/* ============================================
   源联身份同步平台 — 样式表
   ============================================ */

/* --- 基础重置 & 变量 --- */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #fafbfc;
  --bg-alt: #f3f5f9;
  --surface: #ffffff;
  --text: #1a1d28;
  --text-2: #545a6e;
  --text-3: #8b91a3;
  --border: #e2e6ee;
  --border-light: #eef1f6;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eff6ff;
  --green: #059669;
  --green-soft: #ecfdf5;
  --amber: #d97706;
  --amber-soft: #fffbeb;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.04);
  --shadow: 0 4px 20px rgba(0,0,0,.06);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.08);
  --font: 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  font-size: 15px;
}

a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; }
img, svg { display: block; }
ul { list-style: none; }

/* --- 导航 --- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  height: 72px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.2px;
  color: var(--text);
  flex-shrink: 0;
}

.logo svg { color: var(--accent); }

.logo-icon,
.flow-icon-img,
.ring-core-icon {
  object-fit: contain;
  flex-shrink: 0;
}

.nav .logo-icon {
  width: 32px;
  height: 32px;
}

.footer .logo-icon {
  width: 32px;
  height: 32px;
}

.flow-icon .flow-icon-img {
  width: 32px;
  height: 32px;
}

/* 身份源三合一图标：等比缩放，不超出原有 40x40 视觉尺寸 */
.flow-icon .flow-icon-img--brands {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

.ring-core .ring-core-icon {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 12px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
  margin-left: auto;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-2);
  font-weight: 500;
  transition: color .2s;
}

.nav-links a:hover { color: var(--text); }

.nav-cta {
  padding: 8px 18px;
  background: var(--accent);
  color: #fff !important;
  border-radius: 8px;
  font-weight: 600;
  font-size: 13px;
  transition: background .2s;
  flex-shrink: 0;
}

.nav-cta:hover { background: var(--accent-hover); }

/* --- 首屏 --- */
.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 80px 32px 100px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.hero-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 6px 14px;
  border-radius: 20px;
  margin-bottom: 24px;
}

.hero-text h1 {
  font-size: 56px;
  line-height: 1.12;
  letter-spacing: -2px;
  font-weight: 800;
  margin-bottom: 20px;
}

.text-gradient {
  background: linear-gradient(135deg, #2563eb 0%, #7c3aed 50%, #db2777 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-slogan {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--text);
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 17px;
  color: var(--text-2);
  line-height: 1.7;
  max-width: 480px;
  margin-bottom: 32px;
}

.hero-btns {
  display: flex;
  gap: 12px;
  margin-bottom: 36px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  transition: all .2s;
}

.btn-primary {
  background: var(--text);
  color: #fff;
}

.btn-primary:hover {
  background: #000;
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(0,0,0,.15);
}

.btn-outline {
  border: 1.5px solid var(--border);
  color: var(--text-2);
}

.btn-outline:hover {
  border-color: var(--text-3);
  color: var(--text);
}

.hero-badges {
  display: flex;
  gap: 20px;
}

.hero-badges span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-3);
}

.hero-badges svg { color: var(--green); }

/* 首屏视觉 */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.flow-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px 28px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 12px;
}

.flow-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
  min-width: 110px;
}

.flow-node small {
  font-size: 11px;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: .5px;
  font-weight: 600;
}

.flow-node strong {
  font-size: 12px;
  color: var(--text);
  font-weight: 600;
  line-height: 1.4;
}

.flow-icon {
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-2);
}

.flow-icon.highlight {
  color: var(--accent);
}

.flow-icon-stack {
  display: flex;
  align-items: center;
}

.flow-icon-stack .mini-brand {
  display: flex;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
}

.flow-icon-stack .mini-brand img,
.flow-icon-stack .mini-brand svg {
  display: block;
  border-radius: 6px;
}

.flow-icon-stack .mini-brand + .mini-brand {
  margin-left: -8px;
}

.flow-arrow {
  color: var(--border);
  flex-shrink: 0;
}

/* --- 信任条 --- */
.trust-bar {
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  background: var(--surface);
}

.trust-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 32px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.trust-inner > span {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 1px;
  flex-shrink: 0;
}

.trust-logos {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.trust-logos > span {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}

.trust-logos .brand {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.trust-logos .brand .brand-icon {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  fill: currentColor;
}

/* 三个身份源图标统一尺寸与视觉大小 */
.trust-logos .brand .brand-icon-wide,
.trust-logos .brand .brand-icon-feishu,
.trust-logos .brand .brand-icon[alt="钉钉"] {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  box-sizing: border-box;
  display: block;
  object-fit: contain;
  overflow: hidden;
}

