/* ==========================================================
   上线性能与顺滑度增强引擎 (Smoothness & Performance Optimization)
   ========================================================== */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  width: 100%;
}

*, *::before, *::after {
  box-sizing: border-box;
}

/* 硬件加速与流畅悬停 */
a, button, .media-news-card, .btn-media-primary, .btn-media-secondary, .faq-card, .intro-panel {
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  transform: translateZ(0);
}

/* 移动端平滑滚动与防抖 */
.table-wrapper, .table-container, .code-box, pre {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

/* 媒体图片防溢出与自适应 */
img, svg, video, canvas {
  max-width: 100%;
  height: auto;
  display: block;
}

/* 消除点击高亮延迟 */
a, button, input, select, textarea {
  -webkit-tap-highlight-color: transparent;
}

/* ==========================================================
   Stripe 风格渐变科技，流畅曲线背景 (Stripe-Inspired Gradient & Smooth Curves Theme)
   ========================================================== */

:root {
  --bg-body: #0b0f19;
  --bg-surface: #111827;
  --bg-card: rgba(17, 24, 39, 0.7);
  --bg-card-hover: rgba(31, 41, 55, 0.85);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(168, 85, 247, 0.4);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  /* Stripe 经典标志性高饱和流体渐变配色 */
  --stripe-indigo: #6366f1;
  --stripe-purple: #a855f7;
  --stripe-pink: #ec4899;
  --stripe-cyan: #38bdf8;
  --stripe-teal: #2dd4bf;
  --stripe-amber: #fbbf24;
  
  --grad-primary: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
  --grad-cyan-blue: linear-gradient(135deg, #38bdf8 0%, #6366f1 100%);
  --grad-mesh: radial-gradient(at 10% 10%, rgba(99, 102, 241, 0.25) 0px, transparent 50%),
               radial-gradient(at 90% 20%, rgba(236, 72, 153, 0.2) 0px, transparent 50%),
               radial-gradient(at 50% 80%, rgba(56, 189, 248, 0.2) 0px, transparent 50%),
               radial-gradient(at 80% 90%, rgba(168, 85, 247, 0.25) 0px, transparent 50%);
               
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shadow-stripe: 0 10px 30px -10px rgba(99, 102, 241, 0.3), 0 20px 40px -15px rgba(236, 72, 153, 0.2);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.25);
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

body {
  background-color: var(--bg-body);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* 顶部声明栏 */
.top-declaration-bar {
  background: #070a12;
  border-bottom: 1px solid var(--border-subtle);
  padding: 8px 0;
  font-size: 12.5px;
}

.dec-content {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.dec-badge {
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
  border: 1px solid rgba(99, 102, 241, 0.3);
  padding: 2px 8px;
  border-radius: 6px;
  font-weight: 700;
  font-size: 11px;
}

.dec-text {
  color: var(--text-muted);
  flex: 1;
  margin: 0;
}

/* Header */
.site-header {
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.3px;
}

.gradient-text {
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.main-nav {
  display: flex;
  gap: 24px;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 14.5px;
  transition: var(--transition);
  padding: 8px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--grad-primary);
  border-radius: 2px;
}

.btn-header-action {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #fff;
  font-weight: 700;
  font-size: 13.5px;
  padding: 9px 20px;
  border-radius: 9999px;
  text-decoration: none;
  transition: var(--transition);
  backdrop-filter: blur(8px);
}

.btn-header-action:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-1px);
}

/* Stripe 风格渐变与曲线 Hero 区域 */
.stripe-hero-section {
  position: relative;
  padding: 80px 0 100px;
  background: var(--grad-mesh);
  background-color: var(--bg-body);
  text-align: center;
  overflow: hidden;
}

.stripe-glow-orb {
  position: absolute;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.35;
  pointer-events: none;
  z-index: 1;
}

.orb-left {
  top: -150px;
  left: -100px;
  background: #6366f1;
}

.orb-right {
  top: 50px;
  right: -150px;
  background: #ec4899;
}

.hero-pill-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(12px);
  padding: 6px 18px;
  border-radius: 9999px;
  font-size: 13px;
  font-weight: 600;
  color: #c7d2fe;
  margin-bottom: 24px;
}

