/* ==================== 变量 & 重置 ==================== */
:root {
  --primary: #0066CC;
  --primary-dark: #0052A3;
  --primary-light: #3399FF;
  --accent: #00D4FF;
  --accent-glow: rgba(0, 212, 255, 0.3);
  --dark: #0A1628;
  --dark-2: #0F2137;
  --dark-3: #162D4A;
  --text: #E8F4FF;
  --text-muted: #8BA4C7;
  --white: #FFFFFF;
  --gradient-blue: linear-gradient(135deg, #0066CC 0%, #00D4FF 100%);
  --gradient-dark: linear-gradient(180deg, #0A1628 0%, #0F2137 100%);
  --shadow: 0 4px 24px rgba(0, 102, 204, 0.15);
  --shadow-lg: 0 8px 40px rgba(0, 102, 204, 0.25);
  --radius: 16px;
  --radius-sm: 8px;
  --transition: 0.3s ease;
}

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

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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--dark);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
  padding: 6px 14px;
  background: rgba(0, 212, 255, 0.1);
  border-radius: 20px;
  border: 1px solid rgba(0, 212, 255, 0.2);
}

.section-title {
  font-size: clamp(1.5rem, 5vw, 2.25rem);
  font-weight: 700;
  background: linear-gradient(135deg, var(--white) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
  line-height: 1.3;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ==================== 按钮 ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  min-height: 48px;
  touch-action: manipulation;
}

.btn-primary {
  background: var(--gradient-blue);
  color: var(--white);
  box-shadow: 0 4px 20px rgba(0, 102, 204, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(0, 102, 204, 0.5);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 212, 255, 0.05);
}

.btn-full {
  width: 100%;
}

/* ==================== 导航栏 ==================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 14px 0;
  transition: var(--transition);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(10, 22, 40, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 212, 255, 0.1);
  padding: 10px 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 36px;
  height: 36px;
}

.logo-text {
  font-size: 1.3rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--white) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-left: 10px;
  border-left: 1px solid rgba(255, 255, 255, 0.2);
  display: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-links a {
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text);
  opacity: 0.85;
}

.nav-links a:hover {
  color: var(--accent);
  opacity: 1;
}

.nav-cta {
  padding: 8px 20px !important;
  background: var(--gradient-blue) !important;
  border-radius: 50px !important;
  opacity: 1 !important;
  font-weight: 600 !important;
  font-size: 0.85rem !important;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 102, 204, 0.4);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  margin-right: -8px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: var(--transition);
}

/* ==================== Hero区 ==================== */
.hero {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  position: relative;
  padding: 100px 20px 60px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.25;
  filter: saturate(0.8);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(10, 22, 40, 0.7) 0%,
    rgba(10, 22, 40, 0.85) 50%,
    rgba(10, 22, 40, 1) 100%
  );
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.hero-particles {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--accent);
  border-radius: 50%;
  opacity: 0.5;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0) translateX(0); opacity: 0.5; }
  50% { transform: translateY(-20px) translateX(8px); opacity: 0.8; }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 680px;
  text-align: center;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  background: rgba(0, 212, 255, 0.15);
  border: 1px solid rgba(0, 212, 255, 0.4);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 20px;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(0, 212, 255, 0.4); }
  50% { box-shadow: 0 0 20px 6px rgba(0, 212, 255, 0.15); }
}

.hero-title {
  margin-bottom: 20px;
}

.hero-title-line1 {
  display: block;
  font-size: clamp(2.2rem, 8vw, 4rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--white) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.15;
  text-shadow: 0 0 60px rgba(0, 212, 255, 0.3);
}

.hero-title-line2 {
  display: block;
  font-size: clamp(1.2rem, 4vw, 1.8rem);
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 10px;
}

.hero-desc {
  font-size: clamp(1rem, 2.5vw, 1.15rem);
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-desc .highlight {
  color: var(--accent);
  font-weight: 600;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  align-items: baseline;
  gap: 2px;
}

.stat-num {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-unit {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-left: 8px;
}

