style.css

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

:root {
--primary-color: #007AFF;
--primary-hover: #0051D5;
--background: #F5F5F7;
--surface: #FFFFFF;
--text-primary: #1D1D1F;
--text-secondary: #86868B;
--border: #D2D2D7;
--shadow: rgba(0, 0, 0, 0.1);
--user-message: #007AFF;
--assistant-message: #E5E5EA;
}

body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
background: var(--background);
color: var(--text-primary);
line-height: 1.6;
overflow: hidden;
}

.container {
max-width: 900px;
margin: 0 auto;
height: 100vh;
display: flex;
flex-direction: column;
background: var(--surface);
box-shadow: 0 0 50px var(--shadow);
}

.header {
background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
color: white;
padding: 2rem;
text-align: center;
border-bottom: 1px solid rgba(255, 255, 255, 0.1);
backdrop-filter: blur(10px);
}

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

.title {
font-size: 2rem;
font-weight: 700;
margin-bottom: 0.5rem;
letter-spacing: -0.5px;
}

.subtitle {
font-size: 0.95rem;
opacity: 0.9;
font-weight: 400;
}

.built-with {
display: inline-block;
color: white;
text-decoration: none;
font-size: 0.85rem;
padding: 0.5rem 1rem;
background: rgba(255, 255, 255, 0.15);
border-radius: 20px;
transition: all 0.3s ease;
backdrop-filter: blur(10px);
}

.built-with:hover {
background: rgba(255, 255, 255, 0.25);
transform: translateY(-2px);
}

.chat-container {
flex: 1;
display: flex;
flex-direction: column;
overflow: hidden;
}

.messages-container {
flex: 1;
overflow-y: auto;
padding: 2rem;
scroll-behavior: smooth;
}

.messages-container::-webkit-scrollbar {
width: 8px;
}

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

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

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

.welcome-message {
text-align: center;
padding: 3rem 1rem;
color: var(--text-secondary);
}

.welcome-icon {
font-size: 4rem;
margin-bottom: 1rem;
animation: float 3s ease-in-out infinite;
}

@keyframes float {
0%, 100% { transform: translateY(0px); }
50% { transform: translateY(-10px); }
}

.welcome-message h2 {
font-size: 1.5rem;
color: var(--text-primary);
margin-bottom: 0.5rem;
font-weight: 600;
}

.welcome-message p {
font-size: 1rem;
max-width: 500px;
margin: 0 auto;
}

.message {
display: flex;
margin-bottom: 1.5rem;
animation: slideIn 0.3s ease;
}

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

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

.message-content {
max-width: 70%;
padding: 1rem 1.25rem;
border-radius: 18px;
font-size: 0.95rem;
line-height: 1.5;
word-wrap: break-word;
}

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

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

.typing-indicator {
display: flex;
gap: 4px;
padding: 1rem 1.25rem;
}

.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: 0.7;
}
30% {
transform: translateY(-10px);
opacity: 1;
}
}

.input-container {
padding: 1.5rem;
background: var(--surface);
border-top: 1px solid var(--border);
}

.input-wrapper {
display: flex;
gap: 0.75rem;
align-items: flex-end;
background: var(--background);
border-radius: 24px;
padding: 0.5rem;
border: 2px solid transparent;
transition: all 0.3s ease;
}

.input-wrapper:focus-within {
border-color: var(--primary-color);
background: var(--surface);
}

#userInput {
flex: 1;
border: none;
background: transparent;
padding: 0.75rem 1rem;
font-size: 0.95rem;
font-family: inherit;
resize: none;
max-height: 120px;
outline: none;
color: var(--text-primary);
}

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

.send-btn {
width: 40px;
height: 40px;
border: none;
background: var(--primary-color);
color: white;
border-radius: 50%;
cursor: pointer;
display: flex;
align-items: center;
justify-content: center;
transition: all 0.3s ease;
flex-shrink: 0;
}

.send-btn:hover:not(:disabled) {
background: var(--primary-hover);
transform: scale(1.05);
}

.send-btn:active:not(:disabled) {
transform: scale(0.95);
}

.send-btn:disabled {
background: var(--border);
cursor: not-allowed;
opacity: 0.5;
}

.status {
margin-top: 0.75rem;
text-align: center;
font-size: 0.85rem;
color: var(--text-secondary);
}

.loading-overlay {
position: fixed;
top: 0;
left: 0;
right: 0;
bottom: 0;
background: rgba(0, 0, 0, 0.7);
backdrop-filter: blur(10px);
display: flex;
align-items: center;
justify-content: center;
z-index: 1000;
}

.loading-overlay.hidden {
display: none;
}

.loading-content {
background: var(--surface);
padding: 3rem;
border-radius: 20px;
text-align: center;
max-width: 400px;
box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.loading-spinner {
width: 60px;
height: 60px;
border: 4px solid var(--border);
border-top-color: var(--primary-color);
border-radius: 50%;
animation: spin 1s linear infinite;
margin: 0 auto 1.5rem;
}

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

.loading-content h3 {
font-size: 1.5rem;
margin-bottom: 0.5rem;
font-weight: 600;
}

.loading-content p {
color: var(--text-secondary);
margin-bottom: 1.5rem;
}

.progress-bar {
width: 100%;
height: 8px;
background: var(--border);
border-radius: 4px;
overflow: hidden;
margin-bottom: 0.5rem;
}

.progress-fill {
height: 100%;
background: linear-gradient(90deg, var(--primary-color), #667eea);
width: 0%;
transition: width 0.3s ease;
border-radius: 4px;
}

.progress-text {
font-size: 0.9rem;
color: var(--text-secondary);
font-weight: 500;
}

@media (max-width: 768px) {
.container {
max-width: 100%;
}

.header {
padding: 1.5rem;
}

.title {
font-size: 1.5rem;
}

.messages-container {
padding: 1rem;
}

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

.loading-content {
margin: 1rem;
padding: 2rem;
}
}