/* ==========================================================================
   B体育移动端 · 共享样式表 /assets/site.css
   结构：reset → 变量 → 基础排版 → 工具类 → 头部 → 页脚 → 组件 → 动效 → 响应式
   ========================================================================== */

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

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

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption, blockquote, dl, dd { margin: 0; padding: 0; }

ul, ol { list-style: none; }

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

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

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

section[id], h2[id], h3[id] { scroll-margin-top: 124px; }

/* ---------- 变量 ---------- */
:root {
  --deep: #0A1F3C;
  --deep-2: #071628;
  --blue: #1B57D6;
  --blue-dark: #1342A6;
  --sky: #7FB2FF;
  --orange: #F0650D;
  --orange-light: #FF7A1F;
  --paper: #F6F1E7;
  --paper-2: #FFFDF8;
  --ink: #2A211A;
  --ink-2: #5A6068;
  --line: #C9C2B4;
  --line-soft: rgba(10, 31, 60, 0.10);
  --glass: rgba(255, 255, 255, 0.62);
  --green: #12855A;

  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "SFMono-Regular", Consolas, monospace;

  --container: 1240px;
  --gutter: clamp(16px, 4vw, 48px);
  --radius: 4px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 72px;
}

/* ---------- 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    repeating-linear-gradient(0deg, rgba(10, 31, 60, 0.045) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(90deg, rgba(10, 31, 60, 0.045) 0 1px, transparent 1px 34px);
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--deep);
}

strong { font-weight: 800; }

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

/* ---------- 工具类 ---------- */
.bs-container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.bs-main { display: block; }

.bs-visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.bs-skip {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--orange);
  color: #1A0F04;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  border-radius: 0 0 var(--radius) var(--radius);
  transition: top 0.2s var(--ease);
}

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

/* 面包屑 */
.bs-breadcrumb { padding-block: 16px 0; }

.bs-breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
}

.bs-breadcrumb li { display: flex; align-items: center; gap: 8px; }

.bs-breadcrumb li + li::before {
  content: "/";
  color: var(--line);
}

.bs-breadcrumb a:hover { color: var(--blue); }

/* 章节 */
.bs-section { padding-block: clamp(48px, 7vw, 88px); }
.bs-section--tight { padding-block: clamp(32px, 4vw, 56px); }

.bs-section--panel {
  background: rgba(255, 253, 248, 0.72);
  border-block: 1px solid var(--line);
}

.bs-section--deep {
  background: var(--deep);
  color: rgba(255, 255, 255, 0.78);
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.05) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.05) 0 1px, transparent 1px 34px);
}

.bs-section--deep .bs-section__title { color: var(--paper-2); }
.bs-section--deep .bs-lede { color: rgba(255, 255, 255, 0.72); }
.bs-section--deep .bs-section__head { border-top-color: rgba(255, 255, 255, 0.18); }
.bs-section--deep .bs-section__kicker { color: var(--sky); }

.bs-section__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2.4vw, 30px);
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-bottom: clamp(22px, 3vw, 38px);
}

.bs-section__index {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--blue);
}

.bs-section__kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-2);
  margin-bottom: 8px;
}

.bs-section__title {
  font-size: clamp(21px, 2.8vw, 31px);
}

.bs-lede {
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--ink-2);
  max-width: 34em;
}

.bs-prose p {
  max-width: 34em;
  line-height: 1.85;
}

.bs-prose p + p { margin-top: 1.05em; }

.bs-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* 网格 */
.bs-grid {
  display: grid;
  gap: clamp(14px, 2vw, 24px);
}

.bs-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.bs-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.bs-grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* 卡片 */
.bs-card {
  position: relative;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(18px, 2.2vw, 28px);
  transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease), border-color 0.24s var(--ease);
}

.bs-card:hover {
  transform: translateY(-3px);
  border-color: var(--sky);
  box-shadow: 0 26px 46px -34px rgba(10, 31, 60, 0.55);
}

.bs-card--glass {
  background: var(--glass);
  border-color: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(10px);
}

.bs-card--deep {
  background: var(--deep);
  border-color: rgba(127, 178, 255, 0.28);
  color: rgba(255, 255, 255, 0.78);
}

.bs-card--deep h3,
.bs-card--deep .bs-card__title { color: var(--paper-2); }

/* 按钮 */
.bs-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: 3px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.bs-btn:hover { transform: translateY(-1px); }

