[data-bs-theme="light"] {
    --ob-body-bg: #f0f4f8;
    --ob-card-bg: #ffffff;
    --ob-card-border: rgba(0, 0, 0, 0.06);
    --ob-hero-gradient: linear-gradient(135deg, #e8f0fe 0%, #f0f4f8 50%, #e3f2fd 100%);
    --ob-accent: #0d6efd;
    --ob-accent-hover: #0b5ed7;
    --ob-info-bg: #ffffff;
    --ob-info-border: rgba(0, 0, 0, 0.06);
    --ob-faq-bg: #ffffff;
    --ob-code-bg: #f8f9fa;
    --ob-badge-bg: rgba(13, 110, 253, 0.1);
    --ob-badge-color: #0d6efd;
    --ob-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    color-scheme: light;
}

[data-bs-theme="dark"] {
    --ob-body-bg: #0d1117;
    --ob-card-bg: #161b22;
    --ob-card-border: rgba(255, 255, 255, 0.08);
    --ob-hero-gradient: linear-gradient(135deg, #0d1117 0%, #161b22 50%, #1c2333 100%);
    --ob-accent: #58a6ff;
    --ob-accent-hover: #79b8ff;
    --ob-info-bg: #161b22;
    --ob-info-border: rgba(255, 255, 255, 0.08);
    --ob-faq-bg: #161b22;
    --ob-code-bg: #0d1117;
    --ob-badge-bg: rgba(88, 166, 255, 0.15);
    --ob-badge-color: #58a6ff;
    --ob-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    color-scheme: dark;
}

body {
    background-color: var(--ob-body-bg);
    min-height: 100vh;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.page-header {
    position: relative;
}

.hero {
    background: var(--ob-hero-gradient);
    border-radius: 1rem;
    padding: 2.5rem 1.5rem;
    border: 1px solid var(--ob-card-border);
}

.hero-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--ob-badge-color);
    background: var(--ob-badge-bg);
    padding: 0.35rem 0.85rem;
    border-radius: 2rem;
}

.hero-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.05rem;
    max-width: 36rem;
    margin-left: auto;
    margin-right: auto;
}

.seo-intro {
    max-width: 42rem;
    line-height: 1.65;
}

.back-link {
    font-weight: 500;
    transition: transform 0.15s ease;
}

.back-link:hover {
    transform: translateX(-2px);
}

.tool-card {
    background: var(--ob-card-bg);
    border: 1px solid var(--ob-card-border);
    border-radius: 1rem;
    box-shadow: var(--ob-shadow);
}

.code-area {
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
    font-size: 0.875rem;
    line-height: 1.55;
    background: var(--ob-code-bg);
    border-radius: 0.5rem;
    resize: vertical;
    min-height: 14rem;
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.code-area:focus {
    box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.2);
}

[data-bs-theme="dark"] .code-area:focus {
    box-shadow: 0 0 0 0.2rem rgba(88, 166, 255, 0.25);
}

.tool-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
}

.tool-actions .btn-primary {
    background-color: var(--ob-accent);
    border-color: var(--ob-accent);
}

.tool-actions .btn-primary:hover {
    background-color: var(--ob-accent-hover);
    border-color: var(--ob-accent-hover);
}

.security-notice {
    border-radius: 0.75rem;
    border-left: 4px solid #ffc107;
}

.section-title {
    font-weight: 700;
    letter-spacing: -0.01em;
}

.info-card {
    background: var(--ob-info-bg);
    border: 1px solid var(--ob-info-border);
    border-radius: 0.75rem;
    padding: 1.25rem;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.info-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--ob-shadow);
}

.info-card-title {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--ob-accent);
}

.faq-item {
    background: var(--ob-faq-bg);
    border: 1px solid var(--ob-info-border);
    border-radius: 0.75rem;
    padding: 1rem 1.25rem;
    margin-bottom: 0.75rem;
    cursor: pointer;
    transition: border-color 0.15s ease;
}

.faq-item:hover {
    border-color: var(--ob-accent);
}

.faq-item summary {
    font-weight: 600;
    list-style: none;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::before {
    content: "+ ";
    color: var(--ob-accent);
    font-weight: 700;
}

.faq-item[open] summary::before {
    content: "− ";
}

.site-footer a {
    text-decoration: none;
    font-weight: 500;
}

.site-footer a:hover {
    text-decoration: underline;
}

@media (max-width: 575.98px) {
    .hero {
        padding: 1.75rem 1rem;
    }

    .tool-actions .btn-lg {
        width: 100%;
    }

    .back-link {
        width: 100%;
        text-align: center;
    }
}