* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

body {
    background: #0f172a;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px;
}

/* Container principal – cartão escuro */
.Calculadora {
    background: #1e293b;
    border-radius: 32px;
    padding: 28px 24px 32px;
    box-shadow: 0 20px 35px -10px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.05);
    width: 100%;
    max-width: 480px;
    transition: box-shadow 0.2s;
}

/* Tela – estilo escuro com contraste */
.tela {
    width: 100%;
    background: #0f172a;
    border: 1px solid #334155;
    padding: 24px 20px;
    font-size: 2.4rem;
    font-weight: 500;
    text-align: right;
    color: #f1f5f9;
    border-radius: 24px;
    margin-bottom: 28px;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    letter-spacing: 1px;
    outline: none;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
    transition: all 0.2s;
}

.tela:focus {
    border-color: #3b82f6;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3), 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* Grade de botões */
.botoes {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

/* Botões base */
button {
    background: #0f172a;
    border: 1px solid #334155;
    padding: 16px 0;
    font-size: 1.4rem;
    font-weight: 500;
    border-radius: 20px;
    color: #e2e8f0;
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

button:active {
    transform: scale(0.97);
    background: #1e293b;
    border-color: #475569;
}

/* Botões especiais (C, ⌫, %) */
.especial {
    background: #1e293b;
    color: #f1f5f9;
    border-color: #475569;
    font-weight: 600;
}

/* Botões de operadores (+, -, *, /, .) */
.operador {
    background: #1e293b;
    color: #60a5fa;
    font-weight: 600;
    border-color: #475569;
}

/* Botões numéricos (classe .botao) */
.botao {
    background: #0f172a;
    font-weight: 500;
}

/* Botão de igual */
.botao[value="="] {
    background: #3b82f6;
    color: white;
    border: none;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
}

.botao[value="="]:active {
    background: #2563eb;
    transform: scale(0.97);
}

/* Hover suave */
button:hover {
    background: #1e293b;
    border-color: #5b6e8c;
}

.especial:hover {
    background: #2d3a4e;
}

.operador:hover {
    background: #2d3a4e;
    border-color: #60a5fa;
}

/* Responsividade */
@media (max-width: 500px) {
    .Calculadora {
        padding: 20px 16px;
    }
    .tela {
        padding: 20px 16px;
        font-size: 2rem;
    }
    button {
        padding: 14px 0;
        font-size: 1.2rem;
    }
}

@media (max-width: 380px) {
    .botoes {
        gap: 8px;
    }
    button {
        padding: 12px 0;
        font-size: 1rem;
    }
}