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

:root {
    --bg-canvas: #f6f7f9;
    --bg-surface: #ffffff;
    --bg-surface-raised: #ffffff;
    --bg-subtle: #eeeff2;
    --bg-subtle-hover: #e4e6ea;

    --border-subtle: #e8eaee;
    --border-color: #d2d6dc;
    --border-strong: #9ca3af;

    --text-primary: #191c20;
    --text-secondary: #535a63;
    --text-muted: #727b86;

    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-subtle: #eff6ff;

    --btn-primary-bg: #191c20;
    --btn-primary-text: #ffffff;
    --btn-primary-hover: #2d3239;

    --status-dot: #16a34a;
    --status-bg: #f0fdf4;
    --status-border: #dcfce7;
    --status-text: #15803d;

    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.8125rem;
    --text-base: 0.9375rem;
    --text-md: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.75rem;
    --text-3xl: 2.25rem;

    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;

    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.05);

    --page-max-width: 820px;
    --line-height: 1.6;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-canvas: #0f1115;
        --bg-surface: #171a21;
        --bg-surface-raised: #1c212a;
        --bg-subtle: #202530;
        --bg-subtle-hover: #282f3d;

        --border-subtle: #222733;
        --border-color: #2e3544;
        --border-strong: #465063;

        --text-primary: #e6edf3;
        --text-secondary: #909dab;
        --text-muted: #6b7785;

        --accent: #3b82f6;
        --accent-hover: #60a5fa;
        --accent-subtle: #1e293b;

        --btn-primary-bg: #e6edf3;
        --btn-primary-text: #0f1115;
        --btn-primary-hover: #ffffff;

        --status-dot: #22c55e;
        --status-bg: #052e16;
        --status-border: #14532d;
        --status-text: #4ade80;

        --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3);
    }
}

:root[data-theme="dark"] {
    --bg-canvas: #0f1115;
    --bg-surface: #171a21;
    --bg-surface-raised: #1c212a;
    --bg-subtle: #202530;
    --bg-subtle-hover: #282f3d;

    --border-subtle: #222733;
    --border-color: #2e3544;
    --border-strong: #465063;

    --text-primary: #e6edf3;
    --text-secondary: #909dab;
    --text-muted: #6b7785;

    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --accent-subtle: #1e293b;

    --btn-primary-bg: #e6edf3;
    --btn-primary-text: #0f1115;
    --btn-primary-hover: #ffffff;

    --status-dot: #22c55e;
    --status-bg: #052e16;
    --status-border: #14532d;
    --status-text: #4ade80;

    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3);
}

:root[data-theme="light"] {
    --bg-canvas: #f6f7f9;
    --bg-surface: #ffffff;
    --bg-surface-raised: #ffffff;
    --bg-subtle: #eeeff2;
    --bg-subtle-hover: #e4e6ea;

    --border-subtle: #e8eaee;
    --border-color: #d2d6dc;
    --border-strong: #9ca3af;

    --text-primary: #191c20;
    --text-secondary: #535a63;
    --text-muted: #727b86;

    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-subtle: #eff6ff;

    --btn-primary-bg: #191c20;
    --btn-primary-text: #ffffff;
    --btn-primary-hover: #2d3239;

    --status-dot: #16a34a;
    --status-bg: #f0fdf4;
    --status-border: #dcfce7;
    --status-text: #15803d;

    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.05);
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    background-color: var(--bg-canvas);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--line-height);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0 1rem 3rem;
}

.container {
    width: 100%;
    max-width: var(--page-max-width);
}

.site-header {
    width: 100%;
    max-width: var(--page-max-width);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border-subtle);
    margin-bottom: 2.5rem;
}

.brand-block {
    display: flex;
    align-items: baseline;
    gap: 0.75rem;
}

.brand-title {
    font-size: 1.375rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.brand-tag {
    font-size: var(--text-xs);
    font-family: var(--font-mono);
    color: var(--text-muted);
    background-color: var(--bg-subtle);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-subtle);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.privacy-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--status-text);
    background-color: var(--status-bg);
    border: 1px solid var(--status-border);
    padding: 3px 8px;
    border-radius: var(--radius-sm);
}

.status-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--status-dot);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: var(--text-sm);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    cursor: pointer;
    border: 1px solid transparent;
    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn-primary {
    background-color: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    border-color: var(--btn-primary-bg);
}

.btn-primary:hover {
    background-color: var(--btn-primary-hover);
    border-color: var(--btn-primary-hover);
}

.btn-secondary {
    background-color: var(--bg-surface);
    color: var(--text-primary);
    border-color: var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-subtle-hover);
}

.btn-large {
    font-size: var(--text-base);
    padding: 0.625rem 1.25rem;
}

.theme-btn {
    font-size: var(--text-xs);
    font-weight: 500;
    padding: 4px 10px;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
}

.theme-btn:hover {
    background-color: var(--bg-subtle);
    color: var(--text-primary);
}

.hero-section {
    padding: 1.5rem 0 2.5rem;
    border-bottom: 1px solid var(--border-subtle);
    margin-bottom: 2.5rem;
}

.hero-title {
    font-size: var(--text-3xl);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.hero-subtitle {
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 1rem;
}

.hero-description {
    font-size: var(--text-md);
    color: var(--text-secondary);
    max-width: 680px;
    margin-bottom: 1.75rem;
}

.hero-cta-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
}

.content-section {
    margin-bottom: 2.75rem;
}

.section-title {
    font-size: var(--text-xl);
    font-weight: 600;
    letter-spacing: -0.015em;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.section-intro {
    font-size: var(--text-base);
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 1rem;
}

.feature-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow-card);
}

.feature-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.feature-title {
    font-size: var(--text-md);
    font-weight: 600;
    color: var(--text-primary);
}

.feature-badge {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
    background-color: var(--bg-subtle);
    padding: 1px 6px;
    border-radius: var(--radius-sm);
}

.feature-text {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.5;
}

.steps-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.875rem;
}

.step-item {
    display: flex;
    gap: 1rem;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
}

.step-num {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--accent);
    background-color: var(--accent-subtle);
    border-radius: var(--radius-sm);
    width: 26px;
    height: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.step-content-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.step-content-desc {
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--text-sm);
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.specs-table th,
.specs-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-subtle);
}

.specs-table th {
    background-color: var(--bg-subtle);
    color: var(--text-secondary);
    font-weight: 600;
    width: 25%;
}

.specs-table tr:last-child td,
.specs-table tr:last-child th {
    border-bottom: none;
}

.code-inline {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    background-color: var(--bg-subtle);
    padding: 2px 4px;
    border-radius: var(--radius-sm);
}

.callout-box {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    box-shadow: var(--shadow-card);
    margin-bottom: 3rem;
}

.callout-header {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.callout-title {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--text-primary);
}

.callout-text {
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.callout-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
}

.site-footer {
    width: 100%;
    max-width: var(--page-max-width);
    border-top: 1px solid var(--border-subtle);
    padding-top: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    font-size: var(--text-xs);
    color: var(--text-muted);
}

.footer-nav {
    display: flex;
    gap: 1rem;
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
}

.footer-link:hover {
    color: var(--accent);
    text-decoration: underline;
}

@media (max-width: 640px) {
    .site-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .hero-title {
        font-size: 1.875rem;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .specs-table th {
        width: 35%;
    }

    .callout-box {
        padding: 1.25rem;
    }
}