* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 30px;
    width: 100%;
    max-width: 600px;
}

h1 {
    color: #1a73e8;
    text-align: center;
    margin-bottom: 30px;
    font-size: 2.2rem;
}

.calculator {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.input-group {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.input-field {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-weight: 500;
    color: #5f6368;
}

input[type="date"] {
    padding: 12px;
    border: 1px solid #dadce0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

input[type="date"]:focus {
    outline: none;
    border-color: #1a73e8;
    box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.2);
}

.button-group {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
}

.calculate-btn {
    background: #1a73e8;
    color: white;
}

.calculate-btn:hover {
    background: #1557b0;
}

.reset-btn {
    background: #f0f2f5;
    color: #5f6368;
}

.reset-btn:hover {
    background: #e3e5e8;
}

.result {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 15px;
}

.result-item {
    text-align: center;
    padding: 10px;
}

.result-item span:first-child {
    display: block;
    color: #5f6368;
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.result-item span:last-child {
    display: block;
    font-size: 1.4rem;
    font-weight: 600;
    color: #1a1a1a;
}

@media (min-width: 480px) {
    .input-group {
        grid-template-columns: 1fr 1fr;
    }
}