/* Base Layout */
body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: linear-gradient(to right, #eef2f3, #dfe9e3);
    margin: 0;
    padding: 0;
    color: #1f2d3d;
}

/* Center Container */
.calculator {
    max-width: 500px;
    margin: 60px auto;
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

/* Heading */
h1 {
    text-align: center;
    margin-top: 40px;
    font-weight: 600;
    color: #1b4332;
}

p {
    text-align: center;
    color: #4f4f4f;
}

/* Labels */
.calculator label {
    display: block;
    margin-top: 18px;
    font-weight: 500;
    font-size: 14px;
    color: #344e41;
}

/* Inputs */
input, select {
    width: 100%;
    padding: 10px;
    margin-top: 6px;
    border-radius: 6px;
    border: 1px solid #cfd8dc;
    font-size: 14px;
    transition: border 0.3s ease;
}

input:focus, select:focus {
    border-color: #2d6a4f;
    outline: none;
}

/* Button */
button {
    margin-top: 25px;
    width: 100%;
    padding: 12px;
    background-color: #2d6a4f;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.1s ease;
}

button:hover {
    background-color: #1b4332;
}

button:active {
    transform: scale(0.98);
}

/* Result Box */
#result {
    margin-top: 25px;
    padding: 15px;
    background-color: #f1f8f5;
    border-left: 4px solid #2d6a4f;
    border-radius: 6px;
    font-size: 14px;
    line-height: 1.6;
}