@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Manrope:wght@200..800&family=JetBrains+Mono:wght@100..400&display=swap');

:root {
    --bg: #080808;
    --bg-elevated: #0c0c0c;
    --bg-surface: #141414;
    --text: #e8e8e8;
    --text-muted: #606060;
    --text-dim: #333;
    --accent: #8a9bb5;
    --border: #1a1a1a;
    --font-headline: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

html, body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    overflow-x: hidden;
}

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

html[data-page-loading="true"] body {
    overflow: hidden;
}

html[data-page-loading="true"] body::before {
    content: "";
    position: fixed;
    inset: 0;
    background: rgba(6, 8, 12, 0.98);
    z-index: 9998;
    pointer-events: auto;
}

html[data-page-loading="true"] body::after {
    content: "";
    position: fixed;
    top: 50%;
    left: 50%;
    width: 50px;
    height: 50px;
    margin-top: -25px;
    margin-left: -25px;
    border-radius: 50%;
    border: 2px solid rgba(138, 155, 181, 0.25);
    border-top-color: rgba(138, 155, 181, 0.95);
    animation: page-loader-spin 0.85s linear infinite;
    z-index: 9999;
    pointer-events: none;
}

::selection {
    background: rgba(138, 155, 181, 0.2);
    color: var(--text);
}

a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.25s ease;
}

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

/* ── Landing Page ── */

.landing {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 4rem 2rem;
}

.landing-title {
    font-family: var(--font-headline);
    font-size: clamp(3rem, 9vw, 7rem);
    font-weight: 800;
    line-height: 0.95;
    letter-spacing: -0.04em;
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--text);
}

.landing-subtitle {
    font-size: 0.7rem;
    letter-spacing: 0.35em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 5rem;
    text-align: center;
}

.device-lock-banner {
    max-width: 780px;
    margin: 1.25rem auto -1rem auto;
    padding: 0.85rem 1rem;
    border: 1px solid #5a2d2d;
    background: rgba(110, 40, 40, 0.16);
    color: #f0d6d6;
    font-size: 0.74rem;
    letter-spacing: 0.02em;
    line-height: 1.5;
    text-align: center;
}

.device-lock-banner strong {
    display: inline-block;
    margin-right: 0.35rem;
    font-family: var(--font-headline);
    letter-spacing: 0.01em;
    color: #ffd9d9;
}

.demo-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.2rem;
    max-width: 900px;
    width: 100%;
}

.demo-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
    width: 140px;
    text-align: center;
    color: var(--text);
    transition: opacity 0.25s ease;
    padding: 0.8rem 0.4rem;
}

.demo-card:hover {
    opacity: 0.7;
}

body.mobile-locked .demo-card {
    opacity: 0.36;
    filter: grayscale(1) saturate(0.3);
    pointer-events: none;
}

body.mobile-locked .demo-card .card-title,
body.mobile-locked .demo-card .card-desc {
    color: #727272;
}

.demo-preview {
    width: 72px;
    height: 72px;
    border: 1px solid var(--border);
    image-rendering: pixelated;
    margin-bottom: 0.3rem;
}

.demo-card .card-title {
    font-family: var(--font-headline);
    font-weight: 600;
    font-size: 0.72rem;
    letter-spacing: 0.01em;
    line-height: 1.3;
}

.demo-card .card-desc {
    font-size: 0.58rem;
    color: var(--text-muted);
    font-weight: 400;
    line-height: 1.4;
}

.landing-footer {
    margin-top: 5rem;
    display: flex;
    gap: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
}

.landing-footer span {
    color: var(--text-dim);
}

/* ── Demo Pages ── */

.demo-page {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

.demo-header {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0.6rem 1.5rem;
    flex-shrink: 0;
    border-bottom: 1px solid var(--border);
    position: relative;
}

.demo-header .back {
    position: absolute;
    left: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    color: var(--text-dim);
}

