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

body { 
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    transition: background 0.3s;
}

body.night-mode {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    font-size: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    z-index: 1001;
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(15deg);
    background: rgba(255, 255, 255, 0.3);
}

h2 {
    color: white;
    margin-bottom: 20px;
    font-size: 24px;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    transition: all 0.3s;
}

body.night-mode .card {
    background: #2a2a3e;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

input { 
    padding: 12px 16px;
    width: 100%;
    margin-bottom: 12px;
    box-sizing: border-box;
    font-size: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    transition: all 0.3s;
    font-family: inherit;
    background: white;
    color: #333;
}

body.night-mode input {
    background: #1a1a2e;
    border-color: #3a3a4e;
    color: #e0e0e0;
}

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

body.night-mode input:focus {
    border-color: #8b9eff;
    box-shadow: 0 0 0 3px rgba(139, 158, 255, 0.2);
}

button { 
    padding: 12px 24px;
    cursor: pointer;
    font-size: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

button:active {
    transform: translateY(0);
}

.item {
    padding: 16px;
    border-bottom: 1px solid #f0f0f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s;
    border-radius: 8px;
    margin-bottom: 4px;
    color: #333;
}

body.night-mode .item {
    border-bottom: 1px solid #3a3a4e;
    color: #e0e0e0;
}

.item:hover {
    background-color: #f8f9ff;
}

body.night-mode .item:hover {
    background-color: #3a3a4e;
}

.item.highlight {
    background: linear-gradient(90deg, #fff3cd 0%, #fffaeb 100%);
    border-left: 4px solid #ffc107;
    padding-left: 12px;
    box-shadow: 0 2px 8px rgba(255, 193, 7, 0.3);
}

.item:last-child {
    border-bottom: none;
}

.term { 
    font-weight: 600;
    color: #667eea;
    font-size: 16px;
}

.item button {
    padding: 6px 14px;
    font-size: 13px;
    background: #ff4757;
    box-shadow: 0 2px 8px rgba(255, 71, 87, 0.3);
    margin-left: 6px;
}

.item button:hover {
    background: #ff3838;
    box-shadow: 0 4px 12px rgba(255, 71, 87, 0.5);
}

.item button.edit-btn {
    background: linear-gradient(135deg, #4dabf7 0%, #339af0 100%);
    box-shadow: 0 2px 8px rgba(77, 171, 247, 0.3);
}

.item button.edit-btn:hover {
    background: linear-gradient(135deg, #339af0 0%, #228be6 100%);
    box-shadow: 0 4px 12px rgba(77, 171, 247, 0.5);
}

.button-group {
    display: flex;
    gap: 6px;
}

.input-container { 
    position: relative;
    margin-bottom: 12px;
}

.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 2px solid #667eea;
    border-top: none;
    border-radius: 0 0 10px 10px;
    max-height: 250px;
    overflow-y: auto;
    display: none;
    z-index: 1000;
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.3);
    margin-top: -10px;
}

body.night-mode .dropdown {
    background: #1a1a2e;
    border-color: #8b9eff;
    box-shadow: 0 8px 24px rgba(139, 158, 255, 0.3);
}

.dropdown-item {
    padding: 14px 16px;
    cursor: pointer;
    border-bottom: 1px solid #f0f0f0;
    transition: all 0.2s;
}

body.night-mode .dropdown-item {
    border-bottom: 1px solid #3a3a4e;
}

.dropdown-item:last-child {
    border-bottom: none;
}

.dropdown-item:hover {
    background: linear-gradient(90deg, #e8f0fe 0%, #f0e7ff 100%);
    padding-left: 20px;
}

.dropdown-item.active {
    background: linear-gradient(90deg, #e8f0fe 0%, #f0e7ff 100%);
    padding-left: 20px;
}

body.night-mode .dropdown-item:hover {
    background: linear-gradient(90deg, #2a2a4e 0%, #3a3a5e 100%);
    padding-left: 20px;
}

.dropdown-item .match-term { 
    font-weight: 600;
    color: #667eea;
    font-size: 15px;
}

body.night-mode .dropdown-item .match-term {
    color: #8b9eff;
}

.dropdown-item .match-translation { 
    color: #666;
    margin-left: 8px;
    font-size: 14px;
}

body.night-mode .dropdown-item .match-translation {
    color: #b0b0b0;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #999;
    font-style: italic;
}

body.night-mode .empty-state {
    color: #666;
}

.tag-input-container {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
    align-items: center;
    position: relative;
}

.tag-input-container input {
    margin-bottom: 0;
    flex: 1;
}

.tag-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 2px solid #667eea;
    border-top: none;
    border-radius: 0 0 10px 10px;
    max-height: 150px;
    overflow-y: auto;
    display: none;
    z-index: 1000;
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.3);
    margin-top: -10px;
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    backdrop-filter: blur(5px);
}

