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

html,
body {
  height: 100vh;
  max-width: 100vw;
  overflow: hidden;
}

body {
  display: flex;
  flex-direction: column;
}

header {
  padding: 10px 20px;
  background-color: aliceblue;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 15px;
  padding: 15px;
  min-height: 0;
  overflow: hidden;
}

#chat-display-area {
  background-color: aliceblue;
  border: 1px solid;
  border-radius: 5px;
  width: 100%;
  max-width: 800px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 10px;
  overflow-y: auto;
  scroll-behavior: smooth;
}

.chat-thread {
  background-color: white;
  border: navy solid 1.5px;
  width: 100%;
  max-width: 95%;
  border-radius: 5px;
  flex-shrink: 0;
  min-height: 80px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.message-in-thread {
  height: 8vh;
  word-break: break-word;
}

.info-in-thread {
  background-color: navy;
  color: white;
  display: flex;
  justify-content: space-between;
  padding: 4px 8px;
}

.timestamp-in-thread {
  font-size: small;
  display: flex;
  align-items: center;
}

.user-name-in-thread {
  color: white;
  display: flex;
  justify-content: flex-end;
  padding-right: 5px;
}

#message-form {
  border: 1px solid;
  border-radius: 5px;
  width: 100%;
  max-width: 800px;
  padding: 10px;
  background: white;
  flex-shrink: 0;
}

#message-input {
  height: 60px;
  width: 100%;
  padding: 8px;
  resize: none;
  margin-bottom: 8px;
}

#signature-and-send-area {
  display: flex;
  justify-content: space-between;
}

#user-name-input {
  padding: 5px;
}

#message-submit-button {
  padding: 5px;
}

footer {
  text-align: center;
  padding: 8px;
  background-color: aliceblue;
  font-size: 0.9rem;
  flex-shrink: 0;
}