/* ===== 严海留学 - 主样式 ===== */
:root {
  --primary: #1a3a5c;
  --accent: #f0a500;
  --light: #f5f8fc;
  --text: #333;
  --text-light: #666;
  --white: #fff;
  --border: #e0e8f0;
}

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

body {
  font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--accent); }

img { max-width: 100%; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 导航 ===== */
nav {
  background: var(--primary);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  color: var(--white);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 1px;
}

.logo span { color: var(--accent); }

.nav-links {
  display: flex;
  list-style: none;
  gap: 28px;
}

.nav-links a {
  color: rgba(255,255,255,0.85);
  font-size: 0.92rem;
  transition: color 0.2s;
}

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

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  transition: 0.3s;
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #2a5a8c 100%);
  color: var(--white);
  padding: 90px 0 80px;
  text-align: center;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero h1 span { color: var(--accent); }

.hero p {
  font-size: 1.15rem;
  opacity: 0.88;
  max-width: 600px;
  margin: 0 auto 36px;
}

.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: 0.25s;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: var(--primary);
  border-color: var(--accent);
}

.btn-primary:hover { background: #d4920a; color: var(--primary); }

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: rgba(255,255,255,0.6);
}

.btn-outline:hover { border-color: var(--white); color: var(--white); background: rgba(255,255,255,0.1); }

/* ===== Section ===== */
section { padding: 72px 0; }

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

.section-title h2 {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 10px;
}

.section-title p { color: var(--text-light); font-size: 1.05rem; }

.section-title .line {
  width: 50px;
  height: 3px;
  background: var(--accent);
  margin: 12px auto 0;
  border-radius: 2px;
}

/* ===== 卡片网格 ===== */
.grid { display: grid; gap: 28px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px 24px;
  transition: box-shadow 0.25s, transform 0.25s;
}

.card:hover {
  box-shadow: 0 8px 30px rgba(26,58,92,0.12);
  transform: translateY(-3px);
}

.card-icon { font-size: 2.4rem; margin-bottom: 14px; }
.card h3 { color: var(--primary); font-size: 1.15rem; margin-bottom: 10px; }
.card p { color: var(--text-light); font-size: 0.95rem; }

/* ===== 背景色区块 ===== */
.bg-light { background: var(--light); }
.bg-primary { background: var(--primary); color: var(--white); }
.bg-primary h2, .bg-primary p { color: var(--white); }

/* ===== 统计数字 ===== */
.stats { display: flex; gap: 0; }
.stat {
  flex: 1;
  text-align: center;
  padding: 40px 20px;
  border-right: 1px solid rgba(255,255,255,0.15);
}
.stat:last-child { border-right: none; }
.stat .num { font-size: 2.8rem; font-weight: 800; color: var(--accent); }
.stat .label { color: rgba(255,255,255,0.8); font-size: 0.95rem; margin-top: 6px; }

/* ===== 步骤 ===== */
.steps { counter-reset: step; }
.step {
  display: flex;
  gap: 24px;
  margin-bottom: 36px;
  align-items: flex-start;
}
.step-num {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.step-content h3 { color: var(--primary); margin-bottom: 6px; }
.step-content p { color: var(--text-light); }

/* ===== FAQ Accordion ===== */
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  width: 100%;
  text-align: left;
  padding: 20px 0;
  background: none;
  border: none;
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-q::after { content: '+'; font-size: 1.4rem; color: var(--accent); transition: transform 0.2s; }
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a { display: none; padding: 0 0 20px; color: var(--text-light); }
.faq-item.open .faq-a { display: block; }

/* ===== 联系表单 ===== */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 6px; font-weight: 600; color: var(--primary); }
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
}
.form-group textarea { height: 130px; resize: vertical; }

/* ===== 标签 ===== */
.tag {
  display: inline-block;
  background: rgba(240,165,0,0.12);
  color: var(--accent);
  border: 1px solid rgba(240,165,0,0.3);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 600;
}

/* ===== 成功案例卡片 ===== */
.case-card {
  background: var(--white);
  border-radius: 12px;
  padding: 28px;
  border: 1px solid var(--border);
}
.case-card .avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), #2a5a8c);
  color: var(--white);
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}
.case-card .name { font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.case-card .meta { color: var(--text-light); font-size: 0.88rem; margin-bottom: 12px; }
.case-card .quote { color: var(--text); font-size: 0.95rem; font-style: italic; }

/* ===== 页面 Banner ===== */
.page-banner {
  background: linear-gradient(135deg, var(--primary) 0%, #2a5a8c 100%);
  color: var(--white);
  padding: 60px 0;
  text-align: center;
}
.page-banner h1 { font-size: 2.2rem; margin-bottom: 10px; }
.page-banner p { opacity: 0.85; font-size: 1.05rem; }

/* ===== Footer ===== */
footer {
  background: #0f2035;
  color: rgba(255,255,255,0.7);
  padding: 56px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-brand .logo { font-size: 1.3rem; }
.footer-brand p { margin-top: 12px; font-size: 0.9rem; line-height: 1.8; }
footer h4 { color: var(--white); margin-bottom: 14px; font-size: 0.95rem; }
footer ul { list-style: none; }
footer ul li { margin-bottom: 8px; }
footer ul li a { color: rgba(255,255,255,0.65); font-size: 0.88rem; }
footer ul li a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .hamburger { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--primary);
    flex-direction: column;
    padding: 20px;
    gap: 16px;
  }
  .nav-links.open { display: flex; }
  .hero h1 { font-size: 1.9rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .stats { flex-direction: column; }
  .stat { border-right: none; border-bottom: 1px solid rgba(255,255,255,0.15); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .section-title h2 { font-size: 1.6rem; }
  .footer-grid { grid-template-columns: 1fr; }
}