:root {
  --primary: #4F46E5;
  --primary-dark: #3730A3;
  --primary-light: #EEF2FF;
  --accent: #F59E0B;
  --accent-light: #FEF3C7;
  --green: #10B981;
  --green-light: #D1FAE5;
  --text-dark: #1E293B;
  --text-mid: #475569;
  --text-gray: #94A3B8;
  --bg: #F8FAFC;
  --border: #E2E8F0;
  --white: #FFFFFF;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-hover: 0 8px 32px rgba(79,70,229,0.15);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  background: var(--bg);
  color: var(--text-dark);
  font-size: 15px;
  line-height: 1.6;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; padding: 0; margin: 0; }
img { max-width: 100%; }
.container { width: 90%; max-width: 1200px; margin: 0 auto; }

/* ========== 导航 ========== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: 60px;
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}
.nav-logo {
  font-size: 20px; font-weight: 800; color: var(--primary);
  display: flex; align-items: center; gap: 6px;
}
.nav-logo span { font-size: 17px; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { font-size: 14px; font-weight: 500; color: var(--text-mid); transition: color 0.2s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-links .nav-cta {
  background: var(--primary); color: #fff !important;
  padding: 7px 18px; border-radius: 20px; font-weight: 600;
  transition: background 0.2s !important;
}
.nav-links .nav-cta:hover { background: var(--primary-dark) !important; }
.nav-hamburger {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 6px;
}
.nav-hamburger span {
  display: block; width: 22px; height: 2px; background: var(--text-dark); border-radius: 2px; transition: 0.3s;
}

/* ========== Hero ========== */
.hero {
  background: linear-gradient(135deg, #1E1B4B 0%, #312E81 40%, #4F46E5 100%);
  padding: 110px 0 80px;
  text-align: center;
  color: #fff;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero > * { position: relative; }
.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}
.hero-title {
  font-size: 44px; font-weight: 900; line-height: 1.2;
  margin-bottom: 16px; letter-spacing: -0.5px;
}
.hero-title span { color: #FCD34D; }
.hero-sub {
  font-size: 17px; opacity: 0.85; margin-bottom: 32px; line-height: 1.7;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; margin-bottom: 48px; flex-wrap: wrap; }
.btn-primary-lg {
  display: inline-block;
  background: var(--accent); color: #1E1B4B;
  padding: 14px 36px; border-radius: 30px;
  font-size: 17px; font-weight: 700;
  box-shadow: 0 6px 24px rgba(245,158,11,0.4);
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-primary-lg:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(245,158,11,0.5); }
.btn-ghost-lg {
  display: inline-block;
  border: 2px solid rgba(255,255,255,0.5); color: #fff;
  padding: 12px 32px; border-radius: 30px;
  font-size: 16px; font-weight: 600;
  transition: border-color 0.2s, background 0.2s;
}
.btn-ghost-lg:hover { border-color: #fff; background: rgba(255,255,255,0.1); }
.hero-stats {
  display: flex; justify-content: center; align-items: center;
  gap: 0; background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 14px; padding: 20px 40px;
  display: inline-flex; backdrop-filter: blur(8px);
}
.stat-item { text-align: center; padding: 0 28px; }
.stat-item strong { display: block; font-size: 26px; font-weight: 800; color: #FCD34D; }
.stat-item span { font-size: 12px; opacity: 0.8; }
.stat-divider { width: 1px; height: 40px; background: rgba(255,255,255,0.2); }

/* ========== 通用 section ========== */
section { padding: 80px 0; }
.section-title { text-align: center; margin-bottom: 48px; }
.section-title h2 { font-size: 30px; font-weight: 800; color: var(--text-dark); margin-bottom: 10px; }
.section-title p { font-size: 16px; color: var(--text-mid); }

/* ========== 为什么选我们 ========== */
.why-us { background: #fff; }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  padding: 28px 24px; border: 1px solid var(--border); border-radius: var(--radius);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
  background: #fff;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--primary); }
.feature-icon { font-size: 36px; margin-bottom: 14px; display: block; }
.feature-card h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; color: var(--text-dark); }
.feature-card p { font-size: 14px; color: var(--text-mid); line-height: 1.7; }

