/* ============================================
   Hisense AI Customer Service - Stylesheet
   ============================================ */

:root {
    --hisense-teal: #00a7a0;
    --hisense-teal-dark: #008c86;
    --hisense-teal-light: #e0f5f4;
    --hisense-teal-10: rgba(0, 167, 160, 0.1);
    --bg-primary: #f7f8fa;
    --bg-white: #ffffff;
    --bg-sidebar: #1a1a2e;
    --bg-sidebar-hover: #252542;
    --text-primary: #1a1a2e;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --text-sidebar: #e0e0e0;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --transition: all 0.2s ease;
    --sidebar-width: 280px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

/* ============ App Layout ============ */
.app-container {
    display: flex;
    height: 100vh;
}

/* ============ Sidebar ============ */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    transition: transform 0.3s ease;
    z-index: 100;
}

.sidebar-header {
    padding: 20px 16px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sidebar-logo {
    height: 32px;
    width: auto;
    object-fit: contain;
    filter: brightness(0) invert(1);
}

.new-chat-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    background: var(--hisense-teal);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    width: 100%;
    justify-content: center;
}

.new-chat-btn:hover {
    background: var(--hisense-teal-dark);
}

.conversation-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.conversation-list::-webkit-scrollbar {
    width: 4px;
}

.conversation-list::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 2px;
}

.conv-item {
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--text-sidebar);
    font-size: 13px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 2px;
    position: relative;
}

.conv-item:hover {
    background: var(--bg-sidebar-hover);
}

.conv-item.active {
    background: var(--bg-sidebar-hover);
    color: white;
}

.conv-item .conv-icon {
    flex-shrink: 0;
    opacity: 0.6;
}

.conv-item .conv-title {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
}

.conv-item .conv-delete {
    display: none;
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 2px;
    border-radius: 4px;
    flex-shrink: 0;
}

.conv-item:hover .conv-delete {
    display: block;
}

.conv-item .conv-delete:hover {
    color: #ef4444;
    background: rgba(239,68,68,0.1);
}

.sidebar-footer {
    padding: 12px 16px;
    border-top: 1px solid rgba(255,255,255,0.08);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sidebar-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: none;
    border: none;
    color: var(--text-sidebar);
    cursor: pointer;
    font-size: 13px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    width: 100%;
}

.sidebar-btn:hover {
    background: var(--bg-sidebar-hover);
}

.lang-switch {
    display: flex;
    gap: 4px;
    background: rgba(255,255,255,0.06);
    padding: 3px;
    border-radius: 6px;
}

.lang-btn {
    flex: 1;
    padding: 6px 12px;
    border: none;
    background: none;
    color: var(--text-sidebar);
    cursor: pointer;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    transition: var(--transition);
}

.lang-btn.active {
    background: var(--hisense-teal);
    color: white;
}

/* ============ Chat Main ============ */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    position: relative;
}

.chat-header {
    display: none;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    z-index: 10;
}

.menu-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    color: var(--text-primary);
    border-radius: 6px;
}

.menu-btn:hover {
    background: var(--bg-primary);
}

.chat-header-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 15px;
    flex: 1;
}

.header-logo {
    height: 24px;
    width: auto;
}

.header-actions {
    display: flex;
    align-items: center;
}

.lang-switch-mobile {
    display: flex;
    gap: 2px;
    background: var(--bg-primary);
    padding: 2px;
    border-radius: 6px;
}

.lang-switch-mobile .lang-btn {
    padding: 4px 10px;
    color: var(--text-secondary);
    font-size: 12px;
}

.lang-switch-mobile .lang-btn.active {
    background: var(--hisense-teal);
    color: white;
}

/* ============ Welcome Screen ============ */
.welcome-screen {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    overflow-y: auto;
}

.welcome-content {
    text-align: center;
    max-width: 600px;
}

.welcome-logo {
    height: 48px;
    width: auto;
    margin-bottom: 24px;
}

.welcome-content h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.welcome-content p {
    font-size: 15px;
    color: var(--text-secondary);
    margin-bottom: 36px;
    line-height: 1.5;
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.quick-action-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px 16px;
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 500;
}

.quick-action-btn:hover {
    border-color: var(--hisense-teal);
    background: var(--hisense-teal-light);
    color: var(--hisense-teal-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-action-btn svg {
    color: var(--hisense-teal);
}

/* ============ Messages ============ */
.messages-area {
    flex: 1;
    overflow-y: auto;
    scroll-behavior: smooth;
}

.messages-area::-webkit-scrollbar {
    width: 6px;
}

.messages-area::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 3px;
}

.messages-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 24px 20px;
}

.message {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 14px;
    font-weight: 600;
}

.message.user .message-avatar {
    background: var(--hisense-teal-10);
    color: var(--hisense-teal);
}

.message.assistant .message-avatar {
    background: linear-gradient(135deg, var(--hisense-teal), var(--hisense-teal-dark));
    color: white;
}

.message-body {
    flex: 1;
    min-width: 0;
}

.message-content {
    font-size: 14px;
    line-height: 1.7;
    color: var(--text-primary);
    word-break: break-word;
}

.message.user .message-content {
    background: var(--hisense-teal);
    color: white;
    padding: 10px 16px;
    border-radius: var(--radius-md);
    border-top-right-radius: 4px;
    display: inline-block;
    max-width: 85%;
}

