/* ==========================================================================
   优盈指南 /assets/site.css
   共享外壳：重置、变量、中文排版、页头、页脚、按钮、面包屑、章节、图位
   ========================================================================== */

:root {
  --ink-900: #041A2B;
  --ink-700: #0A3350;
  --ink-500: #14547F;
  --mist-100: #E3EFF6;
  --coral-500: #FF6A45;
  --coral-600: #E8552F;
  --coral-200: #FFD8CC;
  --palm-500: #2E9C7C;
  --sand: #F8F4EC;
  --text: #0E1A22;
  --line: #A9C4D4;
  --line-soft: rgba(169, 196, 212, 0.45);
  --white: #FFFFFF;

  --font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", ui-monospace, "Roboto Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --fs-display: clamp(32px, 5vw, 68px);
  --fs-h2: clamp(26px, 3.2vw, 44px);
  --fs-h3: clamp(20px, 2vw, 30px);
  --fs-h4: 22px;
  --fs-body: 17px;
  --fs-small: 15px;
  --fs-mono: 13px;

  --w-max: 1200px;
  --pad-x: clamp(18px, 4vw, 48px);
  --radius: 4px;
  --radius-sm: 2px;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --shadow-soft: 0 18px 40px -28px rgba(4, 26, 43, 0.55);
}

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

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

body {
  margin: 0;
  background: var(--sand);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  font-weight: 500;
  line-height: 1.75;
  letter-spacing: 0.005em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 { margin: 0; font-weight: 800; letter-spacing: -0.02em; line-height: 1.12; color: var(--ink-700); }
h1 { font-size: var(--fs-display); line-height: 1.05; color: var(--ink-900); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); line-height: 1.2; }
h4 { font-size: var(--fs-h4); line-height: 1.3; letter-spacing: -0.01em; }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }

hr { border: 0; }

:focus-visible {
  outline: 2px solid var(--coral-500);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.mono,
code,
kbd {
  font-family: var(--font-mono);
  font-size: 0.88em;
  letter-spacing: 0.04em;
  font-weight: 500;
}

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 12px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--coral-500);
  color: #1B0E08;
  font-weight: 800;
  font-size: 14px;
  border-radius: var(--radius-sm);
  transform: translateY(-160%);
  transition: transform 0.18s var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); outline-offset: 2px; }

/* ==========================================================================
   页头框架
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--ink-900);
  color: #DCE9F1;
  border-bottom: 1px solid rgba(169, 196, 212, 0.3);
}

.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(169, 196, 212, 0.22);
  pointer-events: none;
}
.progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--coral-500), var(--coral-200));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

.header-meta {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 6px var(--pad-x);
  border-bottom: 1px dashed rgba(169, 196, 212, 0.24);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #8FB0C4;
}
.header-meta__item { white-space: nowrap; }
.header-meta__item:nth-child(2) { color: #6E93AC; }

.header-shell {
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 12px var(--pad-x);
  display: grid;
  grid-template-columns: auto auto 1fr;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}
.brand__mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--coral-500);
  border-radius: var(--radius-sm);
  background: linear-gradient(150deg, rgba(255, 106, 69, 0.18), rgba(20, 84, 127, 0.35));
  color: #FFD8CC;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
}
.brand__text { display: flex; flex-direction: column; min-width: 0; }
.brand__name {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #FFFFFF;
  line-height: 1.3;
}
.brand__tag {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: #7FA3B9;
  line-height: 1.4;
  white-space: nowrap;
}
.brand:hover .brand__mark { border-color: var(--coral-200); }

/* 第二栏固定锚点：换设备注册 */
.switch-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 12px 7px 8px;
  border: 1px solid rgba(255, 106, 69, 0.55);
  border-radius: var(--radius-sm);
  background: rgba(255, 106, 69, 0.1);
  color: #FFE2D9;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.switch-chip__idx {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  padding: 2px 5px;
  background: var(--coral-500);
  color: #1B0E08;
  border-radius: 1px;
}
.switch-chip:hover { background: rgba(255, 106, 69, 0.22); border-color: var(--coral-500); }

