:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-secondary: #7c3aed;
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-bg: #ffffff;
    --color-bg-secondary: #f9fafb;
    --color-border: #e5e7eb;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    line-height: 1.6;
    background: var(--color-bg);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Main Layout */
.main-container {
    padding-top: 3rem;
    padding-bottom: 3rem;
}

/* Profile Header */
.profile-header {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
}

.profile-header h1 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.bio {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: 1rem;
}

.header-links {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    font-size: 0.875rem;
}

.header-links a {
    color: var(--color-primary);
    text-decoration: none;
}

.header-links a:hover {
    text-decoration: underline;
}

.separator {
    color: var(--color-text-light);
}

/* Tabs */
.tabs {
    display: flex;
    gap: 2rem;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: 2rem;
}

.tab {
    background: none;
    border: none;
    padding: 0.75rem 0;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text-light);
    cursor: pointer;
    position: relative;
    transition: color 0.2s;
    text-decoration: none;
    display: inline-block;
}

.tab:hover {
    color: var(--color-text);
}

.tab.active {
    color: var(--color-text);
}

.tab.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--color-primary);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Buttons */
.button {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
}

.button.primary {
    background: var(--color-primary);
    color: white;
}

.button.primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
}

.button.secondary {
    border: 2px solid var(--color-border);
    color: var(--color-text);
}

.button.secondary:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* Projects Section */
.projects-section {
    margin-top: 2rem;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    padding: 1.5rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.project-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.project-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.project-card p {
    color: var(--color-text-light);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech-tag {
    padding: 0.25rem 0.75rem;
    background: var(--color-bg-secondary);
    border-radius: 0.25rem;
    font-size: 0.875rem;
    font-family: var(--font-mono);
    color: var(--color-text-light);
}

.project-link {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.project-link:hover {
    text-decoration: underline;
}

.project-card .project-link:last-child {
    display: block;
    margin-top: 0.5rem;
}



/* Responsive */
@media (max-width: 768px) {
    .project-grid {
        grid-template-columns: 1fr;
    }
    
    .header-links {
        flex-wrap: wrap;
    }
}