* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: rgba(255, 255, 255, 0.95);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    margin-bottom: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

header h1 {
    color: #4a5568;
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    color: #666;
    font-size: 1.1rem;
}

.auth-section {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.auth-buttons {
    display: flex;
    gap: 10px;
}

.auth-btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    font-weight: 500;
    background: #667eea;
    color: white;
}

.auth-btn:hover {
    background: #5a67d8;
    transform: translateY(-1px);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
    background: rgba(72, 187, 120, 0.1);
    padding: 10px 15px;
    border-radius: 8px;
    border: 1px solid rgba(72, 187, 120, 0.3);
}

.user-info span {
    color: #2f855a;
    font-weight: 500;
}

.auth-switch {
    text-align: center;
    margin-top: 15px;
    color: #666;
}

.auth-switch a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.auth-switch a:hover {
    text-decoration: underline;
}

.loading {
    text-align: center;
    padding: 20px;
    color: #666;
}

.loading p {
    margin: 0;
    font-style: italic;
}

.offline-mode {
    background: rgba(255, 193, 7, 0.1);
    border: 1px solid rgba(255, 193, 7, 0.3);
    padding: 10px 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
    color: #856404;
}

/* 게스트 모드 스타일 */
.guest-mode {
    background: linear-gradient(135deg, #a8e6cf, #88d8a3);
    color: #2d3436;
    padding: 15px 20px;
    border-radius: 8px;
    margin: 20px 0;
    border: 2px solid #00b894;
    box-shadow: 0 2px 10px rgba(0, 184, 148, 0.2);
}

.guest-mode-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.guest-login-btn {
    background: #00b894;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.guest-login-btn:hover {
    background: #00a085;
    transform: translateY(-1px);
}

.read-only-badge {
    background: #74b9ff;
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8em;
    font-weight: 500;
}

.sync-status {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.sync-status.online {
    background: rgba(72, 187, 120, 0.1);
    color: #2f855a;
}

.sync-status.offline {
    background: rgba(255, 193, 7, 0.1);
    color: #856404;
}

.sync-status.syncing {
    background: rgba(102, 126, 234, 0.1);
    color: #4c51bf;
}

.search-section {
    background: rgba(255, 255, 255, 0.95);
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 30px;
    display: flex;
    gap: 15px;
    align-items: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    flex-wrap: wrap;
}

.search-section input,
.search-section select {
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    flex: 1;
    min-width: 200px;
}

.search-section input:focus,
.search-section select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-section button {
    padding: 12px 20px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.search-section button:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

.form-section {
    background: rgba(255, 255, 255, 0.95);
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.form-section h2 {
    color: #4a5568;
    margin-bottom: 25px;
    font-size: 1.8rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #4a5568;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-group small {
    color: #666;
    font-size: 0.9rem;
    margin-top: 5px;
    display: block;
}

.form-buttons {
    display: flex;
    gap: 15px;
    margin-top: 25px;
}

.form-buttons button {
    padding: 12px 25px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
}

#submitBtn {
    background: #48bb78;
    color: white;
}

#submitBtn:hover {
    background: #38a169;
    transform: translateY(-2px);
}

#cancelBtn {
    background: #e2e8f0;
    color: #4a5568;
}

#cancelBtn:hover {
    background: #cbd5e0;
    transform: translateY(-2px);
}

.list-section {
    background: rgba(255, 255, 255, 0.95);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 15px;
}

.list-header h2 {
    color: #4a5568;
    font-size: 1.8rem;
}

.sort-options select {
    padding: 10px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
}

.file-list {
    display: grid;
    gap: 20px;
}

.file-item {
    background: #f7fafc;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 20px;
    transition: all 0.3s ease;
    position: relative;
}

.file-item:hover {
    border-color: #667eea;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.15);
}

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

.file-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 5px;
}

.file-meta {
    display: flex;
    gap: 15px;
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.file-description {
    color: #4a5568;
    margin-bottom: 15px;
    line-height: 1.5;
}

.file-tags {
    display: flex;
    gap: 8px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.tag {
    background: #e6fffa;
    color: #234e52;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.85rem;
    border: 1px solid #b2f5ea;
}

.file-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.file-actions button {
    padding: 8px 15px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    font-weight: 500;
}

.edit-btn {
    background: #3182ce;
    color: white;
}

.edit-btn:hover {
    background: #2c5282;
}

.delete-btn {
    background: #e53e3e;
    color: white;
}

.delete-btn:hover {
    background: #c53030;
}

.download-btn {
    background: #38a169;
    color: white;
}

.download-btn:hover {
    background: #2f855a;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #666;
}

.empty-state p {
    font-size: 1.2rem;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background: white;
    margin: 5% auto;
    padding: 30px;
    border-radius: 15px;
    width: 90%;
    max-width: 600px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

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

.modal-content h2 {
    color: #4a5568;
    margin-bottom: 25px;
    font-size: 1.8rem;
}

.files-list {
    margin-top: 10px;
}

.file-attachment {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    background: #f7fafc;
    border-radius: 6px;
    margin-bottom: 5px;
    border: 1px solid #e2e8f0;
}

.file-attachment span {
    font-size: 0.9rem;
    color: #4a5568;
}

.remove-file {
    background: #e53e3e;
    color: white;
    border: none;
    border-radius: 4px;
    padding: 4px 8px;
    cursor: pointer;
    font-size: 0.8rem;
}

.remove-file:hover {
    background: #c53030;
}

.category-badge {
    background: #bee3f8;
    color: #2c5282;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid #90cdf4;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .search-section {
        flex-direction: column;
        align-items: stretch;
    }
    
    .search-section input,
    .search-section select,
    .search-section button {
        width: 100%;
        min-width: auto;
    }
    
    .form-buttons {
        flex-direction: column;
    }
    
    .file-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .file-actions {
        justify-content: flex-start;
    }
    
    .list-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .modal-content {
        margin: 10% auto;
        width: 95%;
        padding: 20px;
    }
    
    .file-actions {
        flex-direction: column;
    }
    
    .file-actions button {
        width: 100%;
    }
    
    .guest-mode-content {
        flex-direction: column;
        text-align: center;
    }
    
    .guest-login-btn {
        margin-top: 10px;
    }
}