/* ========== 学科 ========== */
.subjects-section { background: var(--bg); }
.subjects-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 16px; }
.subject-card {
  display: flex; flex-direction: column; align-items: center;
  padding: 20px 12px; background: #fff;
  border: 1px solid var(--border); border-radius: var(--radius);
  text-align: center; transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
  cursor: pointer;
}
.subject-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--primary); }
.subject-card.highlight { border-color: var(--accent); background: var(--accent-light); }
.subj-icon { font-size: 30px; margin-bottom: 8px; }
.subj-name { font-size: 15px; font-weight: 700; color: var(--text-dark); margin-bottom: 4px; }
.subj-tag { font-size: 11px; color: var(--text-gray); line-height: 1.4; }

/* ========== 老师卡片 ========== */
.teachers-section { background: #fff; }
.teachers-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 36px; }
.teacher-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; transition: transform 0.2s, box-shadow 0.2s;
}
.teacher-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.tc-avatar {
  width: 56px; height: 56px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), #818CF8);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 700; color: #fff; margin-bottom: 12px;
}
.tc-name { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.tc-edu {
  display: inline-block; padding: 2px 10px;
  background: var(--primary-light); color: var(--primary);
  border-radius: 10px; font-size: 12px; font-weight: 600; margin-bottom: 8px;
}
.tc-subjects { font-size: 13px; color: var(--text-mid); margin-bottom: 8px; }
.tc-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 12px; }
.tc-tag {
  padding: 2px 8px; background: var(--green-light); color: var(--green);
  border-radius: 8px; font-size: 11px; font-weight: 600;
}
.tc-price { font-size: 14px; font-weight: 700; color: var(--primary); margin-bottom: 12px; }
.tc-cta {
  display: block; text-align: center;
  background: var(--primary); color: #fff;
  padding: 8px; border-radius: 8px; font-size: 13px; font-weight: 600;
  transition: background 0.2s;
}
.tc-cta:hover { background: var(--primary-dark); }
.center-action { text-align: center; }
.btn-outline-lg {
  display: inline-block;
  border: 2px solid var(--primary); color: var(--primary);
  padding: 12px 36px; border-radius: 28px; font-size: 16px; font-weight: 600;
  transition: all 0.2s;
}
.btn-outline-lg:hover { background: var(--primary); color: #fff; }

/* ========== 流程 ========== */
.process-section { background: linear-gradient(135deg, #F0F0FF 0%, #EEF2FF 100%); }
.process-steps {
  display: flex; align-items: flex-start; justify-content: center; gap: 0;
  flex-wrap: wrap;
}
.step { text-align: center; max-width: 200px; padding: 0 10px; }
.step-num {
  width: 52px; height: 52px; border-radius: 50%;
  background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 800; margin: 0 auto 14px;
  box-shadow: 0 4px 16px rgba(79,70,229,0.3);
}
.step-body h3 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.step-body p { font-size: 13px; color: var(--text-mid); line-height: 1.6; }
.step-arrow {
  font-size: 24px; color: var(--primary); opacity: 0.4;
  padding: 0 8px; align-self: center; margin-top: -20px;
}

/* ========== 评价 ========== */
.reviews-section { background: #fff; }
.reviews-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card {
  padding: 28px; background: var(--bg); border-radius: var(--radius);
  border: 1px solid var(--border); transition: box-shadow 0.2s;
}
.review-card:hover { box-shadow: var(--shadow-hover); }
.review-stars { color: #F59E0B; font-size: 18px; margin-bottom: 12px; letter-spacing: 2px; }
.review-text { font-size: 14px; color: var(--text-mid); line-height: 1.7; margin-bottom: 18px; font-style: italic; }
.review-author { display: flex; align-items: center; gap: 12px; }
.review-avatar {
  width: 42px; height: 42px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), #818CF8);
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700; color: #fff;
}
.review-author strong { display: block; font-size: 14px; }
.review-author span { font-size: 12px; color: var(--text-gray); }