/* 移动按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 11px;
  background: transparent;
  border: 1px solid rgba(169, 196, 212, 0.45);
  border-radius: var(--radius-sm);
  color: #DCE9F1;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.nav-toggle:hover { border-color: var(--coral-500); background: rgba(255, 106, 69, 0.12); }
.nav-toggle__bars { display: inline-flex; flex-direction: column; gap: 4px; width: 16px; }
.nav-toggle__bars span {
  display: block;
  height: 2px;
  width: 100%;
  background: currentColor;
  transition: transform 0.18s var(--ease);
}
.site-header[data-nav-open="true"] .nav-toggle__bars span:first-child { transform: translateY(3px) rotate(45deg); }
.site-header[data-nav-open="true"] .nav-toggle__bars span:last-child { transform: translateY(-3px) rotate(-45deg); }

/* 导航 */
.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(10px, 1.6vw, 22px);
  min-width: 0;
}
.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.nav-list__item { display: block; }
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 9px 11px;
  border-radius: var(--radius-sm);
  color: #C9DEEA;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  white-space: nowrap;
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.nav-link__idx {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: #6E93AC;
  transition: color 0.18s var(--ease);
}
.nav-link:hover { color: #FFFFFF; background: rgba(227, 239, 246, 0.09); }
.nav-link:hover .nav-link__idx { color: var(--coral-200); }
.nav-link[aria-current="page"] {
  background: var(--coral-500);
  color: #1B0E08;
}
.nav-link[aria-current="page"] .nav-link__idx { color: rgba(27, 14, 8, 0.62); }
.nav-link[aria-current="page"]:hover { background: var(--coral-600); color: #1B0E08; }

.nav-tools { display: flex; align-items: center; gap: 8px; }

/* ==========================================================================
   按钮
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.01em;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.btn--primary { background: var(--coral-500); color: #1B0E08; }
.btn--primary:hover { background: #FF825F; }
.btn--ghost {
  background: transparent;
  color: #E3EFF6;
  border-color: rgba(169, 196, 212, 0.55);
}
.btn--ghost:hover { background: rgba(227, 239, 246, 0.14); border-color: #E3EFF6; }
.btn--line {
  background: transparent;
  color: var(--ink-700);
  border-color: var(--ink-500);
}
.btn--line:hover { background: var(--mist-100); }
.btn--block { display: flex; width: 100%; }

/* ==========================================================================
   版面容器与网格
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding-left: var(--pad-x);
  padding-right: var(--pad-x);
}

.section { padding: clamp(40px, 6vw, 88px) 0; }
.section--sand { background: var(--sand); }
.section--mist { background: var(--mist-100); }
.section--dark { background: var(--ink-900); color: #D7E6EF; }
.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4 { color: #FFFFFF; }
.section--dark .lede { color: #B7D0DF; }

.grid { display: grid; gap: clamp(16px, 2.4vw, 32px); }
.grid--split { grid-template-columns: 7fr 5fr; align-items: start; }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ---------- 章节标记 ---------- */
[data-chapter] { scroll-margin-top: 112px; }

.chapter { margin-bottom: clamp(18px, 2.6vw, 30px); }
.chapter__index {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ink-500);
  opacity: 0.6;
  transition: color 0.18s var(--ease), opacity 0.18s var(--ease);
}
.chapter__title { color: var(--ink-900); }
.chapter__line {
  display: block;
  height: 1px;
  margin-top: 14px;
  background: var(--line);
}
[data-chapter][data-current] .chapter__index { color: var(--coral-500); opacity: 1; }
[data-chapter][data-current] .chapter__line { background: linear-gradient(90deg, var(--coral-500), var(--line)); }
.section--dark .chapter__title { color: #FFFFFF; }
.section--dark .chapter__index { color: #8FB0C4; }
.section--dark [data-chapter][data-current] .chapter__index { color: var(--coral-500); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ink-500);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--coral-500);
}
.section--dark .eyebrow { color: #9FBCCE; }

.lede {
  max-width: 62ch;
  font-size: clamp(17px, 1.5vw, 19px);
  line-height: 1.7;
  color: var(--ink-700);
}

.rule { height: 1px; margin: clamp(24px, 4vw, 44px) 0; background: var(--line); }

