:root {
    --bg: #050010;
    --bg-accent: #0a0222;
    --cyan: #00f7ff;
    --cyan-soft: rgba(0, 247, 255, 0.35);
    --pink: #ff4df7;
    --green: #45ff7c;
    --danger: #ff4e64;
    --text: #f3fbff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
}

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: radial-gradient(circle at 30% 20%, #130537 0, var(--bg) 55%, #020007 100%);
    color: var(--text);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    touch-action: none;
}

canvas {
    display: block;
    width: 100vw;
    height: 100vh;
    box-shadow: inset 0 0 120px rgba(0, 0, 0, 0.85);
}

.scanlines {
    position: fixed;
    inset: 0;
    pointer-events: none;
    background:
        linear-gradient(to bottom, rgba(255, 255, 255, 0) 50%, rgba(0, 247, 255, 0.05) 50%) 0 0/100% 4px,
        radial-gradient(circle at center, rgba(255, 255, 255, 0.05), transparent 70%);
    mix-blend-mode: overlay;
    z-index: 5;
}

.top-controls {
    position: fixed;
    top: max(10px, env(safe-area-inset-top));
    right: max(10px, env(safe-area-inset-right));
    display: flex;
    gap: 8px;
    z-index: 40;
}

.small-btn,
.btn {
    border: 2px solid var(--cyan);
    color: var(--cyan);
    background: rgba(0, 0, 0, 0.35);
    text-shadow: 0 0 6px var(--cyan);
    box-shadow: 0 0 10px var(--cyan-soft), inset 0 0 10px rgba(0, 247, 255, 0.18);
    cursor: pointer;
    transition: transform 120ms ease, filter 120ms ease, background-color 120ms ease;
}

.small-btn {
    padding: 8px 10px;
    font-size: clamp(12px, 2.2vw, 15px);
    min-height: 38px;
}

.small-btn:hover,
.btn:hover {
    filter: brightness(1.18);
}

.small-btn:active,
.btn:active {
    transform: scale(0.97);
}

.small-btn.danger {
    border-color: var(--danger);
    color: var(--danger);
    text-shadow: 0 0 6px var(--danger);
    box-shadow: 0 0 10px rgba(255, 78, 100, 0.3), inset 0 0 10px rgba(255, 78, 100, 0.15);
}

.ui-layer {
    position: fixed;
    inset: 0;
    z-index: 30;
    display: grid;
    place-items: center;
    padding: max(12px, env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) max(12px, env(safe-area-inset-bottom)) max(12px, env(safe-area-inset-left));
}

.panel {
    width: min(760px, 95vw);
    background: linear-gradient(170deg, rgba(8, 5, 30, 0.85), rgba(2, 2, 12, 0.8));
    border: 2px solid var(--cyan);
    border-radius: 14px;
    padding: clamp(16px, 3vw, 30px);
    box-shadow: 0 0 30px rgba(0, 247, 255, 0.28);
    text-align: center;
}

.hidden {
    display: none !important;
}

.title {
    font-size: clamp(2rem, 8vw, 4.3rem);
    letter-spacing: clamp(2px, 1vw, 6px);
    text-shadow: 0 0 10px var(--cyan), 0 0 20px var(--cyan), 0 0 40px var(--cyan);
    margin-bottom: 0.4em;
}

.title-sm {
    font-size: clamp(1.6rem, 6vw, 3rem);
    letter-spacing: 2px;
    text-shadow: 0 0 10px var(--cyan);
    margin-bottom: 0.4em;
}

.subtitle {
    font-size: clamp(1rem, 2.8vw, 1.35rem);
    color: #d9ebff;
    line-height: 1.45;
    margin-bottom: 0.85em;
}

.hint {
    margin-bottom: 0.9em;
    color: #9ee6ff;
    font-size: clamp(0.95rem, 2.5vw, 1.1rem);
}

.difficulty-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(120px, 1fr));
    gap: 12px;
}

.btn {
    min-height: 54px;
    padding: 12px;
    font-size: clamp(1rem, 3.2vw, 1.25rem);
    font-weight: 700;
    text-transform: uppercase;
}

.btn.secondary {
    border-color: #99bdff;
    color: #99bdff;
    box-shadow: 0 0 10px rgba(153, 189, 255, 0.25), inset 0 0 10px rgba(153, 189, 255, 0.14);
    text-shadow: 0 0 6px #99bdff;
}

.hud {
    position: fixed;
    left: max(10px, env(safe-area-inset-left));
    top: max(10px, env(safe-area-inset-top));
    z-index: 35;
    display: grid;
    gap: 6px;
    font-size: clamp(0.9rem, 2.7vw, 1.1rem);
    text-shadow: 0 0 8px var(--cyan);
}

.hud > div {
    padding: 4px 8px;
    border: 1px solid rgba(0, 247, 255, 0.4);
    background: rgba(0, 12, 25, 0.45);
    border-radius: 8px;
    min-width: min(280px, 78vw);
}

@media (max-width: 640px) {
    .top-controls {
        gap: 6px;
    }

    .small-btn {
        padding: 8px;
        min-width: 68px;
        font-size: 12px;
    }

    .difficulty-grid {
        grid-template-columns: 1fr;
    }

    .hud > div {
        min-width: min(230px, 84vw);
    }
}