.modal {
    background: white;
    padding: 24px;
    border-radius: 16px;
    max-width: 500px;
    width: 90%;
    box-shadow: 0 20px 50px rgba(0,0,0,0.3);
    animation: modalSlideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

body.night-mode .modal {
    background: #2a2a3e;
    color: #e0e0e0;
}

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

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin: 20px 0;
}

.comparison-col h4 {
    margin-bottom: 12px;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: #667eea;
}

.comparison-box {
    background: #f8f9ff;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
}

body.night-mode .comparison-box {
    background: #1a1a2e;
    border-color: #3a3a4e;
}

.comp-field {
    margin-bottom: 8px;
}

.comp-label {
    font-size: 12px;
    color: #888;
    margin-bottom: 2px;
}

.comp-value {
    font-weight: 500;
    word-break: break-word;
    font-size: 14px;
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 24px;
    flex-wrap: wrap;
}

.btn-secondary {
    background: #e0e0e0;
    color: #333;
    box-shadow: none;
}

.btn-secondary:hover {
    background: #d0d0d0;
}

body.night-mode .btn-secondary {
    background: #3a3a4e;
    color: #e0e0e0;
}

.btn-danger {
    background: #ff4757;
    box-shadow: 0 4px 12px rgba(255, 71, 87, 0.3);
}

.btn-danger:hover {
    background: #ff3838;
}

body.night-mode .tag-dropdown {
    background: #1a1a2e;
    border-color: #8b9eff;
    box-shadow: 0 8px 24px rgba(139, 158, 255, 0.3);
}

.tag-dropdown-item {
    color: #667eea;
    padding: 10px 12px;
    cursor: pointer;
    border-bottom: 1px solid #f0f0f0;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 8px;
}

body.night-mode .tag-dropdown-item {
    border-bottom: 1px solid #3a3a4e;
}

.tag-dropdown-item:last-child {
    border-bottom: none;
}

.tag-dropdown-item:hover {
    background: linear-gradient(90deg, #e8f0fe 0%, #f0e7ff 100%);
    padding-left: 16px;
}

body.night-mode .tag-dropdown-item:hover {
    background: linear-gradient(90deg, #2a2a4e 0%, #3a3a5e 100%);
    padding-left: 16px;
}

.tag-dropdown-item.active {
    background: linear-gradient(90deg, #e8f0fe 0%, #f0e7ff 100%);
    padding-left: 16px;
}

.tag-dropdown-item .mini-tag {
    display: inline-block;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    flex-shrink: 0;
}

.export-import-container {
    display: flex;
    gap: 8px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 2px solid #f0f0f0;
}

body.night-mode .export-import-container {
    border-top-color: #3a3a4e;
}

.export-import-container button {
    flex: 1;
    padding: 10px 16px;
    font-size: 14px;
    background: linear-gradient(135deg, #20c997 0%, #12b886 100%);
    box-shadow: 0 4px 12px rgba(32, 201, 151, 0.4);
}

.export-import-container button:hover {
    box-shadow: 0 6px 20px rgba(32, 201, 151, 0.6);
}

.export-import-container button.import-btn {
    background: linear-gradient(135deg, #4dabf7 0%, #339af0 100%);
    box-shadow: 0 4px 12px rgba(77, 171, 247, 0.4);
}

.export-import-container button.import-btn:hover {
    box-shadow: 0 6px 20px rgba(77, 171, 247, 0.6);
}

#importFile {
    display: none;
}

.import-status {
    margin-top: 12px;
    padding: 12px;
    border-radius: 8px;
    font-size: 14px;
    text-align: left;
    white-space: pre-wrap;
    display: none;
}

.import-status.success {
    background: #d3f9d8;
    color: #2b8a3e;
    display: block;
}

body.night-mode .import-status.success {
    background: #2b8a3e;
    color: #d3f9d8;
}

.import-status.error {
    background: #ffe3e3;
    color: #c92a2a;
    display: block;
}

body.night-mode .import-status.error {
    background: #c92a2a;
    color: #ffe3e3;
}

.color-picker {
    display: flex;
    gap: 6px;
    padding: 8px;
    background: rgba(0,0,0,0.05);
    border-radius: 10px;
    flex-wrap: wrap;
}

body.night-mode .color-picker {
    background: rgba(255,255,255,0.05);
}

.color-option {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    border: 3px solid transparent;
    transition: all 0.3s;
    position: relative;
}

.color-option:hover {
    transform: scale(1.15);
}

.color-option.selected {
    border-color: white;
    box-shadow: 0 0 0 2px rgba(0,0,0,0.2);
    transform: scale(1.2);
}

body.night-mode .color-option.selected {
    box-shadow: 0 0 0 2px rgba(255,255,255,0.3);
}

.color-option.red { background: linear-gradient(135deg, #ff6b6b 0%, #ee5a6f 100%); }
.color-option.blue { background: linear-gradient(135deg, #4dabf7 0%, #339af0 100%); }
.color-option.green { background: linear-gradient(135deg, #51cf66 0%, #40c057 100%); }
.color-option.yellow { background: linear-gradient(135deg, #ffd43b 0%, #fab005 100%); }
.color-option.purple { background: linear-gradient(135deg, #b197fc 0%, #9775fa 100%); }
.color-option.orange { background: linear-gradient(135deg, #ff922b 0%, #fd7e14 100%); }
.color-option.pink { background: linear-gradient(135deg, #f06595 0%, #e64980 100%); }
.color-option.teal { background: linear-gradient(135deg, #20c997 0%, #12b886 100%); }

