/* ==========================================================================
   红蓝电竞 · 伟德官网 共享样式 /assets/site.css
   深空黑底 · 红蓝对抗 · 数据等宽 · 极细边界
   ========================================================================== */

/* ---------- 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, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }

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

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

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

button { background: none; border: 0; }

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

table { border-collapse: collapse; width: 100%; }

main { display: block; }

/* ---------- 2. 变量 ---------- */
:root {
  --rb-black: #0B0D12;
  --rb-carbon: #14171F;
  --rb-red: #FF2D55;
  --rb-blue: #1E5EFF;
  --rb-blue-soft: #6E9BFF;
  --rb-cyan: #22F5C8;
  --rb-paper: #F5F7FA;
  --rb-mist: #E6E9F0;
  --rb-steel: #6B7280;
  --rb-amber: #FFB020;
  --rb-slate: #1B2436;

  --rb-line: 1px solid rgba(245, 247, 250, 0.10);
  --rb-line-strong: 1px solid rgba(245, 247, 250, 0.18);
  --rb-glass: rgba(20, 23, 31, 0.86);
  --rb-shadow: 0 18px 44px -34px rgba(0, 0, 0, 1);
  --rb-shadow-red: 0 12px 30px -18px rgba(255, 45, 85, 0.85);
  --rb-shadow-blue: 0 12px 30px -18px rgba(30, 94, 255, 0.85);

  --rb-font-display: "Noto Sans SC", "HarmonyOS Sans SC", "PingFang SC",
    "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --rb-font-body: system-ui, -apple-system, "PingFang SC", "Noto Sans SC",
    "Microsoft YaHei", "Segoe UI", sans-serif;
  --rb-font-editorial: "Noto Serif SC", "Songti SC", "Source Han Serif SC",
    Georgia, "Times New Roman", serif;
  --rb-font-num: "JetBrains Mono", "IBM Plex Mono", ui-monospace,
    SFMono-Regular, Menlo, Consolas, monospace;

  --rb-w: 1240px;
  --rb-gutter: clamp(18px, 4vw, 48px);
  --rb-radius: 18px;
  --rb-radius-sm: 12px;
  --rb-ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}

/* ---------- 3. 基础与中文排版 ---------- */
body {
  background-color: var(--rb-black);
  background-image:
    radial-gradient(60vw 40vw at 10% -8%, rgba(255, 45, 85, 0.13), transparent 62%),
    radial-gradient(58vw 40vw at 94% 2%, rgba(30, 94, 255, 0.16), transparent 64%);
  background-repeat: no-repeat;
  color: var(--rb-paper);
  font-family: var(--rb-font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 { text-wrap: balance; }
p { text-wrap: pretty; }

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

::selection { background: rgba(255, 45, 85, 0.35); color: var(--rb-paper); }

:focus-visible {
  outline: 2px solid var(--rb-cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 4. 排版组件 ---------- */
.rb-eyebrow {
  font-family: var(--rb-font-num);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--rb-steel);
}

.rb-display {
  font-family: var(--rb-font-display);
  font-weight: 900;
  font-size: clamp(2.55rem, 7.4vw, 6rem);
  line-height: 1.02;
  letter-spacing: -0.03em;
}

.rb-title {
  font-family: var(--rb-font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 3.2vw, 2.45rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
}

.rb-lead {
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  line-height: 1.7;
  color: var(--rb-mist);
  max-width: 36ch;
}

.rb-body {
  max-width: 36em;
  line-height: 1.75;
  color: rgba(245, 247, 250, 0.88);
}

.rb-body p + p { margin-top: 1.05em; }
.rb-body h3 { margin-top: 1.6em; }

.rb-serif {
  font-family: var(--rb-font-editorial);
  font-weight: 500;
  letter-spacing: 0.02em;
}

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

.rb-divider {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, rgba(255, 45, 85, 0.5), rgba(245, 247, 250, 0.08) 45%, rgba(30, 94, 255, 0.5));
}

.rb-note {
  border-left: 2px solid var(--rb-amber);
  background: rgba(255, 176, 32, 0.06);
  padding: 12px 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--rb-mist);
  border-radius: 0 var(--rb-radius-sm) var(--rb-radius-sm) 0;
}

