:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-700: #374151;
    --gray-900: #111827;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 40px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

main {
    padding: 40px;
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    border-bottom: 2px solid var(--gray-200);
}

.tab {
    padding: 12px 24px;
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-size: 1rem;
    color: var(--gray-700);
    transition: all 0.3s;
}

.tab:hover {
    color: var(--primary);
}

.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
    font-weight: 600;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
}

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

input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--gray-200);
    border-radius: 8px;
    font-size: 1rem;
}

.btn {
    padding: 12px 32px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
}

.btn-primary:disabled {
    background: var(--gray-200);
    cursor: not-allowed;
}

.file-upload-area {
    border: 2px dashed var(--gray-200);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    margin-bottom: 20px;
}

.upload-icon {
    font-size: 4rem;
}

.chat-messages {
    height: 400px;
    overflow-y: auto;
    padding: 20px;
    background: var(--gray-50);
}

.message {
    margin-bottom: 16px;
    padding: 12px 16px;
    border-radius: 12px;
    max-width: 80%;
}

.message.user {
    background: var(--primary);
    color: white;
    margin-left: auto;
}

.message.assistant {
    background: white;
}

.results.hidden {
    display: none;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    margin: 0 auto;
    animation: spin 1s linear infinite;
}

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

.result-content {
    background: var(--gray-50);
    padding: 30px;
    border-radius: 12px;
    white-space: pre-wrap;
}

.result-content.hidden {
    display: none;
}