/* ---------- 框景 ---------- */
.frame {
  position: relative;
  padding: clamp(16px, 2.4vw, 26px);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.frame::before,
.frame::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border: 2px solid var(--coral-500);
}
.frame::before { top: -2px; left: -2px; border-right: 0; border-bottom: 0; }
.frame::after { bottom: -2px; right: -2px; border-left: 0; border-top: 0; }
.frame--dark {
  background: linear-gradient(155deg, rgba(20, 84, 127, 0.55), rgba(4, 26, 43, 0.85));
  border-color: rgba(169, 196, 212, 0.4);
  color: #D7E6EF;
}
.frame--dark h2,
.frame--dark h3 { color: #FFFFFF; }

/* ---------- 卡片 ---------- */
.card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2vw, 26px);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.card:hover { border-color: var(--ink-500); transform: translateY(-2px); }
.card__title { font-size: var(--fs-h4); font-weight: 800; color: var(--ink-900); line-height: 1.3; }
.card__text { font-size: var(--fs-small); line-height: 1.7; color: var(--ink-700); }
.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-500);
}
.section--dark .card {
  background: rgba(227, 239, 246, 0.06);
  border-color: rgba(169, 196, 212, 0.35);
}
.section--dark .card__title { color: #FFFFFF; }
.section--dark .card__text { color: #B7D0DF; }

/* ---------- 标签 ---------- */
.tag {
  display: inline-block;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background: var(--mist-100);
  color: var(--ink-700);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  line-height: 1.6;
}
.tag--coral { background: var(--coral-200); color: #8A2E14; }
.tag--palm { background: #D7EEE6; color: #146049; }

/* ---------- 横向数据带 ---------- */
.databand {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.databand__item { padding: 14px 16px; background: var(--white); }
.databand__key {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ink-500);
  text-transform: uppercase;
}
.databand__val {
  display: block;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink-900);
  line-height: 1.3;
}
.section--dark .databand { border-color: rgba(169, 196, 212, 0.35); background: rgba(169, 196, 212, 0.25); }
.section--dark .databand__item { background: rgba(4, 26, 43, 0.72); }
.section--dark .databand__key { color: #8FB0C4; }
.section--dark .databand__val { color: #FFFFFF; }

/* ---------- 图位基础规则 ---------- */
.figure { margin: 0; display: flex; flex-direction: column; gap: 10px; }
.figure__media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
  background: linear-gradient(150deg, var(--ink-500), var(--ink-900) 72%);
}
.figure__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, rgba(169, 196, 212, 0.22) 0 1px, transparent 1px 56px),
    repeating-linear-gradient(0deg, rgba(169, 196, 212, 0.18) 0 1px, transparent 1px 56px);
  pointer-events: none;
}
.figure__media::before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 38%;
  height: 30%;
  background: linear-gradient(135deg, transparent 48%, var(--coral-500) 48%, var(--coral-500) 52%, transparent 52%);
  opacity: 0.55;
  pointer-events: none;
  z-index: 2;
}
.figure__img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure__media--wide { aspect-ratio: 21 / 9; }
.figure__media--tall { aspect-ratio: 3 / 4; }
.figure__media--square { aspect-ratio: 1 / 1; }
.figure__cap {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-500);
}
.section--dark .figure__cap { color: #8FB0C4; }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-500);
}
.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb__sep { color: var(--line); }
.breadcrumb a:hover { color: var(--coral-500); }
.section--dark .breadcrumb { color: #9FBCCE; }
.section--dark .breadcrumb__sep { color: rgba(169, 196, 212, 0.5); }

/* ---------- 入场动效 ---------- */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease);
}
.has-js [data-reveal].is-revealed { opacity: 1; transform: none; }

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  position: relative;
  margin-top: clamp(40px, 6vw, 80px);
  background: var(--ink-900);
  color: #C3D8E4;
  border-top: 2px solid var(--coral-500);
  background-image:
    linear-gradient(180deg, rgba(20, 84, 127, 0.35), rgba(4, 26, 43, 0) 45%),
    repeating-linear-gradient(90deg, rgba(169, 196, 212, 0.08) 0 1px, transparent 1px 88px);
}
.footer-shell {
  max-width: var(--w-max);
  margin: 0 auto;
  padding: clamp(34px, 5vw, 62px) var(--pad-x) 24px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.05fr 2fr;
  gap: clamp(24px, 4vw, 64px);
  padding-bottom: clamp(24px, 3vw, 40px);
  border-bottom: 1px dashed rgba(169, 196, 212, 0.28);
}

