/* ==================== 페이지 헤더 스타일 ==================== */
.page-header {
    text-align: center;
    padding: 10px 15px 20px;
    margin-bottom: 25px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.03);
}

.page-header h1 {
    color: #005792;
    font-size: 2.2em;
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}

.page-header h1::after {
    content: "";
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 2px;
    background-color: #4facfe;
}

.page-header p {
    color: #555;
    font-size: 1em;
    max-width: 600px;
    margin: 15px auto 0;
}

/* ==================== 프로젝트 섹션 스타일 ==================== */
.project-section {
    margin-bottom: 20px;
    padding: 16px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.04);
    position: relative;
    overflow: hidden;
}

.project-section::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, #4facfe, #00c6ff);
    border-radius: 8px 8px 0 0;
}

/* CLS 방지 */
.project-list { min-height: 80px; }

.section-title {
    color: #0f2044;
    font-size: 1.1em;
    font-weight: 700;
    margin-bottom: 16px;
    padding: 5px 12px 5px 14px;
    border-left: 3px solid #4facfe;
    background: linear-gradient(90deg, rgba(79, 172, 254, 0.07), transparent);
    border-radius: 0 5px 5px 0;
    border-bottom: none;
    display: flex;
    align-items: center;
}

.section-title i {
    color: #4facfe;
    margin-right: 8px;
}

/* ==================== 프로젝트 리스트 ==================== */
.project-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.project-item {
    display: flex;
    padding: 12px 14px;
    background-color: #f8f9fa;
    border-radius: var(--card-radius, 8px);
    transition: var(--card-transition, all 0.3s ease);
    box-shadow: 0 1px 4px rgba(0,0,0,0.03);
    position: relative;
    overflow: hidden;
    border-left: 2px solid var(--color-accent, #4facfe);
}

.project-item:hover {
    background-color: #f0f7ff;
    box-shadow: 0 3px 8px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

.project-item.past-item {
    padding: 15px;
    background-color: #f8f9fa;
    box-shadow: 0 1px 4px rgba(0,0,0,0.03);
    border-left: 2px solid #4facfe;
}

.project-item.past-item:hover {
    background-color: #f0f7ff;
    box-shadow: 0 3px 8px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

.project-icon, .project-icon.small {
    display: none;
}

.project-content {
    margin-left: 0;
    width: 100%;
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 15px;
}

.project-info {
    flex: 1;
}

.project-name {
    color: #005792;
    font-size: 1.1em;
    margin-bottom: 8px;
    line-height: 1.4;
}

.project-period, .project-funding, .project-desc, .project-achievement {
    margin-bottom: 6px;
    color: #555;
    font-size: 0.9em;
    line-height: 1.5;
}

.project-period i, .project-funding i, .project-desc i, .project-achievement i {
    color: #4facfe;
    margin-right: 4px;
}

.project-funding strong, .project-desc strong, .project-achievement strong {
    color: #444;
    font-weight: bold;
    margin-right: 4px;
}

/* ==================== 세부사항 버튼 ==================== */
.details-btn {
    background: #17a2b8;
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.8em;
    transition: all 0.3s ease;
    margin-left: 8px;
}

.details-btn:hover {
    background: #138496;
    transform: scale(1.05);
}

/* ==================== 더 많은 프로젝트 표시 ==================== */
.more-projects {
    display: none;
}

.more-projects .project-item:not(:first-child) {
    margin-top: 20px;
}

.more-projects.visible {
    display: block;
    animation: fadeIn 0.4s ease-in-out;
}

.show-more-button {
    text-align: center;
    margin-top: 20px;
}

.show-more-button button {
    background-color: transparent;
    color: #162d55;
    border: 1.5px solid #24488c;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9em;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    margin: 0 auto;
}

.show-more-button button:hover {
    background-color: #eef2f8;
}

.show-more-button button i {
    margin-left: 6px;
    transition: transform 0.3s ease;
}

.show-more-button button.active i {
    transform: rotate(180deg);
}

/* ==================== 애니메이션 효과 ==================== */
.hidden {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

.visible {
    opacity: 1;
    transform: translateY(0);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== 로그인 및 인증 스타일 ==================== */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.auth-section {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-right: 20px;
}

.login-btn, .logout-btn {
    background: rgba(255, 255, 255, 0.12);
    color: white;
    border: 1.5px solid rgba(255, 255, 255, 0.65);
    padding: 7px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9em;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.login-btn:hover, .logout-btn:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: white;
    transform: translateY(-2px);
}

.user-info {
    color: #005792;
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* ==================== 로그인 모달 ==================== */
.login-modal {
    display: none;
    position: fixed;
    z-index: 1001;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    animation: fadeIn 0.3s ease;
}