/* 企业微信：原图标偏大，去掉内缩 */
.trust-logos .brand .brand-icon-wide {
  padding: 0;
}

/* 飞书：原图标偏扁，放大 1.1 倍 */
.trust-logos .brand .brand-icon-feishu {
  transform: scale(1.1);
}

/* 钉钉：原图标填满，缩小 0.85 倍 */
.trust-logos .brand .brand-icon[alt="钉钉"] {
  transform: scale(0.85);
}

/* 微软 AD 图标 - 调小 */
.trust-logos .brand .brand-icon-ms {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

/* 大图标：群晖 / 威联通 */
.trust-logos .brand .brand-icon-large {
  width: 62px;
  height: 62px;
  flex-shrink: 0;
}

.trust-logos .brand img {
  border-radius: 4px;
}

.sep {
  width: 3px;
  height: 3px;
  background: var(--border);
  border-radius: 50%;
}

/* --- 通用 Section --- */
.section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 100px 32px;
}

.section.alt {
  background: var(--bg-alt);
  max-width: none;
  padding: 100px 32px;
}

.section.alt > .section-hd,
.section.alt > .scenario-cards,
.section.alt > .faq-list {
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.section-hd {
  text-align: center;
  margin-bottom: 60px;
}

.kicker {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 1.8px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-hd h2 {
  font-size: 38px;
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1.2;
}

/* --- 能力卡片 --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: box-shadow .2s, border-color .2s;
}

.feature-card:hover {
  box-shadow: var(--shadow);
  border-color: var(--border);
}

.f-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 12px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card > p {
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.65;
  margin-bottom: 16px;
}

.feature-card ul {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.feature-card ul li {
  font-size: 13px;
  color: var(--text-3);
  padding-left: 18px;
  position: relative;
}

.feature-card ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 7px;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  opacity: .5;
}

/* --- 场景卡片 --- */
.scenario-cards {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.scenario {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  display: flex;
  gap: 24px;
  transition: box-shadow .2s, border-color .2s;
}

.scenario:hover {
  box-shadow: var(--shadow);
  border-color: var(--border);
}

.scenario-num {
  font-size: 28px;
  font-weight: 800;
  color: var(--accent);
  opacity: .25;
  line-height: 1;
  flex-shrink: 0;
}

.scenario-body h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 6px;
}

.scenario-body > p {
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.6;
  margin-bottom: 14px;
}

.scenario-flow {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.scenario-flow span {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 12px;
  background: var(--bg-alt);
  border-radius: 6px;
  color: var(--text-2);
}

.s-arrow {
  background: none !important;
  color: var(--text-3) !important;
  padding: 0 !important;
  font-size: 14px !important;
}

/* --- 工作步骤 --- */
.steps-grid {
  display: flex;
  align-items: flex-start;
  gap: 0;
  margin-bottom: 40px;
  overflow-x: auto;
}

.step {
  flex: 1;
  text-align: center;
  min-width: 160px;
}

.step-circle {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 18px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.step h4 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
}

.step p {
  font-size: 13px;
  color: var(--text-2);
  line-height: 1.6;
  max-width: 200px;
  margin: 0 auto;
}

.step-connector {
  flex: 0 0 80px;
  height: 2px;
  background: var(--border);
  margin-top: 24px;
}

.deploy-note {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--accent-soft);
  border-radius: var(--radius);
  max-width: 560px;
  margin: 0 auto;
  font-size: 14px;
  color: var(--text-2);
}

.deploy-note strong { color: var(--text); }

.deploy-icon {
  color: var(--accent);
  flex-shrink: 0;
}

/* --- FAQ --- */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
}

details {
  border-bottom: 1px solid var(--border-light);
}

details:last-child { border-bottom: none; }

summary {
  padding: 20px 0;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  list-style: none;
}

summary::-webkit-details-marker { display: none; }

summary::after {
  content: '+';
  font-size: 20px;
  font-weight: 300;
  color: var(--text-3);
  transition: transform .25s;
}

details[open] summary::after {
  content: '−';
  transform: rotate(0);
}

.faq-answer {
  padding: 0 0 20px;
}

.faq-answer p {
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.7;
}

/* --- CTA --- */
.cta-card {
  background: var(--text);
  border-radius: var(--radius-xl);
  padding: 64px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 60px;
  align-items: center;
  color: #fff;
  overflow: hidden;
}

.cta-card .kicker {
  color: rgba(255,255,255,.5);
}

.cta-card h2 {
  font-size: 38px;
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1.2;
  margin-bottom: 16px;
}