.footer-brand { display: flex; flex-direction: column; gap: 12px; }
.footer-brand__name {
  margin: 0;
  font-size: clamp(26px, 2.6vw, 34px);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.15;
  color: #FFFFFF;
}
.footer-brand__desc {
  margin: 0;
  max-width: 34ch;
  font-size: var(--fs-small);
  line-height: 1.7;
  color: #9FBCCE;
}
.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: #C3D8E4;
}
.footer-status__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--palm-500);
  box-shadow: 0 0 0 3px rgba(46, 156, 124, 0.22);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 2.4vw, 32px);
}
.footer-col { display: flex; flex-direction: column; gap: 10px; }
.footer-col__title {
  margin: 0;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(169, 196, 212, 0.3);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--coral-200);
}
.footer-list { display: flex; flex-direction: column; gap: 6px; }
.footer-list__item { display: block; }
.footer-link {
  position: relative;
  display: inline-block;
  padding: 2px 0;
  font-size: var(--fs-small);
  font-weight: 500;
  color: #B7D0DF;
  transition: color 0.18s var(--ease);
}
.footer-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--coral-500);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.18s var(--ease);
}
.footer-link:hover { color: #FFFFFF; }
.footer-link:hover::after { transform: scaleX(1); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 10px clamp(16px, 2.4vw, 32px);
  padding: clamp(20px, 3vw, 28px) 0;
}
.footer-contact__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin: 0;
  font-size: var(--fs-small);
}
.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: #8FB0C4;
}
.footer-contact__value { color: #E3EFF6; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-top: 18px;
  border-top: 1px solid rgba(169, 196, 212, 0.22);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: #8FAEC2;
}
.footer-legal__copy,
.footer-legal__icp { margin: 0; }
.footer-legal__icp { color: #9FBCCE; }
.footer-legal__links { display: flex; flex-wrap: wrap; gap: 14px; }
.footer-legal__links .footer-link { font-size: 12px; font-family: var(--font-mono); }

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1100px) {
  .brand__tag { display: none; }
  .nav-link { padding: 9px 8px; font-size: 13.5px; }
  .nav-tools .btn { padding: 9px 12px; font-size: 13px; }
}

@media (max-width: 960px) {
  .grid--split,
  .grid--4 { grid-template-columns: 1fr; }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-top { grid-template-columns: 1fr; }
}

@media (max-width: 900px) {
  .header-shell {
    grid-template-columns: 1fr auto auto;
    gap: 10px;
    padding: 10px var(--pad-x);
  }
  .header-meta { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    grid-column: 1 / -1;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 12px;
    margin: 2px calc(var(--pad-x) * -1) -10px;
    padding: 12px var(--pad-x) 18px;
    background: var(--ink-700);
    border-top: 1px solid rgba(169, 196, 212, 0.35);
    box-shadow: inset 3px 0 0 var(--coral-500);
  }
  .site-nav[data-open] { display: flex; }

  .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav-link {
    justify-content: flex-start;
    padding: 11px 12px;
    font-size: 15px;
    border-radius: var(--radius-sm);
  }
  .nav-link__idx { width: 22px; }
  .nav-tools { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
  .nav-tools .btn { width: 100%; padding: 11px 12px; }

  .switch-chip { padding: 6px 10px 6px 7px; font-size: 12.5px; }
  .switch-chip__idx { font-size: 9px; padding: 2px 4px; }

  .footer-cols { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
}

@media (max-width: 720px) {
  :root { --fs-body: 16px; }
  .brand__mark { width: 32px; height: 32px; font-size: 14px; }
  .brand__name { font-size: 16px; }
  .footer-cols { grid-template-columns: 1fr 1fr; }
  .footer-legal { flex-direction: column; align-items: flex-start; gap: 8px; }
}

@media (max-width: 600px) {
  .grid--3 { grid-template-columns: 1fr; }
  .nav-toggle__label { display: none; }
  .switch-chip__label { font-size: 12px; }
  .footer-cols { grid-template-columns: 1fr; }
  .figure__media { aspect-ratio: 4 / 3; }
}

@media (max-width: 380px) {
  .switch-chip__idx { display: none; }
}

/* ---------- 动效偏好 ---------- */
@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;
  }
  .has-js [data-reveal] { opacity: 1; transform: none; }
  .card:hover { transform: none; }
  .progress__bar { transition: none; }
}