:root {
    --bg-primary: #f8f9fb;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f3f7;
    --border: #e2e5ea;
    --border-light: #d0d4dc;
    --accent: #d97706;
    --accent-hover: #b45309;
    --accent-dim: rgba(217, 119, 6, 0.08);
    --text-primary: #1a1d23;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --danger: #dc2626;
    --success: #16a34a;
    --info: #2563eb;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Login Page */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background: linear-gradient(135deg, #f0f2f5 0%, #e4e7ec 50%, #dde1e8 100%);
}

.login-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 48px;
    width: 400px;
    max-width: 90vw;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

.login-logo {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 2px;
}

.login-logo p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-top: 8px;
}

.login-input {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 15px;
    outline: none;
    transition: border-color 0.2s;
}

.login-input::placeholder { color: var(--text-muted); }

.login-input:focus {
    border-color: var(--accent);
}

.login-btn {
    width: 100%;
    padding: 12px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    margin-top: 16px;
    transition: background 0.2s;
}

.login-btn:hover { background: var(--accent-hover); }
.login-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.login-error {
    color: var(--danger);
    font-size: 13px;
    margin-top: 12px;
    text-align: center;
}

/* Main Layout */
.app-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    grid-template-rows: 56px 1fr 48px;
    height: 100vh;
}

/* Header */
.header {
    grid-column: 1 / -1;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-logo .logo-icon {
    color: var(--accent);
    font-size: 20px;
}

.header-logo h1 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.header-logo span {
    font-size: 12px;
    color: var(--text-muted);
    padding: 2px 8px;
    background: var(--bg-card);
    border-radius: 4px;
}

.logout-btn {
    padding: 6px 14px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

.logout-btn:hover {
    border-color: var(--danger);
    color: var(--danger);
}

/* Sidebar */
.sidebar {
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 1px 0 4px rgba(0, 0, 0, 0.03);
}

.sidebar-footer {
    border-top: 1px solid var(--border);
    padding: 12px;
}

.general-feedback-label {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.general-feedback-input {
    width: 100%;
    min-height: 50px;
    max-height: 100px;
    padding: 8px 10px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 12px;
    line-height: 1.4;
    resize: vertical;
    outline: none;
}

.general-feedback-input:focus { border-color: var(--accent); }
.general-feedback-input::placeholder { color: var(--text-muted); }

.general-feedback-btn {
    width: 100%;
    margin-top: 6px;
    padding: 6px;
    background: var(--bg-card-hover);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.general-feedback-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.general-feedback-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.sidebar-header {
    padding: 16px;
    border-bottom: 1px solid var(--border);
}

.new-thread-btn {
    width: 100%;
    padding: 10px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.new-thread-btn:hover { background: var(--accent-hover); }

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

.thread-item {
    padding: 12px;
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 4px;
    transition: background 0.15s;
    border: 1px solid transparent;
}

.thread-item:hover { background: var(--bg-card-hover); }
.thread-item.active {
    background: var(--bg-card);
    border-color: var(--accent);
}

.thread-item-top {
    display: flex;
    align-items: center;
    gap: 8px;
}

.thread-status-dot {
    width: 8px;
    height: 8px;
    min-width: 8px;
    border-radius: 50%;
    background: transparent;
}

.thread-status-dot.processing {
    background: var(--accent);
    animation: pulse 1.2s ease-in-out infinite;
}

.thread-status-dot.unread {
    background: var(--success);
}

.thread-status-dot.read {
    background: transparent;
}

.thread-delete-btn {
    margin-left: auto;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 12px;
    cursor: pointer;
    opacity: 0;
    transition: all 0.2s;
    padding: 2px 4px;
    border-radius: 4px;
}

.thread-item:hover .thread-delete-btn { opacity: 0.6; }
.thread-delete-btn:hover {
    opacity: 1 !important;
    color: var(--danger);
    background: rgba(239, 68, 68, 0.08);
}

