:root {
    --color-bg: #0f172a;
    --color-surface: #111827;
    --color-border: #334155;

    --color-text-primary: #f8fafc;
    --color-text-secondary: #cbd5e1;
    --color-text-accent: #38bdf8;

    --font-main:  Arial, Helvetica, sans-serif;

    --spacing-sm: 12px;
    --spacing-md: 24px;
    --spacing-lg: 48px;
    --spacing-xl: 72px;

    --radius-md: 16px;
    --radius-lg: 20px;
    --radius-pill: 999px;

    --max-width-page: 1000px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-main);
    background: var(--color-bg);
    color: var(--color-text-primary);
}

.site-header {
    position: sticky;
    top: 0;
    backdrop-filter: blur(10px);
    background: rgba(15, 23, 42, 0.7);
    border-bottom: 1px solid var(--color-border);
}

.navbar {
    max-width: var(--max-width-page);
    margin: 0 auto;
    padding: 18px var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: bold;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
}

.nav-links a {
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color 0.2 ease;
}

.nav-links a:hover {
    color: var(--color-text-accent);
}

.page {
    max-width: var(--max-width-page);
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-md);
}

.hero {
    min-height: 70vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.eyerbrow {
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-size: 14px;
}

h1 {
    font-size: clamp(48px, 8vw, 88px);
    margin: var(--spacing-sm) 0;
}

h2 {
    font-size: 32px;
    margin-top: var(--spacing-lg);
}

.intro,
.letter p,
.card p {
    color: var(--color-text-secondary);
    line-height: 1.7;
    font-size: 18px;
}

.button {
    width: fit-content;
    margin-top: var(--spacing-md);
    padding: 14px 20px;
    border-radius: var(--radius-pill);
    background-color: var(--color-text-accent);
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: bold;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-top: var(--spacing-md);
}

.card {
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    transition: transform 0.2 ease, border-color 0.2 ease;
}

.card:hover {
    transform: translateY(-4px);
    border-color: var(--color-text-accent);
}

.card-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.card-tag {
    width: fit-content;
    margin: 0;
    padding: 6px 10px;
    border-radius: var(--radius-pill);
    background: rgba(56, 189, 248, 0.12);
    color: var(--color-text-accent);
    font-size: 14px;
    font-weight: bold;
}

.card h3 {
    margin: 0;
    font-size: 24px;
}

.card-link {
    margin-top: auto;
    color: var(--color-text-accent);
    text-decoration: none;
    font-weight: bold;
}

.contact {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
}

.contact p {
    color: var(--color-text-secondary);
    line-height: 1.7;
    font-size: 18px;
}

.contact-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-top: var(--spacing-md);
}

.contact-links a {
    color: var(--color-text-accent);
    font-weight: bold;
    text-decoration: none;
}