.stat-divider {
  width: 1px;
  height: 32px;
  background: rgba(255, 255, 255, 0.1);
}

/* Hero 浮动卡片 - PC端显示 */
.hero-visual {
  position: absolute;
  right: 5%;
  top: 50%;
  transform: translateY(-50%);
  width: 400px;
  height: 400px;
  z-index: 1;
  display: block;
}

.floating-card {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 22px;
  background: rgba(10, 22, 40, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(0, 212, 255, 0.3);
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  animation: floatCard 4s ease-in-out infinite;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.fc-icon {
  font-size: 1.4rem;
}

.fc-1 { top: 10%; left: 20%; animation-delay: 0s; }
.fc-2 { top: 35%; right: 0; animation-delay: 0.5s; }
.fc-3 { top: 60%; left: 10%; animation-delay: 1s; }
.fc-4 { top: 80%; right: 15%; animation-delay: 1.5s; }

@keyframes floatCard {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-15px); }
}

/* Hero 滚动提示 */
.hero-scroll-hint {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.8rem;
  z-index: 1;
  animation: bounce 2s ease-in-out infinite;
}

.scroll-arrow {
  font-size: 1rem;
  color: var(--accent);
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ==================== 品牌标语区 ==================== */
.brand-banner {
  background: linear-gradient(135deg, var(--dark-2) 0%, var(--dark-3) 100%);
  padding: 60px 0;
  border-top: 1px solid rgba(0, 212, 255, 0.1);
  border-bottom: 1px solid rgba(0, 212, 255, 0.1);
}

.brand-banner-content {
  display: flex;
  align-items: center;
  gap: 40px;
}

.brand-banner-img {
  width: 200px;
  height: 140px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid rgba(0, 212, 255, 0.2);
  flex-shrink: 0;
}

.brand-banner-text {
  flex: 1;
}

.brand-banner-text h2 {
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 12px;
}

.brand-banner-text p {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==================== 课程体系 ==================== */
.courses {
  background: linear-gradient(180deg, var(--dark) 0%, var(--dark-2) 100%);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.course-card {
  background: rgba(15, 33, 55, 0.8);
  border: 1px solid rgba(0, 212, 255, 0.1);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  position: relative;
}

.course-card:hover,
.course-card:active {
  transform: translateY(-8px);
  border-color: rgba(0, 212, 255, 0.4);
  box-shadow: 0 16px 48px rgba(0, 102, 204, 0.3);
}

.course-card-img {
  position: relative;
  height: 140px;
  overflow: hidden;
}

.course-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.course-card:hover .course-card-img img {
  transform: scale(1.08);
}

.course-card-img::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 40%, rgba(15, 33, 55, 0.9) 100%);
}

.course-card-content {
  padding: 20px;
}

.course-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.course-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--white);
}

.course-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 14px;
}

.course-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.course-tags span {
  font-size: 0.7rem;
  padding: 4px 10px;
  background: rgba(0, 102, 204, 0.25);
  border-radius: 20px;
  color: var(--accent);
  border: 1px solid rgba(0, 212, 255, 0.2);
}

/* ==================== 学习场景展示 ==================== */
.scenes {
  background: var(--dark);
  padding: 80px 0;
}

.scenes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(2, 200px);
  gap: 16px;
}

.scene-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(0, 212, 255, 0.15);
}

.scene-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.scene-card:hover img {
  transform: scale(1.1);
}

.scene-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 30%, rgba(10, 22, 40, 0.95) 100%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 20px;
  transition: var(--transition);
}

.scene-card:hover .scene-overlay {
  background: linear-gradient(180deg, rgba(0, 102, 204, 0.2) 0%, rgba(10, 22, 40, 0.98) 100%);
}

.scene-overlay h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 4px;
}

.scene-overlay p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.scene-large {
  grid-column: span 2;
}

/* ==================== 为什么选择我们 ==================== */
.why {
  background: var(--dark-2);
}

.why-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.why-list {
  display: flex;
  flex-direction: column;
  gap: 28px;
  margin-top: 32px;
}