.hero-h1 {
  font-size: 44px;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -1px;
  color: #fff;
  margin-bottom: 20px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-h1 .gradient-title {
  background: linear-gradient(135deg, #ffffff 0%, #c7d2fe 50%, #f472b6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 820px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.btn-stripe-primary {
  background: var(--grad-primary);
  color: #fff;
  font-weight: 700;
  font-size: 16px;
  padding: 14px 34px;
  border-radius: 9999px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-stripe);
  transition: var(--transition);
}

.btn-stripe-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 35px -5px rgba(99, 102, 241, 0.5), 0 25px 45px -10px rgba(236, 72, 153, 0.4);
}

.btn-stripe-secondary {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: #fff;
  font-weight: 700;
  font-size: 16px;
  padding: 14px 32px;
  border-radius: 9999px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  backdrop-filter: blur(12px);
  transition: var(--transition);
}

.btn-stripe-secondary:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.35);
  transform: translateY(-2px);
}

/* 流畅曲线背景分割器 (Smooth Curved Wave Dividers) */
.curve-divider {
  position: relative;
  width: 100%;
  overflow: hidden;
  line-height: 0;
  transform: translateZ(0);
}

.curve-divider svg {
  position: relative;
  display: block;
  width: calc(100% + 1.3px);
  height: 70px;
}

/* Stripe 风格功能卡片区与六宫格 */
.section {
  padding: 60px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 40px;
}

.section-badge {
  display: inline-block;
  background: rgba(168, 85, 247, 0.12);
  color: #d8b4fe;
  border: 1px solid rgba(168, 85, 247, 0.3);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 9999px;
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.section-title {
  font-size: 32px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.5px;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 15px;
  margin-top: 8px;
  max-width: 660px;
  margin-left: auto;
  margin-right: auto;
}

.grid-six {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stripe-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 28px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.stripe-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--grad-primary);
  opacity: 0;
  transition: var(--transition);
}

.stripe-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: 0 16px 32px -8px rgba(0, 0, 0, 0.4), 0 0 20px rgba(168, 85, 247, 0.15);
}

.stripe-card:hover::before {
  opacity: 1;
}

.card-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(236, 72, 153, 0.2) 100%);
  border: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
}

.card-title {
  font-size: 19px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}

.card-desc {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 20px;
  flex: 1;
}

.card-link {
  color: #a5b4fc;
  font-weight: 700;
  font-size: 13.5px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.card-link:hover {
  color: #fff;
  gap: 10px;
}

/* 正文介绍区：“教程中心”与“我们提供什么” */
.intro-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.intro-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 34px;
  position: relative;
  overflow: hidden;
}

.intro-panel-gradient {
  background: linear-gradient(135deg, rgba(17, 24, 39, 0.95) 0%, rgba(30, 27, 75, 0.5) 100%);
}

.panel-title {
  font-size: 22px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.intro-list {
  list-style: none;
}

.intro-list li {
  position: relative;
  padding-left: 26px;
  margin-bottom: 16px;
  color: var(--text-muted);
  font-size: 14.5px;
  line-height: 1.6;
}

.intro-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--stripe-teal);
  font-weight: 900;
  font-size: 15px;
}

.intro-list strong {
  color: #fff;
}

/* 热门教程表格 (Stripe 美学表格) */
.table-wrapper {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.stripe-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.stripe-table th {
  background: rgba(255, 255, 255, 0.03);
  color: #cbd5e1;
  font-weight: 700;
  font-size: 14px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-subtle);
  letter-spacing: 0.3px;
}

.stripe-table td {
  padding: 16px 20px;
  color: var(--text-muted);
  font-size: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.stripe-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
  color: var(--text-main);
}

.badge-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 700;
}

.badge-easy {
  background: rgba(45, 212, 191, 0.15);
  color: #2dd4bf;
  border: 1px solid rgba(45, 212, 191, 0.3);
}

.badge-medium {
  background: rgba(251, 191, 36, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(251, 191, 36, 0.3);
}

