:root {
    --bg-primary: #111111;
    --bg-secondary: #1a1a1a;
    --bg-card: #242424;
    --bg-page: #181818;
    --text-primary: #e4e4e7;
    --text-secondary: #a1a1aa;
    --text-light: #fafafa;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --success: #22c55e;
    --border: #333333;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.4);
    --radius: 12px;
    --radius-lg: 24px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    background: var(--bg-page);
    color: var(--text-primary);
    min-height: 100vh;
}

/* Navigation */
.nav {
    background: var(--bg-primary);
    padding: 0 2rem;
    display: flex;
    align-items: center;
    height: 60px;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    color: var(--text-light);
    font-size: 1.2rem;
    font-weight: 700;
    margin-right: 3rem;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 0.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-light);
    background: var(--bg-secondary);
}

/* Layout */
.container {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1.5rem;
}

/* App layout — sidebar + chat area */
.app-layout {
    display: flex;
    height: calc(100vh - 60px);
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 260px;
    min-width: 260px;
    background: var(--bg-primary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: margin-left 0.3s ease, opacity 0.3s ease;
}

.sidebar--collapsed {
    margin-left: -260px;
}

.sidebar--hidden {
    display: none;
}

.btn--new-chat {
    margin: 0.75rem;
    padding: 0.6rem 1rem;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    text-align: left;
    transition: background 0.2s;
    flex-shrink: 0;
}

.btn--new-chat:hover {
    background: var(--bg-card);
}

.session-list {
    flex: 1;
    overflow-y: auto;
    padding: 0 0.5rem 0.75rem;
}

.session-item {
    padding: 0.6rem 0.75rem;
    border-radius: var(--radius);
    cursor: pointer;
    transition: background 0.15s;
    margin-bottom: 2px;
    display: flex;
    align-items: center;
    gap: 4px;
}

.session-item:hover {
    background: var(--bg-secondary);
}

.session-item--active {
    background: var(--bg-card);
}

.session-info {
    flex: 1;
    min-width: 0;
}

.session-title {
    font-size: 0.85rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.session-time {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 2px;
}

.session-delete-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    border-radius: 6px;
    flex-shrink: 0;
    transition: color 0.15s, background 0.15s;
}

.session-item:hover .session-delete-btn {
    display: flex;
}

.session-delete-btn:hover {
    color: var(--danger);
    background: rgba(239, 68, 68, 0.15);
}

.session-empty {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Sidebar toggle (hamburger) */
.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    margin-right: 0.75rem;
    border-radius: 6px;
    transition: color 0.2s, background 0.2s;
    display: flex;
    align-items: center;
}

.sidebar-toggle:hover {
    color: var(--text-light);
    background: var(--bg-secondary);
}

/* Chat page */
.chat-wrapper {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-width: 0;
    height: 100%;
    transition: all 0.4s ease;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Landing state — input centered on page */
.chat-wrapper--landing {
    justify-content: center;
}

.chat-wrapper--landing .chat-messages {
    display: none;
}

.chat-wrapper--landing .chat-input-area {
    max-width: 720px;
    width: 100%;
    margin: 0 auto;
    padding: 0 1.5rem 0;
}

.landing-hero {
    display: none;
}

.chat-wrapper--landing .landing-hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 0 1.5rem 1.5rem;
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
}

.landing-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.landing-subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.message {
    max-width: 80%;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-lg);
    line-height: 1.6;
    font-size: 0.95rem;
    word-wrap: break-word;
}

.message--user {
    align-self: flex-end;
    background: var(--accent);
    color: white;
    border-bottom-right-radius: 6px;
}

/* User message row wrapper */
.msg-row--user {
    align-self: flex-end;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    max-width: 80%;
}

.msg-row--user .message--user {
    align-self: auto;
    max-width: 100%;
}

/* Hover actions — outside the bubble */
.msg-actions {
    display: none;
    gap: 4px;
    margin-top: 4px;
    padding-right: 4px;
}

.msg-row--user:hover .msg-actions {
    display: flex;
}

.msg-action-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    width: 28px;
    height: 28px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.15s, background 0.15s;
    padding: 0;
}

.msg-action-btn:hover {
    color: var(--text-light);
    background: var(--bg-card);
}

.msg-action-btn--copied {
    color: var(--success);
}

/* Edit mode for user messages */
.msg-edit-area {
    width: 100%;
    background: transparent;
    border: none;
    color: white;
    font-family: inherit;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: none;
    outline: none;
    overflow-y: hidden;
}

.msg-edit-actions {
    display: flex;
    gap: 0.4rem;
    justify-content: flex-end;
    margin-top: 0.4rem;
}

