orange);
  border-color: rgba(255, 107, 53, 0.3);
}

.tag--green {
  background: rgba(0, 255, 170, 0.08);
  color: var(--color-positive);
  border-color: rgba(0, 255, 170, 0.25);
}

.tag--pink {
  background: rgba(255, 77, 157, 0.1);
  color: var(--color-negative);
  border-color: rgba(255, 77, 157, 0.25);
}

/* ---------- 10. 数据与图表 ---------- */
.stat-number {
  font-family: var(--font-heading);
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--color-blue);
}

.stat-number--orange { color: var(--color-orange); }
.stat-number--green { color: var(--color-positive); }

.chart-box {
  position: relative;
  padding: 20px;
  min-height: 140px;
  background: linear-gradient(135deg, rgba(11, 76, 79, 0.3), rgba(61, 44, 92, 0.2));
  border: 1px solid rgba(0, 212, 255, 0.12);
  border-radius: var(--rad-md);
}

.chart-box::after {
  content: "";
  position: absolute;
  inset: 8px;
  border: 1px dashed rgba(0, 212, 255, 0.15);
  border-radius: 3px;
  pointer-events: none;
}

.chart-box > svg {
  position: relative;
  z-index: 1;
  width: 100%;
  height: auto;
}

/* ---------- 11. 目录卡片 ---------- */
.toc-card {
  background: rgba(11, 76, 79, 0.18);
  border: 1px solid rgba(0, 212, 255, 0.14);
  border-radius: var(--rad-md);
  padding: 20px;
}

.toc-card-title {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-orange);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-card-title::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--color-orange);
  transform: rotate(45deg);
  flex-shrink: 0;
}

.toc-card-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
  font-size: 14px;
  color: var(--color-muted);
  border-bottom: 1px dashed rgba(255, 255, 255, 0.06);
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.toc-card-list a::before {
  content: "";
  width: 5px;
  height: 5px;
  background: var(--color-blue);
  transform: rotate(45deg);
  flex-shrink: 0;
  opacity: 0.5;
}

.toc-card-list a:hover {
  color: var(--color-blue);
  padding-left: 8px;
}

/* ---------- 12. 图片占位容器 ---------- */
.img-frame {
  position: relative;
  overflow: hidden;
  min-height: 180px;
  border: 1px solid rgba(0, 212, 255, 0.18);
  border-radius: var(--rad-md);
  background:
    radial-gradient(ellipse at 70% 20%, rgba(255, 107, 53, 0.14), transparent 55%),
    radial-gradient(ellipse at 25% 80%, rgba(0, 212, 255, 0.12), transparent 50%),
    linear-gradient(160deg, #1a2142 0%, #0A0F1E 55%, #0B4C4F 130%);
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 55%, rgba(10, 15, 30, 0.7));
  pointer-events: none;
}

.img-frame--hero { min-height: 340px; border-radius: var(--rad-md); }
.img-frame--card { min-height: 160px; border-radius: var(--rad-sm); }
.img-frame--tall { min-height: 300px; }

/* ---------- 13. 头部 ---------- */
.site-header {
  position: relative;
  z-index: 700;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 16px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--color-orange);
  color: var(--color-deep);
  font-size: 14px;
  font-weight: 700;
  border-radius: 0 0 4px 4px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
  transition: top 0.25s ease;
}

.skip-link:focus { top: 0; }

.masthead {
  position: relative;
  padding: 44px 24px 40px;
  text-align: center;
  background:
    radial-gradient(ellipse 60% 80% at 50% 0%, rgba(61, 44, 92, 0.28), transparent 70%),
    radial-gradient(ellipse 40% 40% at 82% 8%, rgba(255, 107, 53, 0.06), transparent),
    radial-gradient(ellipse 40% 40% at 18% 8%, rgba(0, 212, 255, 0.06), transparent);
  border-bottom: 1px solid transparent;
}

.masthead::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 10%;
  right: 10%;
  height: 2px;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.4), rgba(255, 107, 53, 0.5), rgba(0, 212, 255, 0.4), transparent);
  pointer-events: none;
}

.masthead-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 16px;
}

.masthead-mark {
  display: block;
  width: 40px;
  height: 40px;
  margin: 0 auto 10px;
  position: relative;
}

