:root {
    --ai-message-bg: #f0f0f0;
    --user-message-bg: #007AFF;
    --user-message-color: white;
}

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

.app {
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    padding: 1rem;
    background: #fff;
    border-bottom: 1px solid #eee;
    text-align: center;
}

.logo {
    font-size: 1.2rem;
    font-weight: bold;
}

.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    background: #fafafa;
}

.messages {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    max-width: 70%;
    padding: 0.8rem;
    border-radius: 1rem;
    position: relative;
    overflow-wrap: break-word;
}

.message ul,
.message ol {
    margin: 0;
    padding-left: 1.2em;
}

.message li {
    margin: 0.3em 0;
}

.message-ai {
    align-self: flex-start;
    background: var(--ai-message-bg);
    margin-left: 40px;
}

.message-user {
    align-self: flex-end;
    background: var(--user-message-bg);
    color: var(--user-message-color);
}

.input-area {
    padding: 1rem;
    background: #fff;
    border-top: 1px solid #eee;
}

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

.message-input {
    flex: 1;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 0.5rem;
    resize: none;
    max-height: 150px;
}

.send-btn, .upload-btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.5rem;
    background: #007AFF;
    color: white;
    cursor: pointer;
}

.send-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
}