:root {
    --bg-color: #f0f2f5;
    --panel-bg: rgba(255, 255, 255, 0.8);
    --text-color: #333333;
    --accent-color: #0051ff;
    --accent-glow: none;
    --border-color: rgba(0, 0, 0, 0.1);
    --font-main: 'Outfit', sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.app-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

header h1 {
    font-size: 3rem;
    font-weight: 700;
    letter-spacing: 0.2rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    color: #1a1a1a;
}

.highlight {
    color: var(--accent-color);
    text-shadow: none;
}

.game-wrapper {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.game-container {
    position: relative;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    background: #ffffff;
}

.game-board {
    display: block;
    background-color: #ffffff;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(5px);
    z-index: 10;
}

.overlay-content {
    text-align: center;
}

.overlay h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
    text-shadow: none;
}

.overlay p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.8;
    color: #555;
}

button {
    background: var(--accent-color);
    border: none;
    color: #fff;
    padding: 0.8rem 2rem;
    font-size: 1.2rem;
    font-family: var(--font-main);
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    border-radius: 4px;
    box-shadow: 0 4px 6px rgba(0, 81, 255, 0.2);
}

button:hover {
    background: #003bb3;
    box-shadow: 0 6px 8px rgba(0, 81, 255, 0.3);
    transform: translateY(-1px);
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    width: 200px;
}

.panel {
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.panel h3 {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
    letter-spacing: 1px;
}

.panel .value {
    font-size: 1.8rem;
    font-weight: 700;
    color: #333;
}

.next-piece-board {
    margin: 0 auto;
    display: block;
}

.controls-info {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: #666;
    background: var(--panel-bg);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.key-row {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
}

.key-row:last-child {
    margin-bottom: 0;
}

.key {
    background: #e0e0e0;
    padding: 2px 6px;
    border-radius: 4px;
    margin-right: 8px;
    font-weight: bold;
    color: #333;
    min-width: 24px;
    text-align: center;
    border: 1px solid #ccc;
}

.key.space {
    width: auto;
    padding: 2px 8px;
    font-size: 0.8em;
}