/* 기본 리셋 */
.row,
.row *,
.student-dropdown,
.student-dropdown * {
    box-sizing: border-box;
}

/* 행 레이아웃 */
.classroom-area {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

/* 컬럼 레이아웃 */
.col-md-6 {
    flex: 0 0 50%;
    max-width: 50%;
    padding: 0 15px;
}

.mb-3 {
    margin-bottom: 1rem;
}

.ps-0 {
    padding-left: 0 !important;
}

/* 폼 요소 스타일 */
.form-select {
    width: 100%;
    padding: 0.375rem 2.25rem 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #212529;
    background-color: #fff;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 16px 12px;
    border: 1px solid #dee2e6;
    border-radius: 0.375rem;
    appearance: none;
    cursor: pointer;
}

.form-select:hover {
    border-color: #86b7fe;
}

.form-select:focus {
    border-color: #86b7fe;
    outline: 0;
    box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
}

/* 드롭다운 스타일 */
.student-dropdown {
    position: relative;
    width: 100%;
    display: inline-block;
}

.student-dropdown .selChild {
    display: inline-block;
    max-width: 220px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.classroom-select-button, .student-select-button, .ai-letter__manage-btn ,.ai-letter__manage-btn {height:38px; padding-top:0; padding-bottom:0}
.classroom-select-button, .student-select-button{min-width: 160px;}
.student-select-button {
    width: 100%;

    text-align: left;
    background: white;
    border: 1px solid #dee2e6;
    padding: 0.375rem 0.75rem;
    border-radius: 0.375rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1rem;
    line-height: 1.5;
    color: #212529;
}

.student-select-button i {
    color: #6c757d;
    font-size: 0.75rem;
}

.student-select-button:hover:not(.disabled) {
    border-color: #86b7fe;
}

.student-select-button:focus {
    border-color: #86b7fe;
    outline: 0;
    box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
}

.student-select-button.disabled {
    background-color: #e9ecef;
    cursor: not-allowed;
    opacity: 0.65;
}

.student-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 1px solid #dee2e6;
    border-radius: 0.375rem;
    margin-top: 0.25rem;
    max-height: 300px;
    overflow-y: auto;
    z-index: 1000;
    display: none;
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

.student-dropdown-menu.show {
    display: block;
}

.student-option {
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
}

.student-option:hover {
    background-color: #f8f9fa;
}

.student-option.select-all:hover {
    background-color: #e9ecef;
}

.student-option label {
    cursor: pointer;
    margin: 0;
    flex: 1;
}

.student-option input[type="checkbox"] {
    cursor: pointer;
    margin-left: 0.5rem;
}

.student-option .student-name {
    cursor: pointer;
    margin: 0;
    flex: 1;
}

.dropdown-arrow {
    transition: transform 0.2s;
    font-size: 0.6rem;
    color: #6c757d;
}

.dropdown-arrow.rotate {
    transform: rotate(180deg);
}

.loading-text {
    padding: 0.5rem 0.75rem;
    text-align: center;
    color: #6c757d;
}

.creat-btn-box .btn-blue{background: #c0dff8}
.creat-btn-box .btn-blue:hover{background: #a8d0f0}
.creat-btn-box .btn-yellow{background: #f9e48f}
.creat-btn-box .btn-yellow:hover{background: #f7d96b}
.creat-btn-box .btn-gray{background: #eeeeee}
.creat-btn-box .btn-gray:hover{background: #dddddd}

/* 오버레이 배경 */
.usage-guide-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    z-index: 9998;
}

/* 래퍼 */
.usage-guide-wrapper {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 95vw;
    height: 95vh;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 컨텐츠 (이미지 컨테이너) */
.usage-guide-content {
    position: relative;
    max-width: 100%;
    max-height: 100%;
}

.usage-guide-content img {
    max-width: 100%;
    max-height: 95vh;
    object-fit: contain;
    display: block;
}

/* 닫기 버튼 */
.usage-guide-close {
    position: absolute;
    top: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    border: none;
    color: white;
    font-size: 40px;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 50px;
    height: 45px;
    z-index: 10001;
}

.usage-guide-close:hover {
    background: rgba(0, 0, 0, 0.9);
    color: #fff;
}