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

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: #f7f7f7;
}

.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.app-header {
    background: rgba(0, 0, 0, 0.1);
    color: white;
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.app-header h1 {
    font-size: 28px;
    margin-bottom: 5px;
}

.app-header p {
    font-size: 14px;
    opacity: 0.9;
}

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

.messages-list {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

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

.messages-list::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.1);
}

.messages-list::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 4px;
}

.messages-list::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}

.message {
    display: flex;
    margin-bottom: 8px;
    animation: slideIn 0.3s ease-in-out;
}

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

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

.bot-message {
    justify-content: flex-start;
}

.message-content {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: 12px;
    word-wrap: break-word;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.user-content {
    background: #667eea;
    color: white;
    border-bottom-right-radius: 4px;
}

.bot-content {
    background: white;
    color: #333;
    border-bottom-left-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.message-text {
    margin: 0;
    font-size: 14px;
    line-height: 1.4;
}

.message-time {
    font-size: 12px;
    opacity: 0.6;
}

.typing-indicator {
    display: flex;
    gap: 4px;
    align-items: center;
    padding: 12px 16px;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: white;
    animation: bounce 1.4s infinite;
}

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

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

@keyframes bounce {
    0%, 80%, 100% {
        opacity: 0.5;
        transform: translateY(0);
    }
    40% {
        opacity: 1;
        transform: translateY(-8px);
    }
}

.chat-input-form {
    padding: 16px 20px;
    background: white;
    border-top: 1px solid #e0e0e0;
}

.input-wrapper {
    display: flex;
    gap: 8px;
    align-items: flex-end;
}

.chat-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid #e0e0e0;
    border-radius: 24px;
    font-size: 14px;
    font-family: inherit;
    resize: none;
    max-height: 120px;
    outline: none;
    transition: border-color 0.2s;
}

.chat-input:focus {
    border-color: #667eea;
}

.chat-input:disabled {
    background-color: #f5f5f5;
    opacity: 0.6;
}

.send-button {
    background: #667eea;
    border: none;
    color: white;
    padding: 10px 14px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, transform 0.1s;
    font-size: 18px;
    font-weight: bold;
}

.send-button:hover:not(:disabled) {
    background: #5568d3;
    transform: scale(1.05);
}

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

.send-button:disabled {
    background: #ccc;
    cursor: not-allowed;
    opacity: 0.6;
}

@media (max-width: 768px) {
    .chat-input-form {
        padding: 12px 16px;
    }

    .chat-input {
        font-size: 16px;
    }

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

    .app-header h1 {
        font-size: 22px;
    }
}