/* ========== 咨询表单 ========== */
.contact-section { background: linear-gradient(135deg, #1E1B4B 0%, #312E81 100%); padding: 80px 0; }
.contact-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.contact-left { color: #fff; }
.contact-left h2 { font-size: 30px; font-weight: 800; margin-bottom: 12px; }
.contact-left > p { opacity: 0.8; margin-bottom: 28px; font-size: 16px; }
.contact-wechat {
  display: flex; align-items: center; gap: 14px;
  background: rgba(255,255,255,0.1); border: 1px solid rgba(255,255,255,0.2);
  padding: 14px 18px; border-radius: 12px; margin-bottom: 24px;
}
.wechat-icon { font-size: 28px; }
.contact-wechat strong { display: block; font-size: 14px; }
.wechat-id { font-size: 20px; font-weight: 800; color: #4ADE80; letter-spacing: 1px; }
.contact-promise { display: flex; flex-direction: column; gap: 10px; }
.contact-promise li { font-size: 14px; opacity: 0.85; }

.contact-right { background: #fff; border-radius: 16px; padding: 32px; }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 13px; font-weight: 600; color: var(--text-dark); }
.form-group input, .form-group select, .form-group textarea {
  padding: 10px 14px; border: 1.5px solid var(--border); border-radius: 8px;
  font-size: 14px; color: var(--text-dark);
  transition: border-color 0.2s, box-shadow 0.2s;
  font-family: inherit; background: #fff;
  appearance: auto;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.08);
}
.btn-submit {
  background: var(--primary); color: #fff;
  padding: 14px; border: none; border-radius: 10px;
  font-size: 16px; font-weight: 700; cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  font-family: inherit;
}
.btn-submit:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-submit:active { transform: translateY(0); }
.form-tip { font-size: 12px; color: var(--text-gray); text-align: center; margin-top: 4px; }
.form-success { text-align: center; padding: 30px 20px; }
.success-icon { font-size: 52px; margin-bottom: 12px; }
.form-success h3 { font-size: 22px; font-weight: 700; margin-bottom: 8px; color: var(--green); }
.form-success p { color: var(--text-mid); line-height: 1.7; }
.form-success strong { color: var(--primary); font-size: 16px; }

/* ========== Footer ========== */
.footer { background: #0F0E1A; color: rgba(255,255,255,0.7); padding: 60px 0 0; }
.footer-inner { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; }
.footer-logo { font-size: 20px; font-weight: 800; color: #fff; margin-bottom: 12px; }
.footer-brand p { font-size: 13px; line-height: 1.8; margin-bottom: 14px; }
.footer-wechat { font-size: 14px; }
.footer-wechat strong { color: #4ADE80; }
.footer-links h4 { font-size: 14px; font-weight: 700; color: #fff; margin-bottom: 14px; }
.footer-links a { display: block; font-size: 13px; margin-bottom: 8px; transition: color 0.2s; }
.footer-links a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 20px 0; text-align: center;
  font-size: 12px;
}

/* ========== 悬浮按钮 ========== */
#float-btn {
  position: fixed; right: 20px; bottom: 30px; z-index: 9999;
  background: var(--primary); color: #fff;
  display: flex; flex-direction: column; align-items: center;
  padding: 12px 14px; border-radius: 14px; cursor: pointer;
  box-shadow: 0 6px 24px rgba(79,70,229,0.45);
  transition: transform 0.2s;
}
#float-btn:hover { transform: translateY(-3px); }
.float-icon { font-size: 22px; margin-bottom: 4px; }
.float-text { font-size: 12px; font-weight: 700; white-space: nowrap; }

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .subjects-grid { grid-template-columns: repeat(4, 1fr); }
  .teachers-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
  .hero { padding: 80px 0 60px; }
  .hero-title { font-size: 28px; }
  .hero-sub { font-size: 14px; }
  .hero-stats { padding: 14px 20px; flex-wrap: wrap; }
  .stat-item { padding: 8px 16px; }
  .stat-item strong { font-size: 22px; }
  .stat-divider { display: none; }
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .features-grid { grid-template-columns: 1fr; }
  .subjects-grid { grid-template-columns: repeat(3, 1fr); }
  .teachers-grid { grid-template-columns: repeat(2, 1fr); }
  .process-steps { flex-direction: column; align-items: center; }
  .step-arrow { transform: rotate(90deg); margin: 8px 0; }
  .reviews-grid { grid-template-columns: 1fr; }
  .contact-wrap { grid-template-columns: 1fr; gap: 30px; }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 30px; }
  section { padding: 50px 0; }
  .section-title h2 { font-size: 24px; }
}
@media (max-width: 480px) {
  .subjects-grid { grid-template-columns: repeat(2, 1fr); }
  .teachers-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 24px; }
  .footer-inner { grid-template-columns: 1fr; }
}