:root {
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    --max-width: 900px;
    --radius: 12px;
    --transition: 0.2s ease;
}

[data-theme="dark"] {
    --bg: #0a0a0a;
    --bg-secondary: #141414;
    --bg-card: #1a1a1a;
    --text: #f0f0f0;
    --text-secondary: #999;
    --accent: #ff6d1f;
    --accent-hover: #ff8a47;
    --border: #2a2a2a;
    --code-bg: #111;
}

[data-theme="light"] {
    --bg: #fafafa;
    --bg-secondary: #f0f0f0;
    --bg-card: #fff;
    --text: #111;
    --text-secondary: #666;
    --accent: #e05a10;
    --accent-hover: #c44d0d;
    --border: #e0e0e0;
    --code-bg: #f5f5f5;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    font-size: 18px;
    transition: background var(--transition), color var(--transition);
}

/* Nav */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition), border-color var(--transition);
}

nav {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1.25rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--text);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color var(--transition);
}

.nav-links a:hover {
    color: var(--text);
}

.theme-toggle {
    background: none;
    border: 2px solid var(--border);
    border-radius: 8px;
    padding: 0.4rem;
    cursor: pointer;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition), border-color var(--transition);
}

.theme-toggle:hover {
    color: var(--accent);
    border-color: var(--accent);
}

[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }

/* Main */
main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 6rem 0;
}

section + section {
    border-top: 1px solid var(--border);
}

h1 {
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 1rem;
}

h2 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 3rem;
}

h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

/* Hero */
.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.bio {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin-bottom: 2rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-links a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    transition: color var(--transition);
}

.social-links a:hover {
    color: var(--accent-hover);
}

/* Projects */
.project-grid {
    display: grid;
    gap: 1.5rem;
}

.project-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    text-decoration: none;
    color: var(--text);
    transition: border-color var(--transition), transform var(--transition);
}

.project-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.project-card h3 {
    color: var(--text);
}

.project-card p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.25rem;
}

.project-link {
    color: var(--accent);
    font-weight: 600;
    font-size: 0.95rem;
}

/* SSH */
.ssh-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    transition: background var(--transition), border-color var(--transition);
}

.ssh-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.code-block {
    background: var(--code-bg);
    border-radius: 8px;
    padding: 1rem 1.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    overflow-x: auto;
    transition: background var(--transition);
}

.code-block code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
    white-space: nowrap;
}

.copy-btn {
    background: var(--border);
    border: none;
    border-radius: 6px;
    padding: 0.4rem 0.9rem;
    color: var(--text);
    font-family: var(--font-sans);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: background var(--transition);
}

.copy-btn:hover {
    background: var(--accent);
    color: #fff;
}

.copy-btn.copied {
    background: #22c55e;
    color: #fff;
}

/* Footer */
footer {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 3rem 2rem;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 640px) {
    body { font-size: 16px; }
    nav { padding: 1rem 1.25rem; }
    main { padding: 0 1.25rem; }
    section { padding: 4rem 0; }
    h1 { font-size: 2.5rem; }
    h2 { font-size: 1.6rem; margin-bottom: 2rem; }
    .nav-links { gap: 1rem; }
    .nav-links a { font-size: 0.85rem; }
    .code-block { flex-direction: column; align-items: stretch; }
    .copy-btn { text-align: center; }
}