.thread-delete-btn.confirming {
    opacity: 1 !important;
    color: #fff;
    background: var(--danger);
    font-size: 10px;
    padding: 2px 6px;
}

.thread-status-label {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.thread-status-label.processing { color: var(--accent); }
.thread-status-label.unread { color: var(--success); }
.thread-status-label.read { display: none; }

.thread-item .thread-title {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    cursor: default;
}

.thread-rename-input {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    background: var(--bg-secondary);
    border: 1px solid var(--accent);
    border-radius: 4px;
    padding: 1px 4px;
    flex: 1;
    min-width: 0;
    outline: none;
}

.thread-item .thread-meta {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 4px;
    display: flex;
    justify-content: space-between;
}

/* Main content */
.main-content {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-primary);
}

/* Messages */
.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-muted);
}

.empty-state .empty-icon {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.3;
}

.empty-state p { font-size: 15px; }

/* Message bubbles */
.message {
    max-width: 85%;
    animation: fadeIn 0.3s ease;
}

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

.message.user {
    align-self: flex-end;
}

.message.assistant {
    align-self: flex-start;
    width: 85%;
}

.message-bubble {
    padding: 14px 18px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.6;
}

.message.user .message-bubble {
    background: var(--accent-dim);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: 12px 12px 2px 12px;
}

.message.assistant .message-bubble {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px 12px 12px 2px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
}

.message-meta {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 4px;
    padding: 0 4px;
}

.message.user .message-meta { text-align: right; }

/* Attachment chips in messages */
.attachment-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 8px;
}

.attachment-chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 12px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: border-color 0.2s;
}

.attachment-chip:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Answer block */
.answer-block {
    margin-top: 16px;
    background: rgba(245, 158, 11, 0.05);
    border: 1px solid rgba(245, 158, 11, 0.2);
    border-left: 3px solid var(--accent);
    border-radius: 0 8px 8px 0;
    padding: 16px;
    position: relative;
}

.answer-block-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.answer-block-label {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent);
}

.copy-btn {
    padding: 4px 12px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 4px;
}

.copy-btn:hover { background: var(--accent-hover); }
.copy-btn.copied {
    background: var(--success);
    color: #fff;
}

.answer-content {
    font-family: 'Inter', sans-serif;
    font-size: 14px;
    line-height: 1.7;
    white-space: pre-wrap;
    color: var(--text-primary);
}

/* Collapsible sections */
.collapsible {
    margin-bottom: 8px;
}

.collapsible-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 0;
    color: var(--text-secondary);
    font-size: 13px;
    cursor: pointer;
    user-select: none;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.collapsible-toggle:hover { color: var(--text-primary); }

.collapsible-toggle .arrow {
    transition: transform 0.2s;
    font-size: 10px;
}

.collapsible-toggle.open .arrow {
    transform: rotate(90deg);
}

.collapsible-content {
    padding: 8px 0 8px 16px;
    font-size: 13px;
    line-height: 1.6;
    color: var(--text-secondary);
    border-left: 2px solid var(--border);
    margin-left: 4px;
}

/* Feedback bar */
.feedback-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.correction-btn {
    padding: 5px 12px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-muted);
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 5px;
}

.correction-btn:hover {
    border-color: var(--danger);
    color: var(--danger);
}

.regenerate-btn {
    padding: 5px 12px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-muted);
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 5px;
}

.regenerate-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.regenerate-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.correction-btn.active {
    border-color: var(--danger);
    color: var(--danger);
    background: rgba(239, 68, 68, 0.05);
}

.feedback-input-wrap {
    flex: 1;
    display: flex;
    gap: 6px;
}

.feedback-input {
    flex: 1;
    padding: 6px 10px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 13px;
    outline: none;
}

.feedback-input:focus { border-color: var(--accent); }

.feedback-textarea {
    min-height: 60px;
    max-height: 120px;
    resize: vertical;
    font-family: inherit;
    line-height: 1.4;
    width: 100%;
}

