/* ===== Site-wide styles (nav, footer, page layout) ===== */

:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-tertiary: #1a2035;
    --text-primary: #e5e7eb;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --accent: #3b82f6;
    --accent-dim: #1e3a5f;
    --border: #1f2937;
    --green: #10b981;
    --red: #ef4444;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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


/* ===== Navigation ===== */

.site-nav {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    height: 56px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
    text-decoration: none;
}
.nav-brand:hover {
    text-decoration: none;
    color: #fff;
}

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.15s, background 0.15s;
}
.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
    text-decoration: none;
}
.nav-link.active {
    color: var(--text-primary);
    background: var(--accent-dim);
}

.nav-social {
    display: flex;
    gap: 12px;
    align-items: center;
}

.social-icon {
    color: var(--text-muted);
    transition: color 0.15s;
    display: flex;
    align-items: center;
}
.social-icon:hover {
    color: var(--text-primary);
    text-decoration: none;
}


/* ===== Main Content ===== */

.site-main {
    flex: 1;
}


/* ===== Footer ===== */

.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 20px 24px;
    margin-top: auto;
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-brand {
    font-weight: 600;
    font-size: 14px;
    color: var(--text-secondary);
}

.footer-copy {
    font-size: 12px;
    color: var(--text-muted);
}


/* ===== Generic Page Layout ===== */

.page-section {
    max-width: 720px;
    margin: 0 auto;
    padding: 48px 24px 80px;
}

.page-title {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: -0.5px;
}

.page-body p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
    font-size: 15px;
}

.page-body h2 {
    font-size: 18px;
    font-weight: 600;
    margin-top: 32px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.page-body ul {
    list-style: none;
    padding: 0;
    margin-bottom: 20px;
}
.page-body ul li {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.7;
    padding: 6px 0;
    padding-left: 16px;
    position: relative;
}
.page-body ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 14px;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--accent);
}

.page-intro {
    font-size: 16px !important;
    color: var(--text-secondary);
}


/* ===== Research Placeholder ===== */

.research-placeholder {
    text-align: center;
    padding: 80px 20px;
    color: var(--text-muted);
    font-size: 15px;
}
.research-placeholder svg {
    margin-bottom: 16px;
}


/* ===== Spinner (reuse) ===== */

.spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 12px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}


/* ===== Responsive ===== */

@media (max-width: 640px) {
    .nav-inner {
        padding: 0 16px;
    }
    .nav-links {
        gap: 4px;
    }
    .nav-link {
        padding: 6px 10px;
        font-size: 13px;
    }
    .footer-inner {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }
}