@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
    --bg-primary: #0a0a12;
    --bg-secondary: #12121e;
    --bg-card: rgba(20, 20, 35, 0.7);
    --bg-card-hover: rgba(30, 30, 50, 0.8);
    --border: rgba(255, 255, 255, 0.06);
    --border-accent: rgba(99, 102, 241, 0.3);
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-1: #6366f1;
    --accent-2: #8b5cf6;
    --accent-3: #a78bfa;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --radius: 16px;
    --radius-sm: 10px;
    --radius-xs: 6px;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.15);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Ambient background glow */
body::before {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at 30% 20%, rgba(99, 102, 241, 0.06) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(139, 92, 246, 0.04) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.app {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: 40px 24px 60px;
}

/* ─── Header ─── */
header {
    text-align: center;
    margin-bottom: 48px;
}

header h1 {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 6px;
}

header .subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 400;
    letter-spacing: 2px;
    text-transform: uppercase;
}

header .description {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 10px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

/* ─── Cards ─── */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
    transition: border-color var(--transition);
}

.card:hover {
    border-color: rgba(255, 255, 255, 0.1);
}

.card-title {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--accent-3);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-title::before {
    content: '';
    width: 3px;
    height: 14px;
    background: linear-gradient(to bottom, var(--accent-1), var(--accent-2));
    border-radius: 3px;
}

/* ─── Upload Section ─── */
.upload-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.upload-box {
    position: relative;
    border: 2px dashed rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition);
    background: rgba(255, 255, 255, 0.02);
    overflow: hidden;
}

.upload-box:hover {
    border-color: var(--accent-1);
    background: rgba(99, 102, 241, 0.05);
}

.upload-box.has-image {
    border-color: rgba(34, 197, 94, 0.3);
    border-style: solid;
}

.upload-box input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
    z-index: 2;
}

.upload-box .upload-icon {
    font-size: 2rem;
    margin-bottom: 8px;
    opacity: 0.5;
}

.upload-box .upload-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.upload-box .upload-hint {
    font-size: 0.72rem;
    color: var(--text-muted);
}

.upload-box canvas {
    display: block;
    width: 100%;
    max-width: 250px;
    height: auto;
    aspect-ratio: 1;
    margin: 12px auto 0;
    border-radius: var(--radius-xs);
    background: rgba(0,0,0,0.3);
}

.upload-box canvas.hidden {
    display: none;
}

/* ─── Controls ─── */
.controls-row {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.control-group label {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    white-space: nowrap;
}

.control-group .value-badge {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent-3);
    background: rgba(99, 102, 241, 0.12);
    padding: 3px 10px;
    border-radius: 20px;
    min-width: 55px;
    text-align: center;
}

/* Range input */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 4px;
    outline: none;
    width: 140px;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    cursor: pointer;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.4);
    transition: transform 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

/* Buttons */
.btn-group {
    display: flex;
    gap: 10px;
    margin-left: auto;
}

.btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-xs);
    padding: 10px 20px;
    cursor: pointer;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover:not(:disabled) {
    box-shadow: 0 6px 25px rgba(99, 102, 241, 0.5);
    transform: translateY(-1px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.12);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.btn-danger:hover:not(:disabled) {
    background: rgba(239, 68, 68, 0.2);
}

.btn:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.btn-download {
    background: rgba(34, 197, 94, 0.12);
    color: var(--success);
    border: 1px solid rgba(34, 197, 94, 0.2);
}

.btn-download:hover:not(:disabled) {
    background: rgba(34, 197, 94, 0.2);
}

/* ─── Result Section ─── */
.result-section {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.canvas-wrapper {
    position: relative;
    display: inline-block;
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow), var(--shadow-glow);
    border: 1px solid var(--border);
    background: #000;
    transition: box-shadow var(--transition);
}

.canvas-wrapper.running {
    box-shadow: var(--shadow), 0 0 40px rgba(99, 102, 241, 0.25);
}

.canvas-wrapper canvas {
    display: block;
    width: 100%;
    max-width: 600px;
    height: auto;
}

/* ─── Stats ─── */
.stats-bar {
    display: flex;
    gap: 2px;
    margin-top: 20px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    overflow: hidden;
    width: 100%;
    max-width: 600px;
}

.stat-item {
    flex: 1;
    padding: 14px 16px;
    text-align: center;
    position: relative;
}

.stat-item:not(:last-child)::after {
    content: '';
    position: absolute;
    right: 0;
    top: 20%;
    height: 60%;
    width: 1px;
    background: var(--border);
}

.stat-label {
    font-size: 0.65rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.stat-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}

.stat-value.accent {
    color: var(--accent-3);
}

.stat-value.success {
    color: var(--success);
}

/* ─── Progress bar ─── */
.progress-container {
    width: 100%;
    max-width: 600px;
    margin-top: 12px;
}

.progress-bar {
    height: 3px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
    border-radius: 3px;
    transition: width 0.5s ease;
    width: 0%;
}

.progress-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 6px;
    text-align: center;
}

/* ─── Phase indicator ─── */
.phase-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 5px 14px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.phase-badge.greedy {
    background: rgba(245, 158, 11, 0.12);
    color: var(--warning);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.phase-badge.evolving {
    background: rgba(99, 102, 241, 0.12);
    color: var(--accent-3);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

.phase-badge.idle {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-muted);
    border: 1px solid var(--border);
}

.phase-badge .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: currentColor;
}

.phase-badge.evolving .dot {
    animation: pulse-dot 1.5s ease-in-out infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

/* ─── Responsive ─── */
@media (max-width: 700px) {
    .app {
        padding: 24px 16px 40px;
    }

    header h1 {
        font-size: 2.2rem;
    }

    .upload-grid {
        grid-template-columns: 1fr;
    }

    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }

    .btn-group {
        margin-left: 0;
        justify-content: stretch;
    }

    .btn-group .btn {
        flex: 1;
        justify-content: center;
    }

    .stats-bar {
        flex-direction: column;
    }

    .stat-item:not(:last-child)::after {
        right: 20%;
        top: auto;
        bottom: 0;
        height: 1px;
        width: 60%;
    }
}