.msg-edit-actions button {
    padding: 0.25rem 0.6rem;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    border: none;
}

.msg-edit-save {
    background: white;
    color: var(--accent);
}

.msg-edit-save:hover {
    background: #e0e7ff;
}

.msg-edit-cancel {
    background: rgba(255, 255, 255, 0.15);
    color: white;
}

.msg-edit-cancel:hover {
    background: rgba(255, 255, 255, 0.25);
}

.message--assistant {
    align-self: flex-start;
    background: var(--bg-card);
    color: var(--text-primary);
    border-bottom-left-radius: 6px;
    box-shadow: var(--shadow);
}

.message--welcome {
    color: var(--text-secondary);
}

.message--error {
    align-self: flex-start;
    background: #2a1515;
    color: var(--danger);
    border: 1px solid #5c2020;
}

/* Markdown formatted response styles */
.markdown-body h2, .markdown-body h3, .markdown-body h4 {
    color: var(--text-light);
    margin: 0.75rem 0 0.4rem;
}
.markdown-body h2 { font-size: 1.15rem; }
.markdown-body h3 { font-size: 1.05rem; }
.markdown-body h4 { font-size: 0.95rem; }
.markdown-body h2:first-child, .markdown-body h3:first-child, .markdown-body h4:first-child {
    margin-top: 0;
}

.markdown-body p {
    margin: 0.4rem 0;
}

.markdown-body strong {
    color: var(--text-light);
    font-weight: 600;
}

.markdown-body em {
    font-style: italic;
    color: var(--text-secondary);
}

.markdown-body a {
    color: var(--accent);
    text-decoration: underline;
}

.markdown-body ul, .markdown-body ol {
    margin: 0.4rem 0;
    padding-left: 1.5rem;
}

.markdown-body li {
    margin: 0.2rem 0;
}

.markdown-body pre {
    background: #0d0d0d;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.75rem 1rem;
    margin: 0.5rem 0;
    overflow-x: auto;
}

.markdown-body .code-block {
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.85rem;
    color: #e2e8f0;
    background: none;
    padding: 0;
}

.markdown-body .inline-code {
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.85rem;
    background: #2d2d2d;
    color: #f59e0b;
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 0.75rem 0;
}

.sources-toggle {
    margin-top: 0.75rem;
    background: none;
    border: 1px solid var(--border);
    color: var(--accent);
    padding: 0.3rem 0.75rem;
    border-radius: 999px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 500;
}

.sources-toggle:hover {
    background: #1e2a3a;
}

.sources-panel {
    display: none;
    margin-top: 0.5rem;
    padding: 0.75rem;
    background: var(--bg-page);
    border-radius: var(--radius);
    font-size: 0.85rem;
}

.sources-panel.open {
    display: block;
}

.source-item {
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
}

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

.source-badge {
    display: inline-block;
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-right: 0.4rem;
}

.source-badge--text {
    background: #1e3a5f;
    color: #60a5fa;
}

.source-badge--image {
    background: #3b2f1a;
    color: #fbbf24;
}

.typing-indicator {
    align-self: flex-start;
    padding: 0.75rem 1rem;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    display: flex;
    gap: 4px;
    align-items: center;
}

.typing-dot {
    width: 8px;
    height: 8px;
    background: var(--text-secondary);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

.typing-dot:nth-child(2) { animation-delay: 0.2s; }
.typing-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes typing {
    0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
    30% { transform: translateY(-6px); opacity: 1; }
}

/* Streaming response styles */
.streaming-cursor::after {
    content: '\25CF';
    animation: blink 1s steps(2) infinite;
    color: var(--accent);
    margin-left: 2px;
}

@keyframes blink {
    0% { opacity: 1; }
    50% { opacity: 0; }
}

.streaming-status {
    margin-top: 0.5rem;
    font-size: 0.8rem;
    color: var(--accent);
    font-style: italic;
    animation: pulse-status 1.5s ease-in-out infinite;
}

@keyframes pulse-status {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

.chat-input-area {
    padding: 1rem 1.5rem 1.25rem;
    background: var(--bg-page);
    border-top: none;
    flex-shrink: 0;
}

.input-wrapper {
    display: flex;
    flex-direction: column;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 28px;
    padding: 0.6rem 1rem;
    transition: border-color 0.2s;
}

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

.input-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 0.35rem;
}

.input-toolbar-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn.btn--attach {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.3rem 0.75rem;
    border-radius: 999px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.85rem;
    font-weight: 500;
    flex-shrink: 0;
    transition: color 0.2s, background 0.2s, border-color 0.2s;
    height: 32px;
    white-space: nowrap;
}