.login-modal-content {
    background: white;
    margin: 10% auto;
    padding: 30px;
    border-radius: 15px;
    width: 90%;
    max-width: 400px;
    position: relative;
    animation: slideIn 0.3s ease;
}

.login-form h2 {
    color: #005792;
    text-align: center;
    margin-bottom: 25px;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: bold;
    font-size: 14px;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 2px solid #ddd;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.3s ease;
    box-sizing: border-box;
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none;
    border-color: #4facfe;
    box-shadow: 0 0 0 0.2rem rgba(79, 172, 254, 0.25);
}

.login-submit {
    width: 100%;
    background: #4facfe;
    color: white;
    border: none;
    padding: 12px;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.login-submit:hover {
    background: #005792;
}

.login-close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 28px;
    color: #aaa;
    cursor: pointer;
}

.login-close:hover {
    color: #005792;
}

.login-help {
    text-align: center;
    margin-top: 15px;
    font-size: 0.9em;
    color: #666;
}

/* ==================== 관리자 패널 ==================== */
.admin-panel {
    display: none;
    background: white;
    padding: 10px 20px 20px;
    border-radius: 12px;
    margin-bottom: 25px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border-top: 3px solid #24488c;
}

.admin-panel h3 {
    color: #162d55;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.1em;
    font-weight: 700;
}

.admin-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.admin-btn {
    background: linear-gradient(135deg, #162d55 0%, #24488c 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9em;
    font-weight: 500;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    gap: 8px;
    min-height: 40px;
    white-space: nowrap;
}

.admin-btn:hover {
    background: linear-gradient(135deg, #0f1f3d 0%, #162d55 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(22, 45, 85, 0.35);
}

.admin-btn.edit {
    background: linear-gradient(135deg, #b45309 0%, #d97706 100%);
    color: white;
}

.admin-btn.edit:hover {
    background: linear-gradient(135deg, #92400e 0%, #b45309 100%);
    box-shadow: 0 4px 14px rgba(180, 83, 9, 0.35);
}

.admin-btn.edit.active {
    background: linear-gradient(135deg, #92400e 0%, #b45309 100%);
    box-shadow: 0 0 0 3px rgba(217, 119, 6, 0.3);
}

.admin-btn.delete {
    background: linear-gradient(135deg, #b91c1c 0%, #dc2626 100%);
}

.admin-btn.delete:hover {
    background: linear-gradient(135deg, #991b1b 0%, #b91c1c 100%);
    box-shadow: 0 4px 14px rgba(185, 28, 28, 0.35);
}

.admin-btn.delete.active {
    background: linear-gradient(135deg, #991b1b 0%, #b91c1c 100%);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.3);
}

/* ==================== 프로젝트 폼 스타일 ==================== */
.add-project-form, .edit-project-form {
    display: none;
    background: #f8f9fa;
    padding: 25px;
    border-radius: 12px;
    margin-bottom: 25px;
    border: 2px solid #4facfe;
}

.edit-project-form {
    background: #fff3cd;
    border-color: #ffc107;
}

.add-project-form h4, .edit-project-form h4 {
    color: #005792;
    margin-bottom: 20px;
}

.edit-project-form h4 {
    color: #856404;
}

.form-row {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    align-items: flex-end;
}

.form-row .form-group {
    flex: 1;
    min-width: 0;
}

.form-group textarea {
    min-height: 70px;
    resize: vertical;
    font-family: inherit;
    line-height: 1.4;
}

.form-buttons {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px solid #dee2e6;
}

.submit-btn, .cancel-btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    min-width: 100px;
}

.submit-btn {
    background: #005792;
    color: white;
}

.submit-btn:hover {
    background: #003d6b;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 87, 146, 0.3);
}

.cancel-btn {
    background: #f0f2f5;
    color: #555;
    border: 1px solid #dde2ea;
}

.cancel-btn:hover {
    background: #e2e6ed;
    transform: translateY(-1px);
}

/* ==================== 프로젝트 액션 버튼 ==================== */
.project-actions {
    display: none;
    flex-shrink: 0;
}

.edit-project-btn, .delete-project-btn {
    border: none;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.8em;
    transition: all 0.3s ease;
    margin-right: 8px;
}

.edit-project-btn {
    background: #ffc107;
    color: #212529;
}

.edit-project-btn:hover {
    background: #e0a800;
    transform: scale(1.05);
}

.delete-project-btn {
    background: #dc3545;
    color: white;
}

.delete-project-btn:hover {
    background: #c82333;
    transform: scale(1.05);
}