.feedback-submit {
    padding: 6px 12px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
}

/* Input area */
.input-area {
    padding: 12px 24px;
    border-top: 1px solid var(--border);
    background: var(--bg-secondary);
}

.input-wrapper {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.message-textarea {
    width: 100%;
    min-height: 72px;
    max-height: 200px;
    padding: 12px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 14px;
    line-height: 1.5;
    resize: vertical;
    outline: none;
    transition: border-color 0.2s;
}

.message-textarea:focus { border-color: var(--accent); }
.message-textarea::placeholder { color: var(--text-muted); }

.input-bottom-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.input-bottom-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.upload-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.upload-label:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.upload-label input[type="file"] { display: none; }

.file-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.file-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    background: var(--accent-dim);
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: 6px;
    font-size: 12px;
    color: var(--accent);
}

.file-chip .remove-file {
    cursor: pointer;
    opacity: 0.7;
    font-size: 14px;
}

.file-chip .remove-file:hover { opacity: 1; }

.file-chip.file-error { border-color: var(--error); background: rgba(220,38,38,0.08); color: var(--error); }
.file-chip.file-done { border-color: var(--success); }

.file-progress-bar {
    position: absolute;
    left: 0; bottom: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.2s ease;
}

.file-progress-pct {
    font-size: 11px;
    opacity: 0.7;
    min-width: 30px;
    text-align: right;
}

.file-progress-icon {
    animation: spin 1s linear infinite;
    display: inline-block;
}

.file-error-msg {
    font-size: 10px;
    display: block;
    width: 100%;
    margin-top: 2px;
}

@keyframes spin { to { transform: rotate(360deg); } }

.send-btn {
    padding: 8px 20px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 6px;
    height: 36px;
}

.send-btn:hover { background: var(--accent-hover); }
.send-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

/* Drop zone overlay */
.drop-overlay {
    position: fixed;
    inset: 0;
    background: rgba(245, 158, 11, 0.08);
    border: 3px dashed var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    pointer-events: none;
}

.drop-overlay p {
    font-size: 20px;
    font-weight: 600;
    color: var(--accent);
}

/* Status bar */
.status-bar {
    grid-column: 1 / -1;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 20px;
    font-size: 12px;
    color: var(--text-muted);
    gap: 12px;
}

.status-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--success);
}

.status-dot.busy {
    background: var(--accent);
    animation: pulse 1.2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

/* Streaming indicator */
.streaming-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 13px;
    color: var(--text-secondary);
    animation: fadeIn 0.3s ease;
}

.streaming-dots {
    display: flex;
    gap: 3px;
}

.streaming-dots span {
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--accent);
    animation: bounce 1.4s infinite ease-in-out both;
}

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

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

/* Markdown inside messages */
.message-bubble h1, .message-bubble h2, .message-bubble h3 {
    font-size: 15px;
    font-weight: 600;
    margin: 12px 0 6px;
    color: var(--text-primary);
}

.message-bubble h2 { font-size: 14px; }
.message-bubble h3 { font-size: 13px; }

.message-bubble p { margin: 6px 0; }
.message-bubble ul, .message-bubble ol {
    padding-left: 20px;
    margin: 6px 0;
}

.message-bubble code {
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 13px;
    background: var(--bg-card-hover);
    padding: 2px 6px;
    border-radius: 3px;
}

.message-bubble pre {
    background: var(--bg-card-hover);
    padding: 12px;
    border-radius: 6px;
    overflow-x: auto;
    margin: 8px 0;
}

.message-bubble pre code {
    padding: 0;
    background: none;
}

/* Responsive */
@media (max-width: 768px) {
    .app-layout {
        grid-template-columns: 1fr;
    }
    .sidebar {
        display: none;
    }
    .message { max-width: 95%; }
    .message.assistant { width: 95%; }
}