.btn.btn--attach:hover {
    color: var(--text-primary);
    border-color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

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

.btn--stop {
    background: var(--danger);
    color: white;
    flex-shrink: 0;
    height: 32px;
    border-radius: 999px;
    padding: 0.4rem 1rem;
}

.btn--stop:hover {
    background: var(--danger-hover);
}

.message--status {
    align-self: flex-start;
    background: var(--bg-card);
    color: var(--text-secondary);
    border-bottom-left-radius: 6px;
    box-shadow: var(--shadow);
    font-size: 0.9rem;
}

.upload-progress-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    min-width: 280px;
}

.upload-progress-text {
    font-size: 0.85rem;
}

.upload-progress-bar {
    height: 6px;
    background: var(--bg-page);
    border-radius: 3px;
    overflow: hidden;
}

.upload-progress-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 3px;
    transition: width 0.3s ease;
}

.upload-progress-fill--processing {
    animation: progress-pulse 1.5s infinite;
    background: linear-gradient(90deg, var(--accent), var(--success), var(--accent));
    background-size: 200% 100%;
    animation: progress-shimmer 1.5s infinite;
}

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

.chat-wrapper.drag-active {
    outline: 2px dashed var(--accent);
    outline-offset: -4px;
}

.chat-input {
    width: 100%;
    padding: 0.5rem 0.5rem;
    border: none;
    border-radius: 0;
    font-size: 0.95rem;
    font-family: inherit;
    outline: none;
    background: transparent;
    color: var(--text-primary);
    resize: none;
    overflow-y: hidden;
    min-height: 24px;
    max-height: 200px;
    line-height: 1.5;
}

.chat-input:focus {
    border-color: transparent;
}

.input-hint {
    font-size: 0.7rem;
    color: var(--text-secondary);
    text-align: center;
    padding: 0.25rem 0 0;
    opacity: 0.6;
}

.chat-input::placeholder {
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    padding: 0.65rem 1.25rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

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

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

.btn--primary:disabled {
    background: #1e3a5f;
    cursor: not-allowed;
}

.input-wrapper .btn--primary {
    border-radius: 999px;
    padding: 0.4rem 1rem;
    height: 32px;
    flex-shrink: 0;
}

.btn--danger {
    background: none;
    color: var(--danger);
    border: 1px solid var(--danger);
    padding: 0.4rem 0.75rem;
    font-size: 0.8rem;
}

.btn--danger:hover {
    background: var(--danger);
    color: white;
}

/* Documents page */
.doc-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-top: 1.5rem;
}

.doc-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
}

.doc-info h3 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.doc-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header {
    margin-bottom: 1rem;
}

.page-header h1 {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 200;
    align-items: center;
    justify-content: center;
}

.modal-overlay.open {
    display: flex;
}

.modal {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 2rem;
    max-width: 400px;
    width: 90%;
    box-shadow: var(--shadow-lg);
}

.modal h3 {
    margin-bottom: 0.75rem;
}

.modal p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
}

.btn--ghost {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-primary);
}

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

/* Login page */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1.5rem;
    background: var(--bg-page);
}

.login-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    width: 100%;
    max-width: 400px;
    box-shadow: var(--shadow-lg);
}

.login-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-light);
    margin-bottom: 0.25rem;
    text-align: center;
}

.login-subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.form-group input {
    width: 100%;
    padding: 0.7rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: inherit;
    outline: none;
    transition: border-color 0.2s;
}

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

.form-group input::placeholder {
    color: var(--text-secondary);
}

.login-error {
    color: var(--danger);
    font-size: 0.85rem;
    min-height: 1.25rem;
    margin-bottom: 0.5rem;
}

.login-btn {
    width: 100%;
    justify-content: center;
    padding: 0.75rem;
    font-size: 1rem;
    border-radius: var(--radius);
}

/* Nav user info */
.nav-user {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-user-info {
    text-align: right;
    line-height: 1.3;
}

.nav-user-name {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-light);
}

.nav-user-role {
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.btn--logout {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn--logout:hover {
    color: var(--text-primary);
    border-color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        top: 60px;
        left: 0;
        bottom: 0;
        z-index: 150;
        box-shadow: var(--shadow-lg);
    }
    .sidebar--collapsed {
        margin-left: -260px;
    }
}

@media (max-width: 640px) {
    .nav {
        padding: 0 1rem;
    }
    .nav-brand {
        margin-right: 1rem;
        font-size: 1rem;
    }
    .message {
        max-width: 90%;
    }
    .result-stats {
        gap: 1rem;
    }
}