/* ===== 基础重置 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #DC3545;
  --secondary: #2E5984;
  --accent: #4A90D9;
  --white: #FFFFFF;
  --text: #333333;
  --text-light: #666666;
  --bg-light: #F5F7FA;
  --bg-blue: #EBF3FB;
  --border: #E0E6ED;
  --shadow: rgba(31, 78, 121, 0.12);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: '微软雅黑', 'PingFang SC', -apple-system, sans-serif;
  font-size: 16px;
  color: var(--text);
  line-height: 1.6;
  background: var(--white);
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
}

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

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--white);
  box-shadow: 0 2px 12px var(--shadow);
  z-index: 1000;
  height: 70px;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: bold;
  color: var(--primary);
}

.logo-icon {
  font-size: 28px;
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 15px;
  color: var(--text);
  font-weight: 500;
  transition: color 0.3s;
}

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

.nav-phone {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: var(--white);
  padding: 8px 16px;
  border-radius: 24px;
  font-weight: bold;
  font-size: 15px;
}

.nav-phone .phone-icon {
  font-size: 16px;
}

/* ===== 横幅 ===== */
.hero {
  position: relative;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 120px 20px 80px;
  color: var(--white);
}

.hero-overlay {
  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='0.05'%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-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
}

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.3);
  padding: 6px 20px;
  border-radius: 24px;
  font-size: 14px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 48px;
  font-weight: bold;
  margin-bottom: 16px;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 22px;
  opacity: 0.95;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 16px;
  opacity: 0.8;
  margin-bottom: 36px;
  line-height: 1.8;
}

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

.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: 30px;
  font-size: 16px;
  font-weight: bold;
  transition: all 0.3s;
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  background: #f0f0f0;
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 2px solid var(--white);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.1);
}

.hero-bottom {
  position: relative;
  z-index: 1;
  margin-top: 60px;
}

.hero-stats {
  display: flex;
  gap: 48px;
  justify-content: center;
  flex-wrap: wrap;
}

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

.stat-num {
  font-size: 40px;
  font-weight: bold;
  color: #FFD700;
}

.stat-label {
  font-size: 14px;
  opacity: 0.9;
  margin-top: 4px;
}

/* ===== 通用区块 ===== */
.section {
  padding: 80px 0;
}

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

.section-tag {
  font-size: 13px;
  letter-spacing: 4px;
  color: var(--accent);
  margin-bottom: 12px;
  font-weight: bold;
}

.section-header h2 {
  font-size: 36px;
  color: var(--primary);
  margin-bottom: 16px;
}

.section-line {
  width: 60px;
  height: 4px;
  background: var(--accent);
  margin: 0 auto;
  border-radius: 2px;
}

/* ===== 关于我们 ===== */
.about-section {
  background: var(--white);
}

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

.about-text p {
  color: var(--text-light);
  line-height: 1.9;
  margin-bottom: 16px;
}

.about-lead {
  font-size: 18px !important;
  color: var(--text) !important;
}

.highlight {
  color: var(--primary);
  font-weight: bold;
}

.about-features {
  display: grid;
  gap: 20px;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  background: var(--bg-blue);
  border-radius: 12px;
}

.feature-icon {
  font-size: 32px;
  flex-shrink: 0;
}

.feature-title {
  font-size: 16px;
  font-weight: bold;
  color: var(--primary);
  margin-bottom: 4px;
}

.feature-desc {
  font-size: 14px;
  color: var(--text-light);
}

/* ===== 服务项目 ===== */
.services-section {
  background: var(--bg-light);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--white);
  padding: 32px 24px;
  border-radius: 16px;
  box-shadow: 0 4px 16px var(--shadow);
  transition: transform 0.3s, box-shadow 0.3s;
  position: relative;
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 8px 32px rgba(31, 78, 121, 0.2);
}

.service-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.service-card h3 {
  font-size: 18px;
  color: var(--primary);
  margin-bottom: 12px;
}

.service-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

.service-tag {
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--bg-blue);
  color: var(--accent);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 12px;
}

/* ===== 工程案例 ===== */
.cases-section {
  background: var(--white);
}

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

.case-card {
  background: var(--white);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 20px var(--shadow);
  display: flex;
  flex-direction: column;
}

.case-img {
  height: 200px;
}

.case-info {
  padding: 24px;
}

.case-tag {
  display: inline-block;
  background: var(--bg-blue);
  color: var(--accent);
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 12px;
  margin-bottom: 12px;
}

.case-card h3 {
  font-size: 18px;
  color: var(--primary);
  margin-bottom: 8px;
}

.case-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 12px;
}

.case-meta {
  font-size: 13px;
  color: #999;
}

/* ===== 服务保障 ===== */
.guarantee-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  padding: 80px 0;
}

.guarantee-box {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 20px;
  padding: 48px;
}

.guarantee-content h2 {
  font-size: 32px;
  color: var(--white);
  text-align: center;
  margin-bottom: 40px;
}

.guarantee-items {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.guarantee-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.guarantee-num {
  font-size: 36px;
  font-weight: bold;
  color: #FFD700;
  flex-shrink: 0;
  line-height: 1;
}

.guarantee-item strong {
  display: block;
  color: var(--white);
  font-size: 18px;
  margin-bottom: 6px;
}

.guarantee-item p {
  color: rgba(255,255,255,0.8);
  font-size: 14px;
  line-height: 1.6;
}

/* ===== 联系我们 ===== */
.contact-section {
  background: var(--bg-light);
}

.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact-icon {
  font-size: 28px;
  width: 52px;
  height: 52px;
  background: var(--bg-blue);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-label {
  font-size: 13px;
  color: #999;
  margin-bottom: 4px;
}

.contact-value {
  font-size: 16px;
  color: var(--text);
  font-weight: 500;
}

.contact-form-wrap {
  background: var(--white);
  padding: 32px;
  border-radius: 16px;
  box-shadow: 0 4px 20px var(--shadow);
}

.contact-form-wrap h3 {
  font-size: 20px;
  color: var(--primary);
  margin-bottom: 24px;
  text-align: center;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  color: var(--text);
  margin-bottom: 8px;
  font-weight: 500;
}

.required {
  color: #E65100;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  transition: border-color 0.3s;
  background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group textarea {
  resize: vertical;
}

.btn-full {
  width: 100%;
}

.form-success {
  text-align: center;
  padding: 20px;
  color: #2E7D32;
  font-size: 16px;
}

/* ===== 底部 ===== */
.footer {
  background: var(--primary);
  color: var(--white);
  padding: 60px 0 0;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: bold;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 14px;
  opacity: 0.8;
  line-height: 1.8;
}

.footer h4 {
  font-size: 16px;
  margin-bottom: 20px;
}

.footer ul li {
  margin-bottom: 10px;
}

.footer ul li a,
.footer ul li {
  font-size: 14px;
  opacity: 0.8;
  transition: opacity 0.3s;
}

.footer ul li a:hover {
  opacity: 1;
}

.footer-contact p {
  font-size: 14px;
  margin-bottom: 10px;
  opacity: 0.9;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 20px 0;
  text-align: center;
  font-size: 13px;
  opacity: 0.7;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

  .hero h1 {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 18px;
  }

  .hero-stats {
    gap: 24px;
  }

  .stat-num {
    font-size: 28px;
  }

  .about-content {
    grid-template-columns: 1fr;
  }

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

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

  .guarantee-items {
    grid-template-columns: 1fr;
  }

  .contact-layout {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 480px) {
  .footer-content {
    grid-template-columns: 1fr;
  }

  .hero-btns {
    flex-direction: column;
  }
}