.cta-card .cta-text > p {
  color: rgba(255,255,255,.55);
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 440px;
}

.cta-info {
  margin-bottom: 20px;
}

.cta-info-item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.cta-info-item span {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: rgba(255,255,255,.35);
}

.cta-info-item a {
  font-size: 18px;
  font-weight: 700;
  color: rgba(255,255,255,.8);
}

.cta-card .btn-primary {
  background: #fff;
  color: var(--text);
}

.cta-card .btn-primary:hover {
  background: #f0f2f5;
}

/* CTA 视觉装饰 */
.cta-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.cta-rings {
  width: 240px;
  height: 240px;
  position: relative;
}

.ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,.12);
  inset: 0;
}

.r1 { animation: pulse-ring 3s ease-in-out infinite; }
.r2 { inset: 24px; animation: pulse-ring 3s ease-in-out .3s infinite; }
.r3 { inset: 48px; animation: pulse-ring 3s ease-in-out .6s infinite; }

.ring-core {
  position: absolute;
  inset: 20px;
  border-radius: 50%;
  background: rgba(255,255,255,.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,.6);
  overflow: hidden;
}

@keyframes pulse-ring {
  0%, 100% { opacity: .5; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.04); }
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border-light);
  background: var(--surface);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-brand p {
  font-size: 12px;
  color: var(--text-3);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 13px;
  color: var(--text-3);
  transition: color .2s;
}

.footer-links a:hover { color: var(--text); }

.footer-copy p {
  font-size: 12px;
  color: var(--text-3);
}

/* --- 移动端汉堡菜单 --- */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  margin-left: auto;
  z-index: 101;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform .3s, opacity .3s;
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- 响应式 --- */
@media (max-width: 900px) {
  .nav-inner {
    padding: 0 20px;
    gap: 24px;
  }

  .nav-toggle {
    display: flex;
    order: 3;
    margin-left: 16px;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--surface);
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 80px 28px 28px;
    box-shadow: -8px 0 30px rgba(0,0,0,.08);
    transition: right .35s ease;
    z-index: 100;
    overflow-y: auto;
  }

  .nav-links.open {
    right: 0;
  }

  .nav-links a {
    display: block;
    padding: 14px 0;
    font-size: 16px;
    font-weight: 600;
    border-bottom: 1px solid var(--border-light);
    width: 100%;
  }

  .nav-links a:last-child {
    border-bottom: none;
  }

  .nav-cta {
    order: 2;
    margin-left: auto;
    padding: 10px 18px;
    font-size: 14px;
    border-radius: 8px;
  }

  .nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.35);
    z-index: 99;
  }

  .nav-overlay.active {
    display: block;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-text {
    text-align: center;
  }

  .hero-text h1 { font-size: 40px; }

  .hero-desc {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-btns {
    justify-content: center;
  }

  .hero-badges {
    justify-content: center;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .flow-card {
    flex-direction: column;
    gap: 20px;
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
    padding: 32px 24px;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }

  .flow-node {
    gap: 10px;
  }

  .flow-node strong {
    font-size: 14px;
  }

  .trust-inner {
    flex-direction: column;
    align-items: center;
    gap: 20px;
    padding: 24px 20px;
    text-align: center;
  }

  .trust-inner > span {
    font-size: 13px;
  }

  .trust-logos {
    gap: 14px;
    justify-content: center;
    flex-direction: column;
    align-items: center;
  }

  .trust-logos .brand {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    width: 100%;
    max-width: 200px;
  }

  .trust-logos .brand .brand-icon,
  .trust-logos .brand .brand-icon-wide,
  .trust-logos .brand .brand-icon-feishu,
  .trust-logos .brand .brand-icon[alt="钉钉"] {
    width: 32px;
    height: 32px;
  }

  .trust-logos .brand .brand-icon-ms { width: 24px; height: 24px; }
  .trust-logos .brand .brand-icon-large { width: 44px; height: 44px; }

  .scenario {
    flex-direction: column;
    gap: 12px;
    padding: 24px 20px;
  }

  .scenario-num {
    font-size: 22px;
  }

  .scenario-flow {
    gap: 6px;
  }

  .scenario-flow span {
    font-size: 11px;
    padding: 3px 10px;
  }

  .cta-card {
    grid-template-columns: 1fr;
    padding: 40px 28px;
    gap: 32px;
    text-align: center;
  }

