/* ===== AI 工具训练营 - 蓝色科技风 ===== */
* { box-sizing: border-box; }
:root {
  --ink: #0f172a;
  --blue: #4f46e5;
  --blue-700: #4f46e5;
  --blue-50: #eef2ff;
  --muted: #64748b;
  --soft: #f8fafc;
  --line: #e2e8f0;
  --radius: 16px;
  --shadow: 0 8px 30px rgba(15, 23, 42, 0.06);
}
body {
  margin: 0;
  background: linear-gradient(180deg, #f0f7ff 0%, #ffffff 30%, #f8fbff 100%);
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", Inter, Arial, sans-serif;
  letter-spacing: 0;
  line-height: 1.6;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.container { width: min(100% - 48px, 1180px); margin: 0 auto; }

/* Topline */
.topline {
  background: linear-gradient(90deg, #1e1b4b, #4f46e5);
  color: #dbeafe;
  font-size: 12.5px;
  padding: 8px 0;
  overflow: hidden;
  white-space: nowrap;
}
.topline-track {
  display: inline-flex;
  gap: 60px;
  animation: topline-scroll 30s linear infinite;
  padding-left: 100%;
}
@keyframes topline-scroll {
  to { transform: translateX(-100%); }
}

/* Nav */
.nav {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 76px;
}
.brand { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.brand-logo {
  width: 44px; height: 44px; border-radius: 50%;
  object-fit: cover; display: block; flex: 0 0 auto;
}
.brand-name { font-weight: 800; font-size: 21px; line-height: 1.05; display: block; }
.brand-sub { color: var(--muted); font-size: 12px; margin-top: 4px; display: block; }
.nav-links {
  display: flex; align-items: center; gap: 4px;
  background: rgba(241, 245, 249, 0.7);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: 999px;
  padding: 5px;
}
.nav-links a {
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
  transition: all 0.2s;
}
.nav-links a:hover { background: rgba(79, 70, 229, 0.08); color: var(--blue); }
.nav-links a.active {
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  color: #fff;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}
.nav-actions { display: flex; align-items: center; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 14px; font-weight: 600;
  cursor: pointer; border: none;
  transition: all 0.2s;
  text-decoration: none;
}
.btn-primary {
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  color: #fff;
  box-shadow: 0 6px 16px rgba(79, 70, 229, 0.28);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 8px 20px rgba(79, 70, 229, 0.35); }
.btn-secondary {
  background: rgba(79, 70, 229, 0.08);
  color: var(--blue);
  border: 1px solid rgba(79, 70, 229, 0.2);
}
.btn-secondary:hover { background: rgba(79, 70, 229, 0.14); }

/* Breadcrumb */
.breadcrumb {
  padding: 20px 0;
  font-size: 13px;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 8px;
}
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb .sep { opacity: 0.4; }
.breadcrumb .current { color: var(--ink); font-weight: 600; }

/* Hero - 科技网格背景 */
.hero {
  position: relative;
  padding: 60px 0 80px;
  overflow: hidden;
}
.hero-bg-grid {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image:
    linear-gradient(rgba(79, 70, 229, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79, 70, 229, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}
.hero-inner { position: relative; text-align: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 16px;
  background: var(--blue-50);
  border: 1px solid rgba(79, 70, 229, 0.15);
  border-radius: 999px;
  font-size: 13px; font-weight: 600;
  color: var(--blue);
  margin-bottom: 24px;
}
.eyebrow-dot {
  width: 8px; height: 8px;
  background: var(--blue);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
.hero h1 {
  font-size: 56px;
  font-weight: 800;
  line-height: 1.1;
  margin: 0 0 24px;
  letter-spacing: -1px;
}
.hero h1 .accent {
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-lead {
  font-size: 18px;
  color: var(--muted);
  max-width: 680px;
  margin: 0 auto 36px;
  line-height: 1.7;
}
.hero-lead strong { color: var(--ink); }
.hero-actions {
  display: flex; gap: 12px; justify-content: center;
  margin-bottom: 48px;
}
.hero-stats {
  display: flex; gap: 40px; justify-content: center; flex-wrap: wrap;
}
.stat { text-align: center; }
.stat .num {
  display: block;
  font-size: 28px; font-weight: 800;
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat .lbl { font-size: 13px; color: var(--muted); }