.why-item {
  display: flex;
  gap: 20px;
}

.why-num {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--accent);
  opacity: 0.3;
  line-height: 1;
  flex-shrink: 0;
}

.why-info h4 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 6px;
}

.why-info p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.7;
}

.why-visual {
  position: relative;
}

.why-img-wrap {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(0, 212, 255, 0.2);
}

.why-img-wrap img {
  width: 100%;
  height: 420px;
  object-fit: cover;
  border-radius: var(--radius);
}

.why-badge {
  position: absolute;
  bottom: 24px;
  right: 24px;
  background: rgba(10, 22, 40, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(0, 212, 255, 0.4);
  border-radius: var(--radius);
  padding: 20px 28px;
  text-align: center;
}

.wb-num {
  display: block;
  font-size: 3rem;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
}

.wb-text {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.why-img-small {
  position: absolute;
  bottom: -40px;
  left: -40px;
  width: 160px;
  height: 120px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 3px solid var(--dark-2);
  box-shadow: var(--shadow-lg);
}

.why-img-small img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ==================== 关于我们 ==================== */
.about {
  background: var(--dark);
  position: relative;
  overflow: hidden;
}

.about-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.about-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.1;
}

.about .container {
  position: relative;
  z-index: 1;
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text p {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.85;
  margin-bottom: 20px;
}

.about-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 32px;
}

.af-item {
  text-align: center;
  padding: 24px 16px;
  background: rgba(15, 33, 55, 0.7);
  border-radius: var(--radius);
  border: 1px solid rgba(0, 212, 255, 0.15);
  transition: var(--transition);
}

.af-item:hover {
  border-color: rgba(0, 212, 255, 0.4);
  transform: translateY(-4px);
}

.af-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 12px;
}

.af-item span {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  display: block;
  margin-bottom: 8px;
}

.af-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0;
  line-height: 1.5;
}

.about-img {
  position: relative;
}

.about-img img {
  width: 100%;
  height: 480px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid rgba(0, 212, 255, 0.2);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

/* ==================== 数据展示 ==================== */
.stats {
  background: linear-gradient(135deg, var(--dark-2) 0%, var(--dark-3) 100%);
  padding: 80px 0;
  border-top: 1px solid rgba(0, 212, 255, 0.1);
  border-bottom: 1px solid rgba(0, 212, 255, 0.1);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(0, 212, 255, 0.15);
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-6px);
  border-color: rgba(0, 212, 255, 0.4);
  box-shadow: var(--shadow-lg);
}

.stat-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  filter: brightness(0.6);
}

.stat-card-content {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 20px;
  background: linear-gradient(180deg, transparent 0%, rgba(10, 22, 40, 0.95) 50%);
  text-align: center;
}

.stat-card-num {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--accent);
}

.stat-card-unit {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-card-content p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ==================== 联系我们 ==================== */
.contact {
  background: var(--dark);
  position: relative;
  overflow: hidden;
}

.contact-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.contact-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.08;
}

.contact .container {
  position: relative;
  z-index: 1;
}

.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

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

.ci-item {
  display: flex;
  align-items: center;
  gap: 18px;
}

.ci-icon {
  font-size: 1.8rem;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 102, 204, 0.2);
  border-radius: var(--radius);
  border: 1px solid rgba(0, 212, 255, 0.25);
  flex-shrink: 0;
}

.ci-label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}

.ci-text a,
.ci-text span {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--white);
}

.ci-text a:hover {
  color: var(--accent);
}

/* 联系表单 */
.contact-form {
  background: rgba(15, 33, 55, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--radius);
  padding: 36px 28px;
}

.contact-form h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 28px;
}

.form-group {
  margin-bottom: 18px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 14px 18px;
  background: rgba(10, 22, 40, 0.9);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--radius-sm);
  color: var(--white);
  font-size: 1rem;
  font-family: inherit;
  transition: var(--transition);
  min-height: 50px;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-muted);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.15);
}

.form-group select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%238BA4C7' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
  cursor: pointer;
}

