* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: #ffffff;
    color: #000000;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* ── Header ───────────────────────────────────────────── */
.header {
    display: flex;
    flex-direction: column;
    padding: 10px 20px;
    border-bottom: 2px solid #000;
    flex-shrink: 0;
    gap: 8px;
}

.header h1 {
    font-size: 1.35rem;
    font-weight: bold;
    letter-spacing: -0.02em;
}

.controls-row {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 6px;
}

.control-group label {
    font-size: 0.85rem;
    font-weight: 600;
    white-space: nowrap;
}

.control-group select {
    padding: 4px 8px;
    font-size: 0.85rem;
    border: 1.5px solid #000;
    border-radius: 4px;
    background-color: #fff;
    cursor: pointer;
}

.slider-group {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
}

.slider-group input[type="range"] {
    width: 140px;
    cursor: pointer;
    accent-color: #000;
}

/* ── Buttons ──────────────────────────────────────────── */
.btn {
    padding: 6px 16px;
    font-size: 0.9rem;
    font-weight: bold;
    cursor: pointer;
    background-color: #ffffff;
    color: #000000;
    border: 2px solid #000000;
    border-radius: 4px;
    transition: all 0.2s ease;
    margin-left: auto;
}

.btn:hover {
    background-color: #000000;
    color: #ffffff;
}

.btn:active {
    transform: scale(0.95);
}

/* ── Info bar ─────────────────────────────────────────── */
.info-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 20px;
    border-bottom: 1px solid #ccc;
    background: #f8f8f8;
    flex-shrink: 0;
    flex-wrap: wrap;
}

.info-chip {
    font-size: 0.85rem;
    font-weight: 600;
    padding: 3px 10px;
    border: 1.5px solid #000;
    border-radius: 12px;
    background: #fff;
    white-space: nowrap;
}

.info-text {
    font-size: 0.82rem;
    color: #444;
    font-style: italic;
}

/* ── Main container ───────────────────────────────────── */
.main-container {
    display: flex;
    flex: 1;
    overflow: hidden;
    padding: 10px;
    gap: 10px;
}

.left-pane {
    display: flex;
    flex-direction: column;
    flex: 1;
    gap: 10px;
    min-width: 0;
}

.right-pane {
    display: flex;
    flex-direction: column;
    flex: 1;
    gap: 10px;
    min-width: 0;
}

.bottom-pair {
    display: flex;
    flex: 1;
    gap: 10px;
    min-height: 0;
}

.bottom-pair .canvas-wrapper {
    flex: 1;
    min-width: 0;
}

.canvas-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    border: 2px solid #000;
    border-radius: 4px;
    overflow: hidden;
    min-height: 0;
}

h3 {
    padding: 6px 8px;
    font-size: 0.82rem;
    border-bottom: 1px solid #000;
    background: #fff;
    z-index: 10;
    flex-shrink: 0;
}

canvas {
    flex: 1;
    width: 100%;
    display: block;
    touch-action: none;
    min-height: 0;
}

/* ── Responsive layout ────────────────────────────────── */
@media (max-width: 900px) {
    body {
        overflow: auto;
        height: auto;
    }

    .header {
        padding: 8px 12px;
    }

    .header h1 {
        font-size: 1.1rem;
    }

    .controls-row {
        gap: 10px;
    }

    .slider-group input[type="range"] {
        width: 110px;
    }

    .main-container {
        flex-direction: column;
        min-height: 250vh;
        padding: 8px;
    }

    .left-pane, .right-pane {
        flex: none;
    }

    .left-pane {
        height: 85vh;
    }

    .right-pane {
        height: 65vh;
    }

    .bottom-pair {
        flex-direction: column;
    }

    .info-bar {
        padding: 5px 12px;
    }

    .btn {
        padding: 5px 10px;
        font-size: 0.8rem;
    }
}