:root {
      --primary: #0891b2;
      --accent: #0ea5e9;
      --bg: #ecfeff;
      --ink: #083344;
      --radius-lg: 24px;
      --radius-md: 16px;
      --shadow-soft: 0 20px 35px -10px rgba(8, 145, 178, 0.15), 0 8px 20px rgba(0, 0, 0, 0.05);
      --shadow-hover: 0 30px 50px -15px rgba(8, 145, 178, 0.25), 0 12px 30px rgba(0, 0, 0, 0.08);
      --font-sans: 'Inter', sans-serif;
      --font-mono: 'SFMono-Regular', 'Menlo', 'Consolas', 'Roboto Mono', monospace;
    }

    * { box-sizing: border-box; }
    body {
      background-color: var(--bg);
      color: var(--ink);
      font-family: var(--font-sans);
      font-weight: 400;
      line-height: 1.6;
      overflow-x: hidden;
    }

    h1, h2, h3, .display-title {
      font-weight: 900;
      letter-spacing: -0.02em;
    }

    .navbar {
      background: rgba(236, 254, 255, 0.8);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(8, 145, 178, 0.15);
      padding: 0.9rem 0;
    }
    .navbar-brand {
      font-weight: 900;
      font-size: 1.5rem;
      color: var(--primary) !important;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .navbar-nav .nav-link {
      color: var(--ink);
      font-weight: 600;
      margin: 0 8px;
      border-radius: 50px;
      padding: 8px 16px;
      transition: background 0.2s, color 0.2s;
    }
    .navbar-nav .nav-link:hover {
      background: rgba(14, 165, 233, 0.1);
      color: var(--primary);
    }

    .hero-section {
      position: relative;
      padding: 80px 0 90px;
      background: radial-gradient(circle at 80% 20%, rgba(14, 165, 233, 0.1), transparent 45%);
      overflow: hidden;
      /* 视差效果背景层 */
    }
    .hero-section::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.06"><circle cx="40" cy="40" r="18" fill="none" stroke="%230891b2" stroke-width="3"/><circle cx="150" cy="90" r="25" fill="none" stroke="%230ea5e9" stroke-width="2"/><circle cx="90" cy="160" r="12" fill="%230891b2"/><path d="M180 180 L120 120" stroke="%230ea5e9" stroke-width="4" stroke-linecap="round"/></svg>');
      background-size: 300px 300px;
      background-position: center;
      will-change: transform;
      transform: translateY(0);
      pointer-events: none;
      z-index: 0;
    }
    .hero-content {
      position: relative;
      z-index: 2;
    }

    .big-stat {
      display: inline-block;
      font-family: var(--font-mono);
      font-size: 5rem;
      font-weight: 800;
      line-height: 1;
      color: var(--primary);
      background: rgba(255, 255, 255, 0.4);
      padding: 0.5rem 1.2rem;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-soft);
      backdrop-filter: blur(4px);
      margin-bottom: 1.5rem;
    }

    .hero-title {
      font-size: 4rem;
      font-weight: 900;
      max-width: 850px;
      margin: 0.5rem 0;
    }
    .hero-sub {
      font-size: 1.3rem;
      font-weight: 500;
      color: #155e75;
      max-width: 600px;
      margin: 20px 0 30px;
    }

    .wave-divider {
      position: relative;
      width: 100%;
      height: 90px;
      background: var(--bg);
      z-index: 3;
      margin-top: -1px;
    }
    .wave-divider svg {
      display: block;
      width: 100%;
      height: 100%;
      fill: #ffffff;
    }
    .section-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 30px 28px;
      box-shadow: var(--shadow-soft);
      transition: transform 0.25s, border 0.2s, box-shadow 0.3s;
      border: 1.5px solid rgba(14, 165, 233, 0.2);
      height: 100%;
    }
    .section-card:hover {
      transform: scale(1.02);
      border-color: var(--accent);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 2.6rem;
      font-weight: 900;
      margin: 2.5rem 0 1.8rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -12px;
      width: 60%;
      height: 6px;
      background: var(--accent);
      border-radius: 8px;
    }

