/* ==========================================================================
   必一体育青训资料台 · 共享样式 /assets/site.css
   数据叙事型外壳：悬浮胶囊导航 + 深墨蓝页脚 + 草场绿节点系统
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}
body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, figcaption,
blockquote, dl, dd, address, table, caption { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
img, svg, video { display: block; max-width: 100%; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  --bx-field: #1F7A4C;
  --bx-field-deep: #17613C;
  --bx-ink: #0E1B2A;
  --bx-lime: #C8FF3D;
  --bx-orange: #F26B2F;
  --bx-orange-deep: #B33F13;
  --bx-mist: #F4F7F2;
  --bx-slate: #6B7A8C;
  --bx-sprout: #8FD694;
  --bx-teal: #0B4F4A;
  --bx-half: #C7CFD6;
  --bx-white: #FFFFFF;

  --bx-line: rgba(14, 27, 42, 0.12);
  --bx-line-soft: rgba(14, 27, 42, 0.07);
  --bx-line-mid: rgba(107, 122, 140, 0.42);
  --bx-line-dark: rgba(199, 207, 214, 0.18);
  --bx-on-dark: rgba(244, 247, 242, 0.74);
  --bx-on-dark-strong: rgba(244, 247, 242, 0.94);

  --bx-shadow-s: 0 1px 2px rgba(14, 27, 42, 0.06);
  --bx-shadow-m: 0 18px 36px -30px rgba(14, 27, 42, 0.55);
  --bx-shadow-l: 0 34px 64px -42px rgba(14, 27, 42, 0.68);

  --bx-radius-s: 10px;
  --bx-radius-m: 16px;
  --bx-radius-l: 24px;
  --bx-pill: 999px;

  --bx-gutter: clamp(18px, 4.4vw, 44px);
  --bx-max: 1280px;
  --bx-ease: cubic-bezier(0.22, 0.68, 0.28, 1);

  --bx-font-head: "Roboto Condensed", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --bx-font-serif: "Noto Serif SC", "Songti SC", "Source Han Serif SC", SimSun, Georgia, serif;
  --bx-font-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --bx-font-num: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

/* ---------- 3. 基础元素与中文排版 ---------- */
body {
  font-family: var(--bx-font-body);
  font-size: 17px;
  line-height: 1.75;
  color: var(--bx-ink);
  background-color: var(--bx-mist);
  background-image: repeating-linear-gradient(
    112deg,
    rgba(107, 122, 140, 0.085) 0,
    rgba(107, 122, 140, 0.085) 1px,
    transparent 1px,
    transparent 78px
  );
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--bx-font-head);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: -0.012em;
  color: var(--bx-ink);
}
h1 {
  font-size: clamp(40px, 7vw, 92px);
  line-height: 1.02;
  letter-spacing: -0.028em;
}
h2 { font-size: clamp(28px, 3.7vw, 50px); }
h3 { font-size: clamp(20px, 2.1vw, 27px); }
h4 { font-size: 19px; line-height: 1.3; }

p { text-wrap: pretty; }
strong, b { font-weight: 700; }

.num, code, kbd, samp, time {
  font-family: var(--bx-font-num);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

::selection { background: var(--bx-lime); color: var(--bx-ink); }

/* ---------- 4. 布局骨架 ---------- */
.shell {
  width: 100%;
  max-width: var(--bx-max);
  margin-inline: auto;
  padding-inline: var(--bx-gutter);
}

#main-content { display: block; scroll-margin-top: 120px; }

.section { padding-block: clamp(52px, 7vw, 92px); }

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 14px 28px;
  margin-bottom: clamp(24px, 3vw, 38px);
}

.section__title {
  font-family: var(--bx-font-serif);
  font-weight: 700;
  font-size: clamp(26px, 3.2vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--bx-ink);
}

.section__lead {
  flex: 1 1 320px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--bx-slate);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--bx-font-num);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--bx-field);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--bx-lime);
  border-radius: 2px;
}

.chapter-num {
  display: inline-block;
  font-family: var(--bx-font-num);
  font-weight: 700;
  font-size: clamp(42px, 6vw, 76px);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: rgba(31, 122, 76, 0.2);
  -webkit-text-stroke: 1px rgba(31, 122, 76, 0.5);
  padding: 0;
}

