* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
:root {
    /* ATC Radar Console Palette */
    --atc-bg: #0B0E14;
    --atc-surface: #141922;
    --atc-surface-alt: #1A2030;
    --atc-border: #1E2633;
    --atc-border-light: #2A3545;
    --atc-green: #00FF41;
    --atc-green-dim: #00CC33;
    --atc-green-glow: rgba(0,255,65,0.15);
    --atc-amber: #FFB000;
    --atc-amber-dim: #CC8C00;
    --atc-amber-glow: rgba(255,176,0,0.15);
    --atc-red: #FF2D2D;
    --atc-red-glow: rgba(255,45,45,0.15);
    --atc-cyan: #00D4FF;
    --atc-text: #C8D6E5;
    --atc-text-dim: #6B7B8D;
    /* Team Colors */
    --team-a-primary: #FF6B35;
    --team-a-glow: rgba(255,107,53,0.25);
    --team-b-primary: #00D4FF;
    --team-b-glow: rgba(0,212,255,0.25);
    /* Difficulty */
    --easy: #00CC33;
    --medium: #FFB000;
    --hard: #FF2D2D;
    --purple: #9B59B6;
    /* Legacy compat aliases */
    --bg-dark: var(--atc-bg);
    --bg-card: var(--atc-surface);
    --text-primary: var(--atc-text);
    --text-secondary: var(--atc-text-dim);
    --gold: var(--atc-green);
    --success: var(--atc-green);
    --danger: var(--atc-red);
    /* Safe areas */
    --safe-top: env(safe-area-inset-top);
    --safe-bottom: env(safe-area-inset-bottom);
}
html, body {
    font-family: 'B612', 'Segoe UI', sans-serif;
    color-scheme: dark;
    background: var(--atc-bg);
    min-height: 100vh;
    min-height: -webkit-fill-available;
    min-height: 100dvh;
    color: var(--atc-text);
    overflow-x: hidden;
    font-size: 16px;
    padding-top: var(--safe-top);
    padding-bottom: var(--safe-bottom);
}

/* Lucide Icons */
.lucide { display: inline-block; vertical-align: middle; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; fill: none; }
.icon-xs { width: 14px; height: 14px; }
.icon-sm { width: 16px; height: 16px; }
.icon-md { width: 20px; height: 20px; }
.icon-lg { width: 24px; height: 24px; }
.icon-xl { width: 32px; height: 32px; }
.btn-icon { display: inline-flex; align-items: center; gap: 6px; }
.btn-icon .lucide { flex-shrink: 0; }

/* Radar Grid Background */
.bg-image {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: -2;
    background:
        radial-gradient(circle at 50% 120%, transparent 200px, rgba(0,255,65,0.035) 201px, transparent 202px),
        radial-gradient(circle at 50% 120%, transparent 400px, rgba(0,255,65,0.025) 401px, transparent 402px),
        radial-gradient(circle at 50% 120%, transparent 600px, rgba(0,255,65,0.018) 601px, transparent 602px),
        radial-gradient(circle at 50% 120%, transparent 800px, rgba(0,255,65,0.012) 801px, transparent 802px),
        linear-gradient(0deg, rgba(0,255,65,0.018) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,255,65,0.018) 1px, transparent 1px);
    background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 50px 50px, 50px 50px;
    background-color: var(--atc-bg);
}

/* CRT Scanline Overlay */
.bg-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: -1;
    background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 2px,
        rgba(0,0,0,0.08) 2px,
        rgba(0,0,0,0.08) 4px
    );
    pointer-events: none;
}

/* Header — flat ATC bar */
.header {
    text-align: center;
    padding: clamp(10px, 2.5vw, 16px) clamp(15px, 3vw, 20px);
    background: var(--atc-surface);
    border-bottom: 2px solid var(--atc-green);
    box-shadow: 0 2px 20px rgba(0,255,65,0.08);
}
.header h1 {
    font-family: 'B612', sans-serif;
    font-size: clamp(1.2rem, 4.5vw, 2rem);
    font-weight: 700;
    color: var(--atc-green);
    letter-spacing: clamp(2px, 0.8vw, 5px);
    text-transform: uppercase;
    cursor: default;
    user-select: none;
    text-shadow: 0 0 20px rgba(0,255,65,0.3);
}
.header p {
    font-family: 'B612 Mono', monospace;
    color: var(--atc-text-dim);
    font-size: clamp(0.65rem, 2vw, 0.8rem);
    margin-top: 4px;
    letter-spacing: 2px;
    text-transform: uppercase;
}

/* Sound Toggle — square ATC button */
.sound-toggle {
    position: fixed;
    top: clamp(8px, 2vw, 12px);
    right: clamp(8px, 2vw, 12px);
    background: var(--atc-surface);
    border: 1px solid var(--atc-border-light);
    border-radius: 4px;
    width: clamp(36px, 9vw, 44px);
    height: clamp(36px, 9vw, 44px);
    cursor: pointer;
    font-family: 'B612 Mono', monospace;
    font-size: clamp(0.65rem, 2vw, 0.75rem);
    font-weight: 700;
    color: var(--atc-green);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    transition: all 0.2s;
    letter-spacing: 0;
}
.sound-toggle:hover {
    border-color: var(--atc-green);
    box-shadow: 0 0 10px rgba(0,255,65,0.15);
}

/* Install Prompt Banner */
.install-banner {
    display: none;
    position: fixed; bottom: 0; left: 0; right: 0;
    background: var(--atc-surface);
    border-top: 2px solid var(--atc-green);
    padding: 12px 20px;
    padding-bottom: calc(12px + var(--safe-bottom));
    z-index: 5000;
    animation: slideUp 0.3s ease;
}
.install-banner.show { display: block; }
@keyframes slideUp { from { transform: translateY(100%); } to { transform: translateY(0); } }
.install-banner-content { display: flex; align-items: center; justify-content: space-between; gap: 15px; max-width: 500px; margin: 0 auto; }
.install-banner-text { font-size: 0.85rem; color: var(--atc-text); }
.install-banner-text strong { color: var(--atc-green); }
.install-btn {
    font-family: 'B612', sans-serif; font-size: 0.7rem; font-weight: 700;
    padding: 8px 18px; background: var(--atc-green); color: #000;
    border: none; border-radius: 4px; cursor: pointer; white-space: nowrap;
    letter-spacing: 1px; text-transform: uppercase;
}
.install-close { background: none; border: none; color: var(--atc-text-dim); font-size: 1.5rem; cursor: pointer; padding: 5px; }

/* Landscape phone */
@media (max-height: 500px) and (orientation: landscape) {
    .header { padding: 4px 10px; }
    .header h1 { font-size: 1rem; }
    .header p { display: none; }
    .scoreboard { padding: 4px; gap: 15px; }
    .team-score { padding: 6px 14px; min-width: 120px; }
    .score-value { font-size: 1.4rem; }
    .question-modal { max-height: 95vh; padding: 12px; }
}