.bs-btn--primary { background: var(--blue); color: #fff; }
.bs-btn--primary:hover { background: var(--blue-dark); }

.bs-btn--accent { background: var(--orange); color: #1A0F04; }
.bs-btn--accent:hover { background: var(--orange-light); }

.bs-btn--ghost {
  border-color: var(--deep);
  color: var(--deep);
  background: transparent;
}

.bs-btn--ghost:hover {
  background: var(--deep);
  color: var(--paper-2);
}

/* chip 筛选 */
.bs-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.bs-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 44px;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper-2);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ink-2);
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.bs-chip:hover { border-color: var(--blue); color: var(--blue); }

.bs-chip[aria-pressed="true"],
.bs-chip.is-active {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}

/* 索引长表 */
.bs-index { border-top: 1px solid var(--line); }

.bs-index__row {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr) auto;
  gap: 8px 18px;
  align-items: baseline;
  padding: 15px 4px;
  border-bottom: 1px dashed var(--line);
  transition: background 0.18s var(--ease);
}

.bs-index__row:hover { background: rgba(127, 178, 255, 0.10); }

.bs-index__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.bs-index__title { font-weight: 600; color: var(--deep); }

.bs-index__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-2);
}

/* 标签 */
.bs-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.6);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.bs-badge--live {
  background: var(--orange);
  border-color: var(--orange);
  color: #1A0F04;
}

.bs-badge--ok {
  background: rgba(18, 133, 90, 0.1);
  border-color: rgba(18, 133, 90, 0.42);
  color: var(--green);
}

/* 图片容器 */
.bs-media {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(140deg, #0A1F3C 0%, #1B57D6 68%, #7FB2FF 100%);
}

.bs-media::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.18) 0 1px, transparent 1px 22px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.18) 0 1px, transparent 1px 22px);
  opacity: 0.55;
}

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

.bs-media[data-label]::after {
  content: attr(data-label);
  position: absolute;
  z-index: 2;
  left: 0; right: 0; bottom: 0;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.9);
  background: linear-gradient(0deg, rgba(10, 31, 60, 0.82), rgba(10, 31, 60, 0));
}

.bs-media__note {
  position: absolute;
  z-index: 2;
  left: 0; right: 0; bottom: 0;
  padding: 10px 13px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: #fff;
  background: linear-gradient(0deg, rgba(10, 31, 60, 0.86), rgba(10, 31, 60, 0));
}

.bs-media--portrait { aspect-ratio: 4 / 5; }
.bs-media--wide { aspect-ratio: 16 / 9; }
.bs-media--square { aspect-ratio: 1 / 1; }
.bs-media--tall { aspect-ratio: 9 / 16; }

/* ---------- 头部 ---------- */
.bs-header {
  position: sticky;
  top: 0;
  z-index: 120;
}

.bs-header__top {
  position: relative;
  z-index: 2;
  background: var(--deep);
  color: rgba(255, 255, 255, 0.82);
}

.bs-header__top-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 40px;
  padding-block: 7px;
  font-size: 12.5px;
}

.bs-brand-line {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--paper-2);
  white-space: nowrap;
}

.bs-header__note {
  flex: 1 1 auto;
  min-width: 0;
  padding-left: 18px;
  border-left: 1px solid rgba(255, 255, 255, 0.22);
  color: rgba(255, 255, 255, 0.6);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bs-header__top-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

.bs-ghost-link {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  padding: 7px 12px;
  border: 1px solid rgba(127, 178, 255, 0.45);
  border-radius: 3px;
  color: var(--sky);
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.bs-ghost-link:hover {
  background: rgba(127, 178, 255, 0.16);
  border-color: var(--sky);
  color: #fff;
}

.bs-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 3px;
  background: var(--orange);
  color: #1A0F04;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: background 0.2s var(--ease), transform 0.2s var(--ease);
}

.bs-cta:hover {
  background: var(--orange-light);
  transform: translateY(-1px);
}

.bs-header__bar {
  position: relative;
  z-index: 2;
  background: rgba(255, 253, 248, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.bs-header__bar-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: var(--header-h);
}

.bs-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

.bs-brand__mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 3px;
  background: var(--deep);
  color: var(--paper-2);
  font-family: var(--font-mono);
  font-size: 19px;
  font-weight: 700;
}

