:root {
    --bg-dark: #05070a;
    --accent-cyan: #00f2ff;
    --accent-purple: #7000ff;
    --glass-bg: rgba(15, 23, 42, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background: var(--bg-dark);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
    width: 100vw;
}

#game-container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

canvas {
    display: block;
    background: radial-gradient(circle at center, #111827 0%, #05070a 100%);
}

.hud {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.hud-panel {
    pointer-events: auto;
    padding: 1.5rem;
    width: fit-content;
}

#stats-panel {
    display: flex;
    gap: 2rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-item .label {
    font-size: 0.7rem;
    letter-spacing: 0.1rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.stat-item .value {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-cyan);
    text-shadow: 0 0 10px rgba(0, 242, 255, 0.5);
}

#controls-panel {
    align-self: flex-end;
    min-width: 250px;
}

.control-group {
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

input[type="range"] {
    appearance: none;
    width: 100%;
    height: 4px;
    background: var(--glass-border);
    border-radius: 2px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--accent-cyan);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 10px var(--accent-cyan);
}

#gravity-display {
    font-weight: 600;
    color: var(--accent-cyan);
}

.hints p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 0.4rem;
}

.hints span {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    margin-right: 0.3rem;
    font-weight: 400;
}

#overlay {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
}

#overlay.hidden {
    display: none;
}

.content {
    text-align: center;
    padding: 3rem;
}

h1 {
    font-size: 4rem;
    font-weight: 600;
    letter-spacing: 0.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(to right, var(--accent-cyan), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

button {
    margin-top: 2rem;
    padding: 1rem 2.5rem;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.2rem;
    background: transparent;
    color: var(--accent-cyan);
    border: 1px solid var(--accent-cyan);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

button:hover {
    background: var(--accent-cyan);
    color: var(--bg-dark);
    box-shadow: 0 0 20px rgba(0, 242, 255, 0.6);
}