:root {
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --success: #48bb78;
    --danger: #f56565;
    --bg-primary: #ffffff;
    --bg-secondary: #f7fafc;
    --bg-tertiary: #edf2f7;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 900px;
    height: 90vh;
    max-height: 800px;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
.header {
    padding: 20px 24px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 18px;
}

.reset-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-sm);
    color: white;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.reset-btn:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-1px);
}

/* Chat Container */
.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.welcome-screen.hidden {
    display: none;
}

.welcome-content h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-content p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 500px;
}

.examples {
    width: 100%;
    max-width: 600px;
}

.examples h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
}

.example-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
}

.example-card {
    padding: 16px;
    background: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    text-align: center;
}

.example-card:hover {
    border-color: var(--primary);
    background: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.example-icon {
    font-size: 32px;
}

.example-text {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
}

/* Messages */
.messages {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

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

.message.user {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.message.assistant .message-avatar {
    background: var(--bg-tertiary);
}

.message-content {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    font-size: 15px;
    line-height: 1.6;
}

.message.user .message-content {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-bottom-left-radius: 4px;
}

.message-content.final-prompt {
    background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
    color: white;
    max-width: 85%;
    position: relative;
    padding: 20px;
}

.final-prompt-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 16px;
    margin-bottom: 12px;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.final-prompt-content {
    white-space: pre-wrap;
    line-height: 1.8;
}

.copy-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-sm);
    color: white;
    font-size: 13px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.copy-btn.copied {
    background: rgba(255, 255, 255, 0.3);
}

/* Loading Indicator */
.loading-indicator {
    display: none;
    margin-top: 16px;
}

.loading-indicator.active {
    display: flex;
}

.typing-dots {
    display: flex;
    gap: 6px;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    width: fit-content;
}

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

.typing-dots span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-dots span:nth-child(3) {
    animation-delay: 0.4s;
}

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

.input-wrapper {
    display: flex;
    gap: 12px;
    align-items: flex-end;
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    padding: 12px;
    transition: all 0.2s;
}

.input-wrapper:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

#userInput {
    flex: 1;
    border: none;
    outline: none;
    font-family: inherit;
    font-size: 15px;
    line-height: 1.5;
    resize: none;
    max-height: 120px;
    overflow-y: auto;
}

#userInput::placeholder {
    color: var(--text-muted);
}

.send-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.send-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.input-hint {
    margin-top: 8px;
    font-size: 12px;
    color: var(--text-muted);
    text-align: center;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
        opacity: 0.7;
    }
    30% {
        transform: translateY(-10px);
        opacity: 1;
    }
}

/* Scrollbar */
.chat-container::-webkit-scrollbar {
    width: 8px;
}

.chat-container::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

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

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

/* Responsive */
@media (max-width: 768px) {
    body {
        padding: 0;
    }

    .container {
        max-width: 100%;
        height: 100vh;
        max-height: none;
        border-radius: 0;
    }

    .welcome-content h1 {
        font-size: 24px;
    }

    .welcome-content p {
        font-size: 14px;
    }

    .example-cards {
        grid-template-columns: repeat(2, 1fr);
    }

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