/* === 棱石网络 - 智能抢答器 官网 === */
:root {
  --bg: #ffffff;
  --bg-card: #f8f9fb;
  --bg-surface: #eef1f6;
  --border: #e2e6ed;
  --accent: #2563eb;
  --accent2: #0891b2;
  --accent-light: rgba(37,99,235,0.06);
  --text: #1e293b;
  --text-muted: #64748b;
  --text-bright: #0f172a;
  --font-cn: "PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.1);
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-cn);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* === Header === */
.header {
  position: fixed; top:0; left:0; right:0; z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1300px; margin:0 auto;
  display:flex; align-items:center; justify-content:space-between;
  padding: 0 24px; height: 64px;
}

.logo-box {
  display:flex; align-items:center; gap:12px;
}

.logo-img { height: 36px; width: auto; }

.logo-tagline {
  font-size: 13px; color: var(--text-muted);
  border-left: 1px solid var(--border);
  padding-left: 14px;
}

.nav-links {
  display:flex; align-items:center; gap: 4px; list-style:none;
}

.nav-links a {
  color: var(--text-muted); text-decoration:none;
  padding: 8px 18px; border-radius: 8px;
  font-size: 15px; transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  background: var(--accent-light);
}

.header-actions { display:flex; align-items:center; }

.btn-primary {
  background: var(--accent);
  color: #fff; text-decoration:none;
  padding: 9px 24px; border-radius: 8px;
  font-size:14px; font-weight:600;
  transition: all 0.25s;
}

.btn-primary:hover {
  background: #1d4ed8;
  box-shadow: 0 2px 12px rgba(37,99,235,0.25);
}

/* === Main === */
.main-content { padding-top: 64px; }

/* === Hero === */
.hero {
  padding: 100px 24px 80px;
  text-align:center;
  max-width: 900px; margin:0 auto;
}

.hero-badge {
  display:inline-block;
  padding:6px 16px; border-radius:20px;
  border: 1px solid var(--border);
  background: var(--accent-light);
  color: var(--accent); font-size:13px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 48px; font-weight:800; color: var(--text-bright);
  line-height:1.3; margin-bottom: 16px;
  letter-spacing: -1px;
}

.hero h1 .gradient-text {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 18px; color: var(--text-muted);
  max-width: 600px; margin: 0 auto 36px;
}

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

.btn-hero-primary {
  background: var(--accent);
  color: #fff; text-decoration:none;
  padding: 14px 40px; border-radius: 10px;
  font-size:17px; font-weight:700;
  transition: all 0.25s;
  box-shadow: 0 2px 16px rgba(37,99,235,0.2);
}

.btn-hero-primary:hover {
  background: #1d4ed8;
  transform: translateY(-1px);
  box-shadow: 0 4px 24px rgba(37,99,235,0.3);
}

.btn-hero-secondary {
  color: var(--text); text-decoration:none;
  padding: 14px 36px; border: 1px solid var(--border);
  border-radius: 10px; font-size:17px; font-weight:600;
  transition: all 0.25s;
}

.btn-hero-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* === Hero Visual === */
.hero-visual { margin-top: 60px; }

.hero-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px;
  max-width: 750px; margin:0 auto;
  box-shadow: var(--shadow);
}

.hero-card-grid {
  display:grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
  margin-bottom: 24px;
}

.hero-card-item {
  background: var(--bg);
  border-radius: 10px; padding: 20px; text-align:center;
  border: 1px solid var(--border);
}

.hero-card-item .icon { font-size: 32px; margin-bottom: 8px; }
.hero-card-item .label { font-size: 13px; color: var(--text-muted); }

.hero-card-bar {
  height: 6px; background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 3px;
}

/* === Section === */
.section {
  padding: 80px 24px;
  max-width: 1300px; margin:0 auto;
}

.section-header {
  text-align:center; margin-bottom: 60px;
}

.section-label {
  font-size: 13px; color: var(--accent); font-weight:600;
  text-transform: uppercase; letter-spacing:2px;
  margin-bottom: 12px;
}

.section-title {
  font-size: 34px; font-weight:800; color: var(--text-bright);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px; color: var(--text-muted);
  max-width: 600px; margin:0 auto;
}

/* === Features === */
.features-grid {
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all 0.3s;
}

.feature-card:hover {
  border-color: #cbd5e1;
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.feature-icon { font-size: 36px; margin-bottom: 16px; }
.feature-card h3 { font-size: 20px; color: var(--text-bright); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }

/* === Stats === */
.stats-section {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 60px 0;
}

.stats-grid {
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  max-width: 1000px; margin:0 auto;
  text-align:center;
}

.stat-number {
  font-size: 46px; font-weight:800;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }

/* === Tutorial Cards === */
.tutorial-grid {
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 24px;
}

.tutorial-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow:hidden; transition: all 0.3s;
}

.tutorial-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.tutorial-thumb {
  height: 200px; background: var(--bg-surface);
  display:flex; align-items:center; justify-content:center;
  font-size: 48px;
}

.tutorial-body { padding: 24px; }
.tutorial-body .step { font-size: 12px; color: var(--accent); font-weight:600; margin-bottom: 6px; }
.tutorial-body h3 { font-size: 20px; color: var(--text-bright); margin-bottom: 8px; }
.tutorial-body p { font-size: 14px; color: var(--text-muted); margin-bottom: 16px; }
.tutorial-body .btn-link { color: var(--accent); text-decoration:none; font-size:14px; font-weight:600; }
.tutorial-body .btn-link:hover { color: var(--accent2); }

