:root {
  --scale-blue: #b5e5dc;
  --scale-dark-blue: #95c5bc;
  --scale-gray: #fafaf9;
  --scale-dark-gray: #dadad9;
  --scale-green: #405650;
  --scale-yellow: #e1ae25;
}

html {
  height: 100%;
}

body {
  display: flex;
  height: 100%;
  justify-content: center;
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1em;
}

a {
  color: var(--scale-green);
}

#chat {
  display: flex;
  flex-direction: column;
  max-width: 1140px;
  width: 100%;
}

#header {
  background: white;
  display: flex;
  padding: 0 15px;
}
#header-logo > img {
  height: 25px;
  padding: 15px 0;
}
#header-navigation {
  align-items: center;
  display: flex;
  flex-grow: 1;
  justify-content: end;
  list-style-type: none;
}
#header-navigation > li > a {
  color: var(--scale-green);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1.125rem;
  letter-spacing: 1px;
  margin-left: 35px;
  position: relative;
  text-decoration: none;
  text-transform: uppercase;
}
#header-navigation > li > a:after {
  background: var(--scale-yellow);
  bottom: -8px;
  content: '';
  height: 2px;
  left: 0;
  position: absolute;
  transform: scaleX(0);
  transform-origin: bottom left;
  transition: transform .4s;
  width: 100%;
}
#header-navigation > li > a:hover:after {
  transform: scaleX(1);
  transform-origin: bottom left;
  transition: transform .4s;
}

#history {
  border-radius: 10px;
  flex-grow: 1;
  padding: 15px;
  margin-top: 30px;
  overflow-y: auto;
  display: flex;
  flex-direction: column-reverse;
}

.msg {
  display: flex;
  margin-bottom: 15px;
  line-height: 1.25;
}
.msg:last-of-type {
  margin: 0;
}
.user-msg {
  flex-direction: row-reverse;
}

.bubble {
  border-radius: 10px;
  max-width: calc((100% - 30px) / 2 + 10%);
  padding: 10px;
}
.scale-bubble {
  background: var(--scale-gray);
  border: 1px solid var(--scale-dark-gray);
}
.user-bubble {
  background: var(--scale-blue);
  border: 1px solid var(--scale-dark-blue);
}

.scale-img {
  margin: 10px 10px 10px 0;
  width: 15px;
}
.user-img {
  margin: 10px 0 10px 10px;
  width: 15px;
}
.name {
  font-family: Arial, Helvetica, sans-serif;
  font-weight: bold;
  margin: 0 10px 10px 0;
  text-transform: uppercase;
}

#input {
  align-items: center;
  display: flex;
  margin: 15px;
  position: relative;
}
#textbox {
  appearance: none;
  background: #fff;
  border: 1px solid var(--scale-blue);
  border-radius: 10px;
  box-shadow: 0 0 4px -1px var(--scale-blue);
  flex: 1;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1rem;
  padding: 15px 57px 15px 15px;
}
#textbox:focus {
  border-color: var(--scale-yellow);
  box-shadow: 0 0 4px -1px var(--scale-yellow);
  outline: none;
}
#textbox::placeholder {
  color: #aaa;
}
#button {
  border: none;
  border-radius: 5px;
  background-color: white;
  height: 27px;
  padding: 5px;
  position: absolute;
  right: 15px;
}
#button:hover:enabled {
  background-color: #eee;
  cursor: pointer;
}
#button > img {
  height: 15px;
}

#disclaimer {
  font-size: .7rem;
  padding: 15px;
  text-align: center;
}

@media screen and (max-width: 600px) {
  body {
    font-size: 0.9em; /* slightly smaller text for mobile */
  }
  #chat {
    margin: 0 5px; /* narrower side margins */
    max-width: 100%;
  }
  #header {
    padding: 0 10px;
  }
  #history {
    padding: 10px;
    margin-top: 20px;
  }
  #input {
    margin: 10px;
  }
}