/* roulang page: index */
:root {
      --primary-green: #0A8F3C;
      --energy-orange: #F15A24;
      --dark-rock: #1E1E1E;
      --warm-white: #F9F6F0;
      --light-green-bg: #E6F0E9;
      --gold-accent: #D4A843;
      --text-main: #1E1E1E;
      --text-secondary: #3A3A3A;
      --text-muted: #6B6B6B;
      --border-light: #E0E0E0;
      --white: #FFFFFF;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 32px rgba(0,0,0,0.08);
      --shadow-btn: 0 8px 20px rgba(241,90,36,0.35);
      --radius-card: 16px;
      --radius-img: 12px;
      --radius-btn: 50px;
      --transition: 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--warm-white);
      color: var(--text-secondary);
      line-height: 1.75;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s ease, box-shadow 0.3s ease, padding 0.3s ease;
      background: transparent;
    }

    #header.scrolled {
      background: var(--white);
      box-shadow: 0 4px 20px rgba(0,0,0,0.06);
      padding: 10px 0;
    }

    #header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--white);
      text-decoration: none;
      letter-spacing: -0.02em;
      transition: color 0.3s;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--energy-orange);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
    }

    #header.scrolled .logo {
      color: var(--primary-green);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      color: rgba(255,255,255,0.9);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      white-space: nowrap;
    }

    #header.scrolled .nav-links a {
      color: var(--dark-rock);
    }

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

    .btn-consult {
      background: var(--energy-orange);
      color: white !important;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      letter-spacing: 0.03em;
      box-shadow: 0 4px 12px rgba(241,90,36,0.3);
      transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
      display: inline-block;
    }

    .btn-consult:hover {
      background: #D94A1A;
      transform: translateY(-2px);
      box-shadow: var(--shadow-btn);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      flex-direction: column;
      gap: 5px;
      z-index: 1001;
    }

    .menu-toggle span {
      width: 28px;
      height: 3px;
      background: var(--white);
      border-radius: 3px;
      transition: 0.3s;
    }

    #header.scrolled .menu-toggle span {
      background: var(--dark-rock);
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: var(--white);
      box-shadow: -5px 0 25px rgba(0,0,0,0.1);
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      padding: 90px 30px 30px;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    .mobile-menu.open {
      transform: translateX(0);
    }

    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 600;
      color: var(--dark-rock);
      text-decoration: none;
      padding: 8px 0;
      border-bottom: 1px solid #eee;
    }

    /* 首屏 */
    #hero {
      background: linear-gradient(135deg, #0A3D1F 0%, #0A8F3C 70%, #1E1E1E 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
      position: relative;
      overflow: hidden;
    }

    #hero::before {
      content: "";
      position: absolute;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(255,255,255,0.03) 0%, transparent 70%);
      top: -200px;
      right: -100px;
      border-radius: 50%;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: clamp(2.8rem, 6vw, 4.5rem);
      font-weight: 900;
      line-height: 1.15;
      letter-spacing: -0.02em;
      color: white;
      margin-bottom: 24px;
    }

    .hero-content p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 36px;
      max-width: 500px;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--energy-orange);
      color: white;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      letter-spacing: 0.03em;
      transition: all 0.2s;
      border: none;
      cursor: pointer;
      display: inline-block;
    }

    .btn-primary:hover {
      background: #D94A1A;
      transform: translateY(-2px);
      box-shadow: var(--shadow-btn);
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      transition: 0.2s;
      display: inline-block;
    }

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

    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      height: 500px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      border: 1px solid rgba(255,255,255,0.2);
    }

    /* 通用板块 */
    section {
      padding: 120px 0;
    }

    .section-title {
      font-size: clamp(2rem, 4vw, 2.8rem);
      font-weight: 800;
      color: var(--dark-rock);
      margin-bottom: 16px;
      letter-spacing: -0.01em;
    }

    .section-sub {
      color: var(--text-muted);
      margin-bottom: 56px;
      font-size: 1.1rem;
    }

