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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 10px;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

.subtitle {
    font-size: 1.2rem;
    color: #7f8c8d;
    margin-bottom: 30px;
}

.controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

#numberInput {
    padding: 12px 16px;
    font-size: 1.1rem;
    border: 2px solid #bdc3c7;
    border-radius: 8px;
    width: 200px;
    text-align: center;
    transition: all 0.3s ease;
    background: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#numberInput:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
    transform: translateY(-2px);
}

.show-btn {
    background: linear-gradient(135deg, #27ae60, #2ecc71);
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 1.1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    box-shadow: 0 4px 8px rgba(39, 174, 96, 0.3);
}

.show-btn:hover {
    background: linear-gradient(135deg, #229954, #27ae60);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(39, 174, 96, 0.4);
}

.show-btn:active {
    transform: translateY(0);
}

.reset-btn {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 1.1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    box-shadow: 0 4px 8px rgba(231, 76, 60, 0.3);
}

.reset-btn:hover {
    background: linear-gradient(135deg, #c0392b, #a93226);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(231, 76, 60, 0.4);
}

.reset-btn:active {
    transform: translateY(0);
}

.circles-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px; /* Vertikaler Abstand zwischen den Zeilen */
    margin-top: 20px;
}

.row {
    display: flex;
    justify-content: center;
    gap: 40px; /* Abstand zwischen den zwei Zehnerblöcken einer Zeile */
    align-items: flex-start;
}

.ten-block {
    display: flex;
    gap: 12px; /* Abstand zwischen Zweierblöcken = ein Kreisdurchmesser (60%) */
    align-items: flex-start;
}

.two-block {
    display: flex;
    flex-direction: column;
    gap: 12px; /* Abstand zwischen den zwei Kreisen = ein Kreisdurchmesser (60%) */
    align-items: center;
}

.circle {
    width: 20px;
    height: 20px;
    border: 2px solid #34495e;
    border-radius: 50%;
    background-color: transparent;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
}

.circle:hover {
    transform: scale(1.1);
    border-color: #3498db;
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.5);
}

.circle.filled {
    background-color: #3498db;
    border-color: #2980b9;
    box-shadow: 0 0 8px rgba(52, 152, 219, 0.6);
    animation: fillAnimation 0.3s ease;
}

@keyframes fillAnimation {
    0% {
        transform: scale(1);
        background-color: transparent;
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
        background-color: #3498db;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .controls {
        flex-direction: column;
        gap: 10px;
    }
    
    #numberInput {
        width: 250px;
    }
    
    .row {
        gap: 20px; /* Reduzierter Abstand auf kleineren Bildschirmen */
    }
    
    .ten-block {
        gap: 15px;
    }
    
    .two-block {
        gap: 15px;
    }
    
    .circle {
        width: 18px;
        height: 18px;
    }
    
    .circles-container {
        gap: 20px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    .row {
        gap: 15px;
        flex-wrap: wrap;
    }
    
    .ten-block {
        gap: 12px;
    }
    
    .two-block {
        gap: 12px;
    }
    
    .circle {
        width: 16px;
        height: 16px;
    }
    
    .circles-container {
        gap: 15px;
    }
}

/* Zusätzliche Animationen für bessere UX */
.container {
    animation: fadeIn 0.8s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.controls > * {
    animation: slideIn 0.6s ease forwards;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Fokus-Indikatoren für Barrierefreiheit */
button:focus,
input:focus {
    outline: 3px solid #3498db;
    outline-offset: 2px;
}

/* Hover-Effekte für bessere Interaktivität */
.circle:not(.filled):hover::after {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    border: 2px solid #3498db;
    border-radius: 50%;
    opacity: 0.5;
}