/* Reset i podstawy */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

body {
    background: #eaeaea;
    color: #222;
    line-height: 1.6;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background: white;
    padding: 30px;
    border: 3px solid #bbb;
    box-shadow: 4px 4px 0 #888;
    text-align: center;
    max-width: 400px;
}

/* Nagłówek */
h1 {
    font-size: 1.8rem;
    color: #2c3e50;
    border-bottom: 3px solid #2c3e50;
    padding-bottom: 5px;
    margin-bottom: 20px;
}

/* Pole PIN */
input[type="password"] {
    width: 100%;
    padding: 12px;
    font-size: 1.2rem;
    text-align: center;
    border: 3px solid #222;
    background: #fff;
    border-radius: 0;
    margin-bottom: 15px;
}

/* Klawiatura */
.keyboard {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin-top: 10px;
}

.keyboard button {
    padding: 15px;
    font-size: 1.2rem;
    font-weight: 600;
    border: 3px solid #222;
    background: #3498db;
    color: white;
    cursor: pointer;
    border-radius: 0;
    transition: background 0.2s;
}

.keyboard button:hover {
    background: #2980b9;
}

.keyboard button:last-child {
    grid-column: span 3;
    background: #27ae60;
}

.keyboard button:last-child:hover {
    background: #1e874a;
}

/* Przycisk kasowania */
.keyboard button:nth-last-child(2) {
    background: #c0392b;
}

.keyboard button:nth-last-child(2):hover {
    background: #962d22;
}