/* ===== CSS Variables ===== */
        :root {
            --bg-primary: #06070a;
            --bg-secondary: #0d0f14;
            --bg-card: rgba(255, 255, 255, 0.03);
            --bg-glass: rgba(255, 255, 255, 0.06);
            --border-color: rgba(255, 255, 255, 0.08);
            --border-glow: rgba(255, 255, 255, 0.15);

            --text-primary: #ffffff;
            --text-secondary: rgba(255, 255, 255, 0.7);
            --text-muted: rgba(255, 255, 255, 0.4);

            --accent-cyan: #00d4ff;
            --accent-purple: #a855f7;
            --accent-green: #00ffa3;
            --accent-yellow: #fbbf24;
            --accent-blue: #3b82f6;
            --accent-pink: #ec4899;

            --glow-cyan: 0 0 30px rgba(0, 212, 255, 0.3);
            --glow-purple: 0 0 30px rgba(168, 85, 247, 0.3);
            --glow-green: 0 0 30px rgba(0, 255, 163, 0.3);

            --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
            --font-mono: monospace;

            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 20px;
            --radius-xl: 28px;
        }

        /* ===== Reset & Base ===== */
        *,
        *::before,
        *::after {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-sans);
            background: var(--bg-primary);
            color: var(--text-primary);
            min-height: 100vh;
            line-height: 1.6;
            overflow-x: hidden;
        }

        /* ===== Background Effects ===== */
        .bg-gradient {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            z-index: -1;
            overflow: hidden;
        }

        .bg-gradient::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background:
                radial-gradient(ellipse 80% 50% at 20% 40%, rgba(168, 85, 247, 0.15) 0%, transparent 50%),
                radial-gradient(ellipse 60% 40% at 80% 20%, rgba(0, 212, 255, 0.12) 0%, transparent 50%),
                radial-gradient(ellipse 50% 30% at 50% 80%, rgba(0, 255, 163, 0.08) 0%, transparent 50%);
            animation: bgFloat 20s ease-in-out infinite;
        }

        @keyframes bgFloat {
            0%,
            100% {
                transform: translate(0, 0) rotate(0deg);
            }
            33% {
                transform: translate(2%, 1%) rotate(1deg);
            }
            66% {
                transform: translate(-1%, 2%) rotate(-1deg);
            }
        }

        /* Grid pattern overlay */
        .bg-grid {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            z-index: -1;
            background-image:
                linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
            background-size: 60px 60px;
        }

        /* ===== Container ===== */
        .container {
            max-width: 1000px;
            margin: 0 auto;
            padding: 40px 20px;
        }

        /* ===== Header ===== */
        .header {
            text-align: center;
            margin-bottom: 50px;
        }

        .logo-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            padding: 8px 16px;
            border-radius: 50px;
            font-size: 12px;
            font-weight: 600;
            letter-spacing: 1px;
            text-transform: uppercase;
            color: var(--text-secondary);
            margin-bottom: 24px;
        }

        .logo-badge .dot {
            width: 6px;
            height: 6px;
            background: var(--accent-green);
            border-radius: 50%;
            animation: pulse 2s ease-in-out infinite;
        }

        @keyframes pulse {
            0%,
            100% {
                opacity: 1;
                transform: scale(1);
            }
            50% {
                opacity: 0.5;
                transform: scale(1.2);
            }
        }

        .main-title {
            font-size: clamp(2.5rem, 6vw, 4rem);
            font-weight: 900;
            letter-spacing: -0.03em;
            line-height: 1.1;
            margin-bottom: 16px;
        }

        .main-title .gradient {
            background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple), var(--accent-pink));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .subtitle {
            font-size: 1.1rem;
            color: var(--text-secondary);
            max-width: 600px;
            margin: 0 auto 32px;
        }

        .header-actions {
            display: flex;
            gap: 12px;
            justify-content: center;
            flex-wrap: wrap;
        }

        /* ===== Buttons ===== */
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 24px;
            border-radius: var(--radius-md);
            font-size: 14px;
            font-weight: 600;
            text-decoration: none;
            cursor: pointer;
            border: none;
            transition: all 0.3s ease;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--accent-purple), var(--accent-pink));
            color: white;
            box-shadow: var(--glow-purple);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 0 40px rgba(168, 85, 247, 0.5);
        }

        .btn-secondary {
            background: var(--bg-glass);
            color: var(--text-primary);
            border: 1px solid var(--border-color);
        }

        .btn-secondary:hover {
            background: var(--bg-card);
            border-color: var(--border-glow);
        }

        .btn svg {
            width: 18px;
            height: 18px;
        }

        /* ===== Features Grid ===== */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 16px;
            margin-bottom: 50px;
        }

        .feature-card {
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-md);
            padding: 20px;
            text-align: center;
            transition: all 0.3s ease;
        }

