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

@font-face {
    font-family: 'Space Grotesk';
    font-style: normal;
    font-weight: 300 700;
    font-display: swap;
    src: url('fonts/SpaceGrotesk-Variable.woff2') format('woff2');
}

:root {
    --gold: #F2C230;
    --orange: #F7931A;
    --red: #D7263D;
    --purple: #5C2D6F;
    --ivory: #F4F1E8;
    --black: #000000;
}

[data-theme="dark"] {
    --bg: #000000;
    --bg-elevated: #0a0a0a;
    --text-primary: #FFFFFF;
    --text-secondary: rgba(255, 255, 255, 0.85);
    --text-muted: rgba(255, 255, 255, 0.6);
    --border: rgba(255, 255, 255, 0.08);
}

[data-theme="light"] {
    --bg: #F4F1E8;
    --bg-elevated: #ffffff;
    --text-primary: #000000;
    --text-secondary: rgba(0, 0, 0, 0.6);
    --text-muted: rgba(0, 0, 0, 0.35);
    --border: rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Space Grotesk', -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background 0.6s ease, color 0.6s ease;
    -webkit-font-smoothing: antialiased;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: transparent;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    border-color: var(--text-muted);
}

.footer {
    padding: 60px 40px;
    text-align: center;
    border-top: 1px solid var(--border);
}

.footer-text {
    font-size: 11px;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.footer .footer-text a {
    font-size: 11px;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-muted);
    text-decoration: underline;
    text-underline-offset: 3px;
    transition: color 0.3s ease;
}

.footer .footer-text a:hover {
    color: var(--gold);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@media (max-width: 680px) {
    .footer {
        padding: 40px 24px;
    }
}

/* ===== Article pages (shared by all article/app pages with prose content) ===== */

.top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 28px 40px;
    border-bottom: 1px solid var(--border);
}

.back-link {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 4px;
    color: var(--text-muted);
    text-decoration: none;
    text-transform: uppercase;
    transition: color 0.3s ease;
}

.back-link:hover {
    color: var(--text-secondary);
}

.site-name {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 5px;
    color: var(--text-primary);
    text-transform: uppercase;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 60px 40px 0;
}

.hero {
    padding: 60px 0 80px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 80px;
}

.eyebrow {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 5px;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.hero-title {
    font-size: 64px;
    font-weight: 700;
    letter-spacing: -2px;
    line-height: 1.0;
    color: var(--text-primary);
    margin-bottom: 24px;
    max-width: 18ch;
}

.hero-subtitle {
    font-size: 22px;
    font-weight: 300;
    line-height: 1.4;
    color: var(--text-secondary);
    max-width: 38ch;
    margin-bottom: 32px;
}

.hero-byline {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.section {
    margin-bottom: 80px;
}

.section-label {
    display: inline-block;
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 4px;
    text-transform: uppercase;
    color: var(--text-muted);
    text-decoration: none;
    margin-bottom: 16px;
    transition: color 0.3s ease;
}

.section-label:hover {
    color: var(--gold);
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    letter-spacing: -1px;
    line-height: 1.1;
    color: var(--text-primary);
    margin-bottom: 32px;
}

.section-title-sm {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.5px;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.prose p {
    font-size: 16px;
    font-weight: 300;
    line-height: 1.75;
    color: var(--text-secondary);
    margin-bottom: 24px;
    max-width: 64ch;
}

.prose p:last-child {
    margin-bottom: 0;
}

.prose p strong {
    color: var(--text-primary);
    font-weight: 600;
}

.prose p em {
    color: var(--text-primary);
    font-style: normal;
}

.prose a {
    color: var(--gold);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-thickness: 1px;
}

.prose a:hover {
    color: var(--orange);
}

.prose ul, .prose ol {
    font-size: 16px;
    font-weight: 300;
    line-height: 1.8;
    color: var(--text-secondary);
    max-width: 64ch;
    margin-bottom: 24px;
    padding-left: 24px;
}

