body {
  background-color: #111;
  color: #ddd;
  font-family: Arial, sans-serif;
  margin: 0;
  height: 100vh;
  overflow: hidden;
}

.container {
  display: flex;
  height: 100vh;
  width: 100vw;
}

/* Left: image viewer */
.image-area {
  flex: 4;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #000;
  position: relative;
}

#display {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

/* Countdown timer */
#countdown {
  position: absolute;
  bottom: 10px;
  right: 20px;
  font-size: 1.5em;
  color: #fff;
  background: rgba(0, 0, 0, 0.5);
  padding: 5px 10px;
  border-radius: 6px;
  font-family: monospace;
}

/* Right: controls */
.control-area {
  flex: 1;
  padding: 20px;
  background-color: #181818;
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-sizing: border-box;
}

h1 {
  color: #fff;
  font-size: 1.8em;
  margin-bottom: 20px;
  text-align: left;
}

.group {
  margin-bottom: 15px;
  text-align: left;
}

label {
  display: inline-block;
  margin-right: 6px;
}

input, select, button {
  background: #222;
  color: #ddd;
  border: 1px solid #444;
  padding: 6px 8px;
  border-radius: 4px;
  margin-top: 4px;
}

button:hover {
  background: #333;
  cursor: pointer;
}

.buttons {
  display: flex;
  gap: 10px;
}

.main-controls {
  display: flex;
  gap: 20px;
  margin-top: 10px;
}

.main-controls button {
  background: #222;
  color: #ccc;
  font-size: 1.5rem;        /* make symbols large */
  border: 2px solid #444;
  border-radius: 12px;
  padding: 10px 20px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.main-controls button:hover {
  background: #333;
  color: #fff;
}

.main-controls button:active {
  background: #444;
}


/* Responsive layout */
@media (max-width: 800px) {
  .container {
    flex-direction: column;
  }
  .control-area {
    flex: none;
    height: auto;
    width: 100%;
    flex-wrap: wrap;
  }
  .image-area {
    flex: 1;
  }
  #countdown {
    right: 10px;
    bottom: 10px;
  }
}

#stopClassBtn {
  display: none;
}


.notice {
  background: #222;
  color: #ccc;
  border: 1px solid #444;
  padding: 10px;
  margin: 10px 0;
  border-radius: 8px;
  font-size: 0.9em;
}
.download-btn {
  display: inline-block;
  margin-top: 6px;
  background: #333;
  color: #fff;
  padding: 6px 10px;
  border-radius: 6px;
  text-decoration: none;
}
.download-btn:hover {
  background: #555;
}

kbd {
  background: #333;
  color: #fff;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: monospace;
  border: 1px solid #555;
}