.tag {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-left: 8px;
    color: white;
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

.tag.red, .filter-tag.red { background: linear-gradient(135deg, #ff6b6b 0%, #ee5a6f 100%); }
.tag.blue, .filter-tag.blue { background: linear-gradient(135deg, #4dabf7 0%, #339af0 100%); }
.tag.green, .filter-tag.green { background: linear-gradient(135deg, #51cf66 0%, #40c057 100%); }
.tag.yellow, .filter-tag.yellow { background: linear-gradient(135deg, #ffd43b 0%, #fab005 100%); }
.tag.purple, .filter-tag.purple { background: linear-gradient(135deg, #b197fc 0%, #9775fa 100%); }
.tag.orange, .filter-tag.orange { background: linear-gradient(135deg, #ff922b 0%, #fd7e14 100%); }
.tag.pink, .filter-tag.pink { background: linear-gradient(135deg, #f06595 0%, #e64980 100%); }
.tag.teal, .filter-tag.teal { background: linear-gradient(135deg, #20c997 0%, #12b886 100%); }

.filter-container {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.filter-tag {
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    border: 2px solid transparent;
    color: white;
}

.filter-tag.active {
    border-color: white;
    box-shadow: 0 0 0 2px rgba(255,255,255,0.3);
    transform: scale(1.05);
}

.filter-tag.all {
    background: linear-gradient(135deg, #868e96 0%, #495057 100%);
}

/* Ensure active filter tag is visible in LIGHT mode even if no color class is present */
body:not(.night-mode) .filter-tag.active:not(.red):not(.blue):not(.green):not(.yellow):not(.purple):not(.orange):not(.pink):not(.teal):not(.all) {
    background: #e8ecff;
    color: #1f1f1f;
    border-color: #1f2937;
    box-shadow: 0 0 0 3px rgba(31, 41, 55, 0.6);
}
body:not(.night-mode) .filter-tag.active {
    border-color: #1f2937;
    box-shadow: 0 0 0 3px rgba(31, 41, 55, 0.6);
}

/* Scrollbar styling */
.dropdown::-webkit-scrollbar {
    width: 8px;
}

.dropdown::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

.dropdown::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 10px;
}

.undo-btn {
    margin-top: 12px;
    width: 100%;
    padding: 10px;
    background: linear-gradient(135deg, #ff6b6b 0%, #fa5252 100%);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    font-size: 14px;
    box-shadow: 0 4px 6px rgba(250, 82, 82, 0.25);
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.undo-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 8px rgba(250, 82, 82, 0.35);
}

.undo-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(250, 82, 82, 0.25);
}

.undo-btn::before {
    content: "↺";
    font-size: 18px;
}

/* --- Shared Board Styles --- */
.board-card {
    background: linear-gradient(135deg, rgba(255,255,255,0.9) 0%, rgba(255,255,255,0.7) 100%);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.5);
}

body.night-mode .board-card {
    background: linear-gradient(135deg, rgba(42,42,62,0.9) 0%, rgba(32,32,52,0.7) 100%);
    border-color: rgba(255,255,255,0.1);
}

.board-header {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 16px;
}

.status-badge {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
}

.status-badge::before {
    content: '';
    display: block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.status-badge.offline {
    background: rgba(134, 142, 150, 0.1);
    color: #495057;
}

body.night-mode .status-badge.offline {
    color: #e0e0e0;
}

.status-badge.offline::before {
    background: #adb5bd;
}

.status-badge.online {
    background: rgba(32, 201, 151, 0.1);
    color: #0ca678;
}

body.night-mode .status-badge.online {
    color: #20c997;
}

.status-badge.online::before {
    background: #20c997;
    box-shadow: 0 0 8px #20c997;
}

.board-controls {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.join-container {
    display: flex;
    gap: 8px;
}

.join-container input {
    margin-bottom: 0;
    flex: 1;
}

.join-container button {
    white-space: nowrap;
}

@media (max-width: 600px) {
    body {
        max-width: 100%;
        margin: 0;
        padding: 16px 10px;
    }
    .card {
        padding: 16px;
        margin-bottom: 16px;
        border-radius: 12px;
        width: 100%;
    }
    .theme-toggle {
        top: 10px;
        right: 10px;
        width: 40px;
        height: 40px;
        font-size: 20px;
    }
    input, button {
        font-size: 16px;
    }
    .modal {
        width: 95%;
        padding: 20px;
        max-height: 90vh;
        overflow-y: auto;
    }
    .comparison-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    .modal-actions {
        flex-direction: column;
    }
    .modal-actions button {
        width: 100%;
    }
}