.bs-brand__mark::after {
  content: "";
  position: absolute;
  right: -3px;
  bottom: -3px;
  width: 13px;
  height: 3px;
  background: var(--orange);
}

.bs-brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.bs-brand__name {
  font-size: 16px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.bs-brand__meta {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-2);
}

/* 主导航 */
.bs-nav { margin-left: auto; }

.bs-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.bs-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 10px 13px;
  border-radius: 3px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--deep);
  transition: color 0.18s var(--ease), background 0.18s var(--ease);
}

.bs-nav__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--ink-2);
  transition: color 0.18s var(--ease);
}

.bs-nav__link:hover {
  color: var(--blue);
  background: rgba(27, 87, 214, 0.07);
}

.bs-nav__link:hover .bs-nav__num { color: var(--blue); }

.bs-nav__link[aria-current="page"] { color: var(--blue); }

.bs-nav__link[aria-current="page"] .bs-nav__num { color: var(--orange); }

.bs-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 2px;
  height: 3px;
  background: var(--orange);
}

.bs-nav__foot { display: none; }

/* 移动端开关 */
.bs-nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 10px 15px;
  border: 1px solid var(--deep);
  border-radius: 3px;
  background: var(--paper-2);
  color: var(--deep);
  font-size: 13.5px;
  font-weight: 700;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.bs-nav-toggle__icon {
  position: relative;
  display: block;
  width: 16px;
  height: 12px;
}

.bs-nav-toggle__icon::before,
.bs-nav-toggle__icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform 0.24s var(--ease), top 0.24s var(--ease);
}

.bs-nav-toggle__icon::before { top: 1px; }
.bs-nav-toggle__icon::after { top: 9px; }

.bs-nav-toggle.is-open {
  background: var(--deep);
  border-color: var(--deep);
  color: var(--paper-2);
}

.bs-nav-toggle.is-open .bs-nav-toggle__icon::before { top: 5px; transform: rotate(45deg); }
.bs-nav-toggle.is-open .bs-nav-toggle__icon::after { top: 5px; transform: rotate(-45deg); }

/* 滚动进度 */
.bs-progress {
  height: 3px;
  background: rgba(10, 31, 60, 0.08);
}

.bs-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--orange));
}

/* ---------- 页脚 ---------- */
.bs-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  background: var(--deep);
  color: rgba(255, 255, 255, 0.78);
}

.bs-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--blue), var(--orange) 62%, var(--sky));
}

.bs-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.7fr;
  gap: clamp(20px, 3vw, 42px);
  padding-block: clamp(40px, 5vw, 68px) clamp(24px, 3vw, 40px);
}

.bs-footer__logo {
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--paper-2);
}

.bs-footer__desc {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.66);
  max-width: 26em;
}

.bs-footer__tag {
  display: inline-block;
  margin-top: 16px;
  padding: 5px 10px;
  border: 1px solid rgba(127, 178, 255, 0.42);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--sky);
}

.bs-footer__title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sky);
  margin-bottom: 14px;
}

.bs-footer__links {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.bs-footer__links a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.74);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.bs-footer__links a:hover {
  color: #fff;
  border-bottom-color: var(--orange);
}

.bs-footer__contact {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.bs-footer__contact li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 4px 12px;
}

.bs-footer__label {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--sky);
}

.bs-footer__value {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.88);
  word-break: break-word;
}

.bs-copy {
  min-height: 40px;
  padding: 8px 12px;
  border: 1px solid rgba(127, 178, 255, 0.42);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--sky);
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.bs-copy:hover {
  background: rgba(127, 178, 255, 0.16);
  color: #fff;
}

.bs-copy.is-copied {
  border-color: var(--green);
  background: rgba(18, 133, 90, 0.22);
  color: #6FDCAB;
}

.bs-footer__legacy {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
  padding: 18px 20px;
  border: 1px dashed rgba(127, 178, 255, 0.42);
  border-radius: var(--radius);
  background: rgba(127, 178, 255, 0.07);
}

.bs-footer__legacy-title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--sky);
}

.bs-footer__legacy-text {
  flex: 1 1 260px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

