:root {
  --bg-color: #f0f2f5;
  /* These will be the defaults, but JS will override them with custom colors */
  --header-bg: linear-gradient(to bottom, rgba(93, 173, 236, 0.7), rgba(53, 122, 189, 0.7));
  --button-bg: linear-gradient(to bottom, #5dadec, #4a90e2);
  --button-hover-bg: linear-gradient(to bottom, #6db9f2, #5a9ee8);
  --button-active-bg: linear-gradient(to top, #5dadec, #4a90e2);
  --message-sent-bg: rgba(60, 190, 255, 0.7);
  --button-border-color: #2a6199;
  
  --button-text-color: white;
  --text-color: #333;
  --input-bg: rgba(255, 255, 255, 0.6);
  --message-received-bg: rgba(255, 255, 255, 0.5);
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(255, 255, 255, 0.3);
  --shiny-shadow: 0 4px 12px rgba(31, 38, 135, 0.2);
  --inner-shadow: inset 0 1px 1px rgba(0,0,0,0.15);
  --highlight: inset 0 1px 1px rgba(255,255,255,0.4);
  --message-border-radius: 18px;
  --background-image: none;
  --messages-area-bg: rgba(0, 0, 0, 0.03);
}

body {
  font-family: "Helvetica Neue", Arial, sans-serif;
  background: white;
  background-attachment: fixed;
  color: var(--text-color);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  overflow: hidden;
}

#main-container, #chat-container, #auth-container {
  width: 100%;
  height: 100vh;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
}

#header, .shiny-white-top {
  position: relative;
  background: var(--header-bg);
  color: white;
  text-shadow: 0 1px 2px rgba(0,0,0,0.3);
  padding: 15px;
  border-radius: 0;
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--highlight);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

#header::before, .shiny-white-top::before { display: none; }

#room-title { margin: 0; font-size: 1.2em; font-weight: bold; }

#messages {
  flex-grow: 1;
  padding: 20px;
  overflow-y: auto;
  background-color: var(--messages-area-bg);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

#footer {
  padding: 10px;
  display: flex;
  border-top: 1px solid var(--glass-border);
  background: transparent;
  flex-shrink: 0;
}

#message-input {
  flex-grow: 1;
  border: 1px solid transparent;
  background: var(--input-bg);
  border-radius: 18px;
  padding: 10px 15px;
  font-size: 1em;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  color: #333;
  box-shadow: var(--inner-shadow);
}

#message-input:focus {
  border-color: rgba(255,255,255,0.5);
  box-shadow: var(--inner-shadow), 0 0 5px rgba(53, 122, 189, 0.5);
}

#send-button, #create-room-button, #auth-button, #logout-button, .button {
  position: relative;
  /* Using the new CSS variable for the border */
  border: 1px solid var(--button-border-color);
  border-radius: 18px;
  padding: 10px 20px;
  font-size: 1em;
  font-weight: bold;
  color: var(--button-text-color);
  text-shadow: 0 -1px 0 rgba(0,0,0,0.3);
  background: var(--button-bg);
  cursor: pointer;
  outline: none;
  margin-left: 10px;
  box-shadow: var(--highlight), var(--inner-shadow);
  transition: background 0.2s, border-color 0.2s;
}

#load-more-button {
    margin: 0 auto 15px;
    background: rgba(255,255,255,0.5);
    color: #333;
    border: 1px solid rgba(0,0,0,0.1);
    text-shadow: none;
    box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

#send-button:hover, #create-room-button:hover, #auth-button:hover, #logout-button:hover, .button:hover { background: var(--button-hover-bg); }
#send-button:active, #create-room-button:active, #auth-button:active, #logout-button:active, .button:active { background: var(--button-active-bg); box-shadow: var(--inner-shadow); }

.message { display: flex; margin-bottom: 15px; max-width: 80%; }
.message .user-name { font-size: 0.8em; font-weight: bold; color: #444; text-shadow: 0 1px 1px rgba(255,255,255,0.8); margin-bottom: 4px; }
.message .message-text { padding: 10px 15px; border-radius: var(--message-border-radius); word-wrap: break-word; box-shadow: var(--shiny-shadow); }
.message.sent { margin-left: auto; flex-direction: row-reverse; }
.message.sent .message-text { background-color: var(--message-sent-bg); color: #fff; text-shadow: 0 1px 1px rgba(0,0,0,0.2); border-radius: 18px 18px 0 18px; }
.message.sent .user-name { text-align: right; }
.message.received .message-text { background-color: var(--message-received-bg); border-radius: 18px 18px 18px 0; }

#settings-dialog {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: #333;
    box-shadow: var(--shiny-shadow);
    border-radius: 8px;
    padding: 0;
    width: 400px;
}

#settings-dialog::backdrop {
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(2px);
}

.modal-header {
    padding: 15px;
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 { margin: 0; font-size: 1.1em; }

.close-button { background: none; border: none; font-size: 1.5em; color: #999; cursor: pointer; }

.setting {
    padding: 15px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

#save-settings {
    margin: 20px;
    float: right;
}