:root {
    --white: #ffffff;
    --black: #000000;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;
    background: var(--white);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--gray-900);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 10px;
    pointer-events: none;
}

.toast {
    background: var(--white);
    color: var(--white);
    padding: 12px 20px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 250px;
    max-width: 400px;
    pointer-events: auto;
    animation: slideIn 0.3s ease-out;
    font-size: 14px;
    font-weight: 500;
}

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

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

.toast.success {
    background: var(--success);
}

.toast.warning {
    background: var(--warning);
}

.toast.error {
    background: var(--error);
}

.chat-container {
    width: 100%;
    max-width: 900px;
    height: 100vh;
    display: flex;
    flex-direction: column;
    padding: 0;
    position: relative;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 40px 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.chat-messages::-webkit-scrollbar {
    display: none;
}

.terms-message {
    display: flex;
    justify-content: center;
    padding: 20px;
}

.terms-content {
    background: var(--gray-100);
    border: 1px solid var(--gray-300);
    border-radius: 16px;
    padding: 24px;
    max-width: 500px;
    text-align: center;
}

.terms-content p {
    margin-bottom: 20px;
    color: var(--gray-700);
    font-size: 14px;
    line-height: 1.6;
}

.terms-checkbox {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    cursor: pointer;
    position: relative;
    user-select: none;
}

.terms-checkbox input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: relative;
    height: 22px;
    width: 22px;
    background-color: var(--white);
    border: 2px solid var(--gray-300);
    border-radius: 6px;
    transition: all var(--transition-normal);
    flex-shrink: 0;
}

.terms-checkbox:hover .checkmark {
    border-color: var(--gray-900);
}

.terms-checkbox input:checked ~ .checkmark {
    background-color: var(--gray-900);
    border-color: var(--gray-900);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
    left: 6px;
    top: 2px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.terms-checkbox input:checked ~ .checkmark:after {
    display: block;
}

.checkbox-label {
    font-size: 14px;
    color: var(--gray-700);
}

.message {
    display: flex;
    gap: 12px;
    animation: fadeIn 0.3s ease-in;
    max-width: 100%;
    position: relative;
    align-items: flex-start;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    min-width: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    flex-shrink: 0;
    background: var(--gray-200);
    color: var(--gray-900);
    overflow: hidden;
    margin-top: 0;
}

.message-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.message-content {
    max-width: calc(100% - 60px);
    padding: 12px 16px;
    border-radius: 16px;
    word-wrap: break-word;
    word-break: break-word;
    line-height: 1.5;
    font-size: 15px;
    position: relative;
}

.message.user .message-content {
    background: var(--gray-900);
    color: var(--white);
}

.message.assistant .message-content {
    background: var(--gray-100);
    color: var(--gray-900);
}

.message-content.image-content {
    padding: 0;
    background: transparent;
    overflow: hidden;
    border-radius: 16px;
    cursor: pointer;
    transition: var(--transition-normal);
}

.message-content.image-content:hover {
    opacity: 0.9;
}

.message-content.image-content img {
    width: 100%;
    max-width: 400px;
    height: auto;
    display: block;
    border-radius: 16px;
}

.message-content.file-content {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    border-radius: 16px;
}

.message-actions {
    position: absolute;
    top: 8px;
    right: 8px;
    display: flex;
    gap: 6px;
    opacity: 0;
    transition: all var(--transition-fast);
    z-index: 10;
}

.message:hover .message-actions {
    opacity: 1;
}

.message-action-btn {
    background: rgba(0, 0, 0, 0.6);
    color: var(--white);
    border: none;
    border-radius: 6px;
    padding: 6px 8px;
    font-size: 12px;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 4px;
}

.message-action-btn:hover {
    background: rgba(0, 0, 0, 0.8);
}

.message-action-btn svg {
    width: 14px;
    height: 14px;
}

.message-action-btn.active {
    background: var(--success);
}

.message-action-btn.active.thumbs-down {
    background: var(--error);
}

.chat-input-panel {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 16px 20px;
    background: var(--white);
    flex-shrink: 0;
}

.input-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    min-width: 0;
    position: relative;
}