        .feature-card:hover {
            background: var(--bg-card);
            border-color: var(--border-glow);
            transform: translateY(-4px);
        }

        .feature-card.cyan {
            --card-color: var(--accent-cyan);
        }

        .feature-card.purple {
            --card-color: var(--accent-purple);
        }

        .feature-card.green {
            --card-color: var(--accent-green);
        }

        .feature-card.yellow {
            --card-color: var(--accent-yellow);
        }

        .feature-icon {
            width: 48px;
            height: 48px;
            margin: 0 auto 12px;
            background: rgba(var(--card-color), 0.1);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .feature-icon svg {
            width: 24px;
            height: 24px;
            color: var(--card-color);
        }

        .feature-card h4 {
            font-size: 14px;
            font-weight: 700;
            color: var(--card-color);
            margin-bottom: 4px;
        }

        .feature-card p {
            font-size: 12px;
            color: var(--text-muted);
        }

        /* ===== Tabs ===== */
        .tabs-container {
            margin-bottom: 32px;
        }

        .tabs-nav {
            display: flex;
            gap: 8px;
            background: var(--bg-glass);
            padding: 6px;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-color);
        }

        .tab-btn {
            flex: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            padding: 14px 20px;
            border: none;
            border-radius: var(--radius-md);
            background: transparent;
            color: var(--text-secondary);
            font-size: 14px;
            font-weight: 600;
            font-family: inherit;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .tab-btn:hover {
            color: var(--text-primary);
            background: rgba(255, 255, 255, 0.05);
        }

        .tab-btn.active {
            color: var(--text-primary);
        }

        .tab-btn.active.linux {
            background: linear-gradient(135deg, rgba(168, 85, 247, 0.3), rgba(168, 85, 247, 0.1));
            box-shadow: 0 0 20px rgba(168, 85, 247, 0.2);
        }

        .tab-btn.active.windows {
            background: linear-gradient(135deg, rgba(59, 130, 246, 0.3), rgba(59, 130, 246, 0.1));
            box-shadow: 0 0 20px rgba(59, 130, 246, 0.2);
        }

        .tab-btn svg {
            width: 20px;
            height: 20px;
        }

        /* ===== Tab Content ===== */
        .tab-content {
            display: none;
            animation: fadeSlideUp 0.4s ease forwards;
        }

        .tab-content.active {
            display: block;
        }

        @keyframes fadeSlideUp {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* ===== Content Card ===== */
        .content-card {
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-xl);
            padding: 32px;
            position: relative;
            overflow: hidden;
            backdrop-filter: blur(10px);
        }

        .content-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 1px;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
        }

        .card-header {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            margin-bottom: 24px;
            gap: 12px;
        }

        .card-title {
            font-size: 1.5rem;
            font-weight: 800;
            letter-spacing: -0.02em;
            text-align: center;
        }

        .version-tag {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 6px 14px;
            border-radius: 50px;
            font-size: 13px;
            font-weight: 700;
            font-family: var(--font-mono);
        }

        .version-tag.purple {
            background: linear-gradient(135deg, rgba(168, 85, 247, 0.2), rgba(168, 85, 247, 0.05));
            color: var(--accent-purple);
            border: 1px solid rgba(168, 85, 247, 0.3);
        }

        .version-tag.blue {
            background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(59, 130, 246, 0.05));
            color: var(--accent-blue);
            border: 1px solid rgba(59, 130, 246, 0.3);
        }

        /* ===== Tags ===== */
        .tags-row {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 8px;
            margin-bottom: 28px;
        }

        .tag {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 6px 12px;
            border-radius: 6px;
            font-size: 12px;
            font-weight: 600;
        }

        .tag.purple {
            background: rgba(168, 85, 247, 0.1);
            color: var(--accent-purple);
            border: 1px solid rgba(168, 85, 247, 0.2);
        }

        .tag.green {
            background: rgba(0, 255, 163, 0.1);
            color: var(--accent-green);
            border: 1px solid rgba(0, 255, 163, 0.2);
        }

        .tag.yellow {
            background: rgba(251, 191, 36, 0.1);
            color: var(--accent-yellow);
            border: 1px solid rgba(251, 191, 36, 0.2);
        }

        .tag.blue {
            background: rgba(59, 130, 246, 0.1);
            color: var(--accent-blue);
            border: 1px solid rgba(59, 130, 246, 0.2);
        }

        /* ===== Install Sections ===== */
        .install-section {
            background: var(--bg-secondary);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-lg);
            padding: 24px;
            margin-bottom: 16px;
        }

        .install-section:last-child {
            margin-bottom: 0;
        }

        .install-section.highlight {
            border-color: rgba(0, 255, 163, 0.3);
            background: linear-gradient(135deg, rgba(0, 255, 163, 0.05), transparent);
        }

