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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --shadow: rgba(0, 0, 0, 0.05);
    --shadow-lg: rgba(0, 0, 0, 0.1);
}

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

.app-container {
    display: flex;
    height: 100vh;
    max-width: 1400px;
    margin: 0 auto;
    background: var(--surface);
    box-shadow: 0 0 0 1px var(--border);
}

.sidebar {
    width: 280px;
    background: var(--surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 24px;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.sidebar-header h2 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
}

.upload-section {
    margin-bottom: 24px;
}

.upload-button {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 12px 16px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    justify-content: center;
}

.upload-button:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.upload-button:active {
    transform: translateY(0);
}

.file-info {
    margin-top: 16px;
    padding: 12px;
    background: var(--bg);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.file-name {
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 4px;
    word-break: break-all;
}

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

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

.file-status.ready {
    color: var(--success);
}

.progress-container {
    margin-top: 12px;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 8px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 0%;
    position: relative;
    overflow: hidden;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-text {
    font-size: 11px;
    color: var(--text-light);
    text-align: center;
}

.clear-button {
    margin-top: auto;
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 10px 16px;
    background: transparent;
    color: var(--text-light);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    justify-content: center;
}

.clear-button:hover {
    background: var(--bg);
    color: var(--text);
    border-color: var(--text-light);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    background: var(--bg);
}

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

.chat-messages::-webkit-scrollbar-track {
    background: transparent;
}

.chat-messages::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

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

.welcome-message {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-light);
}

.welcome-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.welcome-message h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

.welcome-message p {
    font-size: 14px;
    color: var(--text-light);
}

.message {
    margin-bottom: 20px;
    animation: fadeIn 0.3s ease;
}

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

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

.message-assistant {
    display: flex;
    justify-content: flex-start;
}

.message-content {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.6;
    word-wrap: break-word;
}

.message-user .message-content {
    background: var(--primary);
    color: white;
    border-bottom-right-radius: 4px;
}

.message-assistant .message-content {
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    border-bottom-left-radius: 4px;
    box-shadow: 0 1px 2px var(--shadow);
}

.chat-input-container {
    padding: 20px 24px;
    background: var(--surface);
    border-top: 1px solid var(--border);
}

.chat-form {
    display: flex;
    gap: 12px;
    align-items: center;
}

.question-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    background: var(--surface);
    color: var(--text);
    outline: none;
    transition: all 0.2s;
}

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

.question-input:disabled {
    background: var(--bg);
    color: var(--text-light);
    cursor: not-allowed;
}

.send-button {
    width: 44px;
    height: 44px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    flex-shrink: 0;
}

.send-button:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.send-button:active:not(:disabled) {
    transform: translateY(0);
}

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

.loading {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
}

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

.error-message {
    background: #fef2f2;
    color: var(--error);
    padding: 12px 16px;
    border-radius: 10px;
    margin: 10px 0;
    border: 1px solid #fecaca;
    font-size: 13px;
}

/* Registration form styles */
.registration-step {
    padding: 40px 20px;
}

.input-container {
    max-width: 500px;
    margin: 30px auto 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.registration-input {
    width: 100%;
    padding: 14px 18px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 16px;
    background: var(--surface);
    color: var(--text);
    outline: none;
    transition: all 0.2s;
}

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

.registration-button {
    padding: 14px 24px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.registration-button:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.registration-button:active {
    transform: translateY(0);
}

.upload-section-main {
    max-width: 500px;
    margin: 30px auto 0;
    text-align: center;
}

.upload-button-main {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 16px 32px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.upload-button-main:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.upload-button-main:active {
    transform: translateY(0);
}

.link-container {
    max-width: 600px;
    margin: 30px auto 0;
    display: flex;
    gap: 12px;
    align-items: center;
}

.link-input {
    flex: 1;
    padding: 14px 18px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    background: var(--bg);
    color: var(--text);
    font-family: monospace;
    outline: none;
}

.copy-button {
    padding: 14px 24px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.copy-button:hover {
    background: var(--primary-dark);
}

.share-buttons {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-top: 24px;
}

.share-label {
    font-size: 13px;
    color: var(--text-light);
}

.share-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-light);
    transition: all 0.2s;
}

.share-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    transform: translateY(-2px);
}

.link-note {
    margin-top: 20px;
    font-size: 13px;
    color: var(--text-light);
}

.user-info {
    margin-bottom: 24px;
    padding: 16px;
    background: var(--bg);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.user-description {
    font-size: 14px;
    color: var(--text-light);
    text-align: center;
}

@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border);
        padding: 16px;
    }

    .message-content {
        max-width: 85%;
    }

    .link-container {
        flex-direction: column;
    }

    .link-input {
        width: 100%;
    }

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