:root {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --target-color: #ef4444;
    --hud-bg: rgba(15, 23, 42, 0.8);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    overflow: hidden;
    user-select: none;
}

#app {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.screen {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 10;
}

.screen.active {
    display: flex;
}

h1 {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

h2 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

p {
    font-size: 1.25rem;
    color: #cbd5e1;
    margin-bottom: 2rem;
}

.primary-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.25rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    font-family: inherit;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

.primary-btn:active {
    transform: scale(0.95);
}

#game-screen {
    background-color: #1e293b;
    z-index: 5;
}

#hud {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    background: var(--hud-bg);
    backdrop-filter: blur(4px);
    z-index: 20;
    font-size: 1.25rem;
    font-weight: 600;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

#game-area {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
    cursor: crosshair;
}

.target {
    position: absolute;
    border-radius: 50%;
    background-color: var(--target-color);
    transform: translate(-50%, -50%);
    box-shadow: 0 0 20px rgba(239, 68, 68, 0.6), inset 0 0 10px rgba(255, 255, 255, 0.3);
    pointer-events: auto;
    transition: transform 0.1s;
}

.target:active {
    transform: translate(-50%, -50%) scale(0.9);
}

.score-popup {
    position: absolute;
    color: #4ade80;
    font-weight: bold;
    font-size: 1.5rem;
    pointer-events: none;
    animation: popup 0.6s ease-out forwards;
    z-index: 15;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

.penalty-popup {
    position: absolute;
    color: #f87171;
    font-weight: bold;
    font-size: 1.25rem;
    pointer-events: none;
    animation: popup 0.6s ease-out forwards;
    z-index: 15;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

@keyframes popup {
    0% {
        opacity: 1;
        transform: translate(-50%, -50%) scale(0.5);
    }
    50% {
        transform: translate(-50%, -100%) scale(1.2);
    }
    100% {
        opacity: 0;
        transform: translate(-50%, -150%) scale(1);
    }
}