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

.message.user .message-body {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.message.assistant .message-content {
    background: var(--bg-white);
    padding: 14px 18px;
    border-radius: var(--radius-md);
    border-top-left-radius: 4px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

/* Markdown rendering */
.message-content p {
    margin-bottom: 8px;
}

.message-content p:last-child {
    margin-bottom: 0;
}

.message-content code {
    background: rgba(0,0,0,0.06);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 13px;
    font-family: "SF Mono", "Fira Code", "Consolas", monospace;
}

.message-content pre {
    background: #1e1e2e;
    color: #cdd6f4;
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 10px 0;
    font-size: 13px;
    line-height: 1.5;
}

.message-content pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.message-content ul, .message-content ol {
    padding-left: 20px;
    margin: 8px 0;
}

.message-content li {
    margin-bottom: 4px;
}

.message-content a {
    color: var(--hisense-teal);
    text-decoration: none;
}

.message-content a:hover {
    text-decoration: underline;
}

.message-content blockquote {
    border-left: 3px solid var(--hisense-teal);
    padding-left: 12px;
    margin: 8px 0;
    color: var(--text-secondary);
}

.message-content table {
    border-collapse: collapse;
    margin: 8px 0;
    width: 100%;
}

.message-content th, .message-content td {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    text-align: left;
    font-size: 13px;
}

.message-content th {
    background: var(--bg-primary);
    font-weight: 600;
}

/* Typing indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 4px 0;
}

.typing-indicator span {
    width: 6px;
    height: 6px;
    background: var(--hisense-teal);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); opacity: 0.4; }
    40% { transform: scale(1); opacity: 1; }
}

/* References */
.references {
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid var(--border-color);
}

.references-title {
    font-size: 12px;
    color: var(--text-light);
    margin-bottom: 6px;
    font-weight: 500;
}

.reference-item {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 8px;
    background: var(--hisense-teal-10);
    color: var(--hisense-teal-dark);
    border-radius: 4px;
    font-size: 11px;
    margin: 2px 4px 2px 0;
    text-decoration: none;
    transition: var(--transition);
}

.reference-item:hover {
    background: var(--hisense-teal-light);
}

/* ============ Input Area ============ */
.input-area {
    padding: 16px 20px 12px;
    background: var(--bg-primary);
}

.input-wrapper {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    align-items: flex-end;
    gap: 8px;
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 8px 12px;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.input-wrapper:focus-within {
    border-color: var(--hisense-teal);
    box-shadow: 0 0 0 3px var(--hisense-teal-10);
}

.input-wrapper textarea {
    flex: 1;
    border: none;
    outline: none;
    resize: none;
    font-size: 14px;
    line-height: 1.5;
    padding: 6px 4px;
    max-height: 150px;
    background: transparent;
    font-family: inherit;
    color: var(--text-primary);
}

.input-wrapper textarea::placeholder {
    color: var(--text-light);
}

.send-btn, .stop-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: var(--transition);
}

.send-btn {
    background: var(--hisense-teal);
    color: white;
}

.send-btn:disabled {
    background: #d1d5db;
    cursor: not-allowed;
}

.send-btn:not(:disabled):hover {
    background: var(--hisense-teal-dark);
    transform: scale(1.05);
}

.stop-btn {
    background: #ef4444;
    color: white;
}

.stop-btn:hover {
    background: #dc2626;
}

.input-footer {
    text-align: center;
    padding-top: 8px;
    font-size: 11px;
    color: var(--text-light);
    max-width: 800px;
    margin: 0 auto;
}

/* ============ Modal ============ */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.modal {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 480px;
    box-shadow: var(--shadow-lg);
    animation: modalIn 0.2s ease;
}

@keyframes modalIn {
    from { opacity: 0; transform: scale(0.95) translateY(10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px 0;
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-light);
    padding: 4px;
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 20px 24px;
}

.form-group {
    margin-bottom: 16px;
}

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

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.form-group input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 14px;
    outline: none;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus {
    border-color: var(--hisense-teal);
    box-shadow: 0 0 0 3px var(--hisense-teal-10);
}

.modal-footer {
    padding: 16px 24px 20px;
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

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

.btn-primary {
    background: var(--hisense-teal);
    color: white;
}

.btn-primary:hover {
    background: var(--hisense-teal-dark);
}

.btn-secondary {
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

/* ============ Mobile Sidebar Overlay ============ */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 99;
}

/* ============ Responsive ============ */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        height: 100%;
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .sidebar.open + .chat-main .sidebar-overlay,
    .sidebar-overlay.open {
        display: block;
    }

    .chat-header {
        display: flex;
    }

    .welcome-content h1 {
        font-size: 22px;
    }

    .quick-actions {
        grid-template-columns: 1fr;
    }

    .messages-container {
        padding: 16px;
    }
}

@media (min-width: 769px) {
    .chat-header {
        display: none;
    }
}

/* ============ Error Message ============ */
.error-message {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: #dc2626;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    margin-top: 8px;
}

/* ============ Loading ============ */
.loading-shimmer {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: 4px;
    height: 14px;
    margin: 6px 0;
}

.loading-shimmer:first-child { width: 90%; }
.loading-shimmer:nth-child(2) { width: 70%; }
.loading-shimmer:nth-child(3) { width: 50%; }

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}