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

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #4a5568;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border: #e5e7eb;
    --highlight: #fef3c7;
    --card-bg: #ffffff;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --accent: #60a5fa;
    --accent-hover: #3b82f6;
    --border: #334155;
    --highlight: #422006;
    --card-bg: #1e293b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s, color 0.3s;
}

header {
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

[data-theme="dark"] header {
    background-color: rgba(15, 23, 42, 0.95);
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
}

.cta-button {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    font-size: 0.95rem;
}

.cta-button:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.icon {
    width: 20px;
    height: 20px;
}

main {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

article {
    animation: fadeIn 0.6s ease-in;
}

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

h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 800;
}

.meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}


.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), #8b5cf6);
    z-index: 101;
    transition: width 0.1s;
}

p {
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
    color: var(--text-primary);
}

h2 {
    font-size: 1.875rem;
    margin-top: 3rem;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
    font-weight: 700;
}

h3 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.highlight-box {
    background: var(--card-bg);
    border-left: 4px solid var(--accent);
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.comparison-table {
    width: 100%;
    margin: 2rem 0;
    border-collapse: collapse;
    background: var(--card-bg);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.comparison-table th,
.comparison-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.comparison-table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-primary);
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

strong {
    color: var(--text-primary);
    font-weight: 600;
}

.cta-section {
    background: linear-gradient(135deg, var(--accent), #8b5cf6);
    color: white;
    padding: 3rem;
    border-radius: 12px;
    text-align: center;
    margin: 3rem 0;
}

.cta-section h2 {
    color: white;
    margin-top: 0;
}

.cta-section p {
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: 2rem;
}

.cta-section .cta-button {
    background: white;
    color: var(--accent);
    font-size: 1.1rem;
    padding: 1rem 2rem;
}

.cta-section .cta-button:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
}

footer {
    background: var(--bg-secondary);
    padding: 2rem;
    text-align: center;
    margin-top: 4rem;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    main {
        padding: 2rem 1.5rem;
    }

    header {
        padding: 1rem;
    }

    .cta-button {
        padding: 0.625rem 1rem;
        font-size: 0.875rem;
    }

    .comparison-table {
        font-size: 0.9rem;
    }

    .comparison-table th,
    .comparison-table td {
        padding: 0.75rem;
    }
}

.logo-icon {
    width: 40px;
    vertical-align: middle;
    height: auto;
    filter: invert(var(--icon-invert));
}

.back {
    text-decoration: none;
    font-style: italic;
    color: #60a5fa;
}