:root {
  --color-surface: #fcfcfc;
  --color-surface-alt: #f3f3f3;
  --color-surface-deep: #e6e7e7;
  --color-ink: #414a4e;
  --color-ink-soft: #657176;
  --color-ink-muted: #768389;
  --color-line: #dadcdd;
  --color-primary: #367d9b;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e0eaee;
  --color-accent: #1a847d;
  --color-accent-ink: #ffffff;
  --color-highlight: #d3e6e5;
  --color-focus: #107f77;
  --color-contrast-surface: #1b262b;
  --color-contrast-ink: #e4e6e7;
  --color-contrast-line: #475054;
  --color-contrast-accent: #2ad5c9;
  --overlay-scrim: linear-gradient(180deg, rgba(27, 38, 43, 0.35) 0%, rgba(27, 38, 43, 0.72) 55%, rgba(27, 38, 43, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 12.2px;
  --text-sm: 14.6px;
  --text-base: 16px;
  --text-lg: 19.2px;
  --text-xl: 23.0px;
  --text-2xl: 27.6px;
  --text-3xl: 33.2px;
  --text-4xl: 39.8px;
  --text-display: clamp(49px, 10.2vw, 130px);
  --text-figure: clamp(41px, 7.3vw, 94px);
  --weight-heading: 682;
  --weight-body: 400;
  --leading-body: 1.72;
  --leading-heading: 1.18;
  --tracking-heading: -0.005em;
  --radius-sm: 14px;
  --radius-md: 16px;
  --radius-lg: 17px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 6px 18px rgba(65, 74, 78, 0.08);
  --shadow-2: 0 18px 44px rgba(65, 74, 78, 0.14);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1200px;
  --measure: 72ch;
  --gutter: 16px;
  --section-y: 89px;
  --section-y-lg: 125px;
}

/* ============================================================
   基础重置
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  background-color: var(--color-surface);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: transparent;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* 背景彩色层：所有玻璃面板都叠在它之上 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(46% 34% at 4% 0%, color-mix(in srgb, var(--color-primary) 26%, transparent), transparent 68%),
    radial-gradient(40% 32% at 98% 6%, color-mix(in srgb, var(--color-accent) 22%, transparent), transparent 70%),
    radial-gradient(64% 46% at 22% 62%, color-mix(in srgb, var(--color-primary-soft) 88%, transparent), transparent 76%),
    radial-gradient(78% 50% at 52% 106%, color-mix(in srgb, var(--color-highlight) 82%, transparent), transparent 74%);
}

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

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

button { font: inherit; color: inherit; }

a { color: var(--color-primary); text-underline-offset: 3px; }

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: 6px;
}
.site-footer :focus-visible { outline-color: var(--color-contrast-accent); }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ============================================================
   中文排版
   ============================================================ */
h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  text-wrap: balance;
}
h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }

p { margin: 0 0 var(--space-3); text-wrap: pretty; }
p:last-child { margin-bottom: 0; }

strong, b { font-weight: var(--weight-heading); color: var(--color-ink); }

code, kbd, samp, .mono { font-family: var(--font-mono); }

::selection {
  background: color-mix(in srgb, var(--color-accent) 30%, transparent);
  color: var(--color-ink);
}

/* ============================================================
   布局基础
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-2);
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--flush-top { padding-top: 0; }

.section__head {
  display: grid;
  gap: var(--space-2);
  max-width: var(--measure);
  margin-bottom: var(--space-6);
}

.eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0;
}

.lede {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-ink-soft);
  max-width: var(--measure);
  margin: 0;
}

.rule {
  height: 0;
  border: 0;
  border-top: var(--border-thin) solid var(--color-line);
  margin: 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.grid--2 > * { grid-column: span 6; }
.grid--3 > * { grid-column: span 4; }
.grid--4 > * { grid-column: span 3; }

