:root {
    --bg-cyber-slate: #2E3440;
    --surface-navy: #3B4252;
    --border-tint: #4C566A;
    --accent-mint: #88C0D0;
    --accent-amber: #EBCB8B;
    --accent-coral: #BF616A;
    --text-white: #ECEFF4;
    --text-muted: #D8DEE9;

    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'Space Mono', monospace;

    --transition: 0.3s ease;
    --border-radius: 8px;
}

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

body {
    background-color: var(--bg-cyber-slate);
    color: var(--text-white);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

/* Typography */
h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h2 {
    font-size: 2rem;
    color: var(--text-white);
    border-bottom: 1px solid var(--border-tint);
    padding-bottom: 0.5rem;
    margin-bottom: 2rem;
}

a {
    color: var(--accent-mint);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--accent-amber);
}

.hidden {
    display: none !important;
}

/* Sticky Header */
.sticky-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(11, 13, 18, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-tint);
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    gap: 1rem;
}

.logo {
    font-family: var(--font-mono);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-mint);
}

.center-links a {
    color: var(--text-muted);
    margin: 0 1rem;
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.center-links a:hover {
    color: var(--text-white);
}

.right-actions {
    display: flex;
    gap: 1rem;
}

.mode-btn {
    background: var(--accent-mint);
    color: var(--bg-cyber-slate);
    border: none;
    padding: 0.5rem 1rem;
    font-family: var(--font-display);
    font-weight: 600;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.mode-btn:hover {
    background: var(--accent-amber);
}

.resume-btn {
    border: 1px solid var(--border-tint);
    color: var(--text-white);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-family: var(--font-display);
    font-size: 0.9rem;
}

.resume-btn:hover {
    background: var(--surface-navy);
}

/* Main Layout */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 100px 2rem 2rem;
}

section {
    margin-bottom: 5rem;
}

@media (max-width: 768px) {
    .sticky-header {
        padding: 1rem;
    }
    main {
        padding: 90px 1.5rem 2rem;
    }
}