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

:root {
    --bg: #FFFFFF;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --accent: #007AFF;
    --border-color: rgba(29, 29, 31, 0.1);
}

:root[data-theme="dark"] {
    --bg: #000000;
    --text-primary: #F5F5F7;
    --text-secondary: #86868B;
    --accent: #0A84FF;
    --border-color: rgba(245, 245, 247, 0.1);
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.7;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

.header {
    margin-bottom: 3rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    margin-bottom: 2rem;
    transition: opacity 0.2s ease;
}

.back-link:hover {
    opacity: 0.7;
}

.back-link svg {
    width: 18px;
    height: 18px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.last-updated {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    font-weight: 400;
}

.content {
    padding-top: 1rem;
}

.section {
    margin-bottom: 2.5rem;
}

.section-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.section-content {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
}

.section-content p {
    margin-bottom: 1rem;
}

.section-content ul {
    list-style: none;
    padding-left: 0;
    margin: 1rem 0;
}

.section-content li {
    margin-bottom: 0.75rem;
    padding-left: 1.5rem;
    position: relative;
}

.section-content li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--text-primary);
}

.theme-toggle {
    position: fixed;
    top: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

:root[data-theme="dark"] .theme-toggle {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.theme-toggle:hover {
    transform: scale(1.05);
    background: var(--accent);
    color: #FFFFFF;
    box-shadow: 0 4px 12px rgba(0, 122, 255, 0.3);
}

:root[data-theme="dark"] .theme-toggle:hover {
    box-shadow: 0 4px 12px rgba(10, 132, 255, 0.4);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    transition: transform 0.3s ease;
}

@media (max-width: 768px) {
    .container {
        padding: 2rem 1.5rem;
    }

    h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.125rem;
    }

    .section-content {
        font-size: 0.9375rem;
    }

    .theme-toggle {
        top: 1rem;
        right: 1rem;
        width: 40px;
        height: 40px;
    }

    .theme-toggle svg {
        width: 20px;
        height: 20px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1.5rem 1rem;
    }

    h1 {
        font-size: 1.75rem;
    }

    .section {
        margin-bottom: 2rem;
    }
}