/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #3B82F6;
  --color-primary-dark: #2563EB;
  --color-primary-light: #EFF6FF;
  --color-accent: #6366F1;
  --color-bg: #F9FAFB;
  --color-surface: #FFFFFF;
  --color-text: #111827;
  --color-text-secondary: #6B7280;
  --color-text-muted: #9CA3AF;
  --color-border: #E5E7EB;
  --color-success: #10B981;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.10);
  --content-max: 640px;      /* Twitter 风格主内容宽度 */
  --page-max: 1040px;         /* 最大页面宽度 */
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
}

/* ===== Navbar（Twitter 风格：毛玻璃 + 细线） ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}

.nav-brand-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  color: var(--color-primary);
}

.nav-badge {
  font-size: 0.78rem;
  padding: 4px 14px;
  border-radius: 999px;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-weight: 500;
}

/* ===== Hero（保留原品牌渐变） ===== */
.hero {
  background: linear-gradient(135deg, #3B82F6 0%, #6366F1 50%, #4338CA 100%);
  color: #fff;
  text-align: center;
  padding: 64px 24px 56px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(255,255,255,0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 50%, rgba(255,255,255,0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: var(--content-max);
  margin: 0 auto;
}

.hero-badge-row {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.hero-badge {
  display: inline-block;
  font-size: 0.82rem;
  padding: 5px 16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(4px);
}

.hero-title {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
  line-height: 1.3;
}

.hero-subtitle {
  font-size: 1.1rem;
  opacity: 0.92;
  margin-bottom: 12px;
  font-weight: 400;
}

.hero-desc {
  font-size: 0.95rem;
  opacity: 0.8;
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ===== Container（流体 + 最大宽度限制） ===== */
.container {
  width: 100%;
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Section ===== */
.section {
  padding: 48px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 36px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.section-subtitle {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  max-width: 520px;
  margin: 0 auto;
}

/* ===== Notice Card ===== */
.section-notice {
  padding-top: 40px;
  padding-bottom: 20px;
}

.notice-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 28px 28px 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  display: flex;
  gap: 18px;
  align-items: flex-start;
}

.notice-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  border-radius: var(--radius-md);
  color: var(--color-primary);
}

.notice-icon svg {
  width: 22px;
  height: 22px;
}

.notice-body {
  flex: 1;
  min-width: 0;
}

.notice-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.notice-body p {
  font-size: 0.93rem;
  color: var(--color-text-secondary);
  line-height: 1.75;
  margin-bottom: 14px;
}

.notice-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.notice-tags span {
  display: inline-block;
  font-size: 0.8rem;
  padding: 4px 12px;
  border-radius: 999px;
  background: #ECFDF5;
  color: #065F46;
  border: 1px solid #A7F3D0;
  font-weight: 500;
}

/* ===== Tool Grid（响应式卡片网格） ===== */
.section-tools {
  padding-top: 24px;
  padding-bottom: 40px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.tool-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  display: flex;
  gap: 16px;
  align-items: flex-start;
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
  cursor: default;
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.tool-icon-wrap {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  border-radius: var(--radius-md);
  color: var(--color-primary);
}

.tool-svg {
  width: 24px;
  height: 24px;
}

.tool-body {
  flex: 1;
  min-width: 0;
}

.tool-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 4px;
}

.tool-desc {
  font-size: 0.86rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* ===== Platform Card ===== */
.section-platform {
  padding-top: 8px;
  padding-bottom: 56px;
}

.platform-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
}

.platform-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  border-radius: var(--radius-md);
  color: var(--color-primary);
}

.platform-icon svg {
  width: 24px;
  height: 24px;
}

.platform-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.platform-desc {
  font-size: 0.93rem;
  color: var(--color-text-secondary);
  max-width: 440px;
  margin: 0 auto;
}

/* ===== Footer ===== */
.footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
  text-align: center;
}

.footer-inner {
  max-width: var(--content-max);
  margin: 0 auto;
}

.footer-info {
  margin-bottom: 14px;
}

.footer-contact {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 6px;
}

.footer-contact a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
}

.footer-contact a:hover {
  text-decoration: underline;
}

.footer-icp {
  font-size: 0.85rem;
}

.footer-icp a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-icp a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .tool-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 12px;
  }

  .tool-card {
    padding: 20px;
    gap: 14px;
  }

  .tool-icon-wrap {
    width: 44px;
    height: 44px;
  }

  .tool-svg {
    width: 22px;
    height: 22px;
  }
}

@media (max-width: 600px) {
  .hero {
    padding: 48px 16px 40px;
  }

  .hero-title {
    font-size: 1.7rem;
  }

  .hero-subtitle {
    font-size: 0.98rem;
  }

  .hero-desc {
    font-size: 0.88rem;
  }

  .hero-badge {
    font-size: 0.76rem;
    padding: 4px 12px;
  }

  .section {
    padding: 32px 0;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .tool-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .notice-card {
    flex-direction: column;
    padding: 20px;
    gap: 14px;
  }

  .notice-icon {
    width: 40px;
    height: 40px;
  }

  .notice-icon svg {
    width: 20px;
    height: 20px;
  }

  .container {
    padding: 0 16px;
  }

  .nav-inner {
    padding: 0 16px;
    height: 50px;
  }

  .nav-badge {
    font-size: 0.72rem;
    padding: 3px 10px;
  }

  .brand-text {
    font-size: 0.95rem;
  }

  .platform-card {
    padding: 28px 20px;
  }
}

@media (max-width: 380px) {
  .hero-title {
    font-size: 1.45rem;
  }

  .nav-brand-icon {
    width: 28px;
    height: 28px;
  }

  .tool-card {
    padding: 16px;
    gap: 12px;
  }

  .tool-icon-wrap {
    width: 40px;
    height: 40px;
  }

  .tool-svg {
    width: 20px;
    height: 20px;
  }
}