.prose li {
    margin-bottom: 8px;
}

.prose li:last-child {
    margin-bottom: 0;
}

.prose code {
    font-family: 'Space Grotesk', monospace;
    font-size: 13px;
    background: var(--bg-elevated);
    padding: 1px 5px;
    color: var(--text-primary);
}

.ref {
    font-size: 12px;
    color: var(--text-muted);
    vertical-align: super;
    margin-left: 1px;
    text-decoration: none;
    font-weight: 400;
}

.ref:hover {
    color: var(--gold);
}

.pullquote {
    border-left: 2px solid var(--gold);
    padding: 16px 0 16px 24px;
    margin: 32px 0;
    font-size: 18px;
    font-weight: 300;
    line-height: 1.6;
    color: var(--text-primary);
    max-width: 60ch;
}

.equation {
    font-family: 'Space Grotesk', monospace;
    font-size: 14px;
    font-weight: 400;
    color: var(--text-primary);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    padding: 12px 18px;
    margin: 24px 0;
    max-width: 64ch;
    overflow-x: auto;
}

.prose table {
    width: 100%;
    max-width: 64ch;
    border-collapse: collapse;
    font-size: 13px;
    font-weight: 300;
    line-height: 1.5;
    color: var(--text-secondary);
    margin: 32px 0;
}

.prose table th,
.prose table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}

.prose table th {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.prose table td strong {
    color: var(--text-primary);
    font-weight: 600;
}

.see-also {
    border: 1px solid var(--border);
    padding: 24px 28px;
    margin: 32px 0 0;
    max-width: 64ch;
    font-size: 14px;
    font-weight: 300;
    line-height: 1.6;
    color: var(--text-secondary);
}

.see-also-label {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.see-also a {
    color: var(--gold);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.rule-table {
    border: 1px solid var(--border);
    margin: 24px 0;
    font-size: 13px;
}

.rule-row {
    display: grid;
    grid-template-columns: 180px 1fr 1.5fr;
    border-bottom: 1px solid var(--border);
}

.rule-row:last-child {
    border-bottom: none;
}

.rule-table-narrow .rule-row {
    grid-template-columns: 1fr 1fr;
}

.rule-header {
    background: var(--bg-elevated);
}

.rule-header .rule-cell {
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    font-size: 10px;
    color: var(--text-muted);
}

.rule-cell {
    padding: 10px 12px;
    border-right: 1px solid var(--border);
    line-height: 1.5;
}

.rule-cell:last-child {
    border-right: none;
}

.references {
    border-top: 1px solid var(--border);
    padding-top: 60px;
    margin-top: 80px;
}

.references-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.references-list li {
    font-size: 12px;
    font-weight: 300;
    line-height: 1.7;
    color: var(--text-muted);
    margin-bottom: 12px;
    padding-left: 24px;
    position: relative;
}

.references-list li::before {
    content: '\00B7';
    position: absolute;
    left: 8px;
    top: 0;
    color: var(--text-muted);
}

.references-list li a {
    color: var(--text-secondary);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-thickness: 1px;
}

.references-list li a:hover {
    color: var(--gold);
}

.references-list li code {
    font-family: 'Space Grotesk', monospace;
    font-size: 11px;
    background: var(--bg-elevated);
    padding: 1px 5px;
    color: var(--text-primary);
}

@media (max-width: 680px) {
    .top-bar {
        padding: 20px 24px;
    }
    .site-name {
        font-size: 9px;
        letter-spacing: 3px;
    }
    .container {
        padding: 40px 24px 0;
    }
    .hero {
        padding: 32px 0 48px;
        margin-bottom: 48px;
    }
    .hero-title {
        font-size: 40px;
        letter-spacing: -1px;
    }
    .hero-subtitle {
        font-size: 17px;
    }
    .section {
        margin-bottom: 56px;
    }
    .section-title {
        font-size: 26px;
    }
    .prose p {
        font-size: 15px;
        line-height: 1.65;
    }
    .prose table {
        font-size: 12px;
    }
    .pullquote {
        font-size: 16px;
    }
}

