:root {
    --bg: #09090b;
    --text-main: #f8fafc;
    --text-muted: #a1a1aa;
    --accent: #818cf8;
    --accent-2: #c084fc;
    --card-bg: rgba(255, 255, 255, 0.03);
    --card-border: rgba(255, 255, 255, 0.08);
    --card-border-hover: rgba(255, 255, 255, 0.15);
    --card-shadow: rgba(0, 0, 0, 0.2);
    --link-bg: rgba(255, 255, 255, 0.03);
    --link-bg-hover: rgba(255, 255, 255, 0.08);
    --bg-glow-1: rgba(76, 29, 149, 0.25);
    --bg-glow-2: rgba(30, 58, 138, 0.18);
}

[data-theme="light"] {
    --bg: #f8fafc;
    --text-main: #09090b;
    --text-muted: #52525b;
    --accent: #4f46e5;
    --accent-2: #9333ea;
    --card-bg: rgba(0, 0, 0, 0.03);
    --card-border: rgba(0, 0, 0, 0.08);
    --card-border-hover: rgba(0, 0, 0, 0.2);
    --card-shadow: rgba(0, 0, 0, 0.08);
    --link-bg: rgba(0, 0, 0, 0.03);
    --link-bg-hover: rgba(0, 0, 0, 0.08);
    --bg-glow-1: transparent;
    --bg-glow-2: transparent;
}

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

html {
    transition: background-color 0.3s ease, color 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background:
        radial-gradient(circle at 80% 5%, var(--bg-glow-1), transparent 35%),
        radial-gradient(circle at 20% 25%, var(--bg-glow-2), transparent 40%),
        var(--bg);
    color: var(--text-main);
    line-height: 1.7;
    min-height: 100vh;
    user-select: none;
    -webkit-user-select: none;
}

.top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    z-index: 100;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.45rem 1rem;
    border-radius: 9999px;
    background: var(--link-bg);
    border: 1px solid var(--card-border);
    color: var(--text-main);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.back-link:hover {
    background: var(--link-bg-hover);
    border-color: var(--card-border-hover);
}

.theme-switch {
    display: flex;
    background: var(--link-bg);
    border: 1px solid var(--card-border);
    border-radius: 9999px;
    padding: 0.3rem;
    backdrop-filter: blur(10px);
}

.theme-switch button {
    background: transparent;
    border: none;
    color: var(--text-main);
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.theme-switch .icon-light,
.theme-switch .icon-dark {
    position: absolute;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.theme-switch .icon-light {
    opacity: 0;
    transform: rotate(-90deg);
}

.theme-switch .icon-dark {
    opacity: 1;
    transform: rotate(0deg);
}

[data-theme="light"] .theme-switch .icon-light {
    opacity: 1;
    transform: rotate(0deg);
}

[data-theme="light"] .theme-switch .icon-dark {
    opacity: 0;
    transform: rotate(90deg);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 8rem 1.5rem 4rem;
}

h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 3rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.5rem;
}

.project-card {
    padding: 1.5rem;
    border-radius: 1rem;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.project-card:hover {
    transform: translateY(-4px);
    border-color: var(--card-border-hover);
    box-shadow: 0 12px 32px var(--card-shadow);
}

.project-card h2 {
    font-size: 1.25rem;
    font-weight: 700;
}

.project-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    flex: 1;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.project-tags span {
    padding: 0.2rem 0.6rem;
    border-radius: 9999px;
    background: var(--link-bg);
    border: 1px solid var(--card-border);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.project-card a {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: auto;
}

.project-card a:hover {
    text-decoration: underline;
}

.project-card.placeholder {
    opacity: 0.6;
}

footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-muted);
    font-size: 0.85rem;
}

@media (max-width: 640px) {
    h1 {
        font-size: 2.25rem;
    }

    .container {
        padding-top: 7rem;
    }

    .project-grid {
        grid-template-columns: 1fr;
    }
}