/* ===========================
   Design Tokens (softwaresoftware-design-system)
   =========================== */
:root {
    --color-bg: #0D0D0D;
    --color-surface: #1A1A1A;
    --color-text: #E8E4DF;
    --color-text-muted: #8A8580;
    --color-accent: #D4A853;
    --color-accent-hover: #E0B86A;
    --color-code: #7B9EB8;
    --color-border: #2A2A2A;
    --color-border-hover: #3A3A3A;
    --color-success: #6BA368;

    --font-heading: 'Space Grotesk', system-ui, sans-serif;
    --font-body: 'Source Serif 4', Georgia, 'Times New Roman', serif;
    --font-mono: 'JetBrains Mono', ui-monospace, 'Cascadia Code', monospace;

    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2.5rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;
    --space-section: 4rem;

    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;

    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --max-width: 896px;
    --max-width-wide: 1140px;
}

/* ===========================
   Reset
   =========================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-bg);
}

img, svg { max-width: 100%; height: auto; display: block; }

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

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--color-text);
}
h1 { font-size: 2rem; font-weight: 700; line-height: 1.2; letter-spacing: -0.02em; }
h2 { font-size: 1.5rem; font-weight: 600; line-height: 1.2; }
h3 { font-size: 1.25rem; font-weight: 600; line-height: 1.3; }

ul { list-style: none; }

/* ===========================
   Layout
   =========================== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}
.container-wide { max-width: var(--max-width-wide); }

section { padding: var(--space-section) 0; }

.section-surface {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

/* ===========================
   Header & Nav
   =========================== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(13, 13, 13, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.nav {
    display: flex;
    align-items: center;
    height: 4rem;
    gap: var(--space-lg);
}

.nav-logo {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--color-text);
    white-space: nowrap;
    flex-shrink: 0;
}
.nav-logo:hover { color: var(--color-accent); }

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-left: auto;
}

.nav-links a {
    font-family: var(--font-heading);
    font-weight: 500;
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
    white-space: nowrap;
}
.nav-links a:hover { color: var(--color-text); }

/* ===========================
   Section Labels
   =========================== */
.section-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

.section-intro {
    color: var(--color-text-muted);
    font-size: 1.0625rem;
    margin-top: var(--space-sm);
    margin-bottom: var(--space-xl);
    max-width: 600px;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-family: var(--font-heading);
    font-weight: 500;
    font-size: 0.9375rem;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: filter var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
    text-decoration: none;
}
.btn-primary {
    background: var(--color-accent);
    color: var(--color-bg);
}
.btn-primary:hover {
    filter: brightness(1.25);
    color: var(--color-bg);
}
.btn-outline {
    border-color: var(--color-border);
    color: var(--color-text);
    background: transparent;
}
.btn-outline:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}
.btn-sm {
    padding: 0.375rem 1rem;
    font-size: 0.8125rem;
}

/* ===========================
   Hero
   =========================== */
.hero {
    padding: var(--space-3xl) 0 var(--space-xl);
    text-align: center;
}

.hero .section-label { margin-bottom: var(--space-md); }

.hero h1 {
    max-width: 600px;
    margin: 0 auto;
}
.hero h1 em {
    font-style: italic;
    font-family: var(--font-body);
    color: var(--color-accent);
}

.hero-sub {
    margin-top: var(--space-md);
    font-size: 1.0625rem;
    color: var(--color-text-muted);
    max-width: 550px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    margin-top: var(--space-xl);
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===========================
   Terminal
   =========================== */
.terminal-section {
    padding: 0 0 var(--space-section);
}

.terminal {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    max-width: 640px;
    margin: 0 auto;
}

.terminal-bar {
    display: flex;
    gap: 6px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--color-border);
}

.terminal-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--color-border-hover);
}

.terminal-body {
    padding: 1.25rem 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    line-height: 1.8;
    word-break: break-word;
}
.terminal-body p { margin: 0; }

.t-muted { color: var(--color-text-muted); }
.t-accent { color: var(--color-accent); }
.t-code { color: var(--color-code); }
.t-text { color: var(--color-text); }
.t-success { color: var(--color-success); }