.chat-input {
    width: 100%;
    padding: 12px 16px;
    padding-right: 60px;
    border: 1px solid var(--gray-300);
    border-radius: 16px;
    font-size: 15px;
    font-family: inherit;
    resize: none;
    outline: none;
    transition: all var(--transition-normal);
    min-height: 48px;
    max-height: 120px;
    background: var(--white);
    color: var(--gray-900);
    overflow-y: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.chat-input::-webkit-scrollbar {
    display: none;
}

.chat-input:focus {
    border-color: var(--gray-900);
}

.chat-input::placeholder {
    color: var(--gray-400);
}

.input-preview {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--gray-100);
    border-radius: 12px;
    padding: 4px 8px;
    max-width: 200px;
}

.input-preview img {
    width: 32px;
    height: 32px;
    object-fit: cover;
    border-radius: 6px;
}

.preview-text {
    font-size: 12px;
    color: var(--gray-600);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 120px;
}

.clear-preview-btn {
    background: transparent;
    border: none;
    color: var(--gray-600);
    cursor: pointer;
    font-size: 18px;
    line-height: 1;
    padding: 0;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
    flex-shrink: 0;
}

.clear-preview-btn:hover {
    color: var(--gray-900);
}

.icon-button {
    width: 48px;
    height: 48px;
    min-width: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--gray-300);
    border-radius: 16px;
    cursor: pointer;
    transition: all var(--transition-normal);
    color: var(--gray-700);
    flex-shrink: 0;
}

.icon-button:hover:not(:disabled) {
    background: var(--gray-100);
    border-color: var(--gray-400);
}

.icon-button:active:not(:disabled) {
    transform: scale(0.95);
}

.icon-button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.send-button:not(:disabled) {
    background: var(--gray-900);
    border-color: var(--gray-900);
    color: var(--white);
}

.send-button:hover:not(:disabled) {
    background: var(--gray-800);
    border-color: var(--gray-800);
}

/* Popup Menu */
.popup-menu {
    position: absolute;
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    padding: 6px;
    z-index: 1000;
    min-width: 220px;
    animation: popupFadeIn 0.2s ease-out;
}

@keyframes popupFadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.popup-menu-item {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 10px 12px;
    background: transparent;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition-fast);
    color: var(--gray-700);
    font-size: 14px;
    text-align: left;
}

.popup-menu-link {
    text-decoration: none;
}

.popup-menu-item:hover {
    background: var(--gray-100);
}

.popup-menu-item svg {
    flex-shrink: 0;
}

.popup-menu-divider {
    height: 1px;
    background: var(--gray-200);
    margin: 4px 0;
}

/* Image Modal */
.image-modal {
    background: rgba(0, 0, 0, 0.9);
    cursor: pointer;
}

.image-modal-content {
    position: relative;
    max-width: 90%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    cursor: default;
}

.image-modal-content img {
    max-width: 100%;
    max-height: calc(90vh - 80px);
    border-radius: 8px;
}

.image-modal-actions {
    display: flex;
    gap: 12px;
}

.image-action-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--white);
    color: var(--gray-900);
    border: none;
    border-radius: 16px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
}

.image-action-btn:hover {
    background: var(--gray-100);
}

.loading {
    display: flex;
    gap: 5px;
    padding: 12px 16px;
}

.loading-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--gray-400);
    animation: bounce 1.4s infinite ease-in-out;
}

.loading-dot:nth-child(1) {
    animation-delay: -0.32s;
}

.loading-dot:nth-child(2) {
    animation-delay: -0.16s;
}

@keyframes bounce {
    0%, 80%, 100% {
        transform: scale(0);
    }
    40% {
        transform: scale(1);
    }
}

.empty-state {
    text-align: center;
    color: var(--gray-400);
    padding: 60px 20px;
    font-size: 16px;
}

.empty-state-icon {
    font-size: 60px;
    margin-bottom: 15px;
    filter: grayscale(1);
    opacity: 0.5;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn 0.2s ease-in;
}

.modal-content {
    background: var(--white);
    border-radius: 16px;
    width: 90%;
    max-width: 500px;
    max-height: 80vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: slideUp 0.3s ease-out;
}

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

.modal-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--gray-900);
}

.modal-close {
    background: transparent;
    border: none;
    font-size: 28px;
    line-height: 1;
    cursor: pointer;
    color: var(--gray-500);
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--transition-fast);
}