/* ---------- 5. 容器与区块 ---------- */
.rb-container {
  width: 100%;
  max-width: var(--rb-w);
  margin-inline: auto;
  padding-inline: var(--rb-gutter);
}

.rb-section {
  padding-block: clamp(46px, 7vw, 96px);
  border-top: var(--rb-line);
}

.rb-section--paper {
  background: var(--rb-mist);
  color: #14171F;
}

.rb-section--paper .rb-lead,
.rb-section--paper .rb-body,
.rb-section--paper .rb-note { color: #2A3040; }

.rb-section--paper .rb-eyebrow { color: #55607A; }

/* ---------- 6. 网格与布局 ---------- */
.rb-grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

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

.rb-split {
  display: grid;
  grid-template-columns: minmax(0, 62fr) minmax(0, 26fr);
  gap: clamp(24px, 6vw, 96px);
  align-items: start;
}

.rb-aside {
  position: sticky;
  top: 118px;
  align-self: start;
}

.rb-toc {
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-left: var(--rb-line);
  padding-left: 16px;
}

.rb-toc__link {
  font-size: 14px;
  color: var(--rb-steel);
  padding: 5px 0;
  transition: color 0.18s var(--rb-ease), transform 0.18s var(--rb-ease);
}

.rb-toc__link:hover { color: var(--rb-paper); transform: translateX(3px); }

.rb-toc__link[aria-current="true"] {
  color: var(--rb-cyan);
  font-weight: 600;
}

/* ---------- 7. 卡片 · 标签 · 横条 ---------- */
.rb-card {
  background: var(--rb-carbon);
  border: var(--rb-line);
  border-radius: var(--rb-radius);
  padding: clamp(18px, 2.4vw, 28px);
  box-shadow: var(--rb-shadow);
}

.rb-card--red { border-color: rgba(255, 45, 85, 0.34); box-shadow: var(--rb-shadow-red); }
.rb-card--blue { border-color: rgba(30, 94, 255, 0.38); box-shadow: var(--rb-shadow-blue); }

.rb-card__title {
  font-family: var(--rb-font-display);
  font-weight: 800;
  font-size: clamp(1.05rem, 1.7vw, 1.35rem);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.rb-card__meta {
  margin-top: 10px;
  font-family: var(--rb-font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--rb-steel);
}

.rb-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--rb-font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid currentColor;
  color: var(--rb-steel);
  white-space: nowrap;
}

.rb-tag--red { color: var(--rb-red); }
.rb-tag--blue { color: var(--rb-blue-soft); }
.rb-tag--cyan { color: var(--rb-cyan); }
.rb-tag--amber { color: var(--rb-amber); }
.rb-tag--quiet { color: var(--rb-steel); }

.rb-stripe {
  width: 100%;
  border-top: 1px solid rgba(255, 45, 85, 0.35);
  border-bottom: 1px solid rgba(30, 94, 255, 0.35);
  background: linear-gradient(90deg, rgba(255, 45, 85, 0.13), rgba(11, 13, 18, 0) 44%, rgba(30, 94, 255, 0.13));
  padding-block: clamp(20px, 3vw, 34px);
}

.rb-stripe__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}

.rb-stripe__value {
  font-family: var(--rb-font-num);
  font-weight: 700;
  font-size: clamp(1.6rem, 3.6vw, 2.6rem);
  line-height: 1.1;
  color: var(--rb-paper);
}

.rb-stripe__label {
  margin-top: 8px;
  font-size: 13px;
  color: var(--rb-steel);
}

.rb-stripe__unit {
  font-family: var(--rb-font-num);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--rb-cyan);
  margin-left: 6px;
}

/* ---------- 8. 按钮 ---------- */
.rb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--rb-font-body);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.18s var(--rb-ease), color 0.18s var(--rb-ease),
    border-color 0.18s var(--rb-ease), transform 0.18s var(--rb-ease);
}

.rb-btn--primary {
  background: var(--rb-red);
  color: #FFFFFF;
  box-shadow: var(--rb-shadow-red);
}

