/* style.css - Full Professional Design */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f6f9;
    margin: 0;
    padding: 0;
    text-align: center;
    color: #333;
}

/* Navigation Bar */
nav {
    background-color: #2c3e50;
    padding: 15px 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
nav a {
    color: white;
    text-decoration: none;
    margin: 0 15px;
    font-weight: 600;
    font-size: 16px;
    text-transform: uppercase;
}
nav a:hover { color: #f1c40f; border-bottom: 2px solid #f1c40f; }

/* Header Area */
header {
    background-color: #ecf0f1;
    padding: 30px 20px;
    border-bottom: 1px solid #bdc3c7;
    margin-bottom: 20px;
}
header h1 { margin: 0; color: #2c3e50; font-size: 28px; }
header p { margin: 10px 0 0; color: #7f8c8d; font-size: 16px; }

/* Ad Box Styles (Banner Placeholder) */
.ad-box {
    width: 100%;
    max-width: 728px;
    min-height: 90px;
    background-color: #dfe6e9; /* Light grey placeholder */
    border: 1px dashed #95a5a6;
    margin: 20px auto;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #7f8c8d;
    font-size: 14px;
}

/* Calculator Container */
.container {
    max-width: 500px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Main Card */
.calculator-card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    margin-bottom: 40px;
    border-top: 5px solid #27ae60; /* Green Top Border */
}

/* Input Fields */
.input-group { margin-bottom: 20px; text-align: left; }
label { display: block; margin-bottom: 8px; font-weight: bold; color: #34495e; }

input, select {
    width: 100%;
    padding: 12px;
    border: 1px solid #bdc3c7;
    border-radius: 6px;
    font-size: 16px;
    box-sizing: border-box; /* Fix padding issue */
    background-color: #fff;
}
input:focus, select:focus {
    border-color: #27ae60;
    outline: none;
}

/* Button */
button {
    width: 100%;
    padding: 15px;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 18px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s;
}
button:hover { background-color: #219150; }

/* Result Box */
.result-box {
    margin-top: 25px;
    padding: 20px;
    background-color: #e8f8f5;
    border: 2px dashed #2ecc71;
    border-radius: 8px;
    display: none; /* Hidden by default */
}
.result-text { font-size: 26px; color: #27ae60; font-weight: bold; display: block; }
.monthly-text { font-size: 18px; color: #2c3e50; margin-top: 10px; display: block; }

/* Footer */
footer {
    background-color: #2c3e50;
    color: #bdc3c7;
    padding: 20px;
    margin-top: 50px;
    font-size: 14px;
}