/* ==================== 위치 선택 관련 스타일 ==================== */
#specificPositionGroup {
    transition: all 0.3s ease;
    opacity: 1;
}

#specificPositionGroup.hidden {
    opacity: 0;
    transform: translateY(-10px);
}

#specificPosition {
    background-color: #f8f9fa;
    border: 2px solid #4facfe;
    font-weight: 500;
}

#insertPosition {
    background-color: #fff;
    border: 2px solid #ddd;
    font-weight: 500;
}

#insertPosition:focus, #specificPosition:focus {
    border-color: #4facfe;
    box-shadow: 0 0 0 0.2rem rgba(79, 172, 254, 0.25);
}

.position-help {
    font-size: 0.8em;
    color: #666;
    margin-top: 5px;
    font-style: italic;
    padding: 5px 8px;
    background: #e9ecef;
    border-radius: 4px;
}


/* ==================== 탭 네비게이션 스타일 ==================== */
.tab-navigation {
    padding: 0 30px;
    background: #2c3e50;
    border-bottom: 2px solid #34495e;
    display: none;
    gap: 0;
}

.tab-btn {
    padding: 20px 40px;
    font-size: 18px;
    font-weight: 600;
    background: transparent;
    color: #bdc3c7;
    border: none;
    cursor: pointer;
    position: relative;
    transition: all 0.3s ease;
    border-radius: 0;
    flex: 1;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.tab-btn::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: linear-gradient(45deg, #3498db, #2ecc71);
    transform: translateX(-50%);
    transition: width 0.3s ease;
}

.tab-btn:hover {
    color: #fff;
    background: rgba(52, 152, 219, 0.1);
}

.tab-btn.active {
    color: #fff;
    background: rgba(52, 152, 219, 0.2);
}

.tab-btn.active::before {
    width: 100%;
}

/* ==================== 탭 컨텐츠 스타일 ==================== */
.tab-content {
    display: none;
    height: 100%;
    width: 100%;
    padding: 30px;
    overflow-y: auto;
    animation: fadeIn 0.4s ease;
}

/* .tab-content.active {
    display: block;
} */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== 이미지 갤러리 스타일 ==================== */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(1000px, 1fr));
    gap: 30px;
    max-width: 1400px;
    margin: 0 auto;
}

.gallery-item {
    background: #2c3e50;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(52, 152, 219, 0.3);
    border-color: #3498db;
}

.gallery-item img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.gallery-item-info {
    padding: 20px;
    background: linear-gradient(135deg, #34495e, #2c3e50);
}

.gallery-item-name {
    font-size: 16px;
    font-weight: 600;
    color: #ecf0f1;
    margin: 0;
    text-align: center;
}

.gallery-item-desc {
    font-size: 14px;
    color: #bdc3c7;
    margin-top: 8px;
    text-align: center;
    line-height: 1.4;
}

/* ==================== 빈 상태 스타일 ==================== */
.no-images {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 60%;
    color: #7f8c8d;
    font-size: 18px;
}

.no-images i {
    font-size: 64px;
    margin-bottom: 20px;
    opacity: 0.5;
}

/* ==================== 전체화면 이미지 모달 ==================== */
.fullscreen-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.95);
    z-index: 1002;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
}

.fullscreen-modal img {
    max-width: 95%;
    max-height: 95%;
    object-fit: contain;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

/* ==================== 스크롤바 스타일링 ==================== */
.tab-content::-webkit-scrollbar {
    width: 8px;
}

.tab-content::-webkit-scrollbar-track {
    background: #2c3e50;
}

.tab-content::-webkit-scrollbar-thumb {
    background: #3498db;
    border-radius: 4px;
}

.tab-content::-webkit-scrollbar-thumb:hover {
    background: #2980b9;
}

.image-modal-body::-webkit-scrollbar {
    width: 8px;
}

.image-modal-body::-webkit-scrollbar-track {
    background: #2c3e50;
}

.image-modal-body::-webkit-scrollbar-thumb {
    background: #3498db;
    border-radius: 4px;
}

.image-modal-body::-webkit-scrollbar-thumb:hover {
    background: #2980b9;
}

/* ==================== 알림 메시지 ==================== */
.alert {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1002;
    max-width: 400px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    animation: slideInRight 0.3s ease;
}

.alert.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert.warning {
    background: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* ==================== 반응형 디자인 ==================== */
@media (max-width: 992px) {
    .section-title {
        font-size: 1.4em;
    }
    
    .project-name {
        font-size: 1.05em;
    }
    
    .image-gallery {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        gap: 20px;
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 10px;
        padding: 12px 3%;
    }

