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

body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f2f5;
    color: #333;
}

#app {
    width: 100%;
    max-width: 420px;
    border: 1px solid #ddd;
    border-radius: 10px;
    overflow: hidden;
    background-color: #fff;
    display: flex;
    flex-direction: column;
    height: 90vh;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

/* Header */
header {
    background-color: #075e54;
    color: #fff;
    padding: 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-content {
    display: flex;
    align-items: center;
    width: 100%;
    justify-content: space-between;
}

.settings-btn {
    font-size: 18px;
    background: none;
    border: none;
    color: white;
    cursor: pointer;
}

/* Chat Box */
#chat-box {
    flex: 1;
    padding: 15px;
    overflow-y: auto;
    background-color: #e5ddd5;
}

.message {
    max-width: 75%;
    margin-bottom: 10px;
    padding: 10px;
    border-radius: 8px;
    font-size: 14px;
    line-height: 1.4;
    position: relative;
}

.message.sent {
    background-color: #dcf8c6;
    align-self: flex-end;
    text-align: right;
}

.message.received {
    background-color: #fff;
    align-self: flex-start;
    text-align: left;
}

/* Message Form */
#message-form {
    display: flex;
    align-items: center;
    padding: 10px;
    background-color: #f0f2f5;
    border-top: 1px solid #ddd;
}

#message-input {
    flex: 1;
    padding: 10px;
    font-size: 16px;
    border: 1px solid #ddd;
    border-radius: 20px;
    margin-right: 10px;
    outline: none;
}

button {
    padding: 10px 15px;
    font-size: 20px;
    color: #fff;
    background-color: #075e54;
    border: none;
    border-radius: 50%;
    cursor: pointer;
}

/* Responsive Design */
@media (max-width: 480px) {
    #app {
        height: 100vh;
        max-width: 100%;
        border-radius: 0;
    }
}