/* ========================================
   德信聚能 V2.3 视觉系统
   ======================================== */

/* 色彩系统 */
:root {
  --primary: #1a3a6b;
  --primary-light: #2a4a8b;
  --accent: #c8392d;
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --text: #1a1a1a;
  --text-secondary: #555;
  --border: #e0e4e8;
  --white: #ffffff;
}

/* 字体系统 */
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  margin: 0;
  padding: 0;
}

/* 间距系统 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 标题层级 */
h1 { font-size: 2.2rem; font-weight: 700; margin: 0 0 24px; line-height: 1.3; }
h2 { font-size: 1.6rem; font-weight: 600; margin: 0 0 20px; }
h3 { font-size: 1.2rem; font-weight: 600; margin: 0 0 12px; }
h4 { font-size: 1rem; font-weight: 600; margin: 0 0 8px; }
p { margin: 0 0 16px; }

/* 按钮规范 */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 4px;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}
.btn-primary {
  background: var(--primary);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--primary-light);
}
.btn-outline {
  background: transparent;
  border: 1px solid var(--primary);
  color: var(--primary);
}
.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}

/* 卡片规范 */
.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  transition: box-shadow 0.2s;
}
.card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}
.card img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}
.card-body {
  padding: 20px;
}
.card-body h3 {
  margin-bottom: 8px;
}
.card-body p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 12px;
}

/* 头部导航 */
header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
header .logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}
header nav {
  display: flex;
  gap: 32px;
}
header nav a {
  color: var(--text);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}
header nav a:hover {
  color: var(--primary);
}
header .contact-bar {
  display: flex;
  align-items: center;
  gap: 16px;
}
header .contact-bar span {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Hero区 */
.hero {
  background: var(--bg-alt);
  padding: 60px 0;
}
.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.hero-tag {
  display: inline-block;
  background: var(--primary);
  color: var(--white);
  padding: 6px 14px;
  border-radius: 4px;
  font-size: 0.85rem;
  margin-bottom: 16px;
}
.hero h1 {
  font-size: 2.4rem;
  margin-bottom: 16px;
}
.hero p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 24px;
}
.hero-btns {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
}
.hero-features {
  list-style: none;
  padding: 0;
  margin: 0;
}
.hero-features li {
  color: var(--text-secondary);
  font-size: 0.95rem;
  padding: 6px 0;
  padding-left: 20px;
  position: relative;
}
.hero-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: bold;
}
.hero-img img {
  width: 100%;
  border-radius: 8px;
  object-fit: cover;
}

/* 产品卡片网格 */
.products-section {
  padding: 64px 0;
}
.products-section h2 {
  text-align: center;
  margin-bottom: 12px;
}
.products-section .section-sub {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 40px;
}
.products-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.products-grid .card-body h3 {
  font-size: 1.1rem;
}
.products-grid .card-body p {
  font-size: 0.9rem;
  margin-bottom: 12px;
}

/* 场景入口 */
.scene-section {
  padding: 64px 0;
  background: var(--bg-alt);
}
.scene-section h2 {
  text-align: center;
  margin-bottom: 12px;
}
.scene-section .section-sub {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 40px;
}
.scene-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.scene-card {
  background: var(--white);
  padding: 24px;
  border-radius: 8px;
  text-align: center;
}
.scene-card h3 {
  margin-bottom: 8px;
}
.scene-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 12px;
}
.scene-tip {
  text-align: center;
  color: var(--text-secondary);
  margin-top: 32px;
  font-size: 0.95rem;
}

/* 服务能力 */
.service-section {
  padding: 64px 0;
}
.service-section h2 {
  text-align: center;
  margin-bottom: 40px;
}
.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.service-item {
  text-align: center;
  padding: 32px 24px;
  background: var(--bg-alt);
  border-radius: 8px;
}
.service-item h3 {
  margin-bottom: 8px;
}
.service-item p {
  color: var(--text-secondary);
  margin: 0;
}

/* CTA区 */
.cta-section {
  background: var(--primary);
  color: var(--white);
  padding: 64px 0;
  text-align: center;
}
.cta-section h2 {
  margin-bottom: 12px;
}
.cta-section .cta-sub {
  opacity: 0.85;
  margin-bottom: 24px;
}
.cta-section .cta-phone {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 24px;
}
.cta-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
}