        .section-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 16px;
        }

        .section-badge {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 28px;
            height: 28px;
            border-radius: 8px;
            font-size: 12px;
            font-weight: 800;
        }

        .section-badge.new {
            background: linear-gradient(135deg, var(--accent-purple), var(--accent-pink));
            color: white;
        }

        .section-badge.upgrade {
            background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
            color: black;
        }

        .section-title {
            font-size: 1rem;
            font-weight: 700;
        }

        .section-desc {
            font-size: 13px;
            color: var(--text-secondary);
            margin-bottom: 16px;
        }

        /* ===== Code Block ===== */
        .code-block {
            position: relative;
            background: rgba(0, 0, 0, 0.5);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-md);
            padding: 16px;
            padding-right: 80px;
            cursor: pointer;
            transition: all 0.3s ease;
            overflow: hidden;
        }

        .code-block:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 30px rgba(0, 212, 255, 0.1);
        }

        .code-block code {
            font-family: var(--font-mono);
            font-size: 13px;
            color: var(--accent-green);
            word-break: break-all;
            line-height: 1.6;
        }

        .copy-btn {
            position: absolute;
            top: 50%;
            right: 12px;
            transform: translateY(-50%);
            display: flex;
            align-items: center;
            gap: 6px;
            padding: 8px 14px;
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: 6px;
            color: var(--text-secondary);
            font-size: 11px;
            font-weight: 600;
            font-family: inherit;
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .copy-btn:hover {
            background: var(--accent-cyan);
            color: black;
            border-color: var(--accent-cyan);
        }

        .copy-btn svg {
            width: 14px;
            height: 14px;
        }

        /* ===== Steps ===== */
        .steps {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }

        .step {
            display: flex;
            gap: 16px;
        }

        .step-number {
            flex-shrink: 0;
            width: 28px;
            height: 28px;
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 13px;
            font-weight: 700;
            color: var(--text-secondary);
        }

        .step-number.done {
            background: var(--accent-green);
            color: black;
            border-color: var(--accent-green);
        }

        .step-content {
            flex: 1;
        }

        .step-title {
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 10px;
        }

        .download-btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 10px 20px;
            background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
            color: white;
            border: none;
            border-radius: var(--radius-sm);
            font-size: 13px;
            font-weight: 600;
            font-family: inherit;
            cursor: pointer;
            text-decoration: none;
            transition: all 0.3s ease;
        }

        .download-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 0 30px rgba(59, 130, 246, 0.4);
        }

        .download-btn svg {
            width: 16px;
            height: 16px;
        }

        /* ===== Login Tip ===== */
        .login-tip {
            position: relative;
            display: inline-flex;
            align-items: center;
            gap: 6px;
            color: var(--accent-green);
            cursor: help;
        }

        .login-tip .tooltip {
            position: absolute;
            left: 0;
            top: 100%;
            margin-top: 12px;
            width: 320px;
            background: var(--bg-secondary);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-md);
            padding: 12px;
            opacity: 0;
            visibility: hidden;
            transform: translateY(10px);
            transition: all 0.3s ease;
            z-index: 100;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
        }

        .login-tip:hover .tooltip {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }

        .tooltip img {
            width: 100%;
            border-radius: 8px;
            margin-bottom: 8px;
        }

        .tooltip-text {
            font-size: 12px;
            color: var(--text-secondary);
            text-align: center;
        }

        /* ===== Command Execution Tips ===== */
        .cmd-tip {
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 10px 14px;
            border-radius: var(--radius-sm);
            font-size: 13px;
            font-weight: 600;
            margin-bottom: 12px;
        }

        .cmd-tip svg {
            width: 18px;
            height: 18px;
            flex-shrink: 0;
        }

        .cmd-tip.linux {
            background: rgba(168, 85, 247, 0.1);
            border: 1px solid rgba(168, 85, 247, 0.3);
            color: var(--accent-purple);
        }

        .cmd-tip.windows {
            background: linear-gradient(135deg, rgba(251, 191, 36, 0.15), rgba(251, 191, 36, 0.05));
            border: 1px solid rgba(251, 191, 36, 0.5);
            color: var(--accent-yellow);
            padding: 12px 16px;
            font-size: 14px;
            animation: windowsTipPulse 2s ease-in-out infinite;
        }

        @keyframes windowsTipPulse {
            0%,
            100% {
                box-shadow: 0 0 0 0 rgba(251, 191, 36, 0.3);
            }
            50% {
                box-shadow: 0 0 15px 3px rgba(251, 191, 36, 0.2);
            }
        }

        .cmd-tip.windows .tip-icon {
            width: 24px;
            height: 24px;
            background: var(--accent-yellow);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: black;
            font-weight: 900;
            font-size: 14px;
        }

        /* ===== Title Preview Tooltip ===== */
        .title-preview {
            position: relative;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            cursor: help;
        }