    .auth-section {
        margin-right: 0;
    }

    .container { padding-top: 140px; }

    .project-section {
        padding: 18px 15px;
    }
    
    .project-item {
        padding: 12px;
        flex-direction: column;
    }
    
    .project-header {
        flex-direction: column;
        gap: 10px;
    }
    
    .page-header h1 {
        font-size: 1.8em;
    }

    .form-row {
        flex-direction: column;
        gap: 0;
    }
    
    .form-row .form-group {
        margin-bottom: 15px;
    }
    
    .add-project-form, .edit-project-form {
        padding: 20px 15px;
    }
    
    .form-buttons {
        flex-direction: column;
        gap: 10px;
    }
    
    .submit-btn, .cancel-btn {
        width: 100%;
    }

    .admin-buttons {
        flex-direction: column;
    }

    /* 탭형 모달 반응형 */
    .image-modal-content {
        width: 95%;
        max-width: none;
        margin: 5% auto;
        max-height: 85vh;
    }
    
    .tab-navigation {
        padding: 0 20px;
    }

    .tab-btn {
        padding: 15px 20px;
        font-size: 16px;
    }

    .tab-content {
        padding: 20px;
    }

    .image-gallery {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 10px;
    }

    .gallery-item img {
        height: 200px;
        object-fit: contain;
    }

    .image-modal-header {
        padding: 15px 20px;
    }

    .image-modal-title {
        font-size: 22px;
    }
}

@media (max-width: 576px) {
    .project-section {
        padding: 15px 12px;
    }
    
    .page-header {
        padding: 20px 12px 15px;
    }
    
    .page-header h1 {
        font-size: 1.8em;
    }
    
    .project-name {
        font-size: 0.95em;
    }
    
    .project-period, .project-funding, .project-desc, .project-achievement {
        font-size: 0.8em;
    }

    .add-project-form, .edit-project-form {
        padding: 15px 12px;
    }
    
    .form-group input, .form-group select, .form-group textarea {
        font-size: 16px; /* 모바일에서 확대 방지 */
    }

    /* 모바일 탭형 모달 */
    .image-modal-content {
        width: 98%;
        margin: 3% auto;
        max-height: 90vh;
    }
    
    .image-gallery {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: 8px;
    }

    .tab-btn {
        padding: 12px 15px;
        font-size: 14px;
    }

    .gallery-item img {
        height: 150px;
    }

    .gallery-item-info {
        padding: 10px;
    }

    .gallery-item-name {
        font-size: 14px;
    }

    .gallery-item-desc {
        font-size: 12px;
    }
}

/* ==================== 추가 유틸리티 클래스 ==================== */
.text-center {
    text-align: center;
}

.mb-20 {
    margin-bottom: 20px;
}

.mt-20 {
    margin-top: 20px;
}

.d-none {
    display: none !important;
}

.d-block {
    display: block !important;
}

.d-flex {
    display: flex !important;
}

/* ==================== 접근성 개선 ==================== */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* 포커스 스타일 개선 */
.tab-btn:focus,
.details-btn:focus,
.admin-btn:focus,
.login-btn:focus,
.logout-btn:focus,
.submit-btn:focus,
.cancel-btn:focus,
.edit-project-btn:focus,
.delete-project-btn:focus {
    outline: 2px solid #4facfe;
    outline-offset: 2px;
}

/* 고대비 모드 지원 */
@media (prefers-contrast: high) {
    .project-item {
        border: 2px solid #000;
    }
    
    .tab-btn {
        border: 1px solid #fff;
    }
    
    .gallery-item {
        border: 2px solid #fff;
    }
}

/* 다크 모드 선호도 감지 */
@media (prefers-color-scheme: dark) {
    .image-modal-content {
        background: #1a1a1a;
        color: #fff;
    }
    
    .tab-navigation {
        background: #2c3e50;
    }
    
    .gallery-item {
        background: #34495e;
    }
}

/* 애니메이션 감소 모드 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .hidden {
        transition: none;
    }
    
    .gallery-item:hover {
        transform: none;
    }
    
    .tab-btn:hover {
        transform: none;
    }
}

/* ==================== 인쇄 스타일 ==================== */
@media print {
    .admin-panel,
    .auth-section,
    .details-btn,
    .edit-project-btn,
    .delete-project-btn,
    .image-modal {
        display: none !important;
    }
    
    .project-item {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ccc;
    }
    
    .page-header h1 {
        color: #000;
    }
    
    .section-title {
        color: #000;
    }
}

/* ==================== 로딩 상태 ==================== */
.loading {
    position: relative;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid #f3f3f3;
    border-top: 2px solid #4facfe;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* ==================== 완성된 스타일시트 끝 ==================== */