style.css

:root {
  --md-sys-color-primary: #6750A4;
  --md-sys-color-on-primary: #FFFFFF;
  --md-sys-color-primary-container: #EADDFF;
  --md-sys-color-on-primary-container: #21005D;
  --md-sys-color-secondary: #625B71;
  --md-sys-color-on-secondary: #FFFFFF;
  --md-sys-color-secondary-container: #E8DEF8;
  --md-sys-color-on-secondary-container: #1D192B;
  --md-sys-color-surface: #FEF7FF;
  --md-sys-color-on-surface: #1D1B20;
  --md-sys-color-surface-variant: #E7E0EC;
  --md-sys-color-on-surface-variant: #49454F;
  --md-sys-color-outline: #79747E;
  --md-sys-color-time: #000000;
}

body {
  font-family: 'Roboto', sans-serif;
  margin: 0;
  padding: 0;
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.container {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  max-width: 100%;
  margin: auto;
  padding: 16px;
}

.card {
  background-color: var(--md-sys-color-surface-variant);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
}

.input-field {
  margin-bottom: 16px;
}

.input-field input {
  width: calc(100% - 24px);
  padding: 12px;
  border: 1px solid var(--md-sys-color-outline);
  border-radius: 4px;
  font-size: 16px;
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
}

.btn {
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  border: none;
  padding: 12px 24px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  text-transform: uppercase;
  cursor: pointer;
  transition: background-color 0.3s;
}

.btn:hover {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}

.chat-container {
  display: none;
  flex-grow: 1;
  overflow: hidden;
}

.user-list {
  width: 200px;
  padding: 16px;
  background-color: var(--md-sys-color-surface-variant);
  border-right: 1px solid var(--md-sys-color-outline);
  overflow-y: auto;
}

#messages {
  list-style-type: none;
  padding: 0;
  margin: 0;
  max-height: calc(100vh - 160px);
  overflow-y: auto;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

#messages li {
  padding: 12px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.message-content {
  max-width: 60%;
  padding: 10px;
  border-radius: 10px;
  margin-bottom: 10px;
  word-wrap: break-word;
  background-color: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface);
  position: relative;
  display: flex;
  flex-direction: column;
}

.message-right {
  align-self: flex-end;
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
}

.message-left {
  align-self: flex-start;
  background-color: var(--md-sys-color-secondary);
  color: var(--md-sys-color-on-secondary);
}

.message-id {
  font-size: 0.8em;
  margin-bottom: 5px;
}

.message-time {
  font-size: 0.8em;
  position: absolute;
  bottom: -1.5em;
  right: 0;
  white-space: nowrap;
  color: var(--md-sys-color-time);
}

#form {
  display: flex;
  align-items: center;
  padding: 8px;
  background-color: var(--md-sys-color-surface-variant);
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  box-sizing: border-box;
}

#input {
  flex-grow: 1;
  margin-right: 8px;
  padding: 12px;
  border: 1px solid var(--md-sys-color-outline);
  border-radius: 20px;
  font-size: 16px;
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
}

.icon-btn {
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.3s;
  padding: 0;
  margin-left: 8px;
}

.icon-btn:hover {
  background-color: var(--md-sys-color-primary-container);
}

.icon-btn svg {
  width: 24px;
  height: 24px;
}

#imageUpload {
  display: none;
}

#locationInfo {
  position: fixed;
  top: 16px;
  right: 90px;
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
  padding: 8px 16px;
  border-radius: 16px;
  font-size: 14px;
  z-index: 1;
}

.menu-container {
  position: fixed;
  top: 16px;
  right: 16px;
  display: flex;
  align-items: center;
  z-index: 2;
}

.menu-btn {
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  border: none;
  padding: 8px 16px;
  border-radius: 16px;
  font-size: 14px;
  cursor: pointer;
}

.menu-content {
  display: none;
  position: absolute;
  top: 40px;
  right: 0;
  background-color: var(--md-sys-color-surface-variant);
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  z-index: 1;
  overflow: hidden;
  transition: max-height 0.3s ease;
  max-height: 0;
}

.menu-content a {
  color: var(--md-sys-color-on-surface);
  padding: 8px 16px;
  text-decoration: none;
  display: block;
  transition: background-color 0.3s;
}

.menu-content a:hover {
  background-color: var(--md-sys-color-outline);
}

.menu-content.show {
  display: block;
  max-height: 500px;
}

.message-image {
  max-width: 100%;
  max-height: 200px;
  margin-top: 10px;
  border-radius: 5px;
}

.header {
  text-align: center;
  margin-top: 16px;
}

.footer {
  text-align: center;
  margin-top: auto;
  padding: 16px;
}

#countdown {
  font-size: 16px;
  color: var(--md-sys-color-on-surface);
  background-color: var(--md-sys-color-surface-variant);
  padding: 10px;
  border-radius: 8px;
  text-align: center;
  margin-bottom: 10px;
}

.read-status {
  font-size: 0.8em;
  color: #888;
  text-align: right;
  margin-top: 5px;
}

.sonnet-message {
  font-style: italic;
  color: #6a5acd;
  background-color: #f0f8ff;
  border-left: 3px solid #6a5acd;
  padding-left: 10px;
}

@media (max-width: 600px) {
  .user-list {
    display: none;
  }
  .message-content {
    max-width: 80%;
  }
  #form {
    flex-wrap: nowrap;
  }
  #input {
    width: auto;
    margin-bottom: 0;
  }
  #imageUpload {
    width: auto;
  }
  #locationInfo {
    right: 60px;
  }
  .menu-container {
    right: 16px;
  }
}