:root {
    --canvas: #000000;
    --surface-1: #15181e;
    --surface-2: #1f232b;
    --surface-3: #3b3d45;
    --hairline: #3b3d45;
    --hairline-soft: #252830;
    --ink: #ffffff;
    --ink-muted: #b2b6bd;
    --ink-subtle: #656a76;
    --accent-blue: #2b89ff;
    --inverse-canvas: #ffffff;
    --inverse-ink: #000000;
}

* {
    box-sizing: border-box;
}

body {
    background-color: var(--canvas);
    color: var(--ink);
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    font-weight: 500;
    line-height: 1.5;
    font-size: 16px;
}

a {
    color: var(--accent-blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

h1, h2, h3 {
    font-weight: 600;
    color: var(--ink);
    letter-spacing: -0.4px;
}

h1 {
    font-size: 40px;
    font-weight: 700;
    line-height: 1.19;
    letter-spacing: -1.0px;
}

h2 {
    font-size: 28px;
    line-height: 1.21;
    letter-spacing: -0.6px;
    margin-top: 2.5rem;
}

h3 {
    font-size: 22px;
    line-height: 1.18;
}

.eyebrow {
    display: inline-block;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.6px;
    text-transform: uppercase;
    color: var(--ink-muted);
    background: var(--surface-1);
    padding: 4px 10px;
    border-radius: 9999px;
    margin-bottom: 1rem;
}

.hero-lead {
    font-size: 18px;
    font-weight: 500;
    line-height: 1.69;
    color: var(--ink-muted);
}

.top-nav {
    background-color: var(--canvas);
    border-bottom: 1px solid var(--hairline-soft);
    height: 64px;
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 50;
}

.top-nav .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.top-nav .brand {
    font-weight: 700;
    color: var(--ink);
    font-size: 18px;
}

.top-nav .nav-links {
    display: flex;
    gap: 24px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.top-nav .nav-links a {
    color: var(--ink-muted);
    font-size: 14px;
    font-weight: 500;
}

.top-nav .nav-links a.active,
.top-nav .nav-links a:hover {
    color: var(--ink);
}

.nav-toggle {
    display: none;
    background: none;
    border: 1px solid var(--hairline);
    color: var(--ink);
    border-radius: 8px;
    padding: 6px 10px;
}

.card {
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    border-radius: 12px;
    padding: 24px;
}

.card-sm {
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    border-radius: 12px;
    padding: 16px;
}

.btn {
    display: inline-block;
    font-size: 14px;
    font-weight: 600;
    border-radius: 8px;
    padding: 10px 18px;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--inverse-canvas);
    color: var(--inverse-ink);
}

.btn-secondary {
    background-color: var(--surface-2);
    color: var(--ink);
}

.breadcrumb-nav {
    font-size: 13px;
    color: var(--ink-subtle);
    margin-bottom: 1.5rem;
}

.breadcrumb-nav a {
    color: var(--ink-subtle);
}

.breadcrumb-nav a:hover {
    color: var(--ink);
}

.toc-box {
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    border-radius: 12px;
    padding: 20px 24px;
    margin: 1.5rem 0 2rem;
}

.toc-box h4 {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    color: var(--ink-muted);
    margin: 0 0 10px;
}

.toc-box ol {
    margin: 0;
    padding-left: 1.2rem;
}

.toc-box a {
    color: var(--ink);
    font-size: 14px;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 1.5rem;
}

@media (max-width: 900px) {
    .related-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .related-grid {
        grid-template-columns: 1fr;
    }
    .top-nav .nav-links {
        display: none;
    }
    .nav-toggle {
        display: inline-block;
    }
    .top-nav.nav-open .nav-links {
        display: flex;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--surface-1);
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--hairline);
    }
}

.related-grid a {
    color: var(--ink);
}

.related-grid .card-sm span {
    display: block;
    color: var(--ink-subtle);
    font-size: 12px;
    margin-top: 6px;
}

.timeline {
    border-left: 1px solid var(--hairline);
    padding-left: 24px;
    margin: 1.5rem 0;
}

