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

body {
  height: 100vh;
  overflow: hidden;
  font-family: sans-serif;
}

#taskbar {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 48px;
  background: #1e1e1e;
  display: flex;
  align-items: center;
  padding: 0 10px;
}

#start-btn {
  background: #333;
  color: #fff;
  border: none;
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
}

#start-btn:hover {
  background: #444;
}

#taskbar-apps {
  display: flex;
  gap: 6px;
  margin-left: 10px;
}

.taskbar-item {
  background: #333;
  color: #fff;
  border: none;
  padding: 6px 12px;
  border-radius: 4px;
  cursor: pointer;
}

#clock {
  margin-left: auto;
  color: #fff;
  font-size: 14px;
}

#start-menu {
  position: fixed;
  bottom: 48px;
  left: 0;
  width: 200px;
  background: #2a2a2a;
  color: #fff;
  padding: 10px;
  border-radius: 4px 4px 0 0;
}

.hidden {
  display: none;
}

.app-window {
  position: absolute;
  top: 80px;
  left: 80px;
  width: 280px;
  background: #fff;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.4);
  z-index: 10;
}

.window-header {
  background: #2a2a2a;
  color: #fff;
  padding: 8px 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: move;
}

.minimize-btn {
  background: none;
  border: none;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
  margin-right: 4px;
}

.close-btn {
  background: none;
  border: none;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
}

.window-body {
  padding: 10px;
  color: #000;
}

#calc-display {
  width: 100%;
  padding: 8px;
  font-size: 16px;
  margin-bottom: 8px;
  box-sizing: border-box;
}

#calc-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
}

#calc-buttons button {
  padding: 10px;
  font-size: 14px;
  cursor: pointer;
}

#calc-clear {
  width: 100%;
  margin-top: 8px;
  padding: 8px;
  cursor: pointer;
}

#files-list {
  list-style: none;
}

#files-list li {
  padding: 8px;
  cursor: pointer;
  border-radius: 4px;
}

#files-list li:hover {
  background: #eee;
}

#files-back {
  margin-bottom: 8px;
  cursor: pointer;
}

body.dark-mode {
  background: #111;
  color: #fff;
}

body.dark-mode .app-window {
  background: #2a2a2a;
  color: #fff;
}

#desktop {
  position: absolute;
  top: 0;
  left: 0;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 90px;
}

.desktop-icon {
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  padding: 8px;
  border-radius: 6px;
  user-select: none;
}

.desktop-icon .icon {
  font-size: 32px;
}

.desktop-icon .icon-label {
  color: #fff;
  font-size: 12px;
  margin-top: 4px;
  text-align: center;
}

.desktop-icon.selected {
  background: rgba(255, 255, 255, 0.2);
}