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

body {
    background: #0a0c0f;
    background-image:
        repeating-linear-gradient(0deg, transparent, transparent 40px, #ffffff03 40px, #ffffff03 41px),
        repeating-linear-gradient(90deg, transparent, transparent 40px, #ffffff03 40px, #ffffff03 41px),
        radial-gradient(ellipse at 50% 0%, #1a2a1a 0%, transparent 60%);
    min-height: 100vh;
    font-family: 'Roboto Mono', monospace;
    color: #e0d5b0;
    padding: 16px 16px;
    overflow-x: hidden;
}

/* ── Header ── */
h1 {
    font-family: 'Exo 2', sans-serif;
    font-size: 1.6rem;
    text-align: center;
    color: #ffb300;
    text-shadow: 0 0 16px #ffb30088, 0 0 40px #ffb30044;
    margin-bottom: 4px;
    letter-spacing: 6px;
    text-transform: uppercase;
}

.subtitle {
    text-align: center;
    color: #ffb300bb;
    font-size: 0.85rem;
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-bottom: 14px;
    font-weight: 700;
}

.game-container {
    max-width: 520px;
    margin: 0 auto;
    text-align: center;
}

/* ── Level tabs ── */
.level-select {
    display: flex;
    gap: 0;
    justify-content: center;
    margin-bottom: 14px;
    border: 1px solid #ffb30044;
}

.level-btn {
    font-family: 'Exo 2', sans-serif;
    font-size: 0.7rem;
    padding: 10px 24px;
    border: none;
    border-right: 1px solid #ffb30044;
    background: transparent;
    color: #ffb30066;
    cursor: pointer;
    letter-spacing: 3px;
    text-transform: uppercase;
    transition: all 0.2s;
    flex: 1;
}

.level-btn:last-child { border-right: none; }
.level-btn:hover { background: #ffb30015; color: #ffb300; }
.level-btn.active {
    background: #ffb30022;
    color: #ffb300;
    text-shadow: 0 0 10px #ffb30088;
    box-shadow: inset 0 -2px 0 #ffb300;
}

/* ── Instrument display card ── */
.card-wrap { margin-bottom: 12px; }

.card {
    background: #050807;
    border: 1px solid #ffb30066;
    border-radius: 4px;
    padding: 28px 40px;
    font-family: 'Exo 2', sans-serif;
    font-size: 7rem;
    font-weight: 900;
    color: #ffb300;
    text-shadow: 0 0 20px #ffb300cc, 0 0 60px #ffb30066;
    box-shadow: 0 0 30px #ffb30011, inset 0 0 60px #000000aa;
    position: relative;
    overflow: hidden;
}

.card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: repeating-linear-gradient(0deg, transparent, transparent 2px, #00000022 2px, #00000022 4px);
    pointer-events: none;
}

.card::before {
    content: '';
    position: absolute;
    inset: 6px;
    border: 1px solid #ffb30022;
    border-radius: 2px;
    pointer-events: none;
}

.card.pop { animation: cardPop 0.25s ease; }

@keyframes cardPop {
    0%   { opacity: 0; transform: scale(0.9); }
    60%  { transform: scale(1.04); }
    100% { opacity: 1; transform: scale(1); }
}

.card.shake { animation: shake 0.4s ease; }

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%       { transform: translateX(-10px); }
    40%       { transform: translateX(10px); }
    60%       { transform: translateX(-8px); }
    80%       { transform: translateX(8px); }
}