:root {
    --bg-color: #05060a;
    --container-bg: #0d0f1a;
    --card-bg: #131627;
    --border-color: #262b45;
    --text-primary: #e8e9f5;
    --text-secondary: #8b90b3;
    --accent-cyan: #22d3ee;
    --accent-rational: #34d399;
    --accent-irrational: #d946ef;
    --accent-red: #f43f5e;
    --accent-gold: #fbbf24;
    --panel-sunken: rgba(0, 0, 0, 0.35);
    --font-header: 'Audiowide', cursive, sans-serif;
    --font-body: 'Exo 2', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --shadow-color: rgba(0, 0, 0, 0.6);

    /* Shared kit mapping */
    --kit-accent: var(--accent-cyan);
    --kit-accent-ink: #001217;
    --kit-accent-glow: rgba(34, 211, 238, 0.25);
    --kit-surface: var(--card-bg);
    --kit-border: var(--border-color);
    --kit-input-bg: var(--container-bg);
    --kit-error: var(--accent-red);
}

body.light-mode {
    --bg-color: #f5f6fa;
    --container-bg: #ffffff;
    --card-bg: #eef0f8;
    --border-color: #cdd2e6;
    --text-primary: #171a2e;
    --text-secondary: #4b5170;
    --accent-cyan: #0891b2;
    --accent-rational: #059669;
    --accent-irrational: #a21caf;
    --accent-red: #be123c;
    --accent-gold: #b45309;
    --panel-sunken: rgba(0, 0, 0, 0.05);
    --shadow-color: rgba(0, 0, 0, 0.12);

    /* Shared kit mapping (light theme) */
    --kit-accent: var(--accent-cyan);
    --kit-accent-ink: #ffffff;
    --kit-accent-glow: rgba(8, 145, 178, 0.18);
    --kit-surface: var(--card-bg);
    --kit-border: var(--border-color);
    --kit-input-bg: var(--container-bg);
    --kit-error: var(--accent-red);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    transition: background-color 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

/* Top Right Theme Toggle */
.top-controls {
    position: fixed;
    top: 20px;
    right: 24px;
    z-index: 1000;
}

.theme-toggle-btn {
    background: var(--container-bg);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    padding: 9px 16px;
    border-radius: 8px;
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 0.85rem;
    cursor: pointer;
    box-shadow: 0 4px 10px var(--shadow-color);
    letter-spacing: 0.3px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.theme-toggle-btn:hover {
    border-color: var(--accent-cyan);
}

/* Main Container */
.facility-container {
    width: 100%;
    max-width: 860px;
    background: var(--container-bg);
    border: 2px solid var(--border-color);
    border-top: 6px solid var(--accent-cyan);
    border-radius: 10px;
    padding: 36px;
    box-shadow: 0 12px 30px var(--shadow-color);
    min-height: 560px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
}

.facility-icon {
    font-size: 2.6rem;
    text-align: center;
    margin-bottom: 8px;
}

.facility-title {
    font-family: var(--font-header);
    font-size: 1.9rem;
    color: var(--accent-cyan);
    text-align: center;
    letter-spacing: 1px;
    margin-bottom: 6px;
}

.facility-subtitle {
    font-family: var(--font-mono);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 22px;
    letter-spacing: 0.3px;
}

/* HUD Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 12px 20px;
    margin-bottom: 22px;
    font-family: var(--font-mono);
}

.status-item {
    display: flex;
    flex-direction: column;
    gap: 2px;
    align-items: center;
    font-size: 0.9rem;
    font-weight: 700;
}

.status-label {
    color: var(--text-secondary);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.status-value {
    color: var(--accent-cyan);
    font-size: 1.05rem;
}

/* Falling Particle Catcher — canvas playfield */
.playfield-wrap {
    background: var(--panel-sunken);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 14px;
    position: relative;
}

.playfield-wrap::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-rational), var(--accent-cyan), var(--accent-irrational));
    opacity: 0.7;
    z-index: 1;
}

#gameCanvas {
    display: block;
    width: 100%;
    height: 380px;
    touch-action: none;
    cursor: grab;
}

#gameCanvas:active {
    cursor: grabbing;
}

.controls-hint {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 14px;
    letter-spacing: 0.2px;
}

kbd {
    font-family: var(--font-mono);
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 1px 6px;
    font-size: 0.85em;
}

/* Feedback Message */
.feedback-line {
    font-family: var(--font-mono);
    text-align: center;
    font-size: 0.95rem;
    font-weight: 700;
    min-height: 24px;
}

.text-success { color: var(--accent-rational); }
.text-error { color: var(--accent-red); }

/* General Screen Centering */
.screen-center {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 10px 0;
}

.action-btn {
    background: var(--accent-cyan);
    color: #001217;
    border: none;
    padding: 14px 36px;
    font-family: var(--font-header);
    font-size: 0.95rem;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 1px;
    cursor: pointer;
    margin-top: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

.action-btn:hover {
    opacity: 0.9;
}

.brief-box {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px 28px;
    text-align: left;
    margin: 20px 0;
    max-width: 680px;
    line-height: 1.7;
    font-size: 0.92rem;
}

.brief-box ul {
    padding-left: 20px;
}

.brief-box li {
    margin-bottom: 8px;
}

footer {
    margin-top: 24px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-align: center;
    letter-spacing: 0.5px;
}