body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
}

.exam-info {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    text-align: center;
}

    .exam-info i {
        font-size: 1.2rem;
        margin-right: 0.5rem;
    }

    .exam-info p {
        margin: 0;
        font-size: 0.95rem;
    }

/* Thêm style cho tooltip */
.error-icon {
    color: var(--accent-color);
    cursor: help;
    margin-right: 5px;
    position: relative;
}

    .error-icon::after {
        content: attr(data-tooltip);
        position: absolute;
        bottom: 100%;
        left: 50%;
        transform: translateX(-50%);
        padding: 5px 10px;
        background-color: var(--accent-color);
        color: white;
        border-radius: 4px;
        font-size: 0.8rem;
        white-space: nowrap;
        visibility: hidden;
        opacity: 0;
        transition: opacity 0.3s, visibility 0.3s;
        z-index: 1000;
        width: max-content;
        max-width: 200px;
        box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    }

    .error-icon::before {
        content: '';
        position: absolute;
        bottom: 100%;
        left: 50%;
        transform: translateX(-50%);
        border-width: 5px;
        border-style: solid;
        border-color: var(--accent-color) transparent transparent transparent;
        visibility: hidden;
        opacity: 0;
        transition: opacity 0.3s, visibility 0.3s;
        z-index: 1000;
    }

    .error-icon:hover::after,
    .error-icon:hover::before {
        visibility: visible;
        opacity: 1;
    }

/* Đảm bảo invalid-feedback hiển thị đúng */
.invalid-feedback {
    display: none;
    width: 100%;
    margin-top: 0.25rem;
    font-size: 0.875em;
    color: var(--accent-color);
    min-height: 20px;
}

.form-group {
    margin-bottom: 1rem;
}

.form-control.is-invalid ~ .invalid-feedback {
    display: block !important;
}

.form-control.is-valid ~ .invalid-feedback {
    display: none !important;
}

.error-message {
    display: inline-block;
    margin-left: 5px;
}

.error-icon {
    display: inline-block;
    margin-right: 5px;
    color: var(--accent-color);
}

    /* Xóa các style tooltip cũ */
    .error-icon::after,
    .error-icon::before {
        display: none;
    }