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

:root {
  --color-primary:   #4f46e5;
  --color-primary-d: #3730a3;
  --color-primary-l: #818cf8;
  --color-accent:    #06b6d4;

  --color-bg:        #f8fafc;
  --color-surface:   #ffffff;
  --color-border:    #e2e8f0;
  --color-text:      #1e293b;
  --color-muted:     #64748b;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --shadow-card: 0 4px 24px rgba(0,0,0,.08);
  --shadow-hero: 0 20px 60px rgba(79,70,229,.18);
}

html { scroll-behavior: smooth; }

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

body.theme-sky {
  --color-primary: #0ea5e9;
  --color-primary-d: #0369a1;
  --color-primary-l: #7dd3fc;
  --color-accent: #22d3ee;
}

body.theme-emerald {
  --color-primary: #10b981;
  --color-primary-d: #047857;
  --color-primary-l: #6ee7b7;
  --color-accent: #14b8a6;
}

body.theme-amber {
  --color-primary: #f59e0b;
  --color-primary-d: #b45309;
  --color-primary-l: #fcd34d;
  --color-accent: #fb7185;
}

body.theme-red {
  --color-primary: #ef4444;
  --color-primary-d: #b91c1c;
  --color-primary-l: #fca5a5;
  --color-accent: #f97316;
}

/* ================================================
   导航栏
=============================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
}

.nav-logo .logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: .85rem;
}

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

.nav-links a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: .9rem;
  transition: color .2s;
}

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

.nav-cta {
  background: var(--color-primary);
  color: #fff !important;
  padding: 7px 18px;
  border-radius: 999px;
  font-weight: 600;
  transition: background .2s !important;
}

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

/* ================================================
   Hero
=============================================== */
.hero {
  background: linear-gradient(135deg, #eef2ff 0%, #e0f2fe 100%);
  padding: 80px 24px 100px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(79,70,229,.12) 0%, transparent 70%);
  top: -200px;
  right: -100px;
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(79,70,229,.1);
  color: var(--color-primary);
  border: 1px solid rgba(79,70,229,.2);
  padding: 4px 14px;
  border-radius: 999px;
  font-size: .82rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  color: var(--color-text);
  margin-bottom: 20px;
}

.hero h1 span {
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.1rem;
  color: var(--color-muted);
  max-width: 560px;
  margin: 0 auto 36px;
}

.hero-btns {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 999px;
  font-size: .95rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  border: none;
  transition: all .2s;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 20px rgba(79,70,229,.35);
}

.btn-primary:hover {
  background: var(--color-primary-d);
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(79,70,229,.45);
}

.btn-outline {
  background: #fff;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover { background: #eef2ff; }

.btn-large {
  font-size: 1rem;
  padding: 14px 36px;
}

/* ================================================
   统计数字
=============================================== */
.stats-wrapper {
  padding: 0 24px;
}

.stats {
  max-width: 800px;
  margin: -40px auto 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  position: relative;
  z-index: 10;
}

.stat-item {
  background: var(--color-surface);
  padding: 28px 20px;
  text-align: center;
}

.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
}

.stat-label {
  font-size: .85rem;
  color: var(--color-muted);
  margin-top: 4px;
}

/* ================================================
   功能特性卡片
=============================================== */
.section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 80px 24px;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  display: inline-block;
  background: rgba(79,70,229,.08);
  color: var(--color-primary);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 14px;
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 12px;
}

.section-desc {
  color: var(--color-muted);
  max-width: 520px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
  border-color: rgba(79,70,229,.3);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.feature-icon-tone-indigo-soft { background: #eef2ff; }
.feature-icon-tone-green-soft { background: #f0fdf4; }
.feature-icon-tone-orange-soft { background: #fff7ed; }
.feature-icon-tone-pink-soft { background: #fdf4ff; }
.feature-icon-tone-blue-soft { background: #eff6ff; }
.feature-icon-tone-yellow-soft { background: #fef9c3; }
.feature-icon-tone-default { background: #eef2ff; }

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: .88rem;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ================================================
   服务承诺
=============================================== */
.promise-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, #312e81 100%);
  color: #fff;
  padding: 80px 24px;
  text-align: center;
}

.promise-section .section-title { color: #fff; }
.promise-section .section-desc { color: rgba(255,255,255,.7); }
.promise-section .section-tag {
  background: rgba(255,255,255,.15);
  color: #fff;
}

.promise-grid {
  max-width: 900px;
  margin: 40px auto 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
}

.promise-item {
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius-md);
  padding: 24px 20px;
}

.promise-item .p-icon { font-size: 2rem; margin-bottom: 12px; }
.promise-item h4 { font-weight: 700; margin-bottom: 6px; }
.promise-item p { font-size: .85rem; color: rgba(255,255,255,.65); }

/* ================================================
   联系 CTA
=============================================== */
.cta-section {
  max-width: 700px;
  margin: 80px auto;
  padding: 0 24px;
  text-align: center;
}

.cta-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 56px 40px;
  box-shadow: var(--shadow-card);
}

.cta-box h2 {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.cta-box p {
  color: var(--color-muted);
  margin-bottom: 32px;
}

/* ================================================
   页脚
=============================================== */
.footer {
  background: #0f172a;
  color: rgba(255,255,255,.5);
  text-align: center;
  padding: 32px 24px;
  font-size: .85rem;
}

.footer a { color: rgba(255,255,255,.6); text-decoration: none; }
.footer a:hover { color: #fff; }

/* ================================================
   响应式
=============================================== */
@media (max-width: 640px) {
  .nav-links { display: none; }
  .hero { padding: 60px 20px 80px; }
  .stats { grid-template-columns: 1fr; }
  .stat-item { padding: 20px; }
  .stat-num { font-size: 1.6rem; }
  .features-grid { grid-template-columns: 1fr; }
  .promise-grid { grid-template-columns: 1fr 1fr; }
  .cta-box { padding: 36px 24px; }
}

@media (max-width: 400px) {
  .promise-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; align-items: center; }
}