/* Section */
section { padding: 60px 0; }
.soft-band { background: var(--soft); }
.section-head { margin-bottom: 40px; }
.kicker {
  font-size: 12px; font-weight: 700;
  color: var(--blue);
  letter-spacing: 1px;
  margin-bottom: 8px;
}
.section-head h2 {
  font-size: 36px; font-weight: 800;
  margin: 0; letter-spacing: -0.5px;
}

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(79, 70, 229, 0.12);
  border-color: rgba(79, 70, 229, 0.2);
}
.card-icon { font-size: 32px; margin-bottom: 16px; }
.feature-card h3 { font-size: 18px; margin: 0 0 10px; }
.feature-card p { font-size: 14px; color: var(--muted); margin: 0; line-height: 1.7; }
.tags { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 14px; }
.tags span {
  padding: 3px 10px;
  background: var(--blue-50);
  color: var(--blue);
  border-radius: 999px;
  font-size: 12px; font-weight: 500;
}

/* Timeline */
.timeline { max-width: 760px; margin: 0 auto; }
.timeline-item {
  display: flex; gap: 24px;
  padding-bottom: 32px;
  position: relative;
}
.timeline-item:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 60px; top: 44px; bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--blue), transparent);
}
.timeline-week {
  flex-shrink: 0;
  width: 60px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  color: #fff;
  border-radius: 12px;
  font-size: 12px; font-weight: 700;
  text-align: center;
  line-height: 1.2;
}
.timeline-content {
  flex: 1;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 24px;
  box-shadow: var(--shadow);
}
.timeline-content h3 { font-size: 17px; margin: 0 0 8px; }
.timeline-content p { font-size: 14px; color: var(--muted); margin: 0 0 12px; line-height: 1.7; }

/* CTA */
.cta-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  background: linear-gradient(135deg, #1e1b4b, #4f46e5);
  border-radius: 24px;
  padding: 48px;
  color: #fff;
  align-items: center;
}
.cta-text .kicker { color: #93c5fd; }
.cta-text h2 { font-size: 30px; margin: 8px 0 12px; }
.cta-text p { font-size: 15px; opacity: 0.85; margin: 0; line-height: 1.7; }
.cta-form { display: flex; flex-direction: column; gap: 12px; }
.cta-form .row { display: flex; gap: 12px; }
.cta-form .field {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  color: #fff;
  font-size: 14px;
  outline: none;
}
.cta-form .field::placeholder { color: rgba(255, 255, 255, 0.5); }
.cta-form .field option { color: #000; }
.cta-form .full { grid-column: 1 / -1; }
.cta-form .btn {
  background: #fff;
  color: var(--blue);
  font-weight: 700;
  padding: 14px;
  border-radius: 10px;
}
.cta-form .btn:hover { transform: translateY(-1px); }
.cta-note { font-size: 12px; opacity: 0.6; text-align: center; }

/* Footer */
.footer {
  background: #1e1b4b;
  color: #dbeafe;
  padding: 18px 0;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 8px;
}
.footer-links {
  display: flex; gap: 22px; font-size: 13px; color: #bfdbfe;
  justify-content: center; flex-wrap: wrap;
}
.footer-links a:hover { color: #fff; }
.footer-icp { font-size: 12px; color: #94a3b8; text-align: center; }

@media (max-width: 900px) {
  .container { width: min(100% - 32px, 1180px); }
  .nav-links { display: none; }
  .hero h1 { font-size: 36px; }
  .hero-stats { gap: 24px; }
  .cta-panel { grid-template-columns: 1fr; padding: 32px 24px; }
  .section-head h2 { font-size: 26px; }
  .timeline-item { flex-direction: column; gap: 12px; }
  .timeline-item:not(:last-child)::after { display: none; }
}