/* FAQ */
.faq-section {
  padding: 64px 0;
  background: var(--bg-alt);
}
.faq-section h2 {
  text-align: center;
  margin-bottom: 32px;
}
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}
details {
  background: var(--white);
  border-radius: 8px;
  margin-bottom: 12px;
  overflow: hidden;
}
summary {
  padding: 16px 20px;
  cursor: pointer;
  font-weight: 500;
  list-style: none;
  position: relative;
}
summary::after {
  content: "+";
  position: absolute;
  right: 20px;
  font-size: 1.2rem;
  color: var(--text-secondary);
}
details[open] summary::after {
  content: "−";
}
details p {
  padding: 0 20px 16px;
  color: var(--text-secondary);
  margin: 0;
}

/* 页脚 */
footer {
  background: #1a1a1a;
  color: rgba(255,255,255,0.7);
  padding: 48px 0 24px;
}
footer .container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
}
footer h4 {
  color: var(--white);
  margin-bottom: 16px;
}
footer p, footer a {
  color: rgba(255,255,255,0.6);
  font-size: 0.9rem;
  line-height: 1.8;
  text-decoration: none;
}
footer a:hover {
  color: var(--white);
}
footer .footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  margin-top: 40px;
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
}

/* 面包屑 */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}
.breadcrumb a:hover {
  color: var(--primary);
}

/* 详情页产品区 */
.product-hero {
  padding: 40px 0;
}
.product-hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.product-hero h1 {
  margin-bottom: 12px;
}
.product-hero .product-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
}
.product-hero .product-contact {
  margin-top: 20px;
  display: flex;
  gap: 16px;
  align-items: center;
}
.product-hero .product-contact p {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--primary);
}
.product-hero img {
  width: 100%;
  border-radius: 8px;
  aspect-ratio: 4/3;
  object-fit: cover;
}

/* 快速判断模块 */
.quick-judge {
  background: var(--bg-alt);
  padding: 40px;
  border-radius: 8px;
  margin: 40px 0;
}
.quick-judge h2 {
  margin-bottom: 12px;
}
.quick-judge ul {
  list-style: none;
  padding: 0;
  margin: 16px 0;
}
.quick-judge li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
}
.quick-judge li::before {
  content: "•";
  position: absolute;
  left: 8px;
  color: var(--primary);
}
.quick-judge p {
  color: var(--text-secondary);
  margin: 0;
}

/* 产品图集 */
.gallery {
  padding: 40px 0;
}
.gallery h2 {
  margin-bottom: 24px;
}
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.gallery-grid img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  border-radius: 4px;
}

/* 联系表单 */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  padding: 48px 0;
}
.contact-info h2 {
  margin-bottom: 24px;
}
.contact-info ul {
  list-style: none;
  padding: 0;
  margin-bottom: 24px;
}
.contact-info li {
  padding: 12px 0;
  font-size: 1rem;
}
.contact-form h2 {
  margin-bottom: 24px;
}
.form-group {
  margin-bottom: 16px;
}
.form-group label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
  font-size: 0.95rem;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 1rem;
  font-family: inherit;
  box-sizing: border-box;
}
.form-group textarea {
  resize: vertical;
}
.form-group button {
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
}
.form-group button:hover {
  background: var(--primary-light);
}

/* 产品内页内容 */
.product-content {
  padding: 40px 0;
}
.product-content h2 {
  margin-top: 40px;
  margin-bottom: 16px;
}
.product-content h2:first-child {
  margin-top: 0;
}
.product-content ul {
  list-style: none;
  padding: 0;
}
.product-content li {
  padding: 8px 0;
  padding-left: 20px;
  position: relative;
}
.product-content li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--primary);
}

/* 响应式 */
@media (max-width: 1024px) {
  .products-grid,
  .scene-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .service-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (max-width: 768px) {
  header .container {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 24px;
    gap: 12px;
  }
  header nav {
    gap: 16px;
    order: 3;
    width: 100%;
    justify-content: center;
    padding: 12px 0;
    border-top: 1px solid var(--border);
  }
  .hero .container,
  .product-hero .container,
  .contact-layout {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 40px 0;
  }
  .hero h1 {
    font-size: 1.8rem;
  }
  .products-grid,
  .scene-grid {
    grid-template-columns: 1fr;
  }
  .service-grid {
    grid-template-columns: 1fr;
  }
  footer .container {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .cta-section .cta-phone {
    font-size: 1.6rem;
  }
}