/* ========================================
   严选讲师网 - 老有所为主题页 公共样式
   ======================================== */

/* CSS Variables */
:root {
  --gold: #C5973E;
  --gold-light: #D4AD5E;
  --gold-dark: #A67C2E;
  --dark: #1A1A2E;
  --dark-soft: #2D2D3F;
  --red: #B8382E;
  --red-light: #D4544A;
  --bg: #FBF8F1;
  --bg-warm: #F5F0E6;
  --white: #FFFFFF;
  --text-primary: #2D2D2D;
  --text-secondary: #5A5A5A;
  --text-light: #8A8A8A;
  --border: #E8E2D6;
  --shadow: rgba(42, 42, 42, 0.08);
  --shadow-md: rgba(42, 42, 42, 0.12);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--gold-dark);
  text-decoration: none;
  transition: color 0.3s;
}

a:hover {
  color: var(--gold);
}

img {
  max-width: 100%;
  height: auto;
}

/* ============ Navigation ============ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s;
}

.nav.scrolled {
  box-shadow: 0 2px 20px var(--shadow);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--dark);
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
  font-weight: 900;
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 500;
  padding: 4px 0;
  position: relative;
  transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--gold-dark);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gold);
  border-radius: 1px;
}

.nav-cta {
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: white !important;
  padding: 8px 24px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: transform 0.2s, box-shadow 0.3s;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(197, 151, 62, 0.4);
  color: white !important;
}

/* ============ Hero Section ============ */
.hero {
  padding: 140px 24px 80px;
  min-height: 85vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 150%;
  background: radial-gradient(ellipse, rgba(197,151,62,0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(197,151,62,0.1);
  border: 1px solid rgba(197,151,62,0.2);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--gold-dark);
  font-weight: 500;
  margin-bottom: 24px;
}

.hero-badge-dot {
  width: 6px;
  height: 6px;
  background: var(--gold);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--dark);
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

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

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 36px;
  max-width: 520px;
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: white;
  padding: 14px 36px;
  border-radius: 28px;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s;
  border: none;
  cursor: pointer;
  text-decoration: none;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(197, 151, 62, 0.35);
  color: white;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--white);
  color: var(--dark);
  padding: 14px 36px;
  border-radius: 28px;
  font-weight: 600;
  font-size: 1rem;
  border: 1.5px solid var(--border);
  transition: all 0.3s;
  cursor: pointer;
  text-decoration: none;
}

.btn-secondary:hover {
  border-color: var(--gold);
  color: var(--gold-dark);
  transform: translateY(-2px);
}

.hero-visual {
  position: relative;
}

.hero-image-wrapper {
  position: relative;
  border-radius: 24px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(42, 42, 42, 0.12);
}

.hero-image-wrapper img {
  width: 100%;
  height: 480px;
  object-fit: cover;
  display: block;
}

.hero-image-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 40%;
  background: linear-gradient(to top, rgba(26,26,46,0.6), transparent);
}

.hero-stat-card {
  position: absolute;
  bottom: -24px;
  left: -24px;
  background: white;
  padding: 20px 28px;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-md);
  display: flex;
  gap: 24px;
  z-index: 2;
}

.hero-stat-item {
  text-align: center;
}

.hero-stat-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--gold-dark);
}

.hero-stat-label {
  font-size: 0.8rem;
  color: var(--text-light);
  margin-top: 2px;
}

/* ============ Section Common ============ */
.section {
  padding: 80px 24px;
}

.section-inner {
  max-width: 1200px;
  margin: 0 auto;
}

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

.section-tag {
  display: inline-block;
  background: rgba(197,151,62,0.1);
  color: var(--gold-dark);
  padding: 4px 16px;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 16px;
  line-height: 1.3;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ============ Feature Cards ============ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--white);
  border-radius: 20px;
  padding: 36px 28px;
  border: 1px solid var(--border);
  transition: all 0.3s;
  cursor: pointer;
  text-decoration: none;
  display: block;
  color: inherit;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px var(--shadow-md);
  border-color: var(--gold-light);
  color: inherit;
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.feature-icon.gold {
  background: rgba(197,151,62,0.1);
}