/* 12 列斜向网格的简化实现 */
.grid { display: grid; gap: clamp(18px, 2.2vw, 28px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* ---------- 5. 跳转链接与焦点 ---------- */
.skip-link {
  position: fixed;
  top: -90px;
  left: 16px;
  z-index: 200;
  padding: 12px 22px;
  border-radius: var(--bx-pill);
  background: var(--bx-lime);
  color: var(--bx-ink);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  box-shadow: var(--bx-shadow-m);
  transition: top 0.24s var(--bx-ease);
}
.skip-link:focus { top: 16px; }

:focus-visible {
  outline: 2px solid var(--bx-field);
  outline-offset: 3px;
  border-radius: 4px;
}
.nav-capsule :focus-visible,
.site-footer :focus-visible {
  outline-color: var(--bx-lime);
}

/* ---------- 6. 头部：悬浮胶囊导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding-top: 14px;
  padding-bottom: 8px;
  transition: padding-top 0.28s var(--bx-ease);
}
.site-header[data-scrolled] { padding-top: 8px; }

.header-shell { display: block; }

.nav-capsule {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 10px 10px 18px;
  border-radius: var(--bx-pill);
  background: rgba(14, 27, 42, 0.94);
  border: 1px solid rgba(199, 207, 214, 0.16);
  box-shadow:
    0 22px 46px -34px rgba(14, 27, 42, 0.95),
    inset 0 1px 0 rgba(244, 247, 242, 0.06);
  transition:
    background 0.28s var(--bx-ease),
    border-color 0.28s var(--bx-ease),
    box-shadow 0.28s var(--bx-ease),
    border-radius 0.28s var(--bx-ease);
}
.site-header[data-scrolled] .nav-capsule {
  background: rgba(14, 27, 42, 0.99);
  border-color: rgba(200, 255, 61, 0.3);
  box-shadow: 0 26px 52px -34px rgba(14, 27, 42, 0.98);
}

/* 品牌区 */
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  flex: 0 0 auto;
  min-width: 0;
}

.brand-mark {
  width: 36px;
  height: 36px;
  flex: 0 0 36px;
  border-radius: 12px;
  background: linear-gradient(148deg, var(--bx-field) 0%, var(--bx-teal) 100%);
  border: 1px solid rgba(200, 255, 61, 0.34);
  display: grid;
  place-items: center;
}

.brand-mark__ladder {
  width: 16px;
  height: 15px;
  background-image:
    linear-gradient(var(--bx-lime) 0 0),
    linear-gradient(var(--bx-lime) 0 0),
    linear-gradient(var(--bx-lime) 0 0);
  background-repeat: no-repeat;
  background-size: 7px 3px, 11px 3px, 16px 3px;
  background-position: 0 100%, 0 50%, 0 0;
  border-radius: 1px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  min-width: 0;
}
.brand-text__name {
  font-family: var(--bx-font-head);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--bx-on-dark-strong);
  white-space: nowrap;
}
.brand-text__sub {
  font-family: var(--bx-font-num);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.24em;
  color: var(--bx-sprout);
  white-space: nowrap;
}

/* 导航 */
.site-nav { margin-left: auto; min-width: 0; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 3px;
}

.nav-list a {
  position: relative;
  display: block;
  padding: 9px 13px;
  border-radius: var(--bx-pill);
  font-size: 14.5px;
  font-weight: 500;
  letter-spacing: 0.015em;
  color: var(--bx-on-dark);
  white-space: nowrap;
  transition: color 0.2s var(--bx-ease), background-color 0.2s var(--bx-ease);
}
.nav-list a:hover {
  color: var(--bx-lime);
  background: rgba(200, 255, 61, 0.1);
}
.nav-list a[aria-current="page"] {
  color: var(--bx-ink);
  background: var(--bx-lime);
  font-weight: 700;
}