/* ============================================================
   玻璃面板与深色看板
   ============================================================ */
.glass-panel {
  position: relative;
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid color-mix(in srgb, #ffffff 76%, transparent);
  background: color-mix(in srgb, #ffffff 58%, transparent);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
  box-shadow:
    var(--shadow-1),
    inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 13%, transparent),
    inset 0 1px 0 color-mix(in srgb, #ffffff 90%, transparent);
  padding: var(--space-4);
}

.glass-panel--tight { padding: var(--space-3); }
.glass-panel--roomy { padding: var(--space-6); }

.glass-panel--deep {
  border-color: color-mix(in srgb, var(--color-contrast-ink) 16%, transparent);
  background: color-mix(in srgb, #ffffff 7%, transparent);
  color: var(--color-contrast-ink);
  box-shadow:
    var(--shadow-1),
    inset 0 0 0 1px color-mix(in srgb, var(--color-contrast-accent) 14%, transparent);
}
.glass-panel--deep h2,
.glass-panel--deep h3,
.glass-panel--deep h4 { color: var(--color-contrast-ink); }

.data-board {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding: var(--space-6);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 12%, transparent);
}
.data-board::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(58% 90% at 88% 0%, color-mix(in srgb, var(--color-contrast-accent) 16%, transparent), transparent 70%);
}
.data-board > * { position: relative; z-index: 1; }

.metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.metric__value {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.1vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-accent);
}
.metric__label {
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.metric--hero .metric__value { font-size: var(--text-figure); }

.data-board .metric__value { color: var(--color-contrast-accent); }
.data-board .metric__label { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

/* ============================================================
   按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid transparent;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}
.btn--primary { background: var(--color-primary); color: var(--color-primary-ink); }
.btn--primary:hover { background: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface)); }
.btn--accent { background: var(--color-accent); color: var(--color-accent-ink); }
.btn--accent:hover { background: color-mix(in srgb, var(--color-accent) 84%, var(--color-contrast-surface)); }
.btn--glass {
  background: color-mix(in srgb, #ffffff 62%, transparent);
  border-color: color-mix(in srgb, var(--color-primary) 32%, transparent);
  color: var(--color-primary);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}
.btn--glass:hover { background: color-mix(in srgb, #ffffff 86%, transparent); }
.btn--ghost { background: transparent; border-color: var(--color-line); color: var(--color-ink); }
.btn--ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn:hover { transform: translateY(-1px); }

/* ============================================================
   面包屑
   ============================================================ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-3);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
}
.breadcrumb li { display: inline-flex; align-items: center; gap: var(--space-1); }
.breadcrumb li + li::before {
  content: "";
  width: 6px;
  height: 6px;
  border-right: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
  transform: rotate(-45deg);
  opacity: 0.9;
}
.breadcrumb a {
  color: var(--color-ink-soft);
  text-decoration: none;
}
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb [aria-current="page"] { color: var(--color-ink); font-weight: 600; }

/* ============================================================
   图片容器与展签
   ============================================================ */
.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 20%, var(--color-line));
  background: var(--color-surface-deep);
  box-shadow: var(--shadow-1);
  isolation: isolate;
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media-frame[data-ratio="16-9"] { aspect-ratio: 16 / 9; }
.media-frame[data-ratio="4-3"] { aspect-ratio: 4 / 3; }
.media-frame[data-ratio="1-1"] { aspect-ratio: 1 / 1; }
.media-frame[data-ratio="3-4"] { aspect-ratio: 3 / 4; }
.media-frame[data-scrim]::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
  z-index: 1;
}
.media-frame--flat { box-shadow: none; }

.media-tag {
  position: absolute;
  left: var(--space-2);
  bottom: var(--space-2);
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  max-width: calc(100% - var(--space-4));
  padding: 6px 12px 6px 10px;
  border-radius: var(--radius-sm);
  border: var(--border-thin) solid color-mix(in srgb, #ffffff 26%, transparent);
  border-left: 3px solid var(--color-contrast-accent);
  background: color-mix(in srgb, var(--color-contrast-surface) 74%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--color-contrast-ink);
  font-size: var(--text-xs);
  line-height: 1.45;
  letter-spacing: 0.04em;
}

