/* ── Variables ───────────────────────────────────────── */
:root {
    --bg:         #ffffff;
    --bg-alt:     #f9fafb;
    --text:       #111827;
    --muted:      #6b7280;
    --border:     #e5e7eb;
    --radius:     12px;
    --font:       'Inter', system-ui, -apple-system, sans-serif;
    --max-width:  900px;
    --nav-h:      64px;
}

/* ── Reset ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ── Nav ─────────────────────────────────────────────── */
nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    height: var(--nav-h);
}
.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.nav-logo {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text);
    text-decoration: none;
    letter-spacing: -0.02em;
}
.nav-links {
    display: flex;
    list-style: none;
    gap: 28px;
}
.nav-links a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.15s;
}
.nav-links a:hover { color: var(--text); }

/* ── Container ───────────────────────────────────────── */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ── Sections ────────────────────────────────────────── */
.section     { padding: 80px 0; }
.section-alt { background: var(--bg-alt); }

.section-label {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 28px;
}

/* ── Hero ────────────────────────────────────────────── */
.hero { padding: 96px 0 80px; }

.hero-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 48px;
}
.hero-text { flex: 1; }

.eyebrow {
    display: block;
    font-size: 0.875rem;
    color: var(--muted);
    margin-bottom: 8px;
}
.hero-text h1 {
    font-size: clamp(2.4rem, 6vw, 3.75rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.08;
    margin-bottom: 10px;
}
.tagline {
    font-size: 1.15rem;
    color: var(--muted);
    font-weight: 400;
    margin-bottom: 16px;
}
.hero-desc {
    max-width: 480px;
    color: var(--muted);
    font-size: 0.975rem;
    margin-bottom: 32px;
}
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }

.btn {
    display: inline-flex;
    align-items: center;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.15s;
}
.btn-primary  { background: var(--text); color: #fff; }
.btn-primary:hover  { opacity: 0.82; }
.btn-secondary {
    background: transparent;
    color: var(--text);
    border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--bg-alt); }

/* Profile photo */
.hero-photo-wrap {
    flex-shrink: 0;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid var(--border);
}
.hero-photo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
}

/* ── About ───────────────────────────────────────────── */
.about-text {
    max-width: 600px;
    color: var(--muted);
    font-size: 1rem;
    margin-bottom: 28px;
}

/* ── Skills ──────────────────────────────────────────── */
.skills-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.skill-tag {
    padding: 5px 13px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 0.8rem;
    color: var(--text);
}

/* ── Projects ────────────────────────────────────────── */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 14px;
}
.project-card {
    display: block;
    padding: 22px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text);
    transition: border-color 0.15s, transform 0.15s;
}
.project-card:hover {
    border-color: var(--text);
    transform: translateY(-2px);
}
.project-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--muted);
    margin-bottom: 14px;
}
.project-card h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 6px;
}
.project-card p {
    font-size: 0.85rem;
    color: var(--muted);
    line-height: 1.55;
}

/* ── Lists (articles + videos) ───────────────────────── */
.list-group { display: flex; flex-direction: column; }
.list-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 0;
    border-bottom: 1px solid var(--border);
    text-decoration: none;
    color: var(--text);
    font-size: 0.925rem;
    gap: 12px;
    transition: color 0.15s;
}
.list-item:first-child { border-top: 1px solid var(--border); }
.list-item:hover { color: var(--muted); }
.ext-arrow { flex-shrink: 0; color: var(--muted); }

/* ── Videos ──────────────────────────────────────────── */
.video-categories { display: flex; flex-direction: column; gap: 40px; }
.category-label {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 4px;
}

/* ── Contact ─────────────────────────────────────────── */
.contact-desc {
    color: var(--muted);
    font-size: 0.95rem;
    margin-bottom: 24px;
}
.social-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.social-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.15s;
}
.social-btn:hover {
    background: var(--text);
    color: #fff;
    border-color: var(--text);
}

/* ── Footer ──────────────────────────────────────────── */
footer {
    padding: 28px 0;
    border-top: 1px solid var(--border);
    text-align: center;
}
footer p { font-size: 0.825rem; color: var(--muted); }

/* ── Responsive ──────────────────────────────────────── */
@media (max-width: 640px) {
    .hero { padding: 60px 0 48px; }
    .hero-inner { flex-direction: column-reverse; align-items: flex-start; gap: 32px; }
    .hero-photo-wrap { width: 120px; height: 120px; }
    .nav-links { gap: 16px; }
    .nav-links li:nth-child(n+4) { display: none; }
    .projects-grid { grid-template-columns: 1fr; }
    .section { padding: 56px 0; }
}