/* ==========================================================
   汤宝子讲HKDSE · 企业官网
   风格：零界面（Zero Interface）· 扁平化
   纯色块 / 无阴影无渐变 / 清晰边界 / 几何图形 / 12px 圆角
   ========================================================== */

/* ---------- 设计系统变量 ---------- */
:root {
  --visible-ui: minimal;
  --bg: #FAFAFA;
  --bg-alt: #F0F0F0;
  --bg-warm: #F5F1E8;
  --bg-card: #FFFFFF;
  --ink: #1C1C1E;
  --ink-soft: #4B5563;
  --line: #E4E4E7;
  --ok-bg: #DCFCE7;
  --ok-ink: #14532D;
  --err-bg: #FEE2E2;
  --err-ink: #7F1D1D;
  --radius: 12px;
  --space: 8px;
  --maxw: 1200px;
  --dur: .2s;
  --ease: cubic-bezier(.4, 0, .2, 1);
}

html[data-theme="dark"] {
  --bg: #17171A;
  --bg-alt: #212126;
  --bg-warm: #26241E;
  --bg-card: #1E1E22;
  --ink: #FAFAFA;
  --ink-soft: #A1A1AA;
  --line: #33333A;
  --ok-bg: #14351F;
  --ok-ink: #BBF7D0;
  --err-bg: #3B1616;
  --err-ink: #FECACA;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img, svg { display: inline-block; vertical-align: middle; }
a { color: var(--ink); text-decoration: none; }
ul, ol { list-style: none; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* 焦点可见 */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- 排版层级 ---------- */
h1, .h1 {
  font-size: clamp(2rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
h2, .h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
h3, .h3 { font-size: 18px; font-weight: 700; line-height: 1.3; }
.small { font-size: 14px; color: var(--ink-soft); line-height: 1.5; }
.tiny { font-size: 13px; font-weight: 500; line-height: 1.4; }

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .14em;
  color: var(--ink-soft);
  margin-bottom: 16px;
}

.lede {
  font-size: 18px;
  color: var(--ink-soft);
  max-width: 34em;
  line-height: 1.6;
}

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 64px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 17px;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand .logo-mark {
  width: 32px;
  height: 32px;
  flex: 0 0 32px;
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--bg);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}
.nav-list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-soft);
  border-radius: var(--radius);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.nav-list a:hover { color: var(--ink); background: var(--bg-alt); }
.nav-list a[aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
  background: var(--bg-alt);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.icon-btn {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  cursor: pointer;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.icon-btn:hover { background: var(--bg-alt); border-color: var(--ink); }
.nav-toggle { display: none; }

/* 移动端导航 */
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  #main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 8px 24px 16px;
  }
  #main-nav.is-open { display: block; }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; margin-left: 0; }
  .nav-list a { width: 100%; min-height: 48px; }
  .header-cta { display: none; }
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 24px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.4;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
              opacity var(--dur) var(--ease);
}
.btn:active { transform: scale(.97); }
.btn-primary { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn-primary:hover { opacity: .85; }
.btn-secondary { background: transparent; color: var(--ink); border-color: var(--ink); }
.btn-secondary:hover { background: var(--bg-alt); }
.btn-ghost {
  background: transparent;
  color: var(--ink-soft);
  border-color: transparent;
  text-decoration: underline;
  text-underline-offset: 4px;
  padding: 10px 12px;
}
.btn-ghost:hover { color: var(--ink); }
.btn-sm { min-height: 40px; padding: 8px 16px; font-size: 14px; }
.btn-lg { min-height: 52px; padding: 14px 32px; font-size: 16px; }
.btn[disabled], .btn[aria-disabled="true"] {
  opacity: .4;
  cursor: not-allowed;
  pointer-events: none;
}
.btn-block { width: 100%; }

/* ---------- 徽标 / chip ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .06em;
  text-transform: uppercase;
  border-radius: var(--radius);
  background: var(--bg-alt);
  color: var(--ink-soft);
  border: 1px solid var(--line);
}
.badge-ok { background: var(--ok-bg); color: var(--ok-ink); border-color: transparent; }
.badge-warm { background: var(--bg-warm); color: var(--ink); border-color: transparent; }
.badge-ink { background: var(--ink); color: var(--bg); border-color: transparent; }

.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-soft);
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.chip strong { color: var(--ink); font-weight: 700; }

/* ---------- 区块 ---------- */
.section { padding: 80px 0; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-warm { background: var(--bg-warm); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 34em; margin-bottom: 40px; }
.section-head .h2 { margin-bottom: 12px; }
.section-head p { color: var(--ink-soft); }

@media (max-width: 640px) {
  .section { padding: 56px 0; }
}

/* ---------- Hero ---------- */
.hero { padding: 88px 0 80px; overflow: hidden; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 48px;
  align-items: center;
}
.hero-title { margin-bottom: 24px; }
.hero-title .accent-block {
  background: var(--bg-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0 12px;
  display: inline-block;
}
.hero-sub {
  font-size: 18px;
  color: var(--ink-soft);
  max-width: 34em;
  margin-bottom: 32px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 40px; }