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

    .adv-card {
      background: white;
      padding: 36px 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .adv-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }

    .adv-icon {
      font-size: 38px;
      color: var(--primary-green);
      margin-bottom: 20px;
    }

    .adv-card h3 {
      font-size: 1.4rem;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--dark-rock);
    }

    /* 亮点网格 */
    #highlights {
      background: var(--light-green-bg);
    }

    .highlight-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      grid-auto-rows: 280px;
      gap: 20px;
    }

    .highlight-item {
      border-radius: var(--radius-img);
      overflow: hidden;
      position: relative;
      background-size: cover;
      background-position: center;
      display: flex;
      align-items: flex-end;
      transition: transform 0.3s;
    }

    .highlight-item:hover {
      transform: scale(1.02);
    }

    .highlight-item:nth-child(1) {
      grid-column: span 2;
      background-image: url('/assets/images/coverpic/cover-2.webp');
    }
    .highlight-item:nth-child(2) {
      background-image: url('/assets/images/coverpic/cover-3.webp');
    }
    .highlight-item:nth-child(3) {
      background-image: url('/assets/images/backpic/back-2.webp');
    }
    .highlight-item:nth-child(4) {
      grid-column: span 2;
      background-image: url('/assets/images/coverpic/cover-4.webp');
    }

    .highlight-overlay {
      background: linear-gradient(to top, rgba(0,0,0,0.7), transparent);
      width: 100%;
      padding: 24px;
      color: white;
    }

    .highlight-overlay h3 {
      font-size: 1.4rem;
      font-weight: 700;
    }

    .tag {
      background: var(--energy-orange);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 8px;
    }

    /* 案例瀑布流 */
    .masonry {
      columns: 3;
      column-gap: 24px;
    }

    .case-card {
      break-inside: avoid;
      background: white;
      border-radius: var(--radius-img);
      box-shadow: 0 2px 12px rgba(0,0,0,0.05);
      margin-bottom: 24px;
      overflow: hidden;
      transition: var(--transition);
    }

    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .case-img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      display: block;
    }

    .case-body {
      padding: 20px;
    }

    .case-body h3 {
      font-weight: 700;
      margin: 8px 0;
    }

    /* 对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }

    .compare-card {
      background: white;
      border-radius: 24px;
      padding: 40px;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }

    .compare-card:hover {
      border-color: var(--primary-green);
      box-shadow: var(--shadow-md);
    }

    .compare-card h3 {
      font-size: 1.8rem;
      margin-bottom: 20px;
    }

    /* FAQ */
    .faq-item {
      background: white;
      border: 1px solid #E8E8E8;
      border-radius: 12px;
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: white;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      background: #fdfdfd;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 24px 20px;
    }

    /* 联系 */
    #contact {
      background: var(--dark-rock);
      color: white;
    }

    .contact-card {
      background: white;
      border-radius: 24px;
      padding: 48px;
      max-width: 600px;
      margin: 0 auto;
      color: var(--dark-rock);
    }

    .contact-card input,
    .contact-card select {
      width: 100%;
      padding: 14px;
      margin-bottom: 16px;
      border-radius: 8px;
      border: 1px solid #D0D0D0;
      font-family: inherit;
    }

    .contact-card input:focus,
    .contact-card select:focus {
      border-color: var(--primary-green);
      outline: none;
      box-shadow: 0 0 0 3px rgba(10,143,60,0.1);
    }

    /* 页脚 */
    footer {
      background: #1E1E1E;
      color: #B0B0B0;
      padding: 60px 0 30px;
    }

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

    .footer-bottom {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 0.85rem;
    }

    @media (max-width: 992px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .advantages-grid {
        grid-template-columns: 1fr 1fr;
      }
      .masonry {
        columns: 2;
      }
      .highlight-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .menu-toggle {
        display: flex;
      }
      .advantages-grid,
      .compare-grid {
        grid-template-columns: 1fr;
      }
      .masonry {
        columns: 1;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .hero-image {
        height: 300px;
      }
    }