/* Base Styles */
body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%); /* Lighter, vibrant gradient */
    color: #333;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start; /* Align top */
    min-height: 100vh;
}

.container {
    background-color: rgba(255, 255, 255, 0.9); /* Slightly less transparent white */
    padding: 30px 40px;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    max-width: 650px;
    width: 90%;
    text-align: center;
    margin-top: 30px; /* Add some space from the top */
}

header h1 {
    font-size: 2.2em;
    margin-bottom: 10px;
    font-weight: 700;
    color: #5a67d8; /* Vibrant blue/purple */
    text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
}

header p {
    font-size: 1.1em;
    margin-bottom: 30px;
    color: #555;
}

/* Form Styling */
#quiz-setup-form {
    text-align: left;
}

.form-section {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 25px;
    border: 1px solid #e9ecef;
}

.form-section h2 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 1.5em;
    color: #6c757d; /* Subdued heading color */
    border-bottom: 2px solid #dee2e6;
    padding-bottom: 10px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #495057;
}

.form-group input[type="number"] {
    width: calc(100% - 24px); /* Full width minus padding */
    padding: 10px 12px;
    border: 1px solid #ced4da;
    border-radius: 5px;
    font-size: 1em;
    transition: border-color 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

.form-group input[type="number"]:focus {
    border-color: #80bdff;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

/* Subject Selection Styling */
.subject-selection {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); /* Responsive grid */
    gap: 15px;
    margin-top: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    background-color: #fff;
    padding: 10px 15px;
    border-radius: 5px;
    border: 1px solid #e0e0e0;
    cursor: pointer;
    transition: background-color 0.2s ease, border-color 0.2s ease;
    position: relative; /* Needed for custom checkbox */
}

.checkbox-label:hover {
    background-color: #f1f3f5;
    border-color: #adb5bd;
}

.checkbox-label input[type="checkbox"] {
    opacity: 0; /* Hide original checkbox */
    position: absolute;
}

.checkbox-custom {
    display: inline-block;
    width: 18px;
    height: 18px;
    border: 2px solid #adb5bd;
    border-radius: 3px;
    margin-right: 10px;
    transition: background-color 0.2s ease, border-color 0.2s ease;
    flex-shrink: 0; /* Prevent shrinking */
}

.checkbox-label input[type="checkbox"]:checked + .checkbox-custom {
    background-color: #5a67d8; /* Match header color */
    border-color: #5a67d8;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%23fff' d='M6.564.75l-3.59 3.6-1.5-1.5L0 4.26 2.974 7.25 8 2.193z'/%3e%3c/svg%3e"); /* Simple checkmark */
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 50% 50%;
}

.checkbox-label input[type="checkbox"]:focus + .checkbox-custom {
     box-shadow: 0 0 0 0.2rem rgba(90, 103, 216, 0.25); /* Focus indicator */
}


/* Error Message Styling */
.error-message {
    color: #dc3545; /* Standard Bootstrap error color */
    font-size: 0.85em;
    display: block; /* Makes it appear below */
    margin-top: 5px;
    min-height: 1.2em; /* Reserve space to prevent layout shifts */
}

/* Input with error */
input.input-error {
    border-color: #dc3545;
}
input.input-error:focus {
     box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.25);
}
.subject-selection.input-error { /* Add border to the container */
     border: 1px solid #dc3545;
     border-radius: 5px; /* Match other inputs */
     padding: 5px; /* Add slight padding to make border visible */
}


/* Action Buttons */
.form-actions {
    display: flex;
    justify-content: space-between; /* Pushes buttons apart */
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #e9ecef;
}

.button {
    padding: 12px 25px;
    border: none;
    border-radius: 25px; /* Pill shape */
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    text-decoration: none; /* For back button if it were an <a> */
    display: inline-flex; /* Align icons/text if needed */
    align-items: center;
    justify-content: center;
}

.primary-button {
    background: linear-gradient(45deg, #667eea, #764ba2); /* Primary action gradient */
    color: white;
}

.primary-button:hover {
    background: linear-gradient(45deg, #5a6fd5, #673f93); /* Darker shade */
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.15);
}

.secondary-button {
    background-color: #6c757d; /* Grey for secondary actions */
    color: white;
}

.secondary-button:hover {
    background-color: #5a6268;
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .container {
        padding: 25px 20px;
    }
    header h1 {
        font-size: 1.8em;
    }
    .subject-selection {
        grid-template-columns: 1fr; /* Stack checkboxes on smaller screens */
    }
    .form-actions {
        flex-direction: column-reverse; /* Stack buttons, Start on top */
        gap: 15px; /* Add space between stacked buttons */
        align-items: center; /* Center stack */
    }
    .button {
        width: 80%; /* Make buttons wider when stacked */
    }
}