/* 云合一官网 — 数字墨屏视觉语言 */
:root {
  --accent: #5b9bd5;
  --accent-dim: #4a7fb0;
  --bg: #0b0e14;
  --bg-elevated: #141a24;
  --epaper: #e4e8ec;
  --epaper-warm: #d8dce0;
  --ink: #3a424c;
  --ink-light: #6b7580;
  --red: #c44;
  --white: #f5f7fa;
  --border: rgba(228, 232, 236, 0.12);
  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", Georgia, serif;
  --max-w: 1120px;
  --radius: 8px;
  --transition: 0.35s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: #7eb3e8;
}

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

/* ── 导航 ── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(11, 14, 20, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.08em;
}

.logo:hover {
  color: var(--white);
}

.logo-mark {
  width: 32px;
  height: 32px;
  background: var(--epaper);
  border-radius: 4px;
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: 0.85rem;
  color: var(--ink);
  font-weight: 900;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  color: var(--ink-light);
  font-size: 0.9rem;
}

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

.nav-cta {
  padding: 8px 18px;
  background: var(--accent);
  color: var(--bg) !important;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.85rem;
}

.nav-cta:hover {
  background: #7eb3e8;
  color: var(--bg) !important;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--white);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px;
}

/* ── 通用区块 ── */
.section {
  padding: 96px 24px;
}

.section-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.35;
}

.section-desc {
  color: var(--ink-light);
  max-width: 640px;
  font-size: 1.05rem;
}

/* ── Hero ── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 24px 80px;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(91, 155, 213, 0.08), transparent),
    var(--bg);
}

.hero-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-text h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 20px;
}

.hero-text h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--ink-light);
  margin-bottom: 28px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 36px;
}

.tag {
  padding: 6px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.82rem;
  color: var(--epaper);
}

.tag--red {
  border-color: rgba(204, 68, 68, 0.4);
  color: #e88;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform 0.15s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  background: #7eb3e8;
  color: var(--bg);
}

.btn-ghost {
  background: transparent;
  color: var(--epaper);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── 电子纸模拟器 ── */
.epd-frame {
  position: relative;
  background: #2a2f38;
  border-radius: 12px;
  padding: 16px;
  box-shadow:
    0 24px 64px rgba(0, 0, 0, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.epd-screen {
  background: var(--epaper);
  border-radius: 4px;
  overflow: hidden;
  aspect-ratio: 5 / 3;
  position: relative;
  transition: aspect-ratio var(--transition);
}

.epd-screen.portrait {
  aspect-ratio: 3 / 5;
  max-width: 280px;
  margin: 0 auto;
}

.epd-content {
  padding: 20px 24px;
  height: 100%;
  display: flex;
  flex-direction: column;
  color: var(--ink);
  font-size: 0.75rem;
}

.epd-brand {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
  letter-spacing: 0.3em;
}

.epd-date {
  font-size: 2.4rem;
  font-weight: 900;
  text-align: center;
  line-height: 1;
  margin: 12px 0 4px;
}

.epd-weekday {
  text-align: center;
  color: var(--ink-light);
  margin-bottom: 16px;
}

.epd-weather {
  display: flex;
  justify-content: center;
  gap: 24px;
  padding: 12px 0;
  border-top: 1px solid var(--epaper-warm);
  border-bottom: 1px solid var(--epaper-warm);
  margin-bottom: 12px;
}

.epd-weather span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.epd-footer-row {
  display: flex;
  justify-content: space-between;
  color: var(--ink-light);
  margin-top: auto;
  font-size: 0.7rem;
}

.epd-toggle {
  position: absolute;
  bottom: -48px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
}

.orient-btn {
  padding: 6px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--ink-light);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all var(--transition);
}

.orient-btn.active,
.orient-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── 卖点卡片 ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.feature-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: border-color var(--transition);
}

.feature-card:hover {
  border-color: rgba(91, 155, 213, 0.35);
}

.feature-icon {
  width: 44px;
  height: 44px;
  background: rgba(91, 155, 213, 0.12);
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  font-size: 1.3rem;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--ink-light);
  font-size: 0.92rem;
}

/* ── 架构图 ── */
.arch-wrap {
  margin-top: 48px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  overflow-x: auto;
}

.arch-wrap svg {
  margin: 0 auto;
}

/* ── 功能矩阵 ── */
.tier-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 48px;
}