/* 号召按钮 */
.nav-cta {
  flex: 0 0 auto;
  padding: 10px 19px;
  border-radius: var(--bx-pill);
  background: var(--bx-field);
  color: var(--bx-white);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.03em;
  white-space: nowrap;
  border: 1px solid rgba(143, 214, 148, 0.42);
  transition: background-color 0.2s var(--bx-ease), transform 0.2s var(--bx-ease);
}
.nav-cta:hover {
  background: var(--bx-field-deep);
  transform: translateY(-1px);
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  flex: 0 0 auto;
  padding: 9px 14px;
  border-radius: var(--bx-pill);
  border: 1px solid rgba(199, 207, 214, 0.3);
  color: var(--bx-on-dark-strong);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  transition: border-color 0.2s var(--bx-ease), color 0.2s var(--bx-ease);
}
.nav-toggle:hover { border-color: rgba(200, 255, 61, 0.6); color: var(--bx-lime); }

.nav-toggle__bars {
  display: grid;
  gap: 5px;
  width: 16px;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.24s var(--bx-ease), opacity 0.24s var(--bx-ease);
}
.site-header[data-open] .nav-toggle__bars::before { transform: translateY(3.5px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { transform: translateY(-3.5px) rotate(-45deg); }
.nav-toggle__label { line-height: 1; }

/* ---------- 7. 滚动进度条 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 120;
  background: rgba(14, 27, 42, 0.1);
  pointer-events: none;
}
.scroll-progress span {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--bx-field) 0%, var(--bx-lime) 78%, var(--bx-orange) 100%);
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 9vw, 118px);
  background: var(--bx-ink);
  color: var(--bx-on-dark);
  border-top: 1px solid rgba(200, 255, 61, 0.2);
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(
      112deg,
      rgba(244, 247, 242, 0.05) 0,
      rgba(244, 247, 242, 0.05) 1px,
      transparent 1px,
      transparent 92px
    ),
    radial-gradient(720px 320px at 84% -12%, rgba(31, 122, 76, 0.5), transparent 72%),
    radial-gradient(560px 260px at 6% 108%, rgba(11, 79, 74, 0.55), transparent 70%);
}

.footer-shell {
  position: relative;
  z-index: 1;
  padding-top: clamp(48px, 6vw, 78px);
  padding-bottom: 30px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 2fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.footer-brand__name {
  display: block;
  font-family: var(--bx-font-head);
  font-size: clamp(24px, 2.6vw, 30px);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--bx-on-dark-strong);
  line-height: 1.2;
}
.footer-brand__sub {
  display: block;
  margin-top: 8px;
  font-family: var(--bx-font-num);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.26em;
  color: var(--bx-lime);
}
.footer-brand__line {
  margin-top: 18px;
  max-width: 36ch;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(244, 247, 242, 0.6);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 2.6vw, 34px);
}

.footer-col__title {
  font-family: var(--bx-font-num);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--bx-sprout);
  margin-bottom: 15px;
}

.footer-list { display: grid; gap: 10px; }

.footer-list a {
  display: inline-block;
  font-size: 15px;
  line-height: 1.6;
  color: rgba(244, 247, 242, 0.78);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--bx-ease), border-color 0.2s var(--bx-ease);
}
.footer-list a:hover {
  color: var(--bx-lime);
  border-bottom-color: rgba(200, 255, 61, 0.5);
}

.footer-list__row {
  display: grid;
  gap: 3px;
}
.footer-list__key {
  font-family: var(--bx-font-num);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(107, 122, 140, 0.95);
}
.footer-list__val {
  font-family: var(--bx-font-num);
  font-size: 13.5px;
  line-height: 1.5;
  color: rgba(244, 247, 242, 0.85);
  word-break: break-word;
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 26px;
  margin-top: clamp(34px, 4.4vw, 56px);
  padding-top: 22px;
  border-top: 1px solid var(--bx-line-dark);
  font-size: 13px;
  color: rgba(244, 247, 242, 0.56);
}
.footer-base__meta {
  font-family: var(--bx-font-num);
  font-size: 12.5px;
  letter-spacing: 0.02em;
}

