:root {
    /* Light Theme Variables */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e2e8f0;
    --card-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --chip-bg: #e2e8f0;
    --chip-text: #334155;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    /* Dark Theme Variables */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --border-color: #334155;
    --card-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --chip-bg: #334155;
    --chip-text: #cbd5e1;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
}

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

/* Header */
.header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color var(--transition-speed) ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.logo p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

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

/* Intro */
.intro {
    padding: 60px 0 40px;
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.intro h2 {
    font-size: 2.25rem;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.intro p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* Projects Grid */
.projects {
    padding: 20px 0 80px;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 32px;
}

/* Project Card */
.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color var(--transition-speed) ease;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
}

.card-img-wrapper {
    width: 100%;
    height: 200px;
    background-color: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.card-img-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.card-placeholder {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.card-content {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 20px;
    flex-grow: 1;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
}

.tech-chip {
    background-color: var(--chip-bg);
    color: var(--chip-text);
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 0.75rem;
    font-weight: 500;
}

.card-links {
    display: flex;
    gap: 16px;
}

.card-link {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color 0.2s;
}

.card-link:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Footer */
.footer {
    border-top: 1px solid var(--border-color);
    padding: 32px 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .intro h2 {
        font-size: 1.75rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
}