.form-group select option {
  background: var(--dark);
  color: var(--white);
}

.form-success {
  display: none;
  text-align: center;
  padding: 48px 20px;
}

.form-success.show {
  display: block;
}

.success-icon {
  font-size: 4rem;
  margin-bottom: 16px;
}

.form-success h4 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 8px;
}

.form-success p {
  color: var(--text-muted);
}

/* ==================== 页脚 ==================== */
.footer {
  background: var(--dark-2);
  padding: 56px 0 28px;
  border-top: 1px solid rgba(0, 212, 255, 0.1);
}

.footer-content {
  display: grid;
  grid-template-columns: 1.2fr 2fr;
  gap: 60px;
  margin-bottom: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand .logo {
  margin-bottom: 18px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 36px;
}

.fl-col h4 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 18px;
}

.fl-col a {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 5px 0;
  transition: var(--transition);
}

.fl-col a:hover {
  color: var(--accent);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-bottom a:hover {
  color: var(--accent);
}

/* ==================== 平板响应式 (≤1024px) ==================== */
@media (max-width: 1024px) {
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  
  .scenes-grid {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(3, 180px);
  }
  
  .scene-large {
    grid-column: span 2;
  }
  
  .why-content,
  .about-content,
  .contact-content {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  
  .hero-visual {
    display: none;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  
  .footer-links {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  
  .brand-banner-content {
    flex-direction: column;
    text-align: center;
  }
  
  .brand-banner-img {
    width: 100%;
    max-width: 300px;
    height: 180px;
  }
}

/* ==================== 移动端响应式 (≤768px) ==================== */
@media (max-width: 768px) {
  .section {
    padding: 60px 0;
  }
  
  .section-header {
    margin-bottom: 36px;
  }
  
  .container {
    padding: 0 16px;
  }
  
  /* 导航 */
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    height: 100dvh;
    background: var(--dark-2);
    flex-direction: column;
    justify-content: center;
    gap: 20px;
    padding: 60px 32px;
    transition: 0.4s ease;
    border-left: 1px solid rgba(0, 212, 255, 0.1);
    z-index: 999;
  }
  
  .nav-links.open {
    right: 0;
  }
  
  .nav-links a {
    font-size: 1rem;
    padding: 10px 0;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  

  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  /* Hero */
  .hero {
    padding: 88px 16px 48px;
    min-height: auto;
  }

  .hero-content {
    text-align: center;
  }

  .hero-badge {
    font-size: 0.8rem;
    padding: 6px 14px;
  }

  .hero-desc {
    font-size: 0.95rem;
    padding: 0 10px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }

  .hero-actions .btn {
    width: 100%;
    max-width: 300px;
    padding: 14px 24px;
    font-size: 0.95rem;
  }

  .hero-stats {
    gap: 16px;
    padding-top: 28px;
  }

  .stat-num {
    font-size: 1.5rem;
  }

  .stat-label {
    display: none;
  }

  .stat-divider {
    display: none;
  }

  .hero-scroll-hint {
    display: none;
  }

  /* Ʒ�Ʊ��� */
  .brand-banner {
    padding: 40px 0;
  }

  .brand-banner-text h2 {
    font-size: 1.2rem;
  }

  .brand-banner-text p {
    font-size: 0.9rem;
  }

  /* �γ� */
  .courses-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .course-card-img {
    height: 160px;
  }

  .course-card-content {
    padding: 16px;
  }

  .course-icon {
    font-size: 1.8rem;
    margin-bottom: 10px;
  }

  .course-card h3 {
    font-size: 1.05rem;
  }

  .course-card p {
    font-size: 0.85rem;
  }

  /* ���� */
  .scenes {
    padding: 60px 0;
  }

  .scenes-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }

  .scene-card,
  .scene-large {
    grid-column: span 1;
    height: 200px;
  }

  /* Ϊʲôѡ�� */
  .why-list {
    gap: 24px;
  }

  .why-item {
    gap: 16px;
  }

  .why-num {
    font-size: 1.3rem;
  }

  .why-info h4 {
    font-size: 1rem;
  }

  .why-info p {
    font-size: 0.85rem;
  }

  .why-img-wrap img {
    height: 300px;
  }

  .why-badge {
    bottom: 16px;
    right: 16px;
    padding: 14px 20px;
  }

  .wb-num {
    font-size: 2.2rem;
  }

  .why-img-small {
    display: none;
  }

  /* ���� */
  .about-features {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .af-item {
    display: flex;
    align-items: center;
    text-align: left;
    padding: 16px 18px;
    gap: 16px;
  }