.modal-close:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

.modal-body {
    padding: 24px;
    overflow-y: auto;
    flex: 1;
}

.modal-body::-webkit-scrollbar {
    width: 6px;
}

.modal-body::-webkit-scrollbar-track {
    background: var(--gray-100);
    border-radius: 10px;
}

.modal-body::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 10px;
}

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

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-700);
}

.setting-hint {
    display: block;
    font-size: 12px;
    font-weight: 400;
    color: var(--gray-500);
    margin-top: 2px;
}

.setting-input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--gray-300);
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    outline: none;
    transition: var(--transition-fast);
    background: var(--white);
    color: var(--gray-900);
}

.setting-input:focus {
    border-color: var(--gray-900);
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.setting-slider {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    outline: none;
    -webkit-appearance: none;
    background: var(--gray-200);
}

.setting-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--gray-900);
    cursor: pointer;
    transition: var(--transition-fast);
}

.setting-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.setting-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--gray-900);
    cursor: pointer;
    border: none;
    transition: var(--transition-fast);
}

.setting-slider::-moz-range-thumb:hover {
    transform: scale(1.2);
}

.slider-value {
    min-width: 40px;
    text-align: right;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-700);
}

.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--gray-200);
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

.modal-button {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
}

.modal-button.primary {
    background: var(--gray-900);
    color: var(--white);
}

.modal-button.primary:hover {
    background: var(--gray-800);
}

.modal-button.secondary {
    background: var(--gray-100);
    color: var(--gray-900);
}

.modal-button.secondary:hover {
    background: var(--gray-200);
}

/* ===== RESPONSIVE DESIGN ===== */

/* Tablet */
@media (max-width: 900px) {
    .chat-messages {
        padding: 30px 16px 16px;
    }
    
    .message-content {
        max-width: calc(100% - 55px);
    }
}

/* Mobile */
@media (max-width: 768px) {
    .toast-container {
        top: 10px;
        right: 10px;
        left: 10px;
    }
    
    .toast {
        min-width: auto;
        width: 100%;
    }
    
    .chat-container {
        max-width: 100%;
    }
    
    .chat-messages {
        padding: 20px 12px 12px;
        gap: 16px;
    }
    
    .message-content {
        max-width: 75%;
        font-size: 14px;
        padding: 10px 14px;
    }
    
    .message-avatar {
        width: 32px;
        height: 32px;
        min-width: 32px;
        font-size: 14px;
    }
    
    .chat-input-panel {
        padding: 12px 16px;
        gap: 6px;
    }
    
    .chat-input {
        font-size: 16px;
        padding: 10px 14px;
        padding-right: 50px;
        min-height: 44px;
    }
    
    .icon-button {
        width: 44px;
        height: 44px;
        min-width: 44px;
    }
    
    .icon-button svg {
        width: 18px;
        height: 18px;
    }
    
    .input-preview {
        max-width: 150px;
    }
    
    .popup-menu {
        min-width: 200px;
    }
    
    .image-modal-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .image-action-btn {
        width: 100%;
        justify-content: center;
    }
}

/* Small mobile */
@media (max-width: 480px) {
    .chat-messages {
        padding: 16px 10px 10px;
        gap: 14px;
    }
    
    .message-content {
        max-width: 80%;
        font-size: 14px;
        padding: 10px 12px;
    }
    
    .message-avatar {
        width: 30px;
        height: 30px;
        min-width: 30px;
        font-size: 13px;
    }
    
    .chat-input-panel {
        padding: 10px 12px;
        gap: 6px;
    }
    
    .icon-button {
        width: 40px;
        height: 40px;
        min-width: 40px;
    }
    
    .icon-button svg {
        width: 16px;
        height: 16px;
    }
    
    .terms-content {
        padding: 16px;
    }
    
    .modal-content {
        width: 95%;
    }
    
    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 16px;
    }
}

/* Landscape on small mobile */
@media (max-height: 500px) and (orientation: landscape) {
    .chat-messages {
        padding: 12px 10px;
    }
    
    .chat-input-panel {
        padding: 8px 12px;
    }
    
    .chat-input {
        min-height: 40px;
        max-height: 80px;
    }
}

/* Desktop - large screens */
@media (min-width: 1200px) {
    .chat-container {
        max-width: 1000px;
    }
    
    .chat-messages {
        padding: 50px 24px 24px;
    }
    
    .message-content {
        font-size: 16px;
        padding: 14px 18px;
    }
}