.timeline-item {
    position: relative;
    margin-bottom: 24px;
}

.timeline-item::before {
    content: "";
    position: absolute;
    left: -29px;
    top: 6px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent-blue);
}

.timeline-item h4 {
    margin: 0 0 4px;
    font-size: 16px;
    color: var(--ink);
}

.timeline-item p {
    margin: 0;
    color: var(--ink-muted);
    font-size: 14px;
}

.faq-item {
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    border-radius: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
}

.faq-item summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--ink);
}

.faq-item p {
    color: var(--ink-muted);
    margin: 10px 0 0;
}

.checklist {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0;
}

.checklist li {
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    border-radius: 8px;
    padding: 12px 16px;
    margin-bottom: 8px;
    display: flex;
    gap: 10px;
    align-items: flex-start;
}

.checklist li::before {
    content: "\2713";
    color: var(--accent-blue);
    font-weight: 700;
}

.form-field {
    margin-bottom: 16px;
}

.form-field label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--ink);
}

.form-field input,
.form-field textarea {
    width: 100%;
    background-color: var(--surface-1);
    border: 1px solid var(--hairline);
    border-radius: 8px;
    padding: 10px 14px;
    color: var(--ink);
    font-family: inherit;
    font-size: 14px;
}

.form-field input:focus,
.form-field textarea:focus {
    outline: 1px solid var(--accent-blue);
}

.field-error {
    display: none;
    color: #e62b1e;
    font-size: 12px;
    margin-top: 4px;
}

.form-field.invalid .field-error {
    display: block;
}

.form-field.invalid input,
.form-field.invalid textarea {
    outline: 1px solid #e62b1e;
}

.form-success {
    display: none;
    background-color: var(--surface-1);
    border: 1px solid rgba(178, 182, 189, 0.1);
    color: var(--ink);
    padding: 14px 18px;
    border-radius: 8px;
    margin-top: 16px;
}

.form-success.visible {
    display: block;
}

footer.site-footer {
    background-color: var(--canvas);
    border-top: 1px solid var(--hairline-soft);
    color: var(--ink-muted);
    padding: 48px 0 32px;
    margin-top: 4rem;
    font-size: 13px;
}

footer.site-footer .footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 32px;
}

@media (max-width: 700px) {
    footer.site-footer .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

footer.site-footer h4 {
    color: var(--ink);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.4px;
    margin-bottom: 10px;
}

footer.site-footer ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

footer.site-footer li {
    margin-bottom: 6px;
}

footer.site-footer .legal-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    border-top: 1px solid var(--hairline-soft);
    padding-top: 20px;
    margin-bottom: 16px;
}

footer.site-footer .disclaimers p {
    color: var(--ink-subtle);
    font-size: 12px;
    margin: 4px 0;
}

.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: var(--surface-1);
    border-top: 1px solid var(--hairline);
    padding: 16px 24px;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
    justify-content: space-between;
    z-index: 100;
}

.cookie-banner p {
    margin: 0;
    color: var(--ink-muted);
    font-size: 14px;
    max-width: 640px;
}

.cookie-actions {
    display: flex;
    gap: 10px;
}

.cookie-actions button {
    border-radius: 8px;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border: none;
}

.btn-accept {
    background-color: var(--inverse-canvas);
    color: var(--inverse-ink);
}

.btn-reject {
    background-color: var(--surface-2);
    color: var(--ink);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.hero {
    padding: 64px 0 32px;
    border-bottom: 1px solid var(--hairline-soft);
    margin-bottom: 32px;
}

img.content-image {
    width: 100%;
    border-radius: 12px;
    display: block;
    margin: 1.5rem 0 0.5rem;
}

.image-caption {
    color: var(--ink-subtle);
    font-size: 13px;
    margin-bottom: 1.5rem;
}

.chapter-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

@media (max-width: 700px) {
    .chapter-grid {
        grid-template-columns: 1fr;
    }
}

.chapter-grid a {
    color: var(--ink);
}

.chapter-grid .card h3 {
    margin-top: 0;
}

.chapter-grid .card p {
    color: var(--ink-muted);
    font-size: 14px;
}