/* roulang page: index */
:root {
            --bg-deep: #0A0E27;
            --accent-cyan: #00F0FF;
            --card-bg: #1E2A4A;
            --warm-orange: #FF6B35;
            --neutral-light: #F0F2F5;
            --text-secondary: #B0B8C5;
            --text-white: #FFFFFF;
            --gradient-btn: linear-gradient(135deg, #00F0FF, #0066FF);
            --gradient-hero: linear-gradient(135deg, #00F0FF, #0066FF);
            --border-glow: rgba(0, 240, 255, 0.15);
            --border-light: rgba(0, 240, 255, 0.1);
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.25);
            --shadow-glow: 0 0 20px rgba(0, 240, 255, 0.4);
            --shadow-glow-hover: 0 0 35px rgba(0, 240, 255, 0.7);
            --radius-lg: 16px;
            --radius-pill: 50px;
            --font-stack: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --section-gap: 100px;
            --container-max: 1200px;
        }

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

        body {
            font-family: var(--font-stack);
            font-size: 16px;
            font-weight: 400;
            line-height: 1.7;
            background-color: var(--bg-deep);
            color: var(--text-secondary);
            overflow-x: hidden;
        }

        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            line-height: 1.3;
            color: var(--text-white);
        }

        h1 {
            font-size: 48px;
        }
        h2 {
            font-size: 36px;
        }
        h3 {
            font-size: 24px;
            font-weight: 600;
        }
        h4 {
            font-size: 20px;
            font-weight: 600;
        }

        a {
            text-decoration: none;
            color: var(--accent-cyan);
            transition: all 0.3s ease;
        }
        a:hover {
            color: var(--accent-cyan);
            text-shadow: 0 0 15px rgba(0, 240, 255, 0.5);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button, input {
            font-family: var(--font-stack);
        }

        .container {
            max-width: var(--container-max);
            padding-left: 20px;
            padding-right: 20px;
            margin: 0 auto;
        }

        section {
            padding-top: var(--section-gap);
            padding-bottom: var(--section-gap);
        }

        @media (max-width: 768px) {
            h1 {
                font-size: 32px;
            }
            h2 {
                font-size: 26px;
            }
            h3 {
                font-size: 20px;
            }
            section {
                padding-top: 60px;
                padding-bottom: 60px;
            }
        }

        /* 导航栏 */
        .navbar {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1050;
            background: rgba(10, 14, 39, 0.85);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid var(--border-light);
            padding: 12px 0;
        }
        .navbar .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: nowrap;
        }
        .navbar-brand {
            font-size: 24px;
            font-weight: 700;
            color: var(--accent-cyan);
            letter-spacing: 1px;
            white-space: nowrap;
            order: 2;
            margin: 0 20px;
            text-shadow: 0 0 18px rgba(0, 240, 255, 0.6);
        }
        .nav-left, .nav-right {
            display: flex;
            align-items: center;
            gap: 28px;
        }
        .nav-left {
            order: 1;
        }
        .nav-right {
            order: 3;
        }
        .nav-link {
            color: var(--text-secondary);
            font-weight: 500;
            font-size: 15px;
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--accent-cyan);
        }
        .navbar-toggler {
            border: 1px solid var(--border-light);
            background: transparent;
            padding: 4px 8px;
            border-radius: 6px;
            order: 3;
        }
        .navbar-toggler-icon {
            background-image: none;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--accent-cyan);
            font-size: 24px;
        }
        .navbar-toggler-icon::before {
            content: "\f0c9";
            font-family: "Font Awesome 6 Free";
            font-weight: 900;
        }
        .offcanvas {
            background: rgba(10, 14, 39, 0.97) !important;
            backdrop-filter: blur(24px);
            -webkit-backdrop-filter: blur(24px);
        }
        .offcanvas-header {
            border-bottom: 1px solid var(--border-light);
        }
        .offcanvas-title {
            color: var(--accent-cyan);
            font-weight: 700;
        }
        .offcanvas .nav-link {
            font-size: 20px;
            font-weight: 500;
            padding: 12px 20px;
            border-bottom: 1px solid rgba(0, 240, 255, 0.08);
        }
        .btn-close {
            filter: invert(1);
        }

        /* 按钮系统 */
        .btn-primary-custom {
            background: var(--gradient-btn);
            border: none;
            color: var(--text-white);
            font-weight: 600;
            font-size: 16px;
            border-radius: var(--radius-pill);
            padding: 14px 36px;
            box-shadow: var(--shadow-glow);
            transition: all 0.3s ease;
            display: inline-block;
            text-align: center;
        }
        .btn-primary-custom:hover {
            box-shadow: var(--shadow-glow-hover);
            transform: translateY(-2px);
            color: #fff;
        }
        .btn-outline-custom {
            background: transparent;
            border: 2px solid var(--accent-cyan);
            color: var(--accent-cyan);
            font-weight: 600;
            border-radius: var(--radius-pill);
            padding: 12px 34px;
            transition: all 0.3s ease;
        }
        .btn-outline-custom:hover {
            background: rgba(0, 240, 255, 0.08);
            color: var(--accent-cyan);
            box-shadow: 0 0 18px rgba(0, 240, 255, 0.3);
        }