/* Hero 纯 CSS 几何装饰 */
.hero-visual {
  position: relative;
  min-height: 380px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  overflow: hidden;
}
.hero-visual .geo { position: absolute; }
.geo-circle {
  width: 200px; height: 200px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  top: 40px; left: 40px;
}
.geo-square {
  width: 140px; height: 140px;
  background: var(--bg-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  bottom: 56px; right: 48px;
}
.geo-block {
  width: 96px; height: 96px;
  background: var(--ink);
  border-radius: var(--radius);
  top: 120px; right: 96px;
}
.geo-ring {
  width: 72px; height: 72px;
  border: 2px solid var(--ink-soft);
  border-radius: 50%;
  bottom: 96px; left: 96px;
}
.geo-dots {
  top: 24px; right: 24px;
  width: 84px; height: 84px;
  background-image: radial-gradient(var(--ink-soft) 2px, transparent 2px);
  background-size: 16px 16px;
  opacity: .5;
}
.geo-label {
  position: absolute;
  left: 24px; bottom: 20px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

@media (max-width: 900px) {
  .hero { padding: 56px 0; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { min-height: 280px; }
  .geo-circle { width: 140px; height: 140px; }
  .geo-square { width: 100px; height: 100px; }
  .geo-block { width: 64px; height: 64px; right: 72px; }
}

/* ---------- 卡片 ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}
.card-grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card-grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 960px) {
  .card-grid, .card-grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .card-grid, .card-grid-2, .card-grid-4 { grid-template-columns: 1fr; }
}

.card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), background var(--dur) var(--ease);
}
a.card:hover, .card-hover:hover {
  border-color: var(--ink);
  transform: translateY(-2px);
}
.card-icon {
  width: 48px; height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  background: var(--bg-alt);
  border: 1px solid var(--line);
  color: var(--ink);
}
.card-warm .card-icon { background: var(--bg-warm); }
.card p { color: var(--ink-soft); font-size: 15px; }
.card-footer { margin-top: auto; padding-top: 8px; }
.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 44px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}
.card-link svg { transition: transform var(--dur) var(--ease); }
.card-link:hover svg { transform: translateX(4px); }

/* ---------- 开关 Toggle ---------- */
.toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.toggle-row:last-child { border-bottom: none; }
.toggle-label .t-title { font-size: 15px; font-weight: 700; }
.toggle-label .t-desc { font-size: 13px; color: var(--ink-soft); }
.toggle {
  position: relative;
  flex: 0 0 auto;
  width: 52px;
  height: 32px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg-alt);
  cursor: pointer;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.toggle::after {
  content: "";
  position: absolute;
  top: 3px; left: 3px;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--line);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}
.toggle[aria-checked="true"] { background: var(--ink); border-color: var(--ink); }
.toggle[aria-checked="true"]::after { transform: translateX(20px); background: var(--bg); border-color: var(--ink); }

/* ---------- 页面头（子页） ---------- */
.page-hero {
  padding: 64px 0 56px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-alt);
}
.page-hero .h1 { font-size: clamp(1.8rem, 4vw, 3rem); margin-bottom: 16px; }
.page-hero .lede { font-size: 17px; }
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-soft);
  margin-bottom: 24px;
}
.breadcrumb a { color: var(--ink-soft); text-decoration: underline; text-underline-offset: 3px; }
.breadcrumb a:hover { color: var(--ink); }
.breadcrumb .sep { opacity: .5; }

/* ---------- 数据/统计 ---------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}
@media (max-width: 960px) { .stat-grid { grid-template-columns: repeat(2, 1fr); } }
.stat {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
}
.stat .num {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.stat .label { font-size: 14px; color: var(--ink-soft); margin-top: 8px; }

/* ---------- 时间线 ---------- */
.timeline { border-left: 2px solid var(--line); padding-left: 32px; display: grid; gap: 32px; }
.timeline-item { position: relative; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -41px; top: 6px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--ink);
  border: 3px solid var(--bg);
}
.timeline-item .t-year {
  font-size: 13px; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--ink-soft); margin-bottom: 4px;
}
.timeline-item .h3 { margin-bottom: 8px; }
.timeline-item p { color: var(--ink-soft); font-size: 15px; max-width: 34em; }

/* ---------- 团队成员 ---------- */
.member-card { text-align: left; }
.avatar {
  width: 72px; height: 72px;
  border-radius: var(--radius);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 900;
  letter-spacing: -0.02em;
  background: var(--bg-warm);
  border: 1px solid var(--line);
  color: var(--ink);
}
.avatar-ink { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.avatar-alt { background: var(--bg-alt); }
.member-role { font-size: 13px; font-weight: 500; text-transform: uppercase; letter-spacing: .1em; color: var(--ink-soft); }

