:root {
    --bg-color: #0f172a;
    --panel-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --accent-danger: #ef4444;
    --accent-danger-hover: #dc2626;
    --border-color: #334155;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 1200px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

header {
    text-align: center;
}

header h1 {
    font-size: clamp(0.8rem, 3.9vw, 2.2rem);
    white-space: nowrap;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #60a5fa, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.main-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

.visualization {
    background: var(--panel-bg);
    border-radius: 12px;
    padding: 1rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    border: 1px solid var(--border-color);
}

#plot {
    width: 100%;
    height: 100%;
    border-radius: 8px;
    overflow: hidden;
}

.controls {
    background: var(--panel-bg);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.controls h2 {
    font-size: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.95rem;
    color: var(--text-muted);
    display: flex;
    justify-content: space-between;
}

.control-group label span {
    color: var(--text-main);
    font-weight: 600;
}

.control-group label.choice {  /* a radio button and its text, side by side */
    justify-content: flex-start;
    gap: 0.5rem;
}

input[type=range] {
    -webkit-appearance: none;
    width: 100%;
    background: transparent;
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 16px;
    width: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    margin-top: -6px;
}

input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    cursor: pointer;
    background: var(--border-color);
    border-radius: 2px;
}

input[type=range]:focus {
    outline: none;
}

.actions {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

/* ---- Controller section ---- */
.controller-section {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.controller-section h3 {
    font-size: 1rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.controller-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
}

.controller-label {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.controller-name {
    font-weight: 700;
    font-size: 1rem;
}

.controller-desc {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* ---- Buttons ---- */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
}

.btn-controller {
    padding: 0.55rem 1rem;
    font-size: 0.9rem;
    width: auto;
    min-width: 110px;
    flex-shrink: 0;
}

.btn-primary {
    background-color: var(--accent);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.btn-danger {
    background-color: var(--accent-danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background-color: var(--accent-danger-hover);
}

.btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

/* ---- Status panel ---- */
.status-panel {
    background: rgba(0, 0, 0, 0.2);
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.status-panel p {
    display: flex;
    justify-content: space-between;
    color: var(--text-muted);
}

.status-on {
    font-weight: 600;
    color: #10b981;
}

.status-off {
    font-weight: 600;
    color: #ef4444;
}

/* ---- Browser (WebAssembly) build additions ---- */
/* The controls column is taller than today's: keep today's plot size instead of stretching. */
.main-content {
    align-items: start;
}

.visualization {
    position: relative;
    min-width: 0;  /* the grid column may shrink below the plot's current width (rotated phone): app.js then resizes it */
}

#plot {
    height: auto;  /* set by fitPlotHeight() in app.js */
}

#scene {
    position: absolute;  /* place and size: fitScene() in app.js */
    pointer-events: none;
}

.notice {
    position: absolute;
    top: 1.5rem;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(239, 68, 68, 0.9);
    color: white;
    padding: 0.4rem 0.9rem;
    border-radius: 6px;
    font-size: 0.9rem;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.4s;
}

.notice.show {
    opacity: 1;
}

.perf-panel {
    font-size: 0.85rem;
}

.perf-panel .muted {
    color: var(--text-muted);
    font-size: 0.78rem;
    line-height: 1.35;
}

@media (max-width: 800px) {
    .container {
        padding: 1rem;
        gap: 1rem;
    }


    .main-content {
        grid-template-columns: 1fr;
    }

    .visualization {
        min-height: 0;
        padding: 0.5rem;
    }

}

.perf-panel[hidden] {
    display: none;
}

/* Start Sim and Start MPC side by side, right under the plot */
.run-row .btn {
    flex: 1;
}

/* Shown over the plot while the WebAssembly controller loads and is timed on this device */
.loading {
    position: absolute;
    top: 1rem;
    left: 1rem;
    right: 1rem;  /* height: the plot's, set by app.js */
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    background: rgba(30, 41, 59, 0.85);
    border-radius: 8px;
    color: var(--text-muted);
    font-size: 0.95rem;
    z-index: 2;
}

.loading[hidden] {
    display: none;
}

.spinner {
    width: 2.5rem;
    height: 2.5rem;
    border: 4px solid rgba(96, 165, 250, 0.25);
    border-top-color: #60a5fa;
    border-radius: 50%;
    animation: spin 0.9s linear infinite;
}

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

@media (max-width: 800px) {
    .loading {
        top: 0.5rem;
        left: 0.5rem;
        right: 0.5rem;
    }
}

.tuning:not([hidden]) {  /* display: flex would override the hidden attribute */
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.legend {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.4rem 0.8rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

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

.legend svg {
    width: 24px;
    height: 14px;
    flex: none;
}

.credits {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.credits a {
    color: var(--text-muted);
}

.credits .credit-main {
    font-size: 1.15rem;
}

.credits p {
    text-wrap: balance;  /* the line with CRVI's full name wraps evenly on phones */
}

.credits .credit-org {
    font-size: 1rem;
}

.note {
    max-width: 40rem;
    margin: 0 auto;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.lang-switch {
    display: flex;
    justify-content: flex-end;
    gap: 0.25rem;
    margin-bottom: 0.25rem;
}

.lang-switch button {
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--text-muted);
    border-radius: 0.375rem;
    padding: 0.1rem 0.5rem;
    font-size: 0.75rem;
    cursor: pointer;
}

.lang-switch button.active {
    color: var(--text-main);
    border-color: var(--accent);
    background: var(--accent);
}