/* roulang page: index */
/* 基础重置与设计变量 */
    :root {
      --deep-wood: #4A3B32;
      --dark-wood: #3C2E26;
      --champagne: #C5A47E;
      --champagne-dark: #B08D62;
      --warm-white: #FAF8F5;
      --stone-warm: #E8E2D9;
      --text-primary: #3C2E26;
      --text-secondary: #6B5E56;
      --text-muted: #8E8279;
    }
    
    * {
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: #FAF8F5;
      color: #3C2E26;
      line-height: 1.6;
      margin: 0;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    /* 自定义滚动条 */
    ::-webkit-scrollbar {
      width: 6px;
    }
    ::-webkit-scrollbar-track {
      background: #F5F0EB;
    }
    ::-webkit-scrollbar-thumb {
      background: #C5A47E;
      border-radius: 10px;
    }
    
    /* 左侧导航栏 (桌面端) */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      width: 5rem;
      background: linear-gradient(180deg, #3C2E26 0%, #4A3B32 100%);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 2rem 0;
      z-index: 50;
      box-shadow: 4px 0 20px rgba(0,0,0,0.1);
      transition: width 0.3s ease;
    }
    
    @media (min-width: 1280px) {
      .side-nav {
        width: 6rem;
      }
    }
    
    .nav-logo {
      font-family: "Inter", "PingFang SC", sans-serif;
      font-weight: 800;
      font-size: 1.5rem;
      color: #C5A47E;
      letter-spacing: -0.5px;
      writing-mode: vertical-rl;
      text-orientation: mixed;
      cursor: pointer;
      transition: color 0.3s;
    }
    
    .nav-logo:hover {
      color: #D4B896;
    }
    
    .nav-items {
      display: flex;
      flex-direction: column;
      gap: 2rem;
      align-items: center;
    }
    
    .nav-item {
      color: #B8A393;
      writing-mode: vertical-rl;
      text-orientation: mixed;
      font-size: 0.9rem;
      font-weight: 500;
      letter-spacing: 2px;
      transition: color 0.3s, transform 0.2s;
      cursor: pointer;
      position: relative;
    }
    
    .nav-item:hover {
      color: #C5A47E;
      transform: translateX(3px);
    }
    
    .nav-item.active {
      color: #C5A47E;
    }
    
    .nav-item.active::after {
      content: '';
      position: absolute;
      right: -8px;
      top: 50%;
      transform: translateY(-50%);
      width: 5px;
      height: 5px;
      background-color: #C5A47E;
      border-radius: 50%;
    }
    
    .nav-footer {
      color: #8E8279;
      font-size: 0.7rem;
      writing-mode: vertical-rl;
      text-orientation: mixed;
      letter-spacing: 1px;
    }
    
    /* 主内容区域 */
    .main-content {
      margin-left: 5rem;
      width: calc(100% - 5rem);
      min-height: 100vh;
    }
    
    @media (min-width: 1280px) {
      .main-content {
        margin-left: 6rem;
        width: calc(100% - 6rem);
      }
    }
    
    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
    }
    
    @media (max-width: 767px) {
      .side-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 4rem;
        background: rgba(60, 46, 38, 0.95);
        backdrop-filter: blur(10px);
        align-items: center;
        justify-content: space-between;
        padding: 0 1.5rem;
        z-index: 50;
        box-shadow: 0 4px 15px rgba(0,0,0,0.2);
      }
      .mobile-logo {
        font-family: "Inter", "PingFang SC", sans-serif;
        font-weight: 800;
        font-size: 1.4rem;
        color: #C5A47E;
        letter-spacing: -0.5px;
      }
      .hamburger {
        color: #C5A47E;
        font-size: 1.8rem;
        cursor: pointer;
        background: none;
        border: none;
      }
      .mobile-menu {
        position: fixed;
        top: 4rem;
        left: 0;
        width: 100%;
        background: #3C2E26;
        flex-direction: column;
        align-items: center;
        padding: 2rem 0;
        gap: 2rem;
        display: none;
        z-index: 49;
        box-shadow: 0 10px 20px rgba(0,0,0,0.3);
      }
      .mobile-menu.open {
        display: flex;
      }
      .mobile-menu a {
        color: #D4C4B2;
        font-size: 1.1rem;
        font-weight: 500;
        letter-spacing: 2px;
        text-decoration: none;
        transition: color 0.2s;
      }
      .mobile-menu a:hover {
        color: #C5A47E;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 4rem;
      }
    }
    
    /* 自定义按钮与组件 */
    .btn-primary {
      background-color: #C5A47E;
      color: #3C2E26;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: 9999px;
      box-shadow: 0 15px 25px -10px rgba(197, 164, 126, 0.4);
      transition: all 0.3s ease;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: #B08D62;
      box-shadow: 0 20px 30px -12px rgba(197, 164, 126, 0.5);
      transform: translateY(-2px);
    }
    
    .btn-outline {
      border: 2px solid #C5A47E;
      color: #C5A47E;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: 9999px;
      background: transparent;
      transition: all 0.3s ease;
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }
    .btn-outline:hover {
      background-color: #C5A47E;
      color: #3C2E26;
      transform: translateY(-2px);
    }
    
    .card-hover {
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: 0 30px 45px -20px rgba(74, 59, 50, 0.25);
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(197, 164, 126, 0.2);
      padding: 1.5rem 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.1rem;
      color: #3C2E26;
    }
    .faq-icon {
      color: #C5A47E;
      font-size: 1.5rem;
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease-out;
      color: #6B5E56;
      line-height: 1.7;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 1rem;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    
    /* 表单输入框 */
    .input-line {
      background: transparent;
      border: none;
      border-bottom: 1px solid rgba(255,255,255,0.4);
      padding: 0.75rem 0.25rem;
      width: 100%;
      color: white;
      font-size: 1rem;
      transition: border-color 0.3s;
      outline: none;
    }
    .input-line:focus {
      border-bottom: 2px solid #C5A47E;
    }
    .input-line::placeholder {
      color: rgba(255,255,255,0.6);
    }