        .title-preview .preview-hint {
            font-size: 12px;
            color: var(--text-muted);
            font-weight: 500;
            padding: 4px 8px;
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: 20px;
            transition: all 0.3s ease;
        }

        .title-preview:hover .preview-hint {
            color: var(--accent-cyan);
            border-color: var(--accent-cyan);
        }

        .title-preview .preview-tooltip {
            position: absolute;
            top: calc(100% + 16px);
            left: 50%;
            transform: translateX(-50%) translateY(10px);
            width: 450px;
            background: var(--bg-secondary);
            border: 1px solid var(--border-glow);
            border-radius: var(--radius-lg);
            padding: 12px;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 200;
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.6);
        }

        .title-preview:hover .preview-tooltip {
            opacity: 1;
            visibility: visible;
            transform: translateX(-50%) translateY(0);
        }

        .preview-tooltip::before {
            content: '';
            position: absolute;
            top: -8px;
            left: 50%;
            transform: translateX(-50%);
            border-left: 8px solid transparent;
            border-right: 8px solid transparent;
            border-bottom: 8px solid var(--border-glow);
        }

        .preview-tooltip img {
            width: 100%;
            border-radius: var(--radius-md);
            display: block;
        }

        .preview-tooltip-text {
            text-align: center;
            margin-top: 10px;
            font-size: 12px;
            color: var(--text-secondary);
        }

        /* ===== Toast ===== */
        .toast {
            position: fixed;
            bottom: 40px;
            left: 50%;
            transform: translateX(-50%) translateY(100px);
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 14px 24px;
            background: var(--bg-secondary);
            border: 1px solid var(--accent-green);
            border-radius: var(--radius-md);
            color: var(--text-primary);
            font-size: 14px;
            font-weight: 600;
            box-shadow: 0 0 30px rgba(0, 255, 163, 0.2);
            opacity: 0;
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            z-index: 1000;
        }

        .toast.show {
            transform: translateX(-50%) translateY(0);
            opacity: 1;
        }

        .toast svg {
            width: 20px;
            height: 20px;
            color: var(--accent-green);
        }

        /* ===== Responsive ===== */
        @media (max-width: 768px) {
            .container {
                padding: 24px 16px;
            }

            .tabs-nav {
                flex-direction: column;
            }

            .tab-btn {
                justify-content: flex-start;
            }

            .content-card {
                padding: 24px 20px;
            }

            .card-header {
                flex-direction: column;
                align-items: flex-start;
            }

            .code-block {
                padding-right: 16px;
                padding-bottom: 50px;
            }

            .copy-btn {
                top: auto;
                bottom: 10px;
                right: 10px;
                transform: none;
            }

            .features-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            .login-tip .tooltip {
                width: 280px;
                left: -100px;
            }

            .title-preview .preview-tooltip {
                width: 300px;
                left: 0;
                transform: translateX(0) translateY(10px);
            }

            .title-preview:hover .preview-tooltip {
                transform: translateX(0) translateY(0);
            }

            .preview-tooltip::before {
                left: 60px;
            }
        }

        @media (max-width: 480px) {
            .features-grid {
                grid-template-columns: 1fr;
            }

            .header-actions {
                flex-direction: column;
            }

            .btn {
                width: 100%;
                justify-content: center;
            }
        }

        /* Selection */
        ::selection {
            background: var(--accent-cyan);
            color: black;
        }

        /* ===== Language Switcher ===== */
        .lang-switcher {
            position: fixed;
            top: 20px;
            right: 20px;
            z-index: 1000;
            display: flex;
            background: var(--bg-glass);
            border: 1px solid var(--border-color);
            border-radius: 50px;
            padding: 4px;
            backdrop-filter: blur(10px);
        }

        .lang-btn {
            padding: 8px 16px;
            border: none;
            background: transparent;
            color: var(--text-secondary);
            font-size: 13px;
            font-weight: 600;
            font-family: inherit;
            cursor: pointer;
            border-radius: 50px;
            transition: all 0.3s ease;
        }

        .lang-btn:hover {
            color: var(--text-primary);
        }

        .lang-btn.active {
            background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
            color: white;
            box-shadow: 0 0 15px rgba(0, 212, 255, 0.3);
        }

        @media (max-width: 768px) {
            .lang-switcher {
                top: 10px;
                right: 10px;
            }

            .lang-btn {
                padding: 6px 12px;
                font-size: 12px;
            }
        }

        /* ===== Footer ===== */
        .footer {
            position: relative;
            padding: 15px 0;
            text-align: center;
            font-size: 14px;
            color: #999;
        }
        
        .footer .icp-record {
            display: inline-block;
            margin-left: 10px;
            color: #999;
            text-decoration: none;
            font-size: 12px;
        }
        
        .footer .icp-record:hover {
            color: #4299e1;
            text-decoration: underline;
        }