.rb-btn--primary:hover { background: #FF4A6C; transform: translateY(-1px); }

.rb-btn--ghost {
  background: rgba(30, 94, 255, 0.12);
  border-color: rgba(110, 155, 255, 0.5);
  color: var(--rb-blue-soft);
}

.rb-btn--ghost:hover {
  background: rgba(30, 94, 255, 0.22);
  color: var(--rb-paper);
  transform: translateY(-1px);
}

.rb-btn--quiet {
  background: transparent;
  border-color: rgba(245, 247, 250, 0.16);
  color: var(--rb-mist);
}

.rb-btn--quiet:hover { border-color: rgba(245, 247, 250, 0.38); color: #FFFFFF; }

/* ---------- 9. 面包屑 ---------- */
.rb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--rb-font-num);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--rb-steel);
}

.rb-breadcrumb a { color: var(--rb-blue-soft); }
.rb-breadcrumb a:hover { color: var(--rb-cyan); }

/* ---------- 10. 图片容器（页面阶段放图） ---------- */
.rb-figure { margin: 0; }

.rb-figure__img {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: var(--rb-line);
  border-radius: 14px;
  background: var(--rb-carbon);
}

.rb-figure__img img,
.rb-figure__img video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.rb-figure__img::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(122deg, rgba(255, 45, 85, 0.16), transparent 46%, rgba(30, 94, 255, 0.2));
}

.rb-figure--wide .rb-figure__img { aspect-ratio: 21 / 9; }
.rb-figure--square .rb-figure__img { aspect-ratio: 1 / 1; }
.rb-figure--portrait .rb-figure__img { aspect-ratio: 3 / 4; }

.rb-figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--rb-steel);
}

/* ---------- 11. 滚动显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s var(--rb-ease), transform 0.4s var(--rb-ease);
  transition-delay: var(--rb-delay, 0ms);
  will-change: opacity, transform;
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 12. 头部：悬浮胶囊导航 ---------- */
.rb-skip {
  position: absolute;
  left: var(--rb-gutter);
  top: -120px;
  z-index: 130;
  padding: 12px 20px;
  border-radius: 999px;
  background: var(--rb-cyan);
  color: #04231C;
  font-size: 14px;
  font-weight: 700;
  transition: top 0.2s var(--rb-ease);
}

.rb-skip:focus { top: 14px; }

.rb-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding-block: clamp(10px, 1.6vw, 18px);
  transition: padding-block 0.25s var(--rb-ease);
}

.rb-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(11, 13, 18, 0.88), rgba(11, 13, 18, 0));
  opacity: 1;
  transition: opacity 0.25s var(--rb-ease);
}

.rb-header[data-scrolled="true"] { padding-block: 8px; }

.rb-header[data-scrolled="true"]::before {
  background: linear-gradient(180deg, rgba(11, 13, 18, 0.97), rgba(11, 13, 18, 0.62));
}

.rb-header__inner {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 16px);
  width: 100%;
  max-width: var(--rb-w);
  margin-inline: auto;
  padding-inline: var(--rb-gutter);
}

/* 品牌浮岛 */
.rb-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 7px 18px 7px 7px;
  border-radius: 999px;
  background: var(--rb-glass);
  border: var(--rb-line);
  box-shadow: var(--rb-shadow);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  transition: padding 0.25s var(--rb-ease);
}

.rb-brand:hover .rb-brand__name { color: #FFFFFF; }

.rb-brand__mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  flex: 0 0 auto;
  font-family: var(--rb-font-num);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #FFFFFF;
  background: linear-gradient(135deg, var(--rb-red), var(--rb-blue));
  box-shadow: inset 0 0 0 1px rgba(245, 247, 250, 0.16);
}

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

.rb-brand__name {
  font-family: var(--rb-font-editorial);
  font-weight: 600;
  font-size: 15.5px;
  letter-spacing: 0.04em;
  color: var(--rb-paper);
  transition: color 0.18s var(--rb-ease);
}

.rb-brand__sub {
  font-family: var(--rb-font-num);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--rb-steel);
}

