:root {
    --bg: #ffffff;
    --text: #0f172a;
    --muted: #64748b;
    --card: #f8fafc;
    --border: #e2e8f0;
    --brand: #2563eb;
    --brand-contrast: #ffffff;
    --shadow: 0 6px 20px rgba(2, 6, 23, 0.08);
}

:root[data-theme="dark"] {
    --bg: #0b1220;
    --text: #e5e7eb;
    --muted: #9aa4b2;
    --card: #121a2a;
    --border: #1f2937;
    --brand: #60a5fa;
    --brand-contrast: #0b1220;
    --shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
}

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

html { color-scheme: light dark; scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.75rem 1rem;
    background: color-mix(in oklab, var(--bg), black 2%);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(6px);
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
    color: inherit;
}
.brand-logo {
    width: 32px;
    height: 32px;
}
.brand-name {
    font-weight: 700;
    letter-spacing: 0.2px;
}

.site-nav .nav-toggle {
    display: none;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text);
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
}
.site-nav .nav-list {
    display: flex;
    list-style: none;
    gap: 1rem;
    margin: 0;
    padding: 0;
}
.site-nav a {
    color: inherit;
    text-decoration: none;
    padding: 0.5rem 0.25rem;
    border-radius: 6px;
}
.site-nav a:hover {
    background: color-mix(in oklab, var(--card), var(--bg) 50%);
}

/* Hero */
.hero {
    padding: 5rem 1rem 3rem;
    text-align: center;
    max-width: 1000px;
    margin: 0 auto;
}
.hero h1 {
    margin: 0 0 0.5rem;
    font-size: clamp(2rem, 3.5vw + 1rem, 3rem);
    line-height: 1.2;
}
.hero p {
    margin: 0 auto 1.25rem;
    max-width: 60ch;
    color: var(--muted);
}
.hero-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
}

/* Sections */
.section {
    padding: 2.5rem 1rem;
    max-width: 1100px;
    margin: 0 auto;
}
.section h2 {
    font-size: 1.75rem;
    margin: 0 0 1rem;
}
.section.alt {
    background: color-mix(in oklab, var(--card), var(--bg) 60%);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

/* Grid + Cards */
.grid {
    display: grid;
    gap: 1rem;
}
.projects-grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    overflow: clip;
    box-shadow: var(--shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 30px rgba(2, 6, 23, 0.12);
    border-color: color-mix(in oklab, var(--border), var(--brand) 35%);
}
.card-link {
    color: inherit;
    text-decoration: none;
    display: grid;
    grid-template-rows: auto 1fr;
    height: 100%;
}
.card-thumb {
    width: 100%;
    height: 140px;
    object-fit: cover;
    background: #0001;
}
.card-body {
    padding: 0.9rem 1rem 1.1rem;
}
.card-body h3 {
    margin: 0 0 0.35rem;
    font-size: 1.05rem;
}
.card-body p {
    margin: 0;
    color: var(--muted);
    font-size: 0.95rem;
}
.badge {
    display: inline-block;
    padding: 0.1rem 0.45rem;
    font-size: 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: color-mix(in oklab, var(--brand), var(--bg) 85%);
}

/* About */
.about {
    display: grid;
    gap: 1rem;
    align-items: start;
}

.avatar {
    width: 96px;
    height: 96px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border);
    background: #0001;
}
.skills {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    padding: 0;
    margin: 0.75rem 0 1rem;
    list-style: none;
}
.skills li {
    border: 1px solid var(--border);
    background: var(--card);
    padding: 0.25rem 0.5rem;
    border-radius: 999px;
    font-size: 0.9rem;
}

/* Contact */
.contact-list {
    list-style: none;
    padding: 0;
    margin: 0.75rem 0 0;
    display: grid;
    gap: 0.5rem;
}
.contact-list a {
    color: var(--brand);
    text-decoration: none;
}
.contact-list a:hover {
    text-decoration: underline;
}

/* Footer */
.site-footer {
    padding: 1.25rem 1rem 2rem;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--muted);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 0.9rem;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    text-decoration: none;
    font-weight: 600;
}
.btn:hover { filter: brightness(1.02); }
.btn.primary {
    background: var(--brand);
    border-color: color-mix(in oklab, var(--brand), black 10%);
    color: var(--brand-contrast);
}
.btn.small { padding: 0.4rem 0.7rem; font-size: 0.9rem; }

/* Responsive nav */
@media (max-width: 720px) {
    .site-nav .nav-toggle { display: inline-block; }
    .site-nav .nav-list {
        position: absolute;
        right: 1rem;
        top: 56px;
        background: var(--card);
        border: 1px solid var(--border);
        border-radius: 10px;
        box-shadow: var(--shadow);
        padding: 0.5rem;
        display: none;
        flex-direction: column;
        min-width: 160px;
    }
    .site-nav .nav-list.open { display: flex; }
    .about { grid-template-columns: 1fr; }
    .avatar { justify-self: center; }
}