/* 1. 默认：浅色主题（Light Mode）变量 */
        :root {
            --primary-color: #4f46e5;
            --text-color: #1f2937;
            --text-secondary: #6b7280;
            --text-muted: #9ca3af;
            --bg-color: #f9fafb;
            --card-bg: #ffffff;
            --border-color: #e5e7eb;
            --warning-bg: #fef2f2;
            --warning-border: #fecaca;
            --warning-text: #991b1b;
        }

        /* 2. 自动跟随系统：暗黑主题（Dark Mode）变量重写 */
        @media (prefers-color-scheme: dark) {
            :root {
                --primary-color: #818cf8;
                --text-color: #f3f4f6;
                --text-secondary: #9ca3af;
                --text-muted: #6b7280;
                --bg-color: #111827;
                --card-bg: #1f2937;
                --border-color: #374151;
                --warning-bg: #451a03;
                --warning-border: #78350f;
                --warning-text: #fcd34d;
            }
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            color: var(--text-color);
            background-color: var(--bg-color);
            line-height: 1.6;
            padding: 20px;
            transition: background-color 0.3s ease, color 0.3s ease;
        }

        [dir="rtl"] body {
            font-family: "Geeza Pro", "Tahoma", "Arial", sans-serif;
        }

        .container {
            max-width: 720px;
            margin: 40px auto;
            background: var(--card-bg);
            padding: 40px;
            border-radius: 12px;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            transition: background-color 0.3s ease, border-color 0.3s ease;
        }

        .top-bar {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            gap: 20px;
            margin-bottom: 30px;
        }

        .header {
            flex: 1;
            text-align: start;
        }

        .header h1 {
            font-size: 24px;
            color: var(--text-color);
            margin-bottom: 8px;
        }

        .header p {
            font-size: 14px;
            color: var(--text-secondary);
        }

        .lang-switch {
            flex-shrink: 0;
        }

        .lang-switch select {
            padding: 6px 12px;
            font-size: 13px;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            background-color: var(--card-bg);
            color: var(--text-color);
            cursor: pointer;
            outline: none;
        }

        .section {
            margin-bottom: 24px;
        }

        .section h2 {
            font-size: 18px;
            margin-bottom: 12px;
            color: var(--primary-color);
            border-bottom: 2px solid var(--border-color);
            padding-bottom: 6px;
        }

        .section p,
        .section li {
            font-size: 14px;
            color: var(--text-secondary);
            margin-bottom: 8px;
        }

        .section ul,
        .section ol {
            padding-inline-start: 20px;
        }

        .section strong {
            color: var(--text-color);
        }

        .footer {
            margin-top: 40px;
            text-align: center;
            font-size: 12px;
            color: var(--text-muted);
            border-top: 1px solid var(--border-color);
            padding-top: 20px;
        }

        @media (max-width: 650px) {
            .container {
                padding: 20px;
                margin: 10px;
            }
            .top-bar {
                flex-direction: column-reverse;
                align-items: stretch;
                gap: 15px;
            }
            .lang-switch {
                text-align: end;
            }
        }

        .alert-box {
            background-color: var(--warning-bg);
            border: 1px solid var(--warning-border);
            border-radius: 8px;
            padding: 16px;
            margin-bottom: 24px;
            color: var(--warning-text);
            font-size: 14px;
        }