.badge-hard {
  background: rgba(236, 72, 153, 0.15);
  color: #f472b6;
  border: 1px solid rgba(236, 72, 153, 0.3);
}

.tbl-link {
  color: #a5b4fc;
  text-decoration: none;
  font-weight: 700;
  transition: var(--transition);
}

.tbl-link:hover {
  color: #fff;
  text-decoration: underline;
}

/* FAQ 常见问答模块 */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
}

.faq-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 26px;
  transition: var(--transition);
}

.faq-card:hover {
  border-color: rgba(99, 102, 241, 0.35);
  transform: translateY(-2px);
}

.faq-q {
  font-size: 16.5px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.faq-q-num {
  color: var(--stripe-pink);
  font-family: var(--font-mono);
  font-size: 14px;
}

.faq-a {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.65;
}

/* 延伸阅读与免责入口卡片 */
.extended-reading {
  background: linear-gradient(135deg, rgba(30, 27, 75, 0.6) 0%, rgba(17, 24, 39, 0.9) 100%);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 30px 36px;
  margin-top: 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
}

.reading-info h4 {
  font-size: 18px;
  color: #fff;
  margin-bottom: 6px;
  font-weight: 800;
}

.reading-info p {
  color: var(--text-muted);
  font-size: 14px;
}

.reading-actions {
  display: flex;
  gap: 14px;
}

/* 子页面通用文章样式 */
.page-hero {
  padding: 60px 0 40px;
  background: var(--grad-mesh);
  background-color: #0d1322;
  border-bottom: 1px solid var(--border-subtle);
  position: relative;
}

.page-title {
  font-size: 34px;
  font-weight: 900;
  color: #fff;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.page-subtitle {
  color: #cbd5e1;
  font-size: 16px;
  max-width: 820px;
}

.content-section {
  padding: 50px 0;
}

.article-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 40px;
  color: #cbd5e1;
  line-height: 1.8;
  box-shadow: var(--shadow-card);
}

.article-content h2 {
  font-size: 24px;
  color: #fff;
  margin: 34px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-content h2::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 20px;
  background: var(--grad-primary);
  border-radius: 2px;
}

.article-content h3 {
  font-size: 18px;
  color: #c7d2fe;
  margin: 24px 0 12px;
}

.article-content p {
  margin-bottom: 16px;
  font-size: 15px;
}

.article-content ul, .article-content ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 8px;
}

.article-content strong {
  color: #fff;
}

.tool-callout {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(236, 72, 153, 0.05) 100%);
  border-left: 4px solid var(--stripe-purple);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: #e2e8f0;
}

.code-box {
  background: #060911;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 18px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: #38bdf8;
  overflow-x: auto;
  margin: 20px 0;
}

/* 页脚 */
.site-footer {
  position: relative;
  margin-top: 60px;
}

.curve-divider-top svg {
  display: block;
  width: 100%;
  height: 60px;
}

.footer-main {
  background: #070a12;
  border-top: 1px solid var(--border-subtle);
  padding: 50px 0 34px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 48px;
  margin-bottom: 36px;
}

.footer-desc {
  color: var(--text-dim);
  font-size: 13.5px;
  margin: 16px 0;
  line-height: 1.6;
  max-width: 420px;
}

.copyright {
  color: var(--text-dim);
  font-size: 12.5px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.link-col h4 {
  color: #f1f5f9;
  font-size: 14.5px;
  margin-bottom: 16px;
  font-weight: 700;
}

.link-col a {
  display: block;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 13.5px;
  margin-bottom: 10px;
  transition: var(--transition);
}

.link-col a:hover {
  color: #c7d2fe;
}

/* 响应式断点 */
@media (max-width: 992px) {
  .grid-six {
    grid-template-columns: repeat(2, 1fr);
  }
  .intro-container {
    grid-template-columns: 1fr;
  }
  .faq-grid {
    grid-template-columns: 1fr;
  }
  .footer-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }
  .hero-h1 {
    font-size: 28px;
  }
  .grid-six {
    grid-template-columns: 1fr;
  }
  .footer-links {
    grid-template-columns: 1fr 1fr;
  }
}