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

body {
    font-family: 'Open Sans', sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
    color: #333;
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

header {
    background: linear-gradient(120deg, #4b6cb7 0%, #182848 100%);
    color: white;
    padding: 2rem 0;
    text-align: center;
    position: relative;
}

header h1 {
    font-family: 'Merriweather', serif;
    font-size: 2.8rem;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

.anycoder-link {
    position: absolute;
    top: 15px;
    right: 20px;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.anycoder-link:hover {
    color: white;
    text-decoration: underline;
}

main {
    padding: 2rem 0;
    min-height: 70vh;
}

.chat-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: 70vh;
}

.chat-history {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.message {
    max-width: 85%;
    padding: 15px;
    border-radius: 18px;
    position: relative;
    animation: fadeIn 0.3s ease-out;
}

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

.user-message {
    background: #e3f2fd;
    align-self: flex-end;
    border-bottom-right-radius: 5px;
}

.bot-message {
    background: #f0f4f8;
    align-self: flex-start;
    border-bottom-left-radius: 5px;
}

.message-content {
    white-space: pre-wrap;
    word-break: break-word;
}

.input-area {
    display: flex;
    padding: 20px;
    background: #f8fafc;
    border-top: 1px solid #eaeef5;
}

#userInput {
    flex: 1;
    padding: 15px;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-family: 'Open Sans', sans-serif;
    font-size: 1rem;
    resize: none;
    min-height: 60px;
    max-height: 150px;
    transition: border-color 0.3s;
}

#userInput:focus {
    outline: none;
    border-color: #4b6cb7;
    box-shadow: 0 0 0 3px rgba(75, 108, 183, 0.2);
}

#sendButton {
    background: linear-gradient(120deg, #4b6cb7 0%, #182848 100%);
    color: white;
    border: none;
    border-radius: 12px;
    padding: 0 25px;
    margin-left: 15px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    white-space: nowrap;
}

#sendButton:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(75, 108, 183, 0.3);
}

#sendButton:active {
    transform: translateY(0);
}

#sendButton:disabled {
    background: #cbd5e0;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

footer {
    background: #1a202c;
    color: #a0aec0;
    text-align: center;
    padding: 1.5rem 0;
    font-size: 0.9rem;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    header h1 {
        font-size: 2.2rem;
    }
    
    .message {
        max-width: 90%;
    }
    
    .input-area {
        flex-direction: column;
    }
    
    #sendButton {
        margin-left: 0;
        margin-top: 15px;
        padding: 15px;
    }
}

/* Loading indicator */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(75, 108, 183, 0.3);
    border-radius: 50%;
    border-top-color: #4b6cb7;
    animation: spin 1s ease-in-out infinite;
    margin-left: 10px;
    vertical-align: middle;
}

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