/* ============================================================
   章节跟随目录
   ============================================================ */
.section-nav {
  position: sticky;
  top: 96px;
  align-self: start;
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid color-mix(in srgb, #ffffff 76%, transparent);
  background: color-mix(in srgb, #ffffff 60%, transparent);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
  box-shadow:
    var(--shadow-1),
    inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 13%, transparent),
    inset 0 1px 0 color-mix(in srgb, #ffffff 90%, transparent);
}
.section-nav__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.section-nav__list { display: grid; gap: 2px; }
.section-nav__link {
  display: block;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.section-nav__link:hover {
  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
  color: var(--color-primary);
}
.section-nav__link.is-active {
  background: var(--color-highlight);
  border-left-color: var(--color-accent);
  color: var(--color-accent);
  font-weight: 600;
}

/* ============================================================
   跳转链接
   ============================================================ */
.skip-link {
  position: fixed;
  top: -120px;
  left: var(--space-2);
  z-index: 200;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow-2);
  transition: top 0.2s ease;
}
.skip-link:focus { top: var(--space-2); }

/* ============================================================
   悬浮胶囊头部
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding: var(--space-2) var(--space-2) 0;
}

.header-shell {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: 8px 8px 8px 10px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid color-mix(in srgb, #ffffff 74%, transparent);
  background: color-mix(in srgb, #ffffff 66%, transparent);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  box-shadow:
    var(--shadow-1),
    inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 14%, transparent),
    inset 0 1px 0 color-mix(in srgb, #ffffff 92%, transparent);
  transition: box-shadow 0.25s ease;
}
.site-header[data-scrolled] .header-shell {
  box-shadow:
    var(--shadow-2),
    inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 22%, transparent),
    inset 0 1px 0 color-mix(in srgb, #ffffff 92%, transparent);
}

.brand-island {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  padding: 6px 18px 6px 6px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 26%, transparent);
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
  text-decoration: none;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}
.brand-island:hover {
  background: color-mix(in srgb, var(--color-primary) 20%, transparent);
  border-color: color-mix(in srgb, var(--color-primary) 42%, transparent);
}

.brand-mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0;
  box-shadow: inset 0 0 0 1px color-mix(in srgb, #ffffff 34%, transparent);
}

.brand-text { display: flex; flex-direction: column; line-height: 1.15; min-width: 0; }
.brand-name {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: -0.01em;
  color: var(--color-ink);
  white-space: nowrap;
}
.brand-line {
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.nav-capsule { flex: 1 1 auto; min-width: 0; }
.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.nav-list a {
  display: inline-block;
  padding: 9px 14px;
  border-radius: var(--radius-pill);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.18s ease, color 0.18s ease;
}
.nav-list a:hover {
  background: color-mix(in srgb, var(--color-primary) 14%, transparent);
  color: var(--color-primary);
}
.nav-list a[aria-current="page"] {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: inset 0 1px 0 color-mix(in srgb, #ffffff 26%, transparent);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 0 0 auto;
  margin-left: auto;
}

.header-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-accent) 34%, transparent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  color: var(--color-accent);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease;
}
.header-chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 20%, transparent);
}
.header-chip:hover {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}
.header-chip:hover::before { background: var(--color-accent-ink); box-shadow: none; }

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  padding: 0;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 34%, transparent);
  background: color-mix(in srgb, #ffffff 72%, transparent);
  color: var(--color-primary);
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}
.nav-toggle:hover { background: color-mix(in srgb, var(--color-primary) 14%, transparent); }

.nav-toggle-bars { display: grid; gap: 4px; width: 18px; }
.nav-toggle-bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s ease, opacity 0.22s ease;
}
.site-header[data-open] .nav-toggle-bars span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle-bars span:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle-bars span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.header-progress {
  position: absolute;
  left: 28px;
  right: 28px;
  bottom: 4px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transform-origin: 0 50%;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.site-header[data-scrolled] .header-progress { opacity: 1; }