/* === Article Cards === */
.article-grid {
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 20px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all 0.25s;
  text-decoration:none; display:block;
}

.article-card:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-hover);
}

.article-card .date { font-size: 12px; color: var(--text-muted); margin-bottom: 8px; }
.article-card h3 { font-size: 18px; color: var(--text-bright); margin-bottom: 8px; line-height: 1.4; }
.article-card p { font-size: 14px; color: var(--text-muted); }

/* === CTA === */
.cta-section {
  text-align:center;
  padding: 80px 24px;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
}

.cta-section h2 { font-size: 34px; color: var(--text-bright); margin-bottom: 16px; }
.cta-section p { font-size: 16px; color: var(--text-muted); margin-bottom: 32px; }

.cta-buttons {
  display:flex; gap:16px; justify-content:center; flex-wrap:wrap;
}

/* === Footer === */
.footer {
  padding: 40px 24px; text-align:center;
  border-top: 1px solid var(--border);
}

.footer-links {
  display:flex; gap:24px; justify-content:center; flex-wrap:wrap;
  margin-bottom: 16px;
}

.footer-links a { color: var(--text-muted); text-decoration:none; font-size:14px; }
.footer-links a:hover { color: var(--accent); }

.copyright { font-size: 13px; color: var(--text-muted); }
.copyright a { color: var(--text-muted); text-decoration:none; }

/* === Sub Pages === */
.page-hero {
  padding: 100px 24px 60px;
  text-align:center;
  max-width: 800px; margin:0 auto;
}

.page-hero h1 {
  font-size: 38px; font-weight:800; color: var(--text-bright);
  margin-bottom: 12px;
}

.page-hero p { font-size: 16px; color: var(--text-muted); }

/* === Tutorial Detail === */
.tutorial-detail {
  max-width: 900px; margin:0 auto;
  padding: 0 24px 80px;
}

.tutorial-step {
  display:flex; gap:24px; margin-bottom: 48px;
  align-items:flex-start;
}

.step-number {
  flex-shrink:0;
  width:48px; height:48px;
  border-radius:50%;
  background: var(--accent);
  color:#fff; font-size:20px; font-weight:700;
  display:flex; align-items:center; justify-content:center;
}

.tutorial-step-content { flex:1; }

.tutorial-step-content h3 {
  font-size: 22px; color:var(--text-bright); margin-bottom:12px;
}

.tutorial-step-content p {
  font-size: 15px; color:var(--text-muted); line-height:1.8;
  margin-bottom:16px;
}

.tutorial-step-content .screenshot {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px; text-align:center;
  margin-top:16px;
}

.tutorial-step-content .screenshot img {
  max-width: 100%; border-radius: 6px;
}

.tip-box {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 10px;
  padding: 14px 20px;
  font-size:14px; color: var(--accent);
  margin: 16px 0;
}

.tip-box strong { color: var(--text-bright); }

.btn-outline {
  color: var(--accent); text-decoration:none;
  padding: 8px 20px; border: 1px solid var(--accent);
  border-radius: var(--radius-sm); font-size:14px;
  display:inline-block; transition: all 0.2s;
}

.btn-outline:hover { background: var(--accent-light); }

/* === Article Detail === */
.article-full {
  max-width: 800px; margin:0 auto;
  padding: 0 24px 80px;
}

.article-full h2 {
  font-size: 28px; color: var(--text-bright);
  margin: 40px 0 16px; padding-top: 24px;
  border-top: 1px solid var(--border);
}

.article-full h3 {
  font-size: 22px; color: var(--text-bright);
  margin: 32px 0 12px;
}

.article-full p {
  font-size: 16px; color: var(--text-muted);
  line-height:1.9; margin-bottom:16px;
}

.article-full ul, .article-full ol {
  padding-left: 24px; margin-bottom: 16px;
}

.article-full li {
  font-size: 15px; color: var(--text-muted);
  line-height:1.9;
}

.article-full .highlight-box {
  background: var(--accent-light);
  border-left: 3px solid var(--accent);
  padding: 20px 24px; border-radius: 0 10px 10px 0;
  margin: 24px 0; font-size: 15px; color: var(--text);
}

/* === Articles List === */
.articles-list {
  max-width: 900px; margin:0 auto;
  padding: 0 24px 60px;
}

.articles-list-item {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}

.articles-list-item:first-child { border-top: 1px solid var(--border); }

.articles-list-item a {
  text-decoration:none;
  display:flex; justify-content:space-between; align-items:center;
}

.articles-list-item h3 { font-size: 18px; color: var(--text-bright); }
.articles-list-item .date { font-size: 13px; color: var(--text-muted); flex-shrink:0; }
.articles-list-item p { font-size: 14px; color: var(--text-muted); margin-top:6px; }
.articles-list-item:hover h3 { color: var(--accent); }

/* === Responsive === */
@media (max-width: 768px) {
  .hero h1 { font-size: 30px; }
  .section-title { font-size: 26px; }
  .hero { padding: 60px 16px 40px; }
  .nav-links a { padding:6px 10px; font-size:13px; }
  .header-inner { padding:0 12px; height:56px; }
  .logo-tagline { display:none; }
  .tutorial-step { flex-direction:column; gap:12px; }
  .hero-card-grid { grid-template-columns: repeat(3,1fr); gap:8px; }
  .hero-card-item { padding:12px; }
  .hero-card-item .icon { font-size:24px; }
  .hero-card-item .label { font-size:11px; }
}