.feature-icon.red {
  background: rgba(184,56,46,0.08);
}

.feature-icon.dark {
  background: rgba(26,26,46,0.08);
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--dark);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.feature-link {
  font-size: 0.9rem;
  color: var(--gold-dark);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.feature-link::after {
  content: '→';
  transition: transform 0.2s;
}

.feature-card:hover .feature-link::after {
  transform: translateX(4px);
}

/* ============ Stats Section ============ */
.stats-section {
  background: var(--dark);
  padding: 64px 24px;
  position: relative;
  overflow: hidden;
}

.stats-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(197,151,62,0.08), transparent);
  pointer-events: none;
}

.stats-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  position: relative;
  z-index: 1;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--gold);
  line-height: 1.1;
}

.stat-suffix {
  font-size: 1.2rem;
  color: var(--gold-light);
  margin-left: 2px;
}

.stat-label {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.7);
  margin-top: 8px;
}

/* ============ Expert Cards ============ */
.experts-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.expert-card {
  background: var(--white);
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--border);
  transition: all 0.3s;
  display: grid;
  grid-template-columns: 180px 1fr;
}

.expert-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--shadow-md);
}

.expert-photo {
  width: 100%;
  height: 100%;
  min-height: 240px;
  object-fit: cover;
}

.expert-info {
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.expert-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 4px;
}

.expert-title {
  font-size: 0.85rem;
  color: var(--gold-dark);
  font-weight: 500;
  margin-bottom: 12px;
}

.expert-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.expert-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.expert-tag {
  padding: 3px 12px;
  background: var(--bg);
  border-radius: 12px;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

/* ============ Process Steps ============ */
.process-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  position: relative;
}

.process-steps::before {
  content: '';
  position: absolute;
  top: 48px;
  left: 15%;
  right: 15%;
  height: 2px;
  background: linear-gradient(to right, var(--gold-light), var(--border), var(--gold-light));
}

.process-step {
  text-align: center;
  position: relative;
  z-index: 1;
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: white;
  font-size: 1.3rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  box-shadow: 0 4px 16px rgba(197,151,62,0.3);
}

.step-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 10px;
}

.step-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 260px;
  margin: 0 auto;
}

/* ============ Quote Section ============ */
.quote-section {
  background: var(--bg-warm);
  padding: 80px 24px;
}

.quote-card {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  padding: 48px;
  background: var(--white);
  border-radius: 24px;
  border: 1px solid var(--border);
  position: relative;
}

.quote-card::before {
  content: '"';
  font-size: 6rem;
  color: var(--gold-light);
  position: absolute;
  top: 10px;
  left: 32px;
  line-height: 1;
  font-family: Georgia, serif;
}

.quote-text {
  font-size: 1.2rem;
  color: var(--text-primary);
  line-height: 1.9;
  font-style: italic;
  margin-bottom: 24px;
}

.quote-author {
  font-size: 0.95rem;
  color: var(--gold-dark);
  font-weight: 600;
}

/* ============ CTA Section ============ */
.cta-section {
  padding: 80px 24px;
  text-align: center;
}

.cta-box {
  max-width: 700px;
  margin: 0 auto;
  background: linear-gradient(135deg, var(--dark), var(--dark-soft));
  border-radius: 28px;
  padding: 64px 48px;
  position: relative;
  overflow: hidden;
}

.cta-box::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -30%;
  width: 60%;
  height: 150%;
  background: radial-gradient(ellipse, rgba(197,151,62,0.15), transparent);
  pointer-events: none;
}

.cta-box h2 {
  font-size: 2rem;
  font-weight: 800;
  color: white;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.cta-box p {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.7);
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}

