:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --background-color: #ffffff;
    --text-color: #000000;
    --border-color: #dee2e6;
    --hover-color: #f8f9fa;
    --message-bg: #f1f0f0;
    --user-message-bg: #007bff;
    --user-message-color: #ffffff;
}

[data-theme="dark"] {
    --primary-color: #0d6efd;
    --secondary-color: #adb5bd;
    --background-color: #212529;
    --text-color: #f8f9fa;
    --border-color: #495057;
    --hover-color: #343a40;
    --message-bg: #343a40;
    --user-message-bg: #0d6efd;
    --user-message-color: #ffffff;
}

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

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

.chat-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--background-color);
}

.chat-header {
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-left h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.welcome-message {
    text-align: center;
    padding: 2rem;
    background-color: var(--message-bg);
    border-radius: 8px;
    margin: 1rem 0;
}

.origin-info {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.origin-info p {
    margin: 0.5rem 0;
    font-size: 0.95rem;
    color: var(--text-color);
    opacity: 0.9;
}

.origin-info p:last-child {
    font-style: italic;
    font-size: 0.9rem;
}

.message {
    max-width: 70%;
    padding: 0.8rem 1rem;
    border-radius: 12px;
    margin-bottom: 0.5rem;
    word-wrap: break-word;
}

.user-message {
    background-color: var(--user-message-bg);
    color: var(--user-message-color);
    align-self: flex-end;
    border-bottom-right-radius: 4px;
}

.bot-message {
    background-color: var(--message-bg);
    align-self: flex-start;
    border-bottom-left-radius: 4px;
}

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

.input-wrapper {
    display: flex;
    gap: 0.5rem;
    align-items: flex-end;
}

textarea {
    flex: 1;
    padding: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    resize: none;
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1rem;
    min-height: 40px;
    max-height: 120px;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.icon-button {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

.icon-button:hover {
    background-color: var(--hover-color);
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    z-index: 1000;
}

.modal-content {
    position: relative;
    background-color: var(--background-color);
    margin: 10% auto;
    padding: 1rem;
    width: 90%;
    max-width: 500px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.close-button {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

/* Theme Toggle */
.theme-toggle {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--secondary-color);
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

/* Responsive Design */
@media (max-width: 768px) {
    .chat-container {
        height: 100vh;
    }
    
    .message {
        max-width: 85%;
    }
    
    .modal-content {
        margin: 20% auto;
        width: 95%;
    }
}