  .af-icon {
    font-size: 1.8rem;
    margin-bottom: 0;
    flex-shrink: 0;
  }

  .af-item span {
    display: inline;
    margin-bottom: 0;
  }

  .af-item p {
    margin-top: 4px;
    font-size: 0.85rem;
  }

  .about-img {
    order: -1;
  }

  .about-img img {
    height: 280px;
  }

  /* ���� */
  .stats {
    padding: 60px 0;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
  }

  .stat-card img {
    height: 140px;
  }

  .stat-card-num {
    font-size: 2rem;
  }

  /* ��ϵ */
  .contact-content {
    gap: 40px;
  }

  .contact-info {
    gap: 20px;
  }

  .ci-item {
    gap: 14px;
  }

  .ci-icon {
    width: 48px;
    height: 48px;
    font-size: 1.5rem;
  }

  .ci-text a,
  .ci-text span {
    font-size: 0.95rem;
  }

  .contact-form {
    padding: 24px 18px;
  }

  .contact-form h3 {
    font-size: 1.15rem;
    margin-bottom: 20px;
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .form-group input,
  .form-group select,
  .form-group textarea {
    padding: 14px 16px;
    font-size: 16px;
  }

  /* ҳ�� */
  .footer {
    padding: 40px 0 20px;
  }

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

  .footer-bottom {
    flex-direction: column;
    gap: 10px;
    text-align: center;
    font-size: 0.75rem;
  }
}

/* ==================== С���ֻ� (��480px) ==================== */
@media (max-width: 480px) {
  .section {
    padding: 48px 0;
  }

  .section-title {
    font-size: 1.4rem;
  }

  .section-desc {
    font-size: 0.9rem;
  }

  .section-tag {
    font-size: 0.7rem;
    padding: 5px 12px;
  }

  .hero {
    padding: 80px 14px 40px;
  }

  .hero-title-line1 {
    font-size: 2rem;
  }

  .hero-title-line2 {
    font-size: 1.1rem;
  }

  .hero-actions .btn {
    max-width: 100%;
    padding: 14px 20px;
    font-size: 0.9rem;
  }

  .course-card-img {
    height: 140px;
  }

  .brand-banner-img {
    height: 140px;
  }

  .why-img-wrap img,
  .about-img img {
    height: 240px;
  }

  .contact-form {
    padding: 20px 16px;
  }

  .contact-form h3 {
    font-size: 1rem;
  }

  .footer-links {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

  .stat-card img {
    height: 120px;
  }
}

/* ==================== ���� (��360px) ==================== */
@media (max-width: 360px) {
  html {
    font-size: 14px;
  }

  .hero-title-line1 {
    font-size: 1.75rem;
  }

  .course-card-img {
    height: 120px;
  }

  .scene-card,
  .scene-large {
    height: 160px;
  }

  .why-badge {
    padding: 10px 14px;
  }

  .wb-num {
    font-size: 1.8rem;
  }
}

/* ==================== ��ȫ�������� ==================== */
@supports (padding: max(0px)) {
  .navbar {
    padding-top: max(14px, env(safe-area-inset-top));
  }

  .hero {
    padding-bottom: max(60px, env(safe-area-inset-bottom));
  }

  .nav-links {
    padding-top: max(60px, env(safe-area-inset-top));
    padding-bottom: max(40px, env(safe-area-inset-bottom));
    padding-right: max(32px, env(safe-area-inset-right));
    padding-left: max(32px, env(safe-area-inset-left));
  }
}