    .faq-accordion .accordion-item {
      border: none;
      background: transparent;
      margin-bottom: 18px;
    }
    .faq-accordion .accordion-button {
      background: white;
      border-radius: var(--radius-md) !important;
      box-shadow: var(--shadow-soft);
      font-weight: 700;
      font-size: 1.15rem;
      padding: 18px 24px;
      border: 1px solid rgba(14, 165, 233, 0.15);
      color: var(--ink);
    }
    .faq-accordion .accordion-button:not(.collapsed) {
      background: #f0f9ff;
      color: var(--primary);
    }
    .faq-accordion .accordion-body {
      background: white;
      border-radius: 0 0 var(--radius-md) var(--radius-md);
      padding: 12px 24px 20px;
      box-shadow: 0 12px 25px -10px rgba(8, 145, 178, 0.2);
    }

    .step-item {
      position: relative;
      padding: 24px 20px 20px;
      background: white;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-soft);
      border: 1px solid rgba(14, 165, 233, 0.1);
    }
    .step-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
      opacity: 0.3;
      line-height: 1;
      display: block;
      margin-bottom: 6px;
    }

    .footer {
      background: #083344;
      color: #cffafe;
      padding: 50px 0 25px;
      margin-top: 70px;
      border-top-left-radius: 48px;
      border-top-right-radius: 48px;
    }
    .footer a {
      color: #a5f3fc;
      text-decoration: none;
    }
    .footer-links a {
      display: inline-block;
      margin-right: 28px;
      font-weight: 500;
    }

    .link-slot {
      background: rgba(255, 255, 255, 0.08);
      padding: 30px 20px;
      border-radius: var(--radius-lg);
      margin-top: 40px;
      text-align: center;
    }

    .btn-outline-primary-custom {
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: 50px;
      font-weight: 700;
      padding: 12px 30px;
      transition: 0.2s;
    }
    .btn-outline-primary-custom:hover {
      background: var(--primary);
      color: white;
    }

    .back-to-top {
      position: fixed;
      bottom: 30px;
      right: 30px;
      width: 52px;
      height: 52px;
      border-radius: 50%;
      background: var(--primary);
      color: white;
      font-size: 1.6rem;
      border: none;
      box-shadow: var(--shadow-hover);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      visibility: hidden;
      transition: 0.3s;
      z-index: 999;
    }
    .back-to-top.show {
      opacity: 1;
      visibility: visible;
    }
    .back-to-top:hover {
      background: var(--accent);
      transform: translateY(-4px);
    }