.rb-header[data-scrolled="true"] .rb-brand__sub { display: none; }

/* 栏目浮岛 */
.rb-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  padding: 6px;
  border-radius: 999px;
  background: var(--rb-glass);
  border: var(--rb-line);
  box-shadow: var(--rb-shadow);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

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

.rb-nav__link {
  display: inline-flex;
  align-items: center;
  padding: 9px 14px;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--rb-mist);
  white-space: nowrap;
  transition: color 0.18s var(--rb-ease), background-color 0.18s var(--rb-ease),
    padding 0.25s var(--rb-ease), font-size 0.25s var(--rb-ease);
}

.rb-nav__link:hover {
  color: #FFFFFF;
  background: rgba(245, 247, 250, 0.07);
}

.rb-nav__link[aria-current="page"] {
  color: #FFFFFF;
  background: linear-gradient(135deg, rgba(255, 45, 85, 0.3), rgba(30, 94, 255, 0.3));
  box-shadow: inset 0 0 0 1px rgba(245, 247, 250, 0.16);
}

.rb-nav__cta {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 4px;
  padding-left: 8px;
  border-left: 1px solid rgba(245, 247, 250, 0.10);
}

.rb-nav__cta .rb-btn { padding: 10px 16px; font-size: 13px; }

.rb-header[data-scrolled="true"] .rb-nav__link { padding: 7px 12px; font-size: 13px; }
.rb-header[data-scrolled="true"] .rb-nav__cta .rb-btn { padding: 9px 14px; }

/* 移动菜单按钮 */
.rb-navtoggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 11px 16px;
  border-radius: 999px;
  background: var(--rb-glass);
  border: var(--rb-line);
  box-shadow: var(--rb-shadow);
  color: var(--rb-paper);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.rb-navtoggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 16px;
}

.rb-navtoggle__bars i {
  display: block;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s var(--rb-ease), opacity 0.2s var(--rb-ease);
}

.rb-navtoggle[aria-expanded="true"] .rb-navtoggle__bars i:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.rb-navtoggle[aria-expanded="true"] .rb-navtoggle__bars i:nth-child(2) { opacity: 0; }
.rb-navtoggle[aria-expanded="true"] .rb-navtoggle__bars i:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

.rb-navtoggle__text { letter-spacing: 0.06em; }

/* ---------- 13. 页脚 ---------- */
.rb-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 96px);
  background: var(--rb-slate);
  border-top: 1px solid rgba(245, 247, 250, 0.10);
  color: var(--rb-mist);
}

.rb-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--rb-red), rgba(11, 13, 18, 0) 46%, var(--rb-blue));
}

.rb-footer__inner {
  width: 100%;
  max-width: var(--rb-w);
  margin-inline: auto;
  padding: clamp(36px, 5vw, 64px) var(--rb-gutter) clamp(20px, 3vw, 30px);
}

.rb-footer__grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, minmax(104px, 0.85fr)) 1.55fr;
  gap: clamp(20px, 3vw, 40px);
}

.rb-footer__nav { display: contents; }

.rb-footer__brand { min-width: 0; }

.rb-footer__logo {
  font-family: var(--rb-font-editorial);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 0.03em;
  color: var(--rb-paper);
}

.rb-footer__desc {
  margin-top: 12px;
  font-size: 13.5px;
  line-height: 1.75;
  max-width: 34ch;
  color: rgba(230, 233, 240, 0.72);
}

.rb-footer__meta {
  margin-top: 14px;
  font-family: var(--rb-font-num);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--rb-steel);
}

.rb-footer__col { min-width: 0; }

.rb-footer__coltitle {
  margin-bottom: 14px;
  font-family: var(--rb-font-num);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--rb-steel);
}

.rb-footer__list { display: flex; flex-direction: column; gap: 2px; }

.rb-footer__link {
  display: inline-block;
  padding: 5px 0;
  font-size: 14px;
  color: rgba(230, 233, 240, 0.86);
  transition: color 0.18s var(--rb-ease), transform 0.18s var(--rb-ease);
}

.rb-footer__link:hover { color: #FFFFFF; transform: translateX(3px); }

.rb-footer__contact { min-width: 0; }

.rb-footer__contact-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 5px 0;
}

