:root {
    --bg-color: var(--apollo-bg-dark);
    --surface-color: rgba(37, 58, 94, 0.7);
    --surface-strong: rgba(23, 32, 56, 0.9);
    --text-color: #eef6f7;
    --muted-text: rgba(164, 221, 219, 0.72);
    --border-color: rgba(115, 190, 211, 0.16);
    --shadow-color: rgba(4, 10, 20, 0.3);
    --hero-glow: rgba(79, 143, 186, 0.14);
    --button-text: var(--apollo-text-dark);
}

body.light-mode {
    --bg-color: #f6efdf;
    --surface-color: rgba(255, 251, 244, 0.82);
    --surface-strong: rgba(255, 250, 241, 0.94);
    --text-color: #251720;
    --muted-text: rgba(77, 43, 50, 0.68);
    --border-color: rgba(122, 72, 65, 0.14);
    --shadow-color: rgba(75, 44, 29, 0.08);
    --hero-glow: rgba(208, 147, 90, 0.15);
    --button-text: var(--apollo-text-light);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    background:
        radial-gradient(circle at top left, var(--hero-glow), transparent 32%),
        linear-gradient(180deg, var(--bg-color), color-mix(in srgb, var(--bg-color) 88%, black));
    color: var(--text-color);
    transition: background-color 0.25s ease, color 0.25s ease;
}

a {
    color: inherit;
    text-decoration: none;
}

.topbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.5rem;
    backdrop-filter: blur(18px);
    background: color-mix(in srgb, var(--bg-color) 82%, transparent);
    border-bottom: 1px solid var(--border-color);
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    min-width: 0;
}

.brand {
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    white-space: nowrap;
}

.nav-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-links a {
    display: inline-flex;
    align-items: center;
    min-height: 2.25rem;
    padding: 0 0.9rem;
    border-radius: 999px;
    color: var(--muted-text);
    transition: color 0.2s ease, background-color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
    color: var(--text-color);
    background: var(--surface-color);
}

.theme-toggle {
    flex-shrink: 0;
    min-width: 5.5rem;
    min-height: 2.5rem;
    padding: 0 1rem;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    background: var(--surface-strong);
    color: var(--text-color);
    font: inherit;
    cursor: pointer;
    transition: transform 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
    transform: translateY(-1px);
    border-color: rgba(115, 190, 211, 0.3);
}

.page-shell {
    width: min(1120px, calc(100% - 3rem));
    margin: 0 auto;
    padding: 7rem 0 5rem;
}

.hero,
.intro {
    max-width: 46rem;
    text-align: left;
}

.hero {
    padding: 1rem 0 2rem;
}

.eyebrow {
    margin: 0 0 1rem;
    color: var(--muted-text);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.hero h1 {
    margin: 0;
    font-size: clamp(3rem, 8vw, 5.5rem);
    line-height: 0.95;
    letter-spacing: -0.06em;
}

.hero-copy,
.intro p,
.project-card p {
    color: var(--muted-text);
    line-height: 1.7;
}

.hero-copy {
    margin: 1.4rem 0 0;
    font-size: 1.05rem;
}

.intro {
    margin: 0 0 2.5rem;
    padding: 1.5rem 0 0;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
}

.project-card {
    --project-accent: var(--apollo-accent-dark);
    position: relative;
    overflow: hidden;
    min-height: 16rem;
    padding: 1.5rem;
    border: 1px solid color-mix(in srgb, var(--project-accent) 25%, var(--border-color));
    border-radius: 1.4rem;
    background:
        linear-gradient(180deg, color-mix(in srgb, var(--project-accent) 14%, transparent), transparent 45%),
        var(--surface-color);
    box-shadow: 0 22px 60px -40px var(--shadow-color);
    transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}

.project-card:hover,
.project-card:focus-within {
    transform: translateY(-4px);
    border-color: color-mix(in srgb, var(--project-accent) 55%, var(--border-color));
    box-shadow: 0 28px 70px -42px color-mix(in srgb, var(--project-accent) 20%, var(--shadow-color));
}

.project-card::before {
    content: "";
    position: absolute;
    inset: 0 auto auto 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--project-accent), transparent 75%);
}

.project-label {
    margin: 0 0 1rem;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    color: var(--project-accent);
}

.project-card h2 {
    margin: 0 0 0.85rem;
    font-size: 1.45rem;
    line-height: 1.1;
}

.project-media {
    margin: 1rem 0 0;
    border: 1px solid color-mix(in srgb, var(--project-accent) 28%, var(--border-color));
    border-radius: 1rem;
    overflow: hidden;
    background: color-mix(in srgb, var(--project-accent) 10%, var(--surface-strong));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.project-media img {
    display: block;
    width: 100%;
    aspect-ratio: 16 / 10;
    object-fit: cover;
}

.project-card a {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    margin-top: 1rem;
    color: var(--project-accent);
    font-weight: 700;
}

.project-card a::after {
    content: "->";
}

.project-bezier {
    --project-accent: var(--apollo-5);
}

.project-encryption {
    --project-accent: var(--apollo-17);
}

.project-regressions {
    --project-accent: var(--apollo-38);
}

.project-riemann {
    --project-accent: var(--apollo-35);
}

@media (max-width: 760px) {
    .topbar {
        align-items: flex-start;
        flex-direction: column;
    }

    .site-nav {
        flex-direction: column;
        align-items: flex-start;
    }

    .page-shell {
        width: min(100% - 1.5rem, 1120px);
        padding-top: 8.5rem;
    }

    .hero h1 {
        font-size: clamp(2.6rem, 15vw, 4rem);
    }

    .project-card {
        min-height: 0;
    }

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