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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --background: #ffffff;
    --sidebar-bg: #f8fafc;
    --border: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --success: #10b981;
    --error: #ef4444;
    --user-message-bg: #dbeafe;
    --assistant-message-bg: #f1f5f9;
}

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

.container {
    display: flex;
    height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 320px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.sidebar-header {
    padding: 24px 20px;
    border-bottom: 1px solid var(--border);
}

.sidebar-header h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

.subtitle {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.upload-section {
    padding: 20px;
}

.upload-label {
    display: block;
}

.upload-button {
    display: block;
    width: 100%;
    padding: 12px 16px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
}

.upload-button:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.documents-section {
    flex: 1;
    padding: 20px;
    min-height: 0;
}

.documents-section h2 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    margin-bottom: 12px;
    letter-spacing: 0.5px;
}

.documents-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    overflow-y: auto;
}

.document-item {
    padding: 12px;
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
}

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

.document-name {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-word;
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.document-meta {
    font-size: 11px;
    color: var(--text-light);
    margin-top: 4px;
}

.delete-button {
    padding: 4px 8px;
    background: transparent;
    border: 1px solid var(--error);
    color: var(--error);
    border-radius: 4px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
    flex-shrink: 0;
}

.delete-button:hover {
    background: var(--error);
    color: white;
}

.empty-state {
    font-size: 13px;
    color: var(--text-light);
    text-align: center;
    padding: 24px 8px;
}

/* Chat Container */
.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--background);
    overflow: hidden;
}

.chat-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    background: var(--background);
}

.chat-header h2 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 4px;
}

.status {
    font-size: 12px;
    color: var(--text-secondary);
}

.status.loading {
    color: var(--primary);
}

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

.message {
    display: flex;
    gap: 12px;
    animation: slideIn 0.3s ease;
}

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

.user-message {
    justify-content: flex-end;
}

.user-message .message-content {
    background: var(--user-message-bg);
    color: var(--text-primary);
    border-radius: 12px;
    max-width: 70%;
}

.assistant-message .message-content {
    background: var(--assistant-message-bg);
    color: var(--text-primary);
    border-radius: 12px;
    max-width: 70%;
}

.message-content {
    padding: 12px 16px;
    word-wrap: break-word;
    word-break: break-word;
}

.message-content p {
    font-size: 14px;
    line-height: 1.5;
    margin: 0;
}

.message-content p + p {
    margin-top: 8px;
}

/* Context Container */
.context-container {
    max-height: 200px;
    border-top: 1px solid var(--border);
    background: #fafafa;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: all 0.3s ease;
}

.context-container.hidden {
    max-height: 0;
}

.context-header {
    padding: 12px 16px;
    background: var(--sidebar-bg);
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.context-header h3 {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.close-button {
    background: none;
    border: none;
    font-size: 20px;
    color: var(--text-light);
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

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

.context-content {
    padding: 12px 16px;
    overflow-y: auto;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Input Area */
.input-container {
    padding: 20px 24px;
    border-top: 1px solid var(--border);
    background: var(--background);
}

.input-wrapper {
    display: flex;
    gap: 12px;
    margin-bottom: 8px;
}

#message-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    color: var(--text-primary);
    outline: none;
    transition: all 0.2s ease;
}

#message-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

#message-input:disabled {
    background: var(--sidebar-bg);
    color: var(--text-light);
    cursor: not-allowed;
}

.send-button {
    padding: 12px 24px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.send-button:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.send-button:disabled {
    background: var(--text-light);
    cursor: not-allowed;
    opacity: 0.6;
}

.send-button.loading {
    opacity: 0.8;
}

.hint {
    font-size: 12px;
    color: var(--text-light);
}

/* Loading Animation */
.loading-spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin-right: 8px;
}

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

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-light);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        max-height: 200px;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }

    .documents-list {
        max-height: 100px;
    }

    .chat-container {
        flex: 1;
    }

    .user-message .message-content,
    .assistant-message .message-content {
        max-width: 90%;
    }

    .input-wrapper {
        flex-direction: column;
    }

    .send-button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .sidebar-header {
        padding: 16px 12px;
    }

    .sidebar-header h1 {
        font-size: 20px;
    }

    .chat-messages {
        padding: 16px;
        gap: 12px;
    }

    .input-container {
        padding: 12px 16px;
    }
}