.rb-footer__contact-label {
  font-family: var(--rb-font-num);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--rb-steel);
  min-width: 40px;
}

.rb-footer__value {
  font-family: var(--rb-font-num);
  font-size: 13px;
  color: var(--rb-paper);
  word-break: break-all;
}

.rb-footer__note {
  margin-top: 12px;
  font-size: 12.5px;
  line-height: 1.7;
  max-width: 32ch;
  color: var(--rb-steel);
}

.rb-copy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(110, 155, 255, 0.4);
  background: transparent;
  color: var(--rb-blue-soft);
  font-family: var(--rb-font-num);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 0.18s var(--rb-ease), color 0.18s var(--rb-ease);
}

.rb-copy:hover { border-color: var(--rb-cyan); color: var(--rb-cyan); }

.rb-copy__status {
  font-family: var(--rb-font-num);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--rb-cyan);
  min-width: 0;
}

.rb-footer__endnote {
  margin-top: clamp(28px, 4vw, 48px);
  padding-bottom: 20px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--rb-steel);
  border-bottom: 1px solid rgba(245, 247, 250, 0.10);
}

.rb-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-top: 20px;
  font-size: 12.5px;
  color: var(--rb-steel);
}

.rb-footer__icp {
  font-family: var(--rb-font-num);
  letter-spacing: 0.06em;
}

.rb-footer__copyline {
  font-family: var(--rb-font-num);
  letter-spacing: 0.04em;
}

.rb-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.rb-footer__legal .rb-footer__link { font-size: 12.5px; }

/* 返回顶部 */
.rb-totop {
  position: fixed;
  right: clamp(14px, 3vw, 30px);
  bottom: clamp(14px, 3vw, 30px);
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 16px;
  border-radius: 999px;
  border: var(--rb-line-strong);
  background: rgba(20, 23, 31, 0.94);
  color: var(--rb-paper);
  font-family: var(--rb-font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  cursor: pointer;
  box-shadow: var(--rb-shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.25s var(--rb-ease), transform 0.25s var(--rb-ease),
    visibility 0.25s var(--rb-ease), color 0.18s var(--rb-ease), border-color 0.18s var(--rb-ease);
}

.rb-totop[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.rb-totop:hover { color: var(--rb-cyan); border-color: rgba(34, 245, 200, 0.5); }

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1080px) {
  .rb-navtoggle { display: inline-flex; }

  .rb-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: var(--rb-gutter);
    right: var(--rb-gutter);
    z-index: 3;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    padding: 14px;
    border-radius: 22px;
    max-height: min(72vh, 560px);
    overflow-y: auto;
  }

  .rb-nav[data-open="true"] { display: flex; }

  .rb-nav__list { flex-direction: column; align-items: stretch; gap: 2px; }

  .rb-nav__link {
    justify-content: space-between;
    padding: 13px 14px;
    font-size: 15px;
  }

  .rb-nav__link[aria-current="page"] { padding-left: 18px; }

  .rb-nav__cta {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    margin: 12px 0 0;
    padding: 12px 0 0;
    border-left: 0;
    border-top: 1px solid rgba(245, 247, 250, 0.10);
  }

  .rb-nav__cta .rb-btn { width: 100%; padding: 13px 18px; font-size: 14px; }

  .rb-header[data-scrolled="true"] .rb-nav__link { padding: 13px 14px; font-size: 15px; }

  .rb-split { grid-template-columns: minmax(0, 1fr); gap: clamp(24px, 5vw, 40px); }

  .rb-aside { position: static; }

  .rb-footer__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .rb-footer__brand { grid-column: 1 / -1; }
  .rb-footer__contact { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .rb-grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .rb-grid--2,
  .rb-grid--3 { grid-template-columns: minmax(0, 1fr); }
  .rb-brand__sub { display: none; }
  .rb-footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .rb-footer__bottom { flex-direction: column; align-items: flex-start; }
  .rb-totop { padding: 10px 14px; font-size: 11.5px; }
}

/* ---------- 15. 减少动态 ---------- */
@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;
    transition-delay: 0ms !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}