/* --- 子页面追加 --- */
/* 页面内微调：关于页专属的少量样式 */
        .about-hero {
            padding: 100px 0 60px;
            background: var(--bg);
            position: relative;
        }
.about-hero .hero-title {
            margin-bottom: 20px;
        }
.about-hero .hero-sub {
            max-width: 700px;
            margin: 0 auto;
        }
.about-section {
            padding: 60px 0;
            border-bottom: 1px solid rgba(8, 145, 178, 0.1);
        }
.about-section:last-of-type {
            border-bottom: none;
        }
.about-section .section-title {
            margin-bottom: 24px;
            font-size: 1.9rem;
        }
.about-content {
            font-size: 1.05rem;
            line-height: 1.8;
            color: var(--ink);
            opacity: 0.92;
            max-width: 800px;
            margin: 0 auto;
        }
.about-content p {
            margin-bottom: 18px;
        }
.about-content strong {
            color: var(--primary);
            font-weight: 600;
        }
.about-quote {
            background: rgba(8, 145, 178, 0.06);
            border-left: 4px solid var(--primary);
            padding: 20px 24px;
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
            margin: 28px 0;
            font-style: italic;
            color: var(--ink);
        }
.value-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 20px;
            margin-top: 30px;
        }
.value-item {
            background: rgba(255,255,255,0.7);
            border: 1px solid rgba(8, 145, 178, 0.15);
            border-radius: var(--radius-md);
            padding: 24px 20px;
            text-align: center;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
.value-item:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
.value-item i {
            font-size: 2rem;
            color: var(--primary);
            margin-bottom: 12px;
        }
.value-item h4 {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--ink);
            margin-bottom: 8px;
        }
.value-item p {
            font-size: 0.9rem;
            color: var(--ink);
            opacity: 0.8;
            line-height: 1.6;
            margin-bottom: 0;
        }
.about-list {
            padding-left: 0;
            list-style: none;
        }
.about-list li {
            padding: 10px 0;
            border-bottom: 1px dashed rgba(8, 145, 178, 0.2);
            display: flex;
            align-items: flex-start;
            gap: 12px;
            font-size: 1rem;
            color: var(--ink);
            opacity: 0.92;
        }
.about-list li:last-child {
            border-bottom: none;
        }
.about-list li i {
            color: var(--primary);
            margin-top: 5px;
            font-size: 0.9rem;
        }
.about-timeline {
            position: relative;
            padding-left: 30px;
            margin-top: 24px;
        }
.about-timeline::before {
            content: '';
            position: absolute;
            left: 10px;
            top: 0;
            bottom: 0;
            width: 2px;
            background: linear-gradient(to bottom, var(--primary), rgba(8,145,178,0.2));
        }
.timeline-item {
            position: relative;
            margin-bottom: 24px;
            padding-left: 20px;
        }
.timeline-item::before {
            content: '';
            position: absolute;
            left: -26px;
            top: 6px;
            width: 10px;
            height: 10px;
            border-radius: 50%;
            background: var(--primary);
            border: 2px solid white;
            box-shadow: 0 0 0 2px var(--primary);
        }
.timeline-item .time {
            font-family: var(--font-mono);
            font-size: 0.85rem;
            color: var(--primary);
            font-weight: 500;
            display: block;
            margin-bottom: 4px;
        }
.timeline-item .desc {
            font-size: 0.95rem;
            color: var(--ink);
            opacity: 0.85;
            line-height: 1.6;
        }
.about-hero { padding: 70px 0 40px; }
.about-section { padding: 40px 0; }
.about-section .section-title { font-size: 1.5rem; }
.value-grid { grid-template-columns: 1fr; }

/* --- 子页面追加 --- */
.rank-card {
            background: linear-gradient(135deg, rgba(8, 145, 178, 0.08), rgba(14, 165, 233, 0.05));
            border: 1px solid rgba(8, 145, 178, 0.2);
            border-radius: var(--radius-md);
            padding: 1.5rem;
            margin-bottom: 1rem;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
.rank-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: var(--primary);
        }
.rank-number {
            font-size: 2.5rem;
            font-weight: 800;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-right: 1rem;
            min-width: 70px;
            text-align: center;
            font-family: var(--font-mono);
        }
.rank-tag {
            display: inline-block;
            padding: 0.2rem 0.8rem;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
            margin-right: 0.4rem;
            background: rgba(8, 145, 178, 0.1);
            color: var(--primary);
            border: 1px solid rgba(8, 145, 178, 0.2);
        }
.rank-stats {
            font-size: 0.85rem;
            color: var(--ink);
            opacity: 0.7;
            margin-top: 0.5rem;
        }
.rank-badge {
            display: inline-flex;
            align-items: center;
            padding: 0.15rem 0.6rem;
            border-radius: 12px;
            font-size: 0.7rem;
            font-weight: 600;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: #fff;
            margin-left: 0.5rem;
        }
.section-header {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            margin-bottom: 2rem;
        }
.section-header i {
            font-size: 1.5rem;
            color: var(--primary);
        }
.category-tabs {
            display: flex;
            gap: 0.5rem;
            flex-wrap: wrap;
            margin-bottom: 2rem;
        }
.category-tab {
            padding: 0.5rem 1.25rem;
            border-radius: 25px;
            font-size: 0.9rem;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 1px solid rgba(8, 145, 178, 0.2);
            background: rgba(8, 145, 178, 0.05);
            color: var(--ink);
            text-decoration: none;
        }
.category-tab:hover, .category-tab.active {
            background: var(--primary);
            color: #fff;
            border-color: var(--primary);
        }

/* --- Bootstrap 组件配色适配(程序自动补,避免白底黑字) --- */
.table { color:#083344 !important; border-color:rgba(0,0,0,.12) !important; --bs-table-bg:transparent !important; --bs-table-color:#083344 !important; }
.accordion-header { background:transparent !important; }