        /* Hero */
        .hero-section {
            min-height: 100vh;
            display: flex;
            align-items: center;
            background: radial-gradient(circle at 20% 30%, #1a2447 0%, var(--bg-deep) 70%);
            position: relative;
            overflow: hidden;
            padding-top: 80px;
        }
        .hero-grid-bg {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: linear-gradient(rgba(0, 240, 255, 0.05) 1px, transparent 1px), linear-gradient(90deg, rgba(0, 240, 255, 0.05) 1px, transparent 1px);
            background-size: 40px 40px;
            pointer-events: none;
        }
        .hero-content {
            position: relative;
            z-index: 2;
        }
        .hero-title {
            font-size: 48px;
            font-weight: 700;
            line-height: 1.2;
            margin-bottom: 1rem;
            background: linear-gradient(to right, #fff, #d0e0ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .hero-subtitle {
            color: var(--text-secondary);
            font-size: 18px;
            margin-bottom: 2rem;
        }
        .mockup-img {
            border-radius: 24px;
            box-shadow: 0 25px 60px rgba(0, 240, 255, 0.25);
            animation: float 6s ease-in-out infinite;
            border: 1px solid rgba(0, 240, 255, 0.2);
        }
        @keyframes float {
            0% { transform: translateY(0); }
            50% { transform: translateY(-12px); }
            100% { transform: translateY(0); }
        }

        /* 卡片玻璃拟态 */
        .glass-card {
            background: rgba(30, 42, 74, 0.6);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border: 1px solid var(--border-glow);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-card);
            padding: 24px;
            transition: all 0.35s ease;
            height: 100%;
        }
        .glass-card:hover {
            border-color: rgba(0, 240, 255, 0.4);
            box-shadow: 0 12px 40px rgba(0, 240, 255, 0.2);
            transform: scale(1.02);
        }

        .icon-cyan {
            color: var(--accent-cyan);
            font-size: 42px;
            margin-bottom: 1rem;
        }

        .text-secondary-custom {
            color: var(--text-secondary);
        }

        .section-title {
            margin-bottom: 3rem;
            position: relative;
        }

        /* 锯齿图文 */
        .feature-row {
            align-items: center;
            margin-bottom: 5rem;
        }
        .feature-img {
            border-radius: 20px;
            border: 1px solid rgba(0, 240, 255, 0.25);
            box-shadow: 0 10px 30px rgba(0,0,0,0.5);
        }

        /* 场景卡片 */
        .scenario-card {
            background: rgba(30, 42, 74, 0.5);
            backdrop-filter: blur(12px);
            border-radius: 20px;
            padding: 24px;
            border: 1px solid rgba(0, 240, 255, 0.12);
            transition: 0.3s;
            height: 100%;
        }
        .scenario-card:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 28px rgba(0, 240, 255, 0.2);
        }

        .highlight-number {
            font-size: 48px;
            font-weight: 800;
            color: var(--warm-orange);
            display: block;
            line-height: 1;
        }

        /* FAQ 手风琴 */
        .accordion-button {
            background-color: rgba(30, 42, 74, 0.7);
            color: var(--accent-cyan);
            font-weight: 600;
            border: none;
            box-shadow: none;
        }
        .accordion-button:not(.collapsed) {
            background-color: rgba(0, 240, 255, 0.1);
            color: var(--accent-cyan);
            box-shadow: none;
        }
        .accordion-item {
            background: transparent;
            border: 1px solid var(--border-light);
            margin-bottom: 12px;
            border-radius: 12px !important;
            overflow: hidden;
        }
        .accordion-body {
            color: var(--text-secondary);
            background: rgba(10, 14, 39, 0.6);
        }

        /* CTA 横幅 */
        .cta-banner {
            background: linear-gradient(180deg, #0f1a3a 0%, #060b1f 100%);
            border-top: 1px solid rgba(0, 240, 255, 0.15);
            border-bottom: 1px solid rgba(0, 240, 255, 0.15);
        }

        /* 页脚 */
        .footer {
            background: #060B1F;
            color: var(--text-secondary);
            font-size: 14px;
        }
        .footer a {
            color: var(--text-secondary);
        }
        .footer a:hover {
            color: var(--accent-cyan);
        }
        .footer-bottom {
            border-top: 1px solid rgba(0, 240, 255, 0.08);
        }

        @media (max-width: 992px) {
            .navbar-brand {
                margin: 0 10px;
            }
            .nav-left, .nav-right {
                display: none;
            }
            .hero-title {
                font-size: 36px;
            }
            .feature-row {
                flex-direction: column;
            }
        }