/* ---------- 9. 通用组件 ---------- */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 25px;
  border-radius: var(--bx-pill);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
  border: 1px solid transparent;
  transition:
    background-color 0.2s var(--bx-ease),
    color 0.2s var(--bx-ease),
    border-color 0.2s var(--bx-ease),
    transform 0.2s var(--bx-ease);
}
.btn:hover { transform: translateY(-1px); }
.btn--primary { background: var(--bx-field); color: var(--bx-white); border-color: rgba(143, 214, 148, 0.4); }
.btn--primary:hover { background: var(--bx-field-deep); }
.btn--lime { background: var(--bx-lime); color: var(--bx-ink); }
.btn--lime:hover { background: #d7ff70; }
.btn--ghost { background: transparent; color: var(--bx-ink); border-color: var(--bx-line-mid); }
.btn--ghost:hover { border-color: var(--bx-field); color: var(--bx-field); }
.btn--outline-light { background: transparent; color: var(--bx-on-dark-strong); border-color: rgba(244, 247, 242, 0.32); }
.btn--outline-light:hover { border-color: var(--bx-lime); color: var(--bx-lime); }

/* 面包屑 */
.breadcrumb {
  font-family: var(--bx-font-num);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--bx-slate);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb li:not(:last-child)::after {
  content: "/";
  color: var(--bx-half);
}
.breadcrumb a { color: var(--bx-slate); transition: color 0.2s var(--bx-ease); }
.breadcrumb a:hover { color: var(--bx-field); }
.breadcrumb [aria-current="page"] { color: var(--bx-ink); font-weight: 600; }

/* 长文容器 */
.prose {
  max-width: 74ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--bx-ink);
}
.prose > * + * { margin-top: 1.12em; }
.prose h2 {
  font-family: var(--bx-font-serif);
  font-size: clamp(24px, 2.6vw, 32px);
  line-height: 1.3;
  margin-top: 2em;
}
.prose h3 {
  font-size: clamp(19px, 2vw, 23px);
  margin-top: 1.6em;
}
.prose ul, .prose ol { display: grid; gap: 0.5em; }
.prose ul li, .prose ol li {
  position: relative;
  padding-left: 22px;
}
.prose ul li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.78em;
  width: 9px;
  height: 2px;
  border-radius: 2px;
  background: var(--bx-field);
}
.prose ol { counter-reset: bx-ol; }
.prose ol li { counter-increment: bx-ol; }
.prose ol li::before {
  content: counter(bx-ol, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--bx-font-num);
  font-size: 13px;
  font-weight: 700;
  color: var(--bx-field);
}
.prose a {
  color: var(--bx-field);
  border-bottom: 1px solid rgba(31, 122, 76, 0.38);
  transition: border-color 0.2s var(--bx-ease);
}
.prose a:hover { border-bottom-color: var(--bx-field); }
.prose blockquote {
  padding: 18px 22px;
  border-left: 3px solid var(--bx-lime);
  background: rgba(200, 255, 61, 0.14);
  border-radius: 0 var(--bx-radius-s) var(--bx-radius-s) 0;
  color: var(--bx-ink);
}
.prose strong { color: var(--bx-ink); }

/* 数据卡片 */
.data-card {
  padding: clamp(18px, 2vw, 24px) clamp(18px, 2vw, 24px);
  background: var(--bx-white);
  border: 1px solid var(--bx-line-mid);
  border-radius: var(--bx-radius-m);
  box-shadow: var(--bx-shadow-m);
}
.data-card__label {
  font-family: var(--bx-font-num);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bx-slate);
}
.data-card__value {
  margin-top: 10px;
  font-family: var(--bx-font-num);
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--bx-ink);
}
.data-card__unit {
  margin-left: 5px;
  font-size: 0.46em;
  font-weight: 600;
  color: var(--bx-field);
}
.data-card__note {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--bx-slate);
}

/* 图片容器（页面阶段放置 <img>） */
.media {
  position: relative;
  overflow: hidden;
  border-radius: var(--bx-radius-m);
  border: 1px solid var(--bx-line-mid);
  background-color: var(--bx-ink);
  background-image:
    repeating-linear-gradient(
      135deg,
      rgba(244, 247, 242, 0.08) 0,
      rgba(244, 247, 242, 0.08) 1px,
      transparent 1px,
      transparent 12px
    ),
    linear-gradient(160deg, rgba(31, 122, 76, 0.55), rgba(14, 27, 42, 0.95));
  aspect-ratio: 16 / 10;
}
.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(rgba(244, 247, 242, 0.22) 1px, transparent 1px);
  background-size: 6px 6px;
  opacity: 0.32;
}
.media--wide { aspect-ratio: 21 / 9; }
.media--portrait { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

