:root {
    --primary-color: #c3002f;
    --secondary-color: #6c757d;
    --background-color: #f8f9fa;
    --surface-color: #ffffff;
    --user-message-bg: var(--primary-color);
    --ai-message-bg: #e9ecef;
    --system-message-bg: #fff3cd;
    --text-color-light: #ffffff;
    --text-color-dark: #212529;
    --font-family: 'Roboto', sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Open Sans', 'Helvetica Neue';
    --border-radius: 12px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

html, body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color-dark);
    line-height: 1.6;
    height: 100%;
}

#app-container {
    display: flex;
    flex-direction: column;
    height: 100%;
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--surface-color);
    box-shadow: var(--box-shadow);
}

header {
    background: var(--primary-color);
    color: var(--text-color-light);
    padding: 1rem 1.5rem;
    border-bottom: 1px solid rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.header-content {
    flex-grow: 1;
    text-align: center;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

header p {
    font-size: 0.9rem;
    opacity: 0.9;
}

#new-chat-button {
    background: none;
    border: 2px solid var(--text-color-light);
    color: var(--text-color-light);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, transform 0.2s;
    flex-shrink: 0;
}

#new-chat-button:hover {
    background-color: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
}

#chat-container {
    flex-grow: 1;
    padding: 1.5rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    display: flex;
    max-width: 85%;
    animation: fadeIn 0.3s ease-in-out;
}

.message div {
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius);
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.user-message {
    align-self: flex-end;
    margin-left: auto;
}

.user-message div {
    background-color: var(--user-message-bg);
    color: var(--text-color-light);
    border-bottom-right-radius: 4px;
}

.user-message img {
    max-width: 100%;
    border-radius: 8px;
    margin-bottom: 8px;
}

.ai-message {
    align-self: flex-start;
}

.ai-message div {
    background-color: var(--ai-message-bg);
    color: var(--text-color-dark);
    border-bottom-left-radius: 4px;
}

.system-message {
    align-self: center;
    width: 100%;
    max-width: 100%;
}

.system-message div {
    background-color: var(--system-message-bg);
    color: var(--text-color-dark);
    border: 1px solid #ffeeba;
    font-size: 0.9rem;
}

.ai-message ul, .ai-message ol {
    padding-left: 20px;
    margin-top: 8px;
    margin-bottom: 8px;
}

.ai-message li {
    margin-bottom: 4px;
}

footer {
    padding: 1rem 1.5rem;
    background-color: var(--surface-color);
    border-top: 1px solid #dee2e6;
}

#image-preview-container {
    position: relative;
    margin-bottom: 0.5rem;
    display: none; /* Hidden by default */
}

.preview-image {
    width: 80px;
    height: 80px;
    object-fit: cover;
    border-radius: var(--border-radius);
    border: 1px solid #dee2e6;
}

.remove-image-btn {
    position: absolute;
    top: -5px;
    right: -5px;
    width: 24px;
    height: 24px;
    background-color: rgba(0,0,0,0.7);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 14px;
}


#message-form {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

#message-input {
    flex-grow: 1;
    padding: 0.75rem;
    border: 1px solid #ced4da;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: var(--font-family);
    transition: border-color 0.2s, box-shadow 0.2s;
    background-color: var(--surface-color);
    color: var(--text-color-dark);
}

#message-input::placeholder {
    color: var(--secondary-color);
}

#message-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(195, 0, 47, 0.25);
}

#upload-button {
    flex-shrink: 0;
    border: none;
    background: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

#upload-button:hover {
    background-color: #e9ecef;
}

#send-button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border: none;
    background-color: var(--primary-color);
    color: var(--text-color-light);
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

#send-button:hover:not(:disabled) {
    background-color: #960025;
}

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

#send-button:disabled {
    background-color: var(--secondary-color);
    cursor: not-allowed;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    padding: 10px 0;
}

.typing-indicator span {
    height: 8px;
    width: 8px;
    float: left;
    margin: 0 2px;
    background-color: var(--secondary-color);
    display: block;
    border-radius: 50%;
    opacity: 0.4;
    animation: typing 1s infinite;
}

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

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

@keyframes typing {
    0% { opacity: 0.4; transform: translateY(0); }
    50% { opacity: 1; transform: translateY(-4px); }
    100% { opacity: 0.4; transform: translateY(0); }
}


/* Stop Generating Button */
#stop-generating-container {
    display: flex;
    justify-content: center;
    padding: 0.5rem 0;
}

#stop-generating-button {
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--secondary-color);
    background-color: transparent;
    color: var(--secondary-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.2s, color 0.2s;
}

#stop-generating-button:hover {
    background-color: var(--secondary-color);
    color: var(--text-color-light);
}

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

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

@media (max-width: 600px) {
    #app-container {
        box-shadow: none;
    }
    header, footer {
        padding: 0.75rem 1rem;
    }
    header {
        flex-direction: row;
        justify-content: space-between;
    }
    .header-content {
       flex-grow: 1;
       text-align: left;
       margin-right: 1rem;
    }
    #new-chat-button {
        order: 2;
    }
    #chat-container {
        padding: 1rem;
    }
}