.cta-box .btn-primary {
  position: relative;
  z-index: 1;
}

/* ============ Footer ============ */
.footer {
  background: var(--dark);
  padding: 48px 24px 32px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: white;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.5);
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: rgba(255,255,255,0.8);
  margin-bottom: 16px;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.45);
  transition: color 0.3s;
}

.footer-col ul a:hover {
  color: var(--gold-light);
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.3);
}

.footer-contact {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.4);
}

.footer-contact span {
  color: var(--gold-light);
}

/* ============ Detail Page Hero ============ */
.detail-hero {
  padding: 120px 24px 64px;
  background: var(--bg-warm);
  position: relative;
}

.detail-hero-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.detail-breadcrumb {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 24px;
}

.detail-breadcrumb a {
  color: var(--text-light);
}

.detail-breadcrumb a:hover {
  color: var(--gold-dark);
}

.detail-hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 16px;
}

.detail-hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 640px;
  line-height: 1.8;
}

/* ============ Content Sections ============ */
.content-section {
  padding: 64px 24px;
}

.content-inner {
  max-width: 900px;
  margin: 0 auto;
}

.content-inner h2 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}

.content-inner h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: 12px;
  margin-top: 32px;
}

.content-inner p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 16px;
}

.content-inner ul {
  list-style: none;
  margin-bottom: 20px;
}

.content-inner ul li {
  padding: 8px 0 8px 24px;
  position: relative;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.content-inner ul li::before {
  content: '';
  position: absolute;
  left: 4px;
  top: 16px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
}

/* ============ Category Cards ============ */
.category-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin: 32px 0;
}

.category-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  transition: all 0.3s;
}

.category-card:hover {
  border-color: var(--gold-light);
  box-shadow: 0 8px 24px var(--shadow);
}

.category-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.category-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ============ FAQ ============ */
.faq-list {
  margin: 32px 0;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 1rem;
  color: var(--dark);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.2s;
}

.faq-question:hover {
  background: var(--bg);
}

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  color: var(--gold);
  font-weight: 300;
}

.faq-answer {
  padding: 0 24px 20px;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ============ Benefit Grid ============ */
.benefit-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin: 32px 0;
}

.benefit-item {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: var(--white);
  border-radius: 16px;
  border: 1px solid var(--border);
}

.benefit-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(197,151,62,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.benefit-text h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: 4px;
}

.benefit-text p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ============ Course Cards ============ */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.course-card {
  background: var(--white);
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--border);
  transition: all 0.3s;
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--shadow-md);
}

.course-card-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.course-card-body {
  padding: 24px;
}

.course-card-body h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
}

.course-card-body p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.course-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
}

.course-format {
  padding: 3px 10px;
  background: rgba(197,151,62,0.1);
  color: var(--gold-dark);
  border-radius: 8px;
  font-weight: 500;
}

.course-price {
  color: var(--red);
  font-weight: 700;
  font-size: 0.95rem;
}

/* ============ Image with caption ============ */
.img-caption {
  margin: 32px 0;
  border-radius: 16px;
  overflow: hidden;
}

.img-caption img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.img-caption figcaption {
  padding: 12px 16px;
  font-size: 0.85rem;
  color: var(--text-light);
  background: var(--bg);
}

/* ============ Responsive ============ */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero h1 {
    font-size: 2.4rem;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stats-inner {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

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

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }

  .course-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding: 120px 20px 60px;
    min-height: auto;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .features-grid,
  .benefit-grid,
  .category-grid {
    grid-template-columns: 1fr;
  }

  .process-steps {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .process-steps::before {
    display: none;
  }

  .stats-inner {
    grid-template-columns: repeat(2, 1fr);
  }

  .stat-number {
    font-size: 2rem;
  }

  .expert-card {
    grid-template-columns: 1fr;
  }

  .expert-photo {
    height: 200px;
    min-height: auto;
  }

  .hero-stat-card {
    position: static;
    margin-top: 20px;
    justify-content: center;
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }

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

  .detail-hero h1 {
    font-size: 1.8rem;
  }
}