/* ===========================
   Problem / Stats
   =========================== */
.problem p {
    color: var(--color-text-muted);
    margin-top: var(--space-md);
    max-width: 650px;
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
    margin-top: var(--space-xl);
}

.stat {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
}

.stat-number {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-accent);
    line-height: 1;
}

.stat-label {
    font-family: var(--font-heading);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--color-text-muted);
}

/* ===========================
   Gates
   =========================== */
.gates-list {
    display: flex;
    flex-direction: column;
    gap: 1px;
    background: var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.gate {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: var(--space-lg);
    align-items: start;
    padding: var(--space-lg);
    background: var(--color-surface);
    transition: padding-left var(--transition);
}
.gate:hover { padding-left: calc(var(--space-lg) + var(--space-sm)); }

.gate-number {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-border-hover);
    min-width: 1.5rem;
    transition: color var(--transition-fast);
}
.gate:hover .gate-number { color: var(--color-accent); }

.gate-content h3 {
    font-size: 1rem;
    margin-bottom: var(--space-xs);
}
.gate-content p {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    line-height: 1.6;
}

.gate-check {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--color-success);
    white-space: nowrap;
    padding-top: 0.15rem;
}

/* ===========================
   Cards
   =========================== */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    transition: border-color var(--transition);
}
.card:hover { border-color: var(--color-border-hover); }
.card h3 { margin-bottom: var(--space-sm); }
.card p { color: var(--color-text-muted); font-size: 0.9375rem; }
.card ul { display: flex; flex-direction: column; gap: var(--space-sm); }
.card li {
    font-size: 0.9375rem;
    color: var(--color-text-muted);
}
.card li strong {
    color: var(--color-text);
    font-weight: 600;
}

/* ===========================
   Grids
   =========================== */
.stack-grid, .features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

/* ===========================
   Install Steps
   =========================== */
.install-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.install-step {
    display: flex;
    gap: var(--space-lg);
    align-items: flex-start;
}

.install-num {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-accent);
    width: 1.75rem;
    height: 1.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--color-accent);
    border-radius: 50%;
    flex-shrink: 0;
    margin-top: 0.1rem;
}

.install-label {
    font-family: var(--font-heading);
    font-weight: 500;
    font-size: 0.9375rem;
    margin-bottom: var(--space-sm);
}

.code-block {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 0.625rem 1rem;
}

.code-block code {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--color-code);
    background: none;
    border: none;
    padding: 0;
    flex: 1;
    word-break: break-all;
}

.copy-btn {
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    padding: 4px;
    flex-shrink: 0;
    transition: color var(--transition-fast);
}
.copy-btn:hover { color: var(--color-accent); }
.copy-btn.copied { color: var(--color-success); }

/* ===========================
   Inline Code
   =========================== */
code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    padding: 0.15em 0.4em;
    border-radius: var(--radius-sm);
    color: var(--color-code);
}

/* ===========================
   Footer
   =========================== */
.site-footer {
    padding: var(--space-xl) 0;
    border-top: 1px solid var(--color-border);
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-footer p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.powered-by {
    font-size: 0.75rem;
    opacity: 0.6;
}

.powered-by a {
    color: var(--color-text-muted);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.powered-by a:hover { color: var(--color-accent); }

/* ===========================
   Animations
   =========================== */
@media (prefers-reduced-motion: no-preference) {
    .fade-in {
        opacity: 0;
        transform: translateY(16px);
        transition: opacity 0.5s ease, transform 0.5s ease;
    }
    .fade-in.visible {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===========================
   Responsive — 640px+
   =========================== */
@media (min-width: 640px) {
    :root { --space-section: 5rem; }
    h1 { font-size: 2.5rem; }
    h2 { font-size: 1.875rem; }
    h3 { font-size: 1.5rem; }
    body { font-size: 1.0625rem; }

    .stats-row { grid-template-columns: repeat(4, 1fr); }
    .stack-grid { grid-template-columns: repeat(2, 1fr); }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .stack-grid { grid-template-columns: repeat(4, 1fr); }
    .features-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 640px) {
    .nav-links a:not(.btn) { display: none; }
    .footer-inner { flex-direction: column; gap: 0.25rem; text-align: center; }
}