.mark-diamond {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 16px;
  height: 16px;
  background: linear-gradient(135deg, var(--color-orange), #ff9155);
  transform: translate(-50%, -50%) rotate(45deg);
  box-shadow: 0 0 20px rgba(255, 107, 53, 0.55), 0 0 6px rgba(0, 212, 255, 0.3);
}

.mark-diamond::before,
.mark-diamond::after {
  content: "";
  position: absolute;
  width: 8px;
  height: 8px;
  transform: rotate(45deg);
}

.mark-diamond::before {
  top: -12px;
  left: 4px;
  background: var(--color-blue);
  box-shadow: 0 0 8px rgba(0, 212, 255, 0.5);
  opacity: 0.85;
}

.mark-diamond::after {
  bottom: -12px;
  left: 4px;
  background: var(--color-positive);
  opacity: 0.7;
}

.brand-link { display: inline-block; }

.brand-name {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: var(--header-huge);
  font-weight: 800;
  letter-spacing: 0.14em;
  color: var(--color-text);
  line-height: 1.15;
  transition: color 0.3s ease, text-shadow 0.3s ease;
}

.brand-link:hover .brand-name {
  color: var(--color-orange);
  text-shadow: 0 0 24px rgba(255, 107, 53, 0.18);
}

.brand-tagline {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.38em;
  text-indent: 0.38em;
  color: var(--color-muted);
}

/* ---------- 14. 导航 ---------- */
.nav-region {
  position: sticky;
  top: 0;
  z-index: 800;
  background: rgba(10, 15, 30, 0.95);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.25);
}

.nav-region-inner {
  display: flex;
  justify-content: center;
  min-height: 52px;
  position: relative;
}

.nav-toggle { display: none; }

.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 52px;
  padding: 0 22px;
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--color-muted);
  position: relative;
  transition: color 0.25s ease, background-color 0.25s ease;
}

.site-nav a:hover {
  color: var(--color-blue);
  background: rgba(0, 212, 255, 0.06);
}

.site-nav a[aria-current="page"] {
  color: var(--color-orange);
  background: rgba(255, 107, 53, 0.05);
}

.site-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-orange), transparent 80%);
}

@media (min-width: 769px) {
  .site-nav a + a::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 1px;
    height: 14px;
    background: rgba(0, 212, 255, 0.15);
  }
}

@media (max-width: 768px) {
  .nav-region-inner {
    flex-direction: column;
    align-items: center;
    min-height: 0;
    padding-top: 10px;
    padding-bottom: 12px;
    gap: 0;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 8px 18px;
    background: rgba(0, 212, 255, 0.08);
    border: 1px solid rgba(0, 212, 255, 0.22);
    border-radius: var(--rad-sm);
    color: var(--color-blue);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.18em;
    align-self: center;
    transition: background-color 0.25s ease, box-shadow 0.25s ease;
  }

  .nav-toggle:hover {
    background: rgba(0, 212, 255, 0.14);
  }

  .nav-toggle[aria-expanded="true"] {
    background: rgba(0, 212, 255, 0.16);
    box-shadow: 0 0 12px rgba(0, 212, 255, 0.15);
  }

  .nav-toggle-box {
    display: block;
    width: 20px;
  }

  .nav-toggle-line {
    display: block;
    width: 20px;
    height: 2px;
    background: currentColor;
    border-radius: 1px;
    transition: transform 0.3s ease, opacity 0.2s ease;
  }

  .nav-toggle-line + .nav-toggle-line {
    margin-top: 5px;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

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

  .nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .site-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    margin-top: 10px;
  }

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

  .site-nav a {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 16px;
    font-size: 14px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
  }

  .site-nav a[aria-current="page"]::after {
    left: 20%;
    right: 20%;
  }
}

/* ---------- 15. 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 1001;
  pointer-events: none;
  background: transparent;
}

.scroll-progress-bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--color-orange), var(--color-blue), var(--color-positive));
  box-shadow: 0 0 10px rgba(255, 107, 53, 0.35);
}