/* ---------- 详情页内容 ---------- */
.detail-grid {
  display: grid;
  grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
  gap: 48px;
  align-items: start;
}
@media (max-width: 900px) { .detail-grid { grid-template-columns: 1fr; gap: 32px; } }

.prose { max-width: 34em; }
.prose h2 { margin: 40px 0 16px; }
.prose h3 { margin: 24px 0 8px; }
.prose p { color: var(--ink-soft); margin-bottom: 16px; }
.prose p strong { color: var(--ink); }
.prose ul { display: grid; gap: 12px; margin-bottom: 24px; }
.prose ul li {
  position: relative;
  padding-left: 32px;
  color: var(--ink-soft);
}
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0; top: 7px;
  width: 16px; height: 16px;
  border-radius: 4px;
  background: var(--ok-bg);
  border: 1px solid var(--ok-ink);
}

.side-panel {
  position: sticky;
  top: 88px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  display: grid;
  gap: 16px;
}
.side-panel .price {
  font-size: 2rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.side-panel .price small { font-size: 14px; font-weight: 400; color: var(--ink-soft); }
.spec-list { display: grid; gap: 0; border-top: 1px solid var(--line); }
.spec-list li {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}
.spec-list .k { color: var(--ink-soft); }
.spec-list .v { font-weight: 700; text-align: right; }

/* FAQ */
.faq { display: grid; gap: 12px; }
.faq details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  overflow: hidden;
}
.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 52px;
  padding: 14px 20px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary .plus { flex: 0 0 auto; transition: transform var(--dur) var(--ease); }
.faq details[open] summary .plus { transform: rotate(45deg); }
.faq .faq-body { padding: 0 20px 20px; color: var(--ink-soft); font-size: 15px; max-width: 34em; }

/* ---------- 表单 ---------- */
.form-panel {
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
}
.form-grid { display: grid; gap: 24px; }
.form-grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
@media (max-width: 640px) { .form-grid-2 { grid-template-columns: 1fr; } }
.field { display: grid; gap: 8px; }
.field label { font-size: 14px; font-weight: 700; }
.field .hint { font-size: 13px; color: var(--ink-soft); }
.field input,
.field textarea,
.field select {
  width: 100%;
  min-height: 48px;
  padding: 12px 16px;
  font-family: inherit;
  font-size: 16px;
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease);
}
.field textarea { min-height: 140px; resize: vertical; }
.field input:hover, .field textarea:hover { border-color: var(--ink-soft); }
.field input:focus-visible, .field textarea:focus-visible { border-color: var(--ink); }
.form-msg {
  display: none;
  padding: 14px 18px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
}
.form-msg.ok { display: block; background: var(--ok-bg); color: var(--ok-ink); }
.form-msg.err { display: block; background: var(--err-bg); color: var(--err-ink); }

/* ---------- CTA 横幅 ---------- */
.cta-banner {
  padding: 64px 48px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--bg);
  display: grid;
  gap: 24px;
  justify-items: start;
}
.cta-banner .h2 { color: var(--bg); }
.cta-banner p { color: var(--bg); opacity: .75; max-width: 34em; }
.cta-banner .btn-primary { background: var(--bg); color: var(--ink); border-color: var(--bg); }
.cta-banner .btn-secondary { color: var(--bg); border-color: var(--bg); }
.cta-banner .btn-secondary:hover { background: rgba(255,255,255,.1); }
@media (max-width: 640px) { .cta-banner { padding: 40px 24px; } }

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: 0;
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding: 64px 24px 48px;
}
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .footer-grid { grid-template-columns: 1fr; gap: 32px; } }
.footer-brand p { color: var(--ink-soft); font-size: 14px; max-width: 26em; margin-top: 16px; }
.footer-col .f-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--ink-soft);
  margin-bottom: 16px;
}
.footer-col ul { display: grid; gap: 4px; }
.footer-col a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  font-size: 14px;
  color: var(--ink);
  border-radius: 8px;
  transition: color var(--dur) var(--ease);
}
.footer-col a:hover { color: var(--ink-soft); text-decoration: underline; text-underline-offset: 3px; }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-soft);
}

/* ---------- 工具类 ---------- */
.mt-8 { margin-top: 8px; } .mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; } .mt-32 { margin-top: 32px; } .mt-40 { margin-top: 40px; }
.mb-16 { margin-bottom: 16px; } .mb-24 { margin-bottom: 24px; }
.flex-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.divider { border: none; border-top: 1px solid var(--line); margin: 40px 0; }

/* 减弱动效 */
html[data-motion="off"] { scroll-behavior: auto; }
html[data-motion="off"] *,
html[data-motion="off"] *::before,
html[data-motion="off"] *::after {
  transition: none !important;
  animation: none !important;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}