/* 状态标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border-radius: var(--bx-pill);
  border: 1px solid var(--bx-line-mid);
  background: var(--bx-white);
  font-family: var(--bx-font-num);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--bx-slate);
  white-space: nowrap;
}
.tag--lime {
  background: var(--bx-lime);
  border-color: var(--bx-lime);
  color: var(--bx-ink);
}
.tag--rise {
  background: rgba(143, 214, 148, 0.24);
  border-color: rgba(31, 122, 76, 0.4);
  color: var(--bx-field-deep);
}
.tag--fall {
  background: rgba(242, 107, 47, 0.14);
  border-color: rgba(242, 107, 47, 0.5);
  color: var(--bx-orange-deep);
}

/* 侧边章节索引 */
.index-nav { display: grid; gap: 3px; }
.index-nav__link {
  display: block;
  padding: 8px 13px;
  border-radius: var(--bx-radius-s);
  border-left: 2px solid transparent;
  font-size: 14px;
  color: var(--bx-slate);
  transition: color 0.2s var(--bx-ease), background-color 0.2s var(--bx-ease), border-color 0.2s var(--bx-ease);
}
.index-nav__link:hover { color: var(--bx-ink); background: rgba(14, 27, 42, 0.05); }
.index-nav__link.is-active {
  color: var(--bx-ink);
  font-weight: 600;
  background: rgba(200, 255, 61, 0.42);
  border-left-color: var(--bx-field);
}

/* ---------- 10. 动效状态协议 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 0.62s var(--bx-ease),
    transform 0.62s var(--bx-ease);
  will-change: opacity, transform;
}
.js [data-reveal][data-revealed] {
  opacity: 1;
  transform: none;
}
.js [data-reveal][data-reveal-delay="2"] { transition-delay: 0.1s; }
.js [data-reveal][data-reveal-delay="3"] { transition-delay: 0.2s; }
.js [data-reveal][data-reveal-delay="4"] { transition-delay: 0.3s; }

/* ---------- 11. 响应式 ---------- */
@media (min-width: 900px) {
  .grid--stagger > *:nth-child(even) { margin-top: 42px; }
}

@media (max-width: 1200px) and (min-width: 901px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* 平板与手机：胶囊展开为浮岛式面板 */
@media (max-width: 1080px) {
  .nav-toggle { display: inline-flex; }

  .nav-capsule {
    flex-wrap: wrap;
    gap: 10px 12px;
    padding: 12px 14px;
    border-radius: 26px;
  }

  .brand { order: 1; margin-right: auto; }
  .nav-cta { order: 2; padding: 9px 15px; font-size: 13px; }
  .nav-toggle { order: 3; }

  .site-nav {
    order: 4;
    flex: 1 1 100%;
    display: none;
    margin-left: 0;
    padding-top: 13px;
    border-top: 1px solid var(--bx-line-dark);
  }
  .site-header[data-open] .site-nav { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }
  .nav-list a {
    padding: 12px 14px;
    border-radius: 13px;
    font-size: 15.5px;
  }
  .nav-list a[aria-current="page"] {
    color: var(--bx-ink);
    background: var(--bx-lime);
  }

  .footer-top { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 900px) {
  .grid--2, .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .section__head { align-items: flex-start; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-base { flex-direction: column; }
}

@media (max-width: 560px) {
  .footer-nav { grid-template-columns: minmax(0, 1fr); }
  .brand-text__sub { letter-spacing: 0.16em; }
  .nav-cta { padding: 8px 13px; font-size: 12.5px; }
}

@media (max-width: 380px) {
  .brand-text__name { font-size: 15px; }
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 9px 12px; }
}

/* ---------- 12. 降级动效 ---------- */
@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;
  }
  .js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
  .btn:hover, .nav-cta:hover { transform: none; }
}