body {
  background-color: #008080;
  font-family: "Courier New", monospace;
  font-size: 16px;
  margin: 0;
}

/* main window */
.window {
  width: 800px;
  margin: 40px auto;
  background: #c0c0c0;

  border-top: 2px solid #ffffff;
  border-left: 2px solid #ffffff;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;
}

a {
  color: black;
  text-decoration: none;
}

a:hover {
  background: #000080;
  color: white;
}

/* title bar */
.titlebar {
  background: #000080;
  color: white;
  padding: 4px 6px;
  font-weight: bold;
  font-size: 14px;
  user-select: none;
  cursor: grab;
}

.titlebar span {
  display: inline-block;
}

.titlebar:active {
  cursor: grabbing;
}

/* layout */
.content {
  display: flex;
}

/* sidebar */
.sidebar {
  font-size: 16px;
  line-height: 1.4;
  width: 180px;
  border-right: 2px solid black;
  padding: 10px;
  background: #c0c0c0;
}

.sidebar a {
  display: block;
  color: black;
  text-decoration: none;
  margin: 4px 0;
}

.sidebar a:hover {
  background: #000080;
  color: white;
}

.sidebar p {
  margin-top: 0;
}

/* main content */
.main {
  flex: 1;
  padding: 10px;
  background: #c0c0c0;
}

.main h1, .main h2 {
  margin-top: 0;
}

.panel {
  padding: 10px;
  background: #c0c0c0;
  margin-bottom: 10px;
  border-top: 2px solid #404040;
  border-left: 2px solid #404040;
  border-right: 2px solid #ffffff;
  border-bottom: 2px solid #ffffff;
}

.button {
  display: inline-block;
  padding: 4px 10px;
  margin: 2px 0;
  margin-right: 6px;
  background: #c0c0c0;
  color: black;
  text-decoration: none;

  border-top: 2px solid #ffffff;
  border-left: 2px solid #ffffff;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;

  font-family: "Courier New", monospace;
  font-size: 14px;
}

.button:hover {
  background: #d4d0c8;
}

.button:active {
  border-top: 2px solid #404040;
  border-left: 2px solid #404040;
  border-right: 2px solid #ffffff;
  border-bottom: 2px solid #ffffff;
}

.button.disabled {
  color: #808080;
  pointer-events: none;
}

/* collapsible menu */
.nav-section ul {
  display: none;
}

input:checked + ul {
  display: block;
}

/* hide checkboxes */
.nav-section input {
  display: none;
}

/* collapsed by default */
.nav-section ul {
  display: none;
  padding-left: 10px;
  margin: 2px 0;
}

.nav-section ul li {
  display: flex;
  align-items: center;
  gap: 6px;
  line-height: 1.2;
}

/* labels (clickable headers) */
.nav-section label {
  display: block;
  cursor: pointer;
  margin-top: 5px;
}

/* links */
.nav-section a {
  color: black;
  text-decoration: none;
}

.nav-section a.active {
  background: #000080;
  color: white;
}

/* expand when checked */
.nav-section input:checked + label + ul {
  display: block;
}

.nav-section label::before {
  content: "+ ";
}

.nav-section input:checked + label::before {
  content: "- ";
}

.nav-section a:hover {
  background: #000080;
  color: white;
}

.nav-section a.active {
  background: #000080;
  color: white;
  padding: 2px 4px;
}

.nav-section a.active::before {
  content: "> ";
}

.nav-section a.active:hover {
  background: #000080;
  color: white;
}

.tree {
  display: inline-block;
  width: 20px;
}

.file.exe a::after {
  content: " [exe]";
  color: #555;
}

.file.txt a::after {
  content: " [txt]";
  color: #555;
}

.file.active {
  background: #000080;
  color: white;
}

.explorer {
  font-family: "Courier New", monospace;
  font-size: 14px;
  margin-bottom: 10px;
}

.file {
  display: flex;
  align-items: center;
  gap: 6px;
}

.file a {
  text-decoration: none;
  color: black;
}

.file a:hover {
  background: #000080;
  color: white;
}

.gallery {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.thumb {
  width: 120px;
  height: 140px; /* fixed total height */
  padding: 6px;
  background: #c0c0c0;

  border-top: 2px solid #ffffff;
  border-left: 2px solid #ffffff;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;

  text-align: center;

  display: flex;
  flex-direction: column;
}

.thumb .icon {
  align-self: flex-start;
  margin-bottom: 4px;
}

.thumb .preview {
  width: 100%;
  height: 80px; /* fixed preview area */

  display: flex;
  align-items: center;
  justify-content: center;

  overflow: hidden;
}

.thumb .preview img {
  max-width: 100%;
  max-height: 100%;
}

.thumb img {
  width: 100%;
  height: auto;
  display: block;
  cursor: pointer;
}

.thumb.selected {
  background: #000080;
  color: white;
}

.preview {
  background: #000;
  width: 100%;
  height: 80px;

  display: flex;
  align-items: center;
  justify-content: center;

  overflow: hidden;
}

.preview img {
  image-rendering: pixelated;
  cursor: default;
}

.preview img:hover {
  background: #000080;
}

.caption {
  font-size: 12px;
  margin-top: 4px;
  text-align: center;
  
  overflow-wrap: break-word;
}

.icon {
  width: 16px !important;
  height: 16px !important;
  image-rendering: pixelated;
}

.file {
  display: flex;
  align-items: center;
  gap: 6px;
}

.tree {
  display: inline-block;
  width: 20px;
}

/* overlay */
.viewer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.4);
}

.hidden {
  display: none;
}

/* window */
.viewer-window {
  position: absolute;
  width: 500px;

  background: #c0c0c0;

  border-top: 2px solid #ffffff;
  border-left: 2px solid #ffffff;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;
}


/* close button */
.close-btn {
  float: right;
  background: #c0c0c0;
  border: none;
  font-family: inherit;
  cursor: pointer;
}

/* image area */
.viewer-content {
  padding: 10px;
  text-align: center;
}

.viewer-content img {
  max-width: 100%;
  height: auto;
}

.close-btn {
  border-top: 2px solid #ffffff;
  border-left: 2px solid #ffffff;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;
  padding: 2px 6px;
}