.tier-card {
  border-radius: var(--radius);
  padding: 36px 32px;
  border: 1px solid var(--border);
}

.tier-card--free {
  background: var(--bg-elevated);
}

.tier-card--vip {
  background: linear-gradient(135deg, rgba(91, 155, 213, 0.1), rgba(204, 68, 68, 0.06));
  border-color: rgba(91, 155, 213, 0.3);
}

.tier-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.tier-badge--free {
  background: rgba(228, 232, 236, 0.1);
  color: var(--epaper);
}

.tier-badge--vip {
  background: rgba(204, 68, 68, 0.2);
  color: #e88;
}

.tier-card h3 {
  font-size: 1.3rem;
  margin-bottom: 20px;
}

.tier-list {
  list-style: none;
}

.tier-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  color: var(--ink-light);
  font-size: 0.92rem;
  display: flex;
  justify-content: space-between;
}

.tier-list li:last-child {
  border-bottom: none;
}

.tier-list strong {
  color: var(--white);
}

/* ── 配网步骤 ── */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.step {
  text-align: center;
  padding: 28px 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.step-num {
  width: 36px;
  height: 36px;
  background: var(--accent);
  color: var(--bg);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  margin: 0 auto 16px;
  font-size: 0.9rem;
}

.step h4 {
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.step p {
  font-size: 0.82rem;
  color: var(--ink-light);
}

/* ── FAQ ── */
.faq-list {
  margin-top: 40px;
  max-width: 720px;
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-q {
  width: 100%;
  background: none;
  border: none;
  color: var(--white);
  text-align: left;
  padding: 20px 0;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq-q::after {
  content: "+";
  color: var(--accent);
  font-size: 1.3rem;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item.open .faq-q::after {
  transform: rotate(45deg);
}

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition);
}

.faq-a-inner {
  padding: 0 0 20px;
  color: var(--ink-light);
  font-size: 0.92rem;
}

.faq-item.open .faq-a {
  max-height: 300px;
}

/* ── CTA ── */
.cta-band {
  background: linear-gradient(135deg, rgba(91, 155, 213, 0.15), rgba(91, 155, 213, 0.05));
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.cta-band .section-title {
  margin-bottom: 12px;
}

.cta-band p {
  color: var(--ink-light);
  margin-bottom: 32px;
}

.qrcode-wrap {
  display: flex;
  justify-content: center;
  margin-bottom: 24px;
}

.qrcode-img {
  border-radius: 8px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  max-width: 200px;
  height: auto;
}

/* ── 页脚 ── */
.site-footer {
  padding: 48px 24px 32px;
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}

.footer-brand p {
  color: var(--ink-light);
  font-size: 0.88rem;
  margin-top: 12px;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.85rem;
  color: var(--epaper);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--ink-light);
  font-size: 0.88rem;
}

.footer-col a:hover {
  color: var(--white);
}

.footer-bottom {
  max-width: var(--max-w);
  margin: 32px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.8rem;
  color: var(--ink-light);
}

/* ── 子页（法务/支持）── */
.page-hero {
  padding: 120px 24px 48px;
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  max-width: var(--max-w);
  margin: 0 auto;
}

.page-hero p {
  max-width: var(--max-w);
  margin: 12px auto 0;
  color: var(--ink-light);
}

.legal-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

.legal-content h2 {
  font-size: 1.2rem;
  margin: 36px 0 12px;
  color: var(--epaper);
}

.legal-content h2:first-child {
  margin-top: 0;
}

.legal-content p,
.legal-content li {
  color: var(--ink-light);
  font-size: 0.92rem;
  margin-bottom: 12px;
}

.legal-content ul {
  padding-left: 20px;
  margin-bottom: 16px;
}

.legal-content .updated {
  font-size: 0.82rem;
  color: var(--ink-light);
  margin-bottom: 32px;
}

/* ── 淡入动画 ── */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* ── 响应式 ── */
@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-text {
    order: 2;
    text-align: center;
  }

  .hero-tags,
  .hero-actions {
    justify-content: center;
  }

  .epd-wrap {
    order: 1;
  }

  .features-grid,
  .tier-grid {
    grid-template-columns: 1fr;
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px 24px;
    gap: 16px;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

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

  .section {
    padding: 72px 20px;
  }
}