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

body {
    background-color: #121212;
    color: #ffffff;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    width: 100%;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

h1 {
    font-weight: 300;
    letter-spacing: 2px;
    margin-bottom: 1.5rem;
    color: #e0e0e0;
}

.btn {
    background-color: #333;
    color: white;
    border: none;
    padding: 12px 30px;
    font-size: 1rem;
    border-radius: 25px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #555;
}

.sounds-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
}

.sound-card {
    background: #1e1e1e;
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
}

.icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.sound-card h3 {
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 1rem;
    color: #aaa;
}

.volume-slider {
    width: 100%;
    cursor: pointer;
    accent-color: #4caf50;
}