.demo-header .back:hover {
    color: var(--text-muted);
}

.demo-header .demo-title {
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.fps {
    position: fixed;
    bottom: 0.5rem;
    right: 0.8rem;
    font-family: var(--font-mono);
    font-size: 0.6rem;
    font-weight: 400;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    z-index: 100;
    pointer-events: none;
}

/* ── Info Bar (always visible) ── */

.info-bar {
    flex-shrink: 0;
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--border);
    background: var(--bg-elevated);
}

.info-grid {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem 2rem;
}

.info-grid h4 {
    font-family: var(--font-mono);
    font-size: 0.55rem;
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.35rem;
}

.info-grid p {
    font-size: 0.72rem;
    line-height: 1.55;
    color: var(--text-muted);
}

.info-grid em {
    font-style: italic;
    color: var(--text-dim);
}

.info-grid a {
    color: var(--text);
    text-decoration: underline;
    text-underline-offset: 2px;
}

@media (max-width: 800px) {
    .info-grid {
        grid-template-columns: 1fr;
    }
    .info-bar {
        max-height: 35vh;
        overflow-y: auto;
    }
}

/* ── Canvas ── */

.canvas-wrap {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 0;
    padding: 0.5rem;
    overflow: hidden;
}

.canvas-wrap canvas {
    display: block;
    border: 1px solid var(--border);
}

/* ── Controls ── */

.controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.4rem;
    padding: 0.6rem 1.5rem;
    flex-shrink: 0;
    border-top: 1px solid var(--border);
    flex-wrap: wrap;
}

.ctrl {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.ctrl label {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    white-space: nowrap;
    user-select: none;
}

.ctrl .val {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--text-dim);
    min-width: 2ch;
    text-align: right;
}

input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 80px;
    height: 2px;
    background: var(--border);
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--text-dim);
    cursor: pointer;
    transition: background 0.2s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--text-muted);
}

input[type="range"]::-moz-range-thumb {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--text-dim);
    border: none;
    cursor: pointer;
}

button, .btn {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    background: none;
    border: 1px solid var(--border);
    color: var(--text-muted);
    padding: 0.4rem 0.8rem;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

button:hover, .btn:hover {
    border-color: var(--text-dim);
    color: var(--text);
}

button.active {
    border-color: var(--accent);
    color: var(--accent);
}

@keyframes flash-hint {
    0%, 100% { border-color: var(--border); color: var(--text-muted); }
    25%, 75% { border-color: #c44; color: #e55; }
    50% { border-color: #e55; color: #f66; }
}

button.flash-hint {
    animation: flash-hint 0.6s ease 2;
}

select {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 400;
    letter-spacing: 0.05em;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-muted);
    padding: 0.4rem 0.6rem;
    cursor: pointer;
    outline: none;
}

select:hover {
    border-color: var(--text-dim);
    color: var(--text);
}

.usage {
    flex-shrink: 0;
    font-family: var(--font-mono);
    font-size: 0.62rem;
    color: var(--text-muted);
    letter-spacing: 0.04em;
    text-align: center;
    padding: 0.45rem 1.5rem;
    border-bottom: 1px solid var(--border);
    line-height: 1.7;
}

.usage .key {
    color: var(--accent);
    font-weight: 500;
}

.usage .sep {
    color: var(--text-dim);
    margin: 0 0.4rem;
}

.status {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--text-dim);
    letter-spacing: 0.06em;
}

/* ── DiffLogic dual canvas ── */

.dual-canvas {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    padding: 0.5rem;
    min-height: 0;
    overflow: hidden;
}

.dual-canvas .panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.3rem;
}

.dual-canvas .panel-label {
    font-family: var(--font-mono);
    font-size: 0.55rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-dim);
}

.dual-canvas canvas {
    display: block;
    image-rendering: pixelated;
    border: 1px solid var(--border);
}

@media (max-width: 700px) {
    .dual-canvas {
        flex-direction: column;
        gap: 0.5rem;
    }
}