.bs-footer__legacy-link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 9px 16px;
  border-radius: 3px;
  background: var(--sky);
  color: var(--deep);
  font-size: 13.5px;
  font-weight: 700;
  transition: background 0.2s var(--ease), transform 0.2s var(--ease);
}

.bs-footer__legacy-link:hover {
  background: #A6CCFF;
  transform: translateY(-1px);
}

.bs-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: clamp(20px, 3vw, 34px);
  padding-block: 18px 26px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.55);
}

/* ---------- 返回顶部（JS 注入） ---------- */
.bs-to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 15px;
  border: 1px solid rgba(127, 178, 255, 0.42);
  border-radius: 3px;
  background: var(--deep);
  color: var(--paper-2);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease), visibility 0.24s var(--ease);
}

.bs-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.bs-to-top:hover { border-color: var(--orange); color: var(--orange); }

/* ---------- 滚动显现 ---------- */
html.bs-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.42s var(--ease), transform 0.42s var(--ease);
}

html.bs-js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式：平板 ---------- */
@media (max-width: 1100px) {
  .bs-header__note { display: none; }
  .bs-nav__link { padding: 10px 10px; font-size: 13.5px; }
  .bs-footer__grid { grid-template-columns: 1.3fr 1fr 1.6fr; }
  .bs-footer__col--contact { grid-column: span 3; }
}

@media (max-width: 900px) {
  .bs-header__top { display: none; }

  .bs-nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .bs-header__bar-inner {
    min-height: 62px;
    gap: 12px;
  }

  .bs-nav {
    position: fixed;
    inset: 0;
    z-index: 1;
    margin: 0;
    padding: calc(78px + env(safe-area-inset-top, 0px)) var(--gutter) calc(96px + env(safe-area-inset-bottom, 0px));
    background: var(--deep);
    background-image:
      repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.055) 0 1px, transparent 1px 34px),
      repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.055) 0 1px, transparent 1px 34px);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.26s var(--ease), transform 0.26s var(--ease), visibility 0.26s var(--ease);
  }

  .bs-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .bs-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .bs-nav__link {
    padding: 16px 6px;
    border-radius: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
    font-size: 19px;
    font-weight: 800;
    color: var(--paper-2);
  }

  .bs-nav__link:hover {
    background: rgba(127, 178, 255, 0.1);
    color: #fff;
  }

  .bs-nav__link[aria-current="page"] { color: #fff; }

  .bs-nav__link[aria-current="page"] .bs-nav__num { color: var(--orange); }

  .bs-nav__link[aria-current="page"]::after {
    left: 0;
    right: auto;
    top: 18px;
    bottom: 18px;
    width: 3px;
    height: auto;
  }

  .bs-nav__num { font-size: 12px; color: var(--sky); }

  .bs-nav__foot {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 30px;
  }

  .bs-nav__foot-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 18px;
    border: 1px solid rgba(127, 178, 255, 0.45);
    border-radius: 3px;
    background: rgba(127, 178, 255, 0.12);
    color: var(--sky);
    font-size: 15px;
    font-weight: 700;
  }

  .bs-nav__foot-note {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.08em;
    color: rgba(255, 255, 255, 0.5);
  }

  html.bs-nav-open,
  html.bs-nav-open body { overflow: hidden; }

  .bs-grid--3,
  .bs-grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .bs-footer__grid { grid-template-columns: 1fr 1fr; }
  .bs-footer__col--contact { grid-column: span 2; }
}

@media (max-width: 620px) {
  :root { --header-h: 58px; }

  .bs-grid--2,
  .bs-grid--3,
  .bs-grid--4 { grid-template-columns: minmax(0, 1fr); }

  .bs-section__head {
    flex-direction: column;
    gap: 10px;
  }

  .bs-index__row { grid-template-columns: 48px minmax(0, 1fr); }
  .bs-index__meta { grid-column: 2; }

  .bs-footer__grid { grid-template-columns: minmax(0, 1fr); }
  .bs-footer__col--contact { grid-column: span 1; }

  .bs-footer__legacy { flex-direction: column; align-items: flex-start; }
  .bs-footer__legacy-link { width: 100%; justify-content: center; }
}

/* ---------- 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: 120ms !important;
    transition-delay: 0ms !important;
  }

  html.bs-js [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .bs-card:hover,
  .bs-btn:hover,
  .bs-cta:hover,
  .bs-footer__legacy-link:hover { transform: none; }
}