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

body {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.tab-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.tab-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 12px 24px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.tab-btn.active {
    background: #3498db;
    border-color: #3498db;
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

.tab-content {
    display: none;
    padding: 30px;
}

.tab-content.active {
    display: block;
}

/* Calculadora Científica */
.calculator {
    max-width: 500px;
    margin: 0 auto;
    background: #2c3e50;
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.display {
    background: #34495e;
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 20px;
    text-align: right;
    color: white;
    min-height: 80px;
}

.previous-operand {
    font-size: 1.2rem;
    color: #bdc3c7;
    margin-bottom: 5px;
    min-height: 25px;
}

.current-operand {
    font-size: 2.5rem;
    font-weight: 700;
    color: #ecf0f1;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.btn {
    padding: 20px;
    border: none;
    border-radius: 15px;
    font-size: 1.2rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    color: white;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.btn.number {
    background: #34495e;
}

.btn.number:hover {
    background: #4a6b8a;
}

.btn.operator {
    background: #e74c3c;
}

.btn.operator:hover {
    background: #c0392b;
}

.btn.function {
    background: #f39c12;
}

.btn.function:hover {
    background: #e67e22;
}

.btn.equals {
    background: #27ae60;
    grid-row: span 2;
}

.btn.equals:hover {
    background: #229954;
}

.btn.zero {
    grid-column: span 2;
}

/* Calculadora de Datas */
.date-calculator {
    max-width: 800px;
    margin: 0 auto;
}

.date-section {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 15px;
    margin-bottom: 25px;
    border: 1px solid #e9ecef;
}

.date-section h3 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #495057;
}

.input-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.input-group input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.calculate-btn {
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-right: 10px;
    margin-bottom: 10px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

.operation-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.result {
    margin-top: 20px;
    padding: 15px;
    background: #d4edda;
    border: 1px solid #c3e6cb;
    border-radius: 10px;
    color: #155724;
    font-weight: 500;
    display: none;
}

.result.show {
    display: block;
}

/* Calculadora Proporcional */
.proportional-calculator {
    max-width: 800px;
    margin: 0 auto;
}

.calculation-section {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 15px;
    margin-bottom: 25px;
    border: 1px solid #e9ecef;
}

.calculation-section h3 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.history-section {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 15px;
    border: 1px solid #e9ecef;
}

.history-section h3 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.history-list {
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: 20px;
}

.history-item {
    background: white;
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 10px;
    border-left: 4px solid #3498db;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.history-item .calculation {
    font-weight: 500;
    color: #2c3e50;
    margin-bottom: 5px;
}

.history-item .result {
    color: #27ae60;
    font-weight: 600;
}

.history-item .timestamp {
    font-size: 0.8rem;
    color: #6c757d;
    margin-top: 5px;
}

.clear-history-btn {
    background: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.clear-history-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(231, 76, 60, 0.4);
}

/* Responsividade */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 15px;
    }
    
    header {
        padding: 20px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .tab-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .tab-btn {
        width: 200px;
    }
    
    .tab-content {
        padding: 20px;
    }
    
    .calculator {
        padding: 15px;
    }
    
    .buttons {
        gap: 8px;
    }
    
    .btn {
        padding: 15px;
        font-size: 1rem;
    }
    
    .date-calculator,
    .proportional-calculator {
        max-width: 100%;
    }
    
    .operation-buttons {
        flex-direction: column;
    }
    
    .calculate-btn {
        width: 100%;
        margin-right: 0;
    }
}

@media (max-width: 480px) {
    .btn {
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .display {
        padding: 15px;
    }
    
    .current-operand {
        font-size: 2rem;
    }
}