body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #eef2f7;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 20px auto;
    padding: 30px;
    border: 1px solid #dcdcdc;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.1);
    background-color: #ffffff;
}

h1 {
    text-align: center;
    color: #013220;
    margin-bottom: 30px;
    font-size: 2.2em;
    border-bottom: 2px solid #013220;
    padding-bottom: 15px;
}

h2 {
    color: #013220;
    margin-top: 30px;
    margin-bottom: 20px;
    font-size: 1.6em;
}

h3 {
    color: #013220;
    margin-top: 20px;
    margin-bottom: 15px;
    font-size: 1.3em;
}

hr {
    border: none;
    border-top: 1px solid #e0e0e0;
    margin: 30px 0;
}

.input-group {
    margin-bottom: 18px;
    display: flex;
    flex-direction: column;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #555;
    font-size: 0.95em;
}

.input-group input[type="number"],
.input-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #c0c0c0;
    border-radius: 8px;
    box-sizing: border-box;
    font-size: 1em;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.input-group input[type="number"]:focus,
.input-group select:focus {
    border-color: #007bff;
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}

.nmt-inputs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.coefficients-display {
    background-color: #f0e6c2;
    border: 1px solid #e0e7ff;
    border-radius: 8px;
    padding: 15px 20px;
    margin-top: 20px;
    margin-bottom: 30px;
}

.coefficients-display p {
    margin: 8px 0;
    font-size: 0.95em;
    color: #013220;
}

.coefficients-display span {
    font-weight: bold;
    color: #cc0033;
}

button {
    display: block;
    width: 100%;
    padding: 15px 25px;
    background-color: #013220; /* Success color */
    color: #F0E6C2;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.2em;
    font-weight: bold;
    transition: background-color 0.3s ease, transform 0.1s ease, box-shadow 0.3s ease;
    margin-top: 30px;
}

button:hover {
    background-color: #F0E6C2;
    color: #013220;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.result-section {
    margin-top: 35px;
    padding: 25px;
    border: 1px solid #013220;
    border-radius: 10px;
    background-color: #F0E6C2;
    text-align: center;
}

.result-section p {
    margin: 10px 0;
    font-size: 1.1em;
}

#finalScore {
    font-size: 2.5em;
    font-weight: bold;
    color: #013220;
    display: block;
    margin-top: 10px;
}

.message {
    padding: 12px 18px;
    border-radius: 8px;
    margin-top: 15px;
    font-size: 0.95em;
    text-align: left;
}

.error {
    background-color: #ffe0e6;
    color: #cc0033;
    border: 1px solid #ffb3c1;
}

.info {
    background-color: #e6f7ff;
    color: #0056b3;
    border: 1px solid #b3d9ff;
}

.note {
    font-size: 0.85em;
    color: #777;
    margin-top: 5px;
}