:root {
    --bg-color: #ffffff;
    --text-color: #111827;
    --muted-color: #6b7280;
    --border-color: #e5e7eb;
    --hover-color: #000000;
}

[data-theme="dark"] {
    --bg-color: #0a0a0a;
    --text-color: #f3f4f6;
    --muted-color: #9ca3af;
    --border-color: #374151;
    --hover-color: #ffffff;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 672px;
    margin: 0 auto;
    padding: 5rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 4rem;
}

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

h1 {
    font-size: 1.5rem;
    font-weight: 500;
    letter-spacing: -0.025em;
}

.subtitle {
    color: var(--muted-color);
    margin-top: 0.25rem;
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.2s;
}

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

.hidden {
    display: none !important;
}

section h2 {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.intro p {
    font-size: 1rem;
}

ul {
    list-style: none;
}

.links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.link-item {
    color: var(--text-color);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    transition: color 0.2s;
}

.link-item:hover {
    color: var(--hover-color);
}

.arrow {
    margin-left: 0.25rem;
    opacity: 0.5;
    transition: opacity 0.2s;
}

.link-item:hover .arrow {
    opacity: 1;
}

.work-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.work-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

@media (min-width: 640px) {
    .work-item {
        flex-direction: row;
        justify-content: space-between;
        align-items: baseline;
    }
}

.work-title {
    font-weight: 500;
    color: var(--text-color);
    text-decoration: none;
}

a.work-title:hover {
    text-decoration: underline;
    text-underline-offset: 4px;
}

.work-desc {
    color: var(--muted-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.work-tech {
    color: var(--muted-color);
    font-size: 0.875rem;
    flex-shrink: 0;
}

.activity-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    font-size: 0.875rem;
}

.activity-list li {
    display: flex;
    gap: 1rem;
}

.year {
    color: var(--muted-color);
    flex-shrink: 0;
    width: 3rem;
}

.activity-desc {
    color: var(--text-color);
}

footer {
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    color: var(--muted-color);
    font-size: 0.875rem;
    text-align: center;
}