:root {
  --bg: #f7f9fc;
  --surface: #ffffff;
  --text: #1f2937;
  --muted: #64748b;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #e2e8f0;
  --radius: 16px;
  --shadow: 0 10px 35px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: "Inter", sans-serif;
  color: var(--text);
  background: var(--bg);
}

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

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

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

.section {
  padding: 72px 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
}

.brand {
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  display: grid;
  place-items: center;
}

.main-nav {
  display: flex;
  gap: 24px;
  color: var(--muted);
}

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

.menu-btn {
  display: none;
  border: 0;
  background: transparent;
  font-size: 1.4rem;
  cursor: pointer;
}

.yang {
  padding: 80px 0 40px;
}

.yang-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
}

.tag {
  color: var(--primary);
  font-weight: 600;
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  margin: 12px 0;
}

.yang-desc {
  color: var(--muted);
  max-width: 60ch;
}

.yang-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 20px;
}

.btn {
  padding: 11px 18px;
  border-radius: 12px;
  font-weight: 600;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
}

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

.yang-panel .stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}

.stat-card p {
  color: var(--muted);
}

.stat-card ul {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.stat-card li {
  margin: 9px 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

.stat-card i {
  color: var(--primary);
}

.section-head {
  text-align: center;
  margin-bottom: 26px;
}

.section-head p {
  color: var(--muted);
}

.app-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.app-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.app-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.app-card-link {
  display: flex;
  gap: 16px;
  padding: 18px;
}

.app-icon {
  width: 74px;
  height: 74px;
  border-radius: 16px;
  object-fit: cover;
  flex-shrink: 0;
}

.app-content p {
  color: var(--muted);
  margin: 8px 0 0;
}

.card-actions {
  margin-top: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chip {
  font-size: 0.76rem;
  background: #dcfce7;
  color: #166534;
  border-radius: 999px;
  padding: 5px 9px;
}

.chip-soft {
  background: #dbeafe;
  color: #1e40af;
}

.text-link {
  color: var(--primary);
  font-weight: 600;
}

.about-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: 1.1fr 0.9fr;
}

.about p {
  color: var(--muted);
}

.about-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.about-box ul {
  list-style: none;
  padding: 0;
}

.about-box li {
  margin: 12px 0;
  display: flex;
  gap: 10px;
  align-items: center;
}

.about-box i {
  color: var(--primary);
}

.site-footer {
  border-top: 1px solid var(--border);
  background: #fff;
}

.footer-wrap {
  min-height: 72px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
}

.footer-links {
  display: flex;
  gap: 16px;
  color: var(--muted);
}

@media (max-width: 900px) {
  .yang-grid,
  .about-grid,
  .app-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .menu-btn {
    display: inline-flex;
  }

  .main-nav {
    position: absolute;
    top: 73px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 14px 4%;
  }

  .main-nav.show {
    display: flex;
  }
}