:root {
            --ff-primary: #0057ff;
            --ff-primary-dark: #0047d5;
            --ff-secondary: #1e3a5f;
        }

        [data-theme="dark"] {
            --theme-bg-primary: #08111f;
            --theme-bg-secondary: #0d1930;
            --theme-surface: rgba(11, 22, 37, 0.88);
            --theme-border: rgba(148, 168, 198, 0.18);
            --theme-text-primary: #f3f7ff;
            --theme-text-secondary: #c2d0e6;
            --theme-text-muted: #8ea2c0;
            --theme-surface-light: rgba(17, 27, 44, 0.92);
            --header-surface: rgba(8, 17, 31, 0.82);
            --header-shadow: 0 24px 64px rgba(2, 8, 17, 0.34);
        }

        [data-theme="light"] {
            --theme-bg-primary: #eff4fb;
            --theme-bg-secondary: #f7fbff;
            --theme-surface: rgba(255, 255, 255, 0.88);
            --theme-border: rgba(7, 16, 31, 0.08);
            --theme-text-primary: #07101f;
            --theme-text-secondary: #42516c;
            --theme-text-muted: #7d8ca8;
            --theme-surface-light: rgba(241, 245, 251, 0.96);
            --header-surface: rgba(255, 255, 255, 0.86);
            --header-shadow: 0 18px 60px rgba(21, 45, 91, 0.08);
        }

        body {
            font-family: 'Inter', sans-serif;
            background: transparent;
            color: var(--theme-text-primary);
            transition: background 0.3s, color 0.3s;
        }

        .page-header {
            background: var(--header-surface);
            border-bottom: 1px solid var(--theme-border);
            padding: 0 24px;
            position: sticky;
            top: 0;
            z-index: 100;
            backdrop-filter: blur(16px);
            box-shadow: var(--header-shadow);
        }

        .header-inner {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 60px;
        }

        .header-brand {
            display: flex;
            align-items: center;
            gap: 14px;
            text-decoration: none;
            color: var(--theme-text-primary);
        }

        .header-logo {
            width: 104px;
            height: 40px;
            background: transparent;
            border-radius: 0;
            padding: 0;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: none;
            flex-shrink: 0;
        }

        .header-logo img {
            width: 100%;
            height: 100%;
            object-fit: contain;
        }

        .header-title {
            font-size: 18px;
            font-weight: 700;
            letter-spacing: -0.02em;
        }

        .header-title span {
            color: var(--ff-primary);
        }

        .header-nav {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .header-nav a {
            color: var(--theme-text-muted);
            text-decoration: none;
            font-size: 13px;
            font-weight: 600;
            padding: 8px 14px;
            border-radius: 999px;
            transition: all 0.15s ease;
        }

        .header-nav a:hover {
            color: var(--theme-text-primary);
            background: var(--theme-surface-light);
        }

        .container {
            max-width: 800px;
            margin: 0 auto;
            padding: 2rem;
        }

        .header {
            background: linear-gradient(145deg, rgba(14, 34, 64, 0.98) 0%, rgba(30, 58, 95, 0.92) 52%, rgba(0, 87, 255, 0.92) 100%);
            color: white;
            padding: 2rem;
            border-radius: 8px;
            margin-bottom: 2rem;
            text-align: center;
        }

        .content {
            background: var(--theme-surface);
            padding: 2rem;
            border-radius: 8px;
            border: 1px solid var(--theme-border);
            backdrop-filter: blur(18px);
            line-height: 1.8;
        }

        h1 {
            font-size: 2rem;
            font-weight: 700;
            margin: 0;
        }

        h2 {
            color: var(--ff-primary);
            font-size: 1.5rem;
            font-weight: 600;
            margin-top: 2rem;
            margin-bottom: 1rem;
        }

        h3 {
            color: var(--theme-text-secondary);
            font-size: 1.2rem;
            font-weight: 600;
            margin-top: 1.5rem;
            margin-bottom: 0.75rem;
        }

        p {
            color: var(--theme-text-secondary);
            margin-bottom: 1rem;
        }

        ul {
            color: var(--theme-text-secondary);
            margin-left: 1.5rem;
            margin-bottom: 1rem;
        }

        li {
            margin-bottom: 0.5rem;
        }

        .last-updated {
            color: var(--theme-text-muted);
            font-size: 0.9rem;
            margin-top: 0.5rem;
        }

        .theme-toggle {
            background: var(--theme-surface);
            border: 1px solid var(--theme-border);
            border-radius: 999px;
            width: 38px;
            height: 38px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.2s;
            color: var(--theme-text-muted);
        }

        .theme-toggle:hover {
            color: var(--theme-text-primary);
            background: var(--theme-surface-light);
            border-color: var(--theme-border);
        }

        .theme-toggle svg {
            width: 16px;
            height: 16px;
        }

        @media (max-width: 768px) {
            .page-header { padding: 0 16px; }
            .header-inner { height: 52px; }
            .header-title { font-size: 16px; }
            .header-nav a { display: none; }
            .theme-toggle { width: 34px; height: 34px; }
        }