/* roulang page: index */
:root {
      --primary: #7C3AED;
      --primary-dark: #6D28D9;
      --accent: #F97316;
      --accent-light: #FED7AA;
      --bg-light: #FAFAFA;
      --bg-white: #FFFFFF;
      --bg-gray: #F3F4F6;
      --bg-dark: #111827;
      --text-main: #111827;
      --text-body: #374151;
      --text-muted: #6B7280;
      --text-light: #F9FAFB;
      --border-light: #E5E7EB;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
      --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);
      --radius-lg: 1rem;
      --radius-xl: 1.25rem;
      --radius-2xl: 1.5rem;
      --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    }
    * {
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: "Inter", "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
      margin: 0;
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .app-shell {
      display: flex;
      min-height: 100vh;
    }
    /* 左侧导航栏 */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      height: 100%;
      width: 5rem;
      background-color: var(--bg-dark);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 2rem 0;
      z-index: 40;
      transition: width 0.3s ease, background-color 0.2s;
      box-shadow: 2px 0 10px rgba(0,0,0,0.3);
    }
    @media (min-width: 1280px) {
      .side-nav {
        width: 16rem;
        align-items: flex-start;
        padding-left: 1.8rem;
        padding-right: 1rem;
      }
    }
    .nav-brand {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 3rem;
      color: white;
      font-weight: 700;
      font-size: 1.25rem;
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .nav-brand span {
      display: none;
    }
    @media (min-width: 1280px) {
      .nav-brand span {
        display: inline;
      }
    }
    .nav-list {
      list-style: none;
      padding: 0;
      margin: 0;
      width: 100%;
      display: flex;
      flex-direction: column;
      gap: 0.75rem;
    }
    .nav-item a {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      padding: 0.7rem 0.5rem;
      border-radius: 0.75rem;
      color: #9CA3AF;
      font-weight: 500;
      transition: all var(--transition);
      position: relative;
      white-space: nowrap;
    }
    @media (min-width: 1280px) {
      .nav-item a {
        padding-left: 1rem;
      }
    }
    .nav-item a:hover {
      color: white;
      background-color: rgba(255,255,255,0.08);
    }
    .nav-item.active a {
      color: var(--primary);
      background-color: rgba(124,58,237,0.15);
    }
    .nav-item.active a::before {
      content: '';
      position: absolute;
      left: 0;
      top: 12%;
      height: 76%;
      width: 4px;
      background-color: var(--primary);
      border-radius: 0 4px 4px 0;
    }
    .nav-text {
      display: none;
    }
    @media (min-width: 1280px) {
      .nav-text {
        display: inline;
      }
    }
    /* 移动端导航 */
    .mobile-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 4rem;
      background: white;
      box-shadow: var(--shadow-sm);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      z-index: 50;
      border-bottom: 1px solid var(--border-light);
    }
    @media (min-width: 1024px) {
      .mobile-nav {
        display: none;
      }
    }
    .hamburger {
      font-size: 1.8rem;
      background: none;
      border: none;
      color: var(--text-main);
      cursor: pointer;
    }
    .drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100%;
      background: var(--bg-dark);
      z-index: 60;
      transition: right 0.3s ease;
      padding: 2rem 1.5rem;
      display: flex;
      flex-direction: column;
      gap: 2rem;
      box-shadow: -5px 0 20px rgba(0,0,0,0.3);
    }
    .drawer.open {
      right: 0;
    }
    .drawer a {
      color: #D1D5DB;
      font-size: 1.25rem;
      font-weight: 500;
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }
    .main-content {
      margin-left: 5rem;
      width: calc(100% - 5rem);
    }
    @media (min-width: 1280px) {
      .main-content {
        margin-left: 16rem;
        width: calc(100% - 16rem);
      }
    }
    @media (max-width: 1023px) {
      .side-nav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 4rem;
      }
    }
    .hero-bg {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-bg::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(255,255,255,0.94) 0%, rgba(250,250,250,0.7) 55%, rgba(124,58,237,0.1) 100%);
    }
    .animate-float {
      animation: float 6s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-15px); }
      100% { transform: translateY(0px); }
    }
    .fade-in-up {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.7s ease, transform 0.7s ease;
    }
    .fade-in-up.visible {
      opacity: 1;
      transform: translateY(0);
    }
    .scrollbar-hide::-webkit-scrollbar {
      display: none;
    }
    .scrollbar-hide {
      -ms-overflow-style: none;
      scrollbar-width: none;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.2s;
    }
    .faq-item.open .faq-answer {
      max-height: 15rem;
      padding-top: 0.75rem;
      padding-bottom: 0.5rem;
    }
    .faq-icon {
      transition: transform 0.25s ease;
    }
    .faq-item.open .faq-icon {
      transform: rotate(180deg);
    }
    input:focus, textarea:focus {
      outline: none;
      border-bottom-color: var(--primary);
      background-color: white;
      box-shadow: 0 2px 0 var(--primary);
    }