  .cta-card h2 { font-size: 28px; }

  .cta-rings {
    width: 180px;
    height: 180px;
  }

  .r2 { inset: 18px; }
  .r3 { inset: 36px; }

  .ring-core { inset: 14px; }

  .steps-grid {
    flex-direction: column;
    align-items: center;
  }

  .step-connector {
    width: 2px;
    height: 32px;
    flex: 0 0 32px;
    margin: 0;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}

@media (max-width: 600px) {
  .nav-inner { height: 72px; padding: 0 16px; }
  .logo { font-size: 15px; gap: 8px; }
  .logo .logo-icon { width: 48px; height: 48px; }
  .nav-cta { padding: 8px 14px; font-size: 13px; }

  .hero { padding: 40px 20px 56px; }
  .hero-text h1 { font-size: 28px; letter-spacing: -1px; }
  .hero-desc { font-size: 15px; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { justify-content: center; }

  .section { padding: 56px 20px; }
  .section.alt { padding: 56px 20px; }
  .section-hd { margin-bottom: 32px; }
  .section-hd h2 { font-size: 24px; }
  .hero-badges { flex-wrap: wrap; gap: 10px; justify-content: center; }

  .feature-card { padding: 24px 20px; }

  .flow-card { padding: 28px 20px; max-width: 280px; }
  .flow-icon { width: 56px; height: 56px; }
  .flow-icon .flow-icon-img { width: 40px; height: 40px; }
  .flow-node strong { font-size: 13px; }

  .trust-inner { padding: 20px 16px; }
  .trust-logos { gap: 14px; }
  .trust-logos .brand { font-size: 13px; }
  .trust-logos .brand .brand-icon,
  .trust-logos .brand .brand-icon-wide,
  .trust-logos .brand .brand-icon-feishu,
  .trust-logos .brand .brand-icon[alt="钉钉"] {
    width: 28px;
    height: 28px;
  }
  .trust-logos .brand .brand-icon-ms { width: 20px; height: 20px; }
  .trust-logos .brand .brand-icon-large { width: 38px; height: 38px; }
  .sep { display: none; }

  .cta-card { padding: 28px 20px; }
  .cta-card h2 { font-size: 22px; }
  .cta-rings { width: 160px; height: 160px; }
  .r2 { inset: 16px; }
  .r3 { inset: 32px; }
  .ring-core { inset: 12px; }

  .faq-list { padding: 0; }
  summary { font-size: 15px; }

  .deploy-note {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  .footer-inner { padding: 24px 20px; }
}

/* ============================================
   能力扩展模块 (#expand)
   ============================================ */
.section-sub {
  max-width: 640px;
  margin: 12px auto 0;
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.6;
}

.expand-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 38px;
}

.expand-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 26px;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.expand-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: var(--accent);
}

.e-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 16px;
}

.expand-card h3 {
  font-size: 18px;
  color: var(--text);
  margin-bottom: 8px;
}

.expand-card > p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.55;
  margin-bottom: 12px;
}

.expand-card ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.expand-card li {
  position: relative;
  padding-left: 20px;
  color: var(--text-2);
  font-size: 13.5px;
  line-height: 1.5;
}

.expand-card li::before {
  content: "+";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
  font-weight: 700;
}

/* --- 响应式 --- */
@media (max-width: 900px) {
  .expand-grid { grid-template-columns: 1fr; gap: 16px; }
}

/* --- 右侧浮动按钮：返回顶部 / 底部 --- */
/* 默认放在屏幕右侧垂直居中位置 */
.scroll-actions {
  position: fixed;
  right: 18px;
  top: 50%;
  transform: translateY(-50%) translateY(12px);
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: 12px;
  opacity: 0;
  visibility: hidden;
  transition: opacity .3s ease, transform .3s ease, visibility .3s ease;
}

.scroll-actions.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(-50%);
}

.scroll-btn {
  width: 46px;
  height: 46px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--text-2);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: color .2s ease, background .2s ease, border-color .2s ease, transform .15s ease;
  -webkit-tap-highlight-color: transparent;
}

.scroll-btn:hover {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.scroll-btn:active {
  transform: translateY(0);
}

/* 移动端：缩小尺寸、靠右缘、保持右侧垂直居中 */
@media (max-width: 640px) {
  .scroll-actions {
    right: 12px;
    gap: 10px;
  }
  .scroll-btn {
    width: 42px;
    height: 42px;
  }
}

/* 尊重减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .scroll-actions {
    transition: opacity .2s ease;
  }
  .scroll-btn {
    transition: color .2s ease, background .2s ease, border-color .2s ease;
  }
  .scroll-btn:hover,
  .scroll-btn:active { transform: translateY(-50%); }
}