/* ===== Chain charts (shared by bitcoin-energy.html and bitcoin-economics.html) ===== */

.chart-grid {
    border: 1px solid var(--border);
    background: var(--bg);
    padding: 24px;
}

.chart-panel {
    position: relative;
    border: 1px solid var(--border);
    background: var(--bg);
    padding: 24px;
}

.chart-panel-loader {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    background: var(--bg);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    z-index: 10;
}

.chart-panel-loader.visible {
    opacity: 1;
    pointer-events: auto;
}

.chart-panel-loader-spinner {
    width: 32px;
    height: 32px;
    border: 2px solid var(--border);
    border-top-color: var(--gold);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.chart-panel-loader-text {
    font-size: 12px;
    color: var(--text-muted);
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.02em;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.chart-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 12px;
}

.panel-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 4px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.scale-toggles {
    display: flex;
    gap: 4px;
}

.scale-btn {
    padding: 4px 10px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
    font-family: Space Grotesk, sans-serif;
    font-size: 10px;
    letter-spacing: 1px;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
}

.scale-btn:hover {
    border-color: var(--text-muted);
    color: var(--text-secondary);
}

.scale-btn.active {
    border-color: var(--gold);
    color: var(--gold);
}

.chain-canvas {
    width: 100%;
    height: 280px;
    display: block;
}

.chart-tooltip {
    position: fixed;
    pointer-events: none;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    padding: 8px 12px;
    border-radius: 4px;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 12px;
    color: var(--text-primary);
    z-index: 100;
    opacity: 0;
    transition: opacity 0.15s;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.chart-tooltip.visible {
    opacity: 1;
}

.chart-tooltip .tt-row {
    display: flex;
    gap: 8px;
    margin-bottom: 2px;
}

.chart-tooltip .tt-row:last-child {
    margin-bottom: 0;
}

.chart-tooltip .tt-label {
    color: var(--text-muted);
}

.chart-tooltip .tt-value {
    font-weight: 500;
    color: var(--text-primary);
}

.header-controls {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
}

.dim-toggles {
    display: flex;
    gap: 4px;
}

.dim-btn {
    padding: 4px 10px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
    font-family: Space Grotesk, sans-serif;
    font-size: 10px;
    letter-spacing: 1px;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
}

.dim-btn:hover {
    border-color: var(--text-muted);
    color: var(--text-secondary);
}

.dim-btn.active {
    border-color: var(--gold);
    color: var(--gold);
}

.dataset-selector {
    display: flex;
    align-items: center;
    gap: 8px;
}

.selector-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.dataset-select {
    padding: 4px 10px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    font-family: Space Grotesk, sans-serif;
    font-size: 10px;
    letter-spacing: 1px;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
    outline: none;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    padding-right: 24px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath fill='%23888' d='M0 0l5 6 5-6z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 8px center;
}

.dataset-select:hover {
    border-color: var(--text-muted);
}

.dataset-select:focus {
    border-color: var(--gold);
    color: var(--gold);
}

.dataset-select option {
    background: var(--bg);
    color: var(--text-secondary);
    text-transform: none;
    letter-spacing: normal;
}

.dataset-download {
    padding: 3px 10px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
    font-family: Space Grotesk, sans-serif;
    font-size: 9px;
    letter-spacing: 1px;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
    outline: none;
}

.dataset-download:hover {
    border-color: var(--gold);
    color: var(--gold);
}

.panel-note {
    font-size: 11px;
    margin-top: 4px;
}

@media (max-width: 680px) {
    .chart-grid {
        padding: 16px;
    }
    .chart-panel {
        padding: 16px;
    }
    .chain-canvas {
        height: 220px;
    }
}