/* IFP Landing Page Styles
   主色 #1677ff,响应式,现代简洁风格 */

:root {
  --color-primary: #1677ff;
  --color-primary-dark: #0958d9;
  --color-primary-light: #4096ff;
  --color-primary-bg: #e6f4ff;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-border: #e5e7eb;
  --color-bg: #ffffff;
  --color-bg-soft: #f9fafb;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 32px rgba(22, 119, 255, 0.16);
  --max-width: 1120px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-primary-dark);
}

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

/* ─── 导航 ──────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
}

.nav-brand:hover {
  color: var(--color-primary);
}

.nav-logo {
  display: block;
}

.nav-title {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--color-text);
  font-size: 15px;
  font-weight: 500;
}

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

.nav-btn {
  padding: 8px 18px;
  background: var(--color-primary);
  color: #fff !important;
  border-radius: var(--radius-sm);
}

.nav-btn:hover {
  background: var(--color-primary-dark);
  color: #fff !important;
}

/* ─── 通用区块 ──────────────────────────────── */
.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 18px;
  color: var(--color-text-light);
  text-align: center;
  margin-bottom: 48px;
}

/* ─── Hero 区 ───────────────────────────────── */
.hero {
  background: linear-gradient(180deg, var(--color-primary-bg) 0%, #ffffff 100%);
  padding: 96px 24px 64px;
  text-align: center;
  overflow: hidden;
}

.hero-inner {
  max-width: 760px;
  margin: 0 auto;
}

.hero-title {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 24px;
  color: var(--color-text);
  font-weight: 600;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 17px;
  color: var(--color-text-light);
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.hero-note {
  font-size: 14px;
  color: var(--color-text-light);
}

/* ─── 按钮 ──────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.btn-icon {
  flex-shrink: 0;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 12px rgba(22, 119, 255, 0.32);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(22, 119, 255, 0.4);
}

.btn-secondary {
  background: #fff;
  color: var(--color-text);
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  transform: translateY(-1px);
}

.btn-lg {
  padding: 14px 30px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

/* ─── 截图区 ────────────────────────────────── */
.screenshot-section {
  max-width: var(--max-width);
  margin: -40px auto 0;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

.screenshot-wrap {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 12px;
  overflow: hidden;
}

.screenshot {
  width: 100%;
  border-radius: var(--radius-sm);
}

/* ─── 功能区 ────────────────────────────────── */
.features {
  background: var(--color-bg-soft);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
}

.feature-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-radius: 14px;
}

.feature-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ─── 价格区 ────────────────────────────────── */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  max-width: 720px;
  margin: 0 auto;
}

.pricing-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px 32px;
  position: relative;
  transition: transform 0.25s, box-shadow 0.25s;
}

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

.pricing-card-featured {
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-lg);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  padding: 4px 16px;
  border-radius: 999px;
  letter-spacing: 0.5px;
}

.pricing-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text-light);
  margin-bottom: 16px;
}

.pricing-price {
  font-size: 48px;
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 28px;
  line-height: 1;
}

.price-currency {
  font-size: 24px;
  font-weight: 600;
  vertical-align: top;
  margin-right: 2px;
}

.price-period {
  font-size: 18px;
  font-weight: 500;
  color: var(--color-text-light);
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
}

.pricing-features li {
  padding: 8px 0;
  font-size: 15px;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-bg-soft);
}

.pricing-features li:last-child {
  border-bottom: none;
}

.pricing-features li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 700;
  margin-right: 10px;
}

.pricing-note {
  text-align: center;
  margin-top: 32px;
  font-size: 14px;
  color: var(--color-text-light);
}

/* ─── CTA 区 ────────────────────────────────── */
.cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  text-align: center;
}

.cta-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
}

.cta-desc {
  font-size: 17px;
  opacity: 0.92;
  margin-bottom: 28px;
}

.cta .btn-primary {
  background: #fff;
  color: var(--color-primary);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.16);
}

.cta .btn-primary:hover {
  background: #f0f7ff;
  color: var(--color-primary-dark);
}

/* ─── Footer ────────────────────────────────── */
.footer {
  background: #1f2937;
  color: #d1d5db;
  padding: 48px 24px 32px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}

.footer-links {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-links a {
  color: #d1d5db;
  font-size: 14px;
}

.footer-links a:hover {
  color: #fff;
}

.footer-copy {
  font-size: 13px;
  color: #9ca3af;
  padding-top: 16px;
  border-top: 1px solid #374151;
  width: 100%;
  text-align: center;
}

/* ─── 响应式 ────────────────────────────────── */
@media (max-width: 900px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    gap: 16px;
  }
  .nav-links a:not(.nav-btn) {
    display: none;
  }
  .nav-links a.nav-btn {
    display: inline-flex;
  }

  .hero {
    padding: 64px 20px 48px;
  }
  .hero-title {
    font-size: 40px;
  }
  .hero-subtitle {
    font-size: 20px;
  }
  .hero-desc {
    font-size: 16px;
  }

  .section-inner {
    padding: 56px 20px;
  }
  .section-title {
    font-size: 28px;
  }
  .section-subtitle {
    font-size: 16px;
    margin-bottom: 36px;
  }

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

  .cta-title {
    font-size: 26px;
  }
}

@media (max-width: 520px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .hero-title {
    font-size: 32px;
  }
  .hero-actions {
    flex-direction: column;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .pricing-card {
    padding: 32px 24px;
  }
  .pricing-price {
    font-size: 40px;
  }
}