/* ============================================================
   阶梯式页脚
   ============================================================ */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: var(--section-y-lg);
  padding: var(--space-8) var(--space-2) var(--space-4);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(52% 70% at 8% 0%, color-mix(in srgb, var(--color-contrast-accent) 18%, transparent), transparent 66%),
    radial-gradient(46% 64% at 94% 6%, color-mix(in srgb, var(--color-primary) 52%, transparent), transparent 70%);
}
.site-footer a { color: var(--color-contrast-ink); text-decoration: none; }
.site-footer a:hover { color: var(--color-contrast-accent); }

.footer-shell {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
}

.footer-step--upper {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr) minmax(0, 1fr) auto;
  gap: var(--space-6) var(--space-4);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 16%, transparent);
  background: color-mix(in srgb, #ffffff 7%, transparent);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
  box-shadow: inset 0 1px 0 color-mix(in srgb, #ffffff 12%, transparent);
}

.footer-brand { display: grid; gap: var(--space-2); align-content: start; }
.footer-brand-name {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}
.footer-brand-desc {
  margin: 0;
  max-width: 34ch;
  font-size: var(--text-sm);
  line-height: 1.75;
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}
.footer-brand-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-accent);
}

.footer-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}
.footer-links { display: grid; gap: 2px; }
.footer-links a {
  display: inline-block;
  padding: 5px 0;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 86%, transparent);
  border-bottom: var(--border-thin) solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.footer-links a:hover { border-bottom-color: var(--color-contrast-accent); }

.footer-action { display: flex; align-items: flex-start; justify-content: flex-end; }

.to-top {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 11px 20px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 28%, transparent);
  background: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}
.to-top:hover {
  background: color-mix(in srgb, var(--color-contrast-accent) 20%, transparent);
  border-color: color-mix(in srgb, var(--color-contrast-accent) 52%, transparent);
  color: var(--color-contrast-accent);
}

.footer-step--lower {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-4);
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.footer-legal { margin: 0; font-family: var(--font-mono); letter-spacing: 0.02em; }
.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.footer-legal-links a {
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 26%, transparent);
  padding-bottom: 1px;
}
.footer-legal-links a:hover { border-bottom-color: var(--color-contrast-accent); }

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-style: normal;
  margin-left: auto;
  font-family: var(--font-mono);
  letter-spacing: 0.01em;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1080px) {
  .footer-step--upper {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr) minmax(0, 1fr);
  }
  .footer-action { grid-column: 1 / -1; justify-content: flex-start; }
  .footer-contact { margin-left: 0; width: 100%; }
}

@media (max-width: 1020px) {
  .site-header { padding: 8px 10px 0; }

  .header-shell {
    flex-wrap: wrap;
    border-radius: var(--radius-lg);
    padding: 8px;
  }

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

  .nav-capsule {
    display: none;
    flex: 1 0 100%;
    margin-top: 8px;
    padding-top: 8px;
    border-top: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 18%, transparent);
  }
  .site-header[data-open] .nav-capsule { display: block; }

  .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav-list a { display: block; padding: 12px 14px; border-radius: var(--radius-sm); }

  .header-progress { left: 18px; right: 18px; bottom: 2px; }

  .grid--2 > *, .grid--3 > *, .grid--4 > * { grid-column: span 6; }

  .section-nav { position: static; top: auto; }
}

@media (max-width: 720px) {
  :root { --section-y: 64px; --section-y-lg: 88px; }

  .brand-line { display: none; }
  .header-chip { display: none; }
  .glass-panel--roomy, .data-board { padding: var(--space-4); }

  .grid--2 > *, .grid--3 > *, .grid--4 > * { grid-column: 1 / -1; }

  .footer-step--upper {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-4);
    padding: var(--space-4);
  }
  .footer-step--lower { margin-top: var(--space-3); }
  .site-footer { padding-top: var(--space-6); }
}

@media (max-width: 440px) {
  .brand-mark { width: 32px; height: 32px; }
  .brand-name { font-size: var(--text-sm); }
  .brand-island { padding-right: 12px; }
}

/* ============================================================
   减弱动效
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .btn:hover { transform: none; }
}