/* ---------- 16. 页脚 ---------- */
.site-footer {
  position: relative;
  background-color: var(--color-deep-alt);
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  border-top: 1px solid rgba(0, 212, 255, 0.12);
  margin-top: var(--space-xl);
}

.footer-decoration {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 28px 24px 0;
}

.footer-deco-line {
  flex: 1;
  max-width: 240px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.3), rgba(255, 107, 53, 0.35));
}

.footer-deco-diamond {
  width: 10px;
  height: 10px;
  background: var(--color-orange);
  transform: rotate(45deg);
  box-shadow: 0 0 10px rgba(255, 107, 53, 0.4);
}

.footer-main {
  display: grid;
  grid-template-columns: 2fr 1fr 0.8fr 1.4fr;
  gap: 40px;
  padding-top: 40px;
  padding-bottom: 48px;
}

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

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

.footer-mark {
  display: block;
  width: 28px;
  height: 28px;
  margin-bottom: 12px;
  position: relative;
}

.footer-mark-core {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 10px;
  height: 10px;
  background: var(--color-orange);
  transform: translate(-50%, -50%) rotate(45deg);
  box-shadow: 0 0 12px rgba(255, 107, 53, 0.45);
}

.footer-mark-core::before,
.footer-mark-core::after {
  content: "";
  position: absolute;
  width: 6px;
  height: 6px;
  transform: rotate(45deg);
}

.footer-mark-core::before {
  top: -8px;
  left: 2px;
  background: var(--color-blue);
  box-shadow: 0 0 6px rgba(0, 212, 255, 0.35);
}

.footer-mark-core::after {
  bottom: -8px;
  left: 2px;
  background: var(--color-positive);
  opacity: 0.75;
}

.footer-brand-name {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 26px;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--color-text);
  margin-bottom: 10px;
  transition: color 0.25s ease;
}

.footer-brand-name:hover { color: var(--color-orange); }

.footer-desc {
  font-size: 14px;
  color: var(--color-muted);
  max-width: 320px;
  line-height: 1.7;
}

.footer-col-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-text);
  margin-bottom: 14px;
}

.footer-col-title::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--color-orange);
  transform: rotate(45deg);
  flex-shrink: 0;
  box-shadow: 0 0 6px rgba(255, 107, 53, 0.3);
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  font-size: 14px;
  color: var(--color-muted);
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-blue);
  padding-left: 4px;
}

.footer-contact-list li {
  display: flex;
  flex-direction: column;
  margin-bottom: 10px;
  font-size: 14px;
}

.footer-contact-label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--color-muted);
  margin-bottom: 2px;
  opacity: 0.75;
}

.footer-contact-value {
  color: var(--color-text);
  line-height: 1.5;
  word-break: break-all;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  padding: 18px 0;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--color-muted);
  gap: 12px;
}

@media (max-width: 960px) {
  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .footer-desc { max-width: 100%; }
}

@media (max-width: 600px) {
  .footer-decoration { padding-top: 20px; gap: 10px; }
  .footer-deco-line { max-width: 80px; }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-brand { grid-column: auto; }

  .footer-bottom-inner {
    flex-direction: column;
    text-align: center;
    gap: 4px;
  }
}

/* ---------- 17. 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 850;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid rgba(0, 212, 255, 0.4);
  background: rgba(10, 15, 30, 0.88);
  color: var(--color-blue);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  background: rgba(0, 212, 255, 0.12);
  box-shadow: 0 0 16px rgba(0, 212, 255, 0.25);
}

.back-to-top-arrow { line-height: 1; }

/* ---------- 18. 显现与动效 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.js [data-reveal][data-revealed] {
  opacity: 1;
  transform: translateY(0);
}

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

  .js [data-reveal],
  .js [data-reveal][data-revealed] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .card,
  .btn,
  .site-nav a,
  .footer-links a,
  .back-to-top,
  .brand-link .brand-name {
    transition: none;
  }
}

/* ---------- 19. 打印 ---------- */
@media print {
  .nav-region,
  .scroll-progress,
  .back-to-top,
  .footer-decoration {
    display: none !important;
  }

  body {
    background: #fff;
    color: #111;
  }

  .card {
    box-shadow: none;
    border: 1px solid #ccc;
    break-inside: avoid;
  }
}