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

:root {
    --blue: #7eb8da;
    --bg-dark: #1e1e28;
    --surface: #3a3a4a;
    --light: #e8e8f0;
    --teal: #5fb5a2;
    --muted: #c0c0d0;
    --surface-alt: #2d2d3a;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'DM Sans', sans-serif;
    background-color: var(--bg-dark);
    color: var(--light);
    overflow-x: hidden;
}

/* Sidebar */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 72px;
    height: 100vh;
    background-color: var(--surface-alt);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 40px;
    gap: 32px;
    z-index: 1000;
    transition: width 0.3s ease;
    overflow: hidden;
}

.sidebar:hover {
    width: 200px;
}

.sidebar-icon {
    display: flex;
    align-items: center;
    gap: 16px;
    width: 100%;
    padding: 8px 20px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.sidebar-icon:hover {
    background-color: var(--surface);
}

.sidebar-label {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted);
    white-space: nowrap;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar:hover .sidebar-label {
    opacity: 1;
}

/* Zones */
.zone {
    min-height: 100vh;
    padding: 80px 80px 80px 152px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* Hero */
.zone-hero {
    align-items: center;
    text-align: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.keyhole-motif {
    animation: float 4s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.hero-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(3rem, 10vw, 9rem);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--light);
    line-height: 1;
}

.hero-subtitle {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.125rem;
    font-weight: 400;
    color: var(--muted);
    max-width: 500px;
}

.hero-line {
    width: 60px;
    height: 2px;
    background-color: var(--blue);
    margin-top: 16px;
}

/* Section Titles */
.section-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(2rem, 5vw, 4rem);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--light);
    margin-bottom: 48px;
}

/* Features */
.zone-features {
    background-color: var(--bg-dark);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.card {
    background-color: var(--surface-alt);
    padding: 32px;
    position: relative;
    transition: transform 0.2s ease;
}

.card:hover {
    transform: translateY(-4px);
}

.card-indicator {
    width: 4px;
    height: 32px;
    background-color: var(--blue);
    position: absolute;
    top: 32px;
    left: 0;
}

.card-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 1.5rem;
    letter-spacing: 0.08em;
    color: var(--light);
    margin-bottom: 12px;
}

.card-text {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.9375rem;
    color: var(--muted);
    line-height: 1.6;
    margin-bottom: 16px;
}

.card-code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8125rem;
    color: var(--teal);
    background-color: var(--bg-dark);
    padding: 8px 12px;
    display: block;
}

/* Code Block */
.zone-code {
    background-color: var(--surface-alt);
}

.code-block {
    background-color: var(--bg-dark);
    max-width: 700px;
    width: 100%;
}

.code-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background-color: var(--surface);
}

.code-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--muted);
}

.code-dot:nth-child(1) { background-color: #ff5f57; }
.code-dot:nth-child(2) { background-color: #ffbd2e; }
.code-dot:nth-child(3) { background-color: #28c840; }

.code-filename {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--muted);
    margin-left: auto;
}

.code-content {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.8;
    padding: 24px;
    color: var(--light);
    overflow-x: auto;
}

.code-keyword { color: var(--blue); }
.code-string { color: var(--teal); }
.code-key { color: var(--light); }
.code-bool { color: #ffbd2e; }
.code-func { color: var(--blue); }

/* Diagram */
.zone-diagram {
    background-color: var(--bg-dark);
}

.diagram-container {
    width: 100%;
    max-width: 900px;
}

.system-svg {
    width: 100%;
    height: auto;
}

.diagram-text {
    font-family: 'JetBrains Mono', monospace;
    font-size: 14px;
}

.diagram-node {
    transition: fill 0.3s ease;
}

.diagram-node:hover {
    fill: var(--surface);
}

.diagram-line {
    opacity: 0;
    animation: drawIn 0.6s ease forwards;
}

@keyframes drawIn {
    to { opacity: 1; }
}

/* Footer */
.footer {
    padding: 32px 80px 32px 152px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--surface);
}

.footer-text {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.875rem;
    color: var(--muted);
}

.footer-text.mono {
    font-family: 'JetBrains Mono', monospace;
}

/* Scroll Animations */
.zone {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.zone.visible {
    opacity: 1;
    transform: translateY(0);
}