/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: #333;
  line-height: 1.6;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== Header ===== */
.header {
  position: fixed; top: 0; width: 100%;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
  z-index: 1000;
}
.header .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 72px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 24px; font-weight: 800;
  background: linear-gradient(135deg, #FF6B6B, #FFA94D);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.logo-icon { font-size: 32px; -webkit-text-fill-color: initial; }
.nav a {
  margin-left: 32px; font-weight: 600; font-size: 15px;
  color: #555; transition: color 0.2s;
}
.nav a:hover { color: #FF6B6B; }
.nav .btn-nav {
  background: linear-gradient(135deg, #FF6B6B, #FFA94D);
  color: #fff !important; padding: 10px 24px; border-radius: 25px;
  margin-left: 24px;
}
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; }
.hamburger span { width: 28px; height: 3px; background: #333; border-radius: 2px; }

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, #FFF5F5 0%, #FFF8F0 50%, #F0FFF4 100%);
}
.hero .container { display: flex; align-items: center; gap: 60px; }
.hero-content { flex: 1; }
.hero-content h1 { font-size: 48px; line-height: 1.2; margin-bottom: 20px; }
.hero-content h1 span { 
  background: linear-gradient(135deg, #FF6B6B, #FFA94D);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-content p { font-size: 18px; color: #666; margin-bottom: 32px; max-width: 520px; }
.hero-image { flex: 1; text-align: center; }
.hero-image img { max-width: 90%; }
.btn-primary {
  display: inline-block;
  background: linear-gradient(135deg, #FF6B6B, #FFA94D);
  color: #fff; padding: 16px 40px; border-radius: 30px;
  font-size: 17px; font-weight: 700; border: none; cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(255,107,107,0.4); }
.btn-secondary {
  display: inline-block;
  background: #fff; color: #FF6B6B; padding: 16px 40px; border-radius: 30px;
  font-size: 17px; font-weight: 700; border: 2px solid #FF6B6B; cursor: pointer;
  margin-left: 16px; transition: all 0.2s;
}
.btn-secondary:hover { background: #FFF5F5; }

/* ===== Sections ===== */
.section { padding: 80px 0; }
.section-title {
  text-align: center; font-size: 36px; margin-bottom: 16px;
  color: #222;
}
.section-subtitle {
  text-align: center; color: #888; font-size: 17px;
  margin-bottom: 56px; max-width: 600px; margin-left: auto; margin-right: auto;
}

/* ===== Features ===== */
.features { background: #fff; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.feature-card {
  background: #f8f9fa; border-radius: 20px; padding: 40px 32px;
  text-align: center; transition: transform 0.3s, box-shadow 0.3s;
}
.feature-card:hover { transform: translateY(-8px); box-shadow: 0 20px 40px rgba(0,0,0,0.08); }
.feature-icon {
  width: 72px; height: 72px; border-radius: 18px;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 20px; font-size: 32px;
}
.feature-card h3 { font-size: 20px; margin-bottom: 12px; }
.feature-card p { color: #777; font-size: 15px; line-height: 1.7; }

/* ===== Courses ===== */
.courses { background: #FFF8F0; }
.course-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.course-card {
  background: #fff; border-radius: 20px; overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05); transition: transform 0.3s;
}
.course-card:hover { transform: translateY(-6px); }
.course-img {
  height: 200px; display: flex; align-items: center; justify-content: center;
  font-size: 48px;
}
.course-body { padding: 24px 28px 28px; }
.course-body h3 { font-size: 20px; margin-bottom: 8px; }
.course-body .meta { color: #FF6B6B; font-weight: 600; font-size: 14px; margin-bottom: 10px; }
.course-body p { color: #777; font-size: 14px; line-height: 1.7; }
.course-body .price { font-size: 22px; font-weight: 800; color: #333; margin: 16px 0 0; }
.course-body .price span { font-size: 14px; font-weight: 400; color: #999; }

/* ===== About ===== */
.about { background: #fff; }
.about .container { display: flex; align-items: center; gap: 60px; }
.about-image { flex: 1; text-align: center; font-size: 180px; line-height: 1; }
.about-content { flex: 1; }
.about-content h2 { font-size: 36px; margin-bottom: 20px; }
.about-content p { color: #666; font-size: 16px; margin-bottom: 16px; }
.about-stats { display: flex; gap: 40px; margin-top: 32px; }
.stat { text-align: center; }
.stat-num { font-size: 36px; font-weight: 800; color: #FF6B6B; }
.stat-label { color: #999; font-size: 14px; }

/* ===== Testimonials ===== */
.testimonials { background: #FFF5F5; }
.testimonial-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; }
.testimonial-card {
  background: #fff; border-radius: 20px; padding: 36px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}
.testimonial-card .stars { color: #FFD43B; font-size: 18px; margin-bottom: 12px; }
.testimonial-card p { color: #555; font-size: 15px; line-height: 1.8; margin-bottom: 20px; }
.testimonial-card .author { display: flex; align-items: center; gap: 12px; }
.testimonial-card .author .avatar {
  width: 44px; height: 44px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 700; color: #fff;
}
.testimonial-card .author .name { font-weight: 700; font-size: 15px; }
.testimonial-card .author .role { color: #999; font-size: 13px; }

/* ===== Contact ===== */
.contact { background: #fff; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; }
.contact-info h3 { font-size: 24px; margin-bottom: 24px; }
.contact-item { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 20px; }
.contact-item .icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: #FFF5F5; display: flex; align-items: center; justify-content: center;
  font-size: 20px; flex-shrink: 0;
}
.contact-item .label { font-weight: 600; font-size: 14px; color: #999; }
.contact-item .value { font-size: 16px; color: #333; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 14px 18px; border: 2px solid #eee; border-radius: 12px;
  font-size: 15px; margin-bottom: 16px; font-family: inherit;
  outline: none; transition: border-color 0.2s;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: #FF6B6B; }
.contact-form textarea { height: 140px; resize: vertical; }

/* ===== Footer ===== */
.footer {
  background: #222; color: #999; padding: 40px 0; text-align: center;
}
.footer .logo { justify-content: center; margin-bottom: 12px; }
.footer p { font-size: 14px; }

/* ===== Modal ===== */
.modal {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,0.5); z-index: 2000;
  align-items: center; justify-content: center;
}
.modal.active { display: flex; }
.modal-content {
  background: #fff; border-radius: 24px; padding: 48px 40px 36px;
  max-width: 480px; width: 90%; text-align: center; position: relative;
}
.modal-content h3 { font-size: 24px; margin-bottom: 12px; }
.modal-content p { color: #777; margin-bottom: 24px; }
.modal-close {
  position: absolute; top: 16px; right: 20px;
  font-size: 28px; cursor: pointer; color: #999; border: none; background: none;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav { display: none; }
  .hamburger { display: flex; }
  .hero .container { flex-direction: column; text-align: center; }
  .hero-content h1 { font-size: 32px; }
  .hero-content p { max-width: 100%; }
  .feature-grid, .course-grid { grid-template-columns: 1fr; }
  .about .container { flex-direction: column; text-align: center; }
  .about-stats { justify-content: center; }
  .testimonial-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .btn-secondary { margin-left: 0; margin-top: 12px; }
}
@media (min-width: 769px) and (max-width: 1024px) {
  .feature-grid, .course-grid { grid-template-columns: repeat(2, 1fr); }
}