/*
 * The screen is a grid of character cells, as it is in the app.  The font is
 * an 8x16 VGA face, so with a line height of 1 a cell is 0.5em wide and 1em
 * tall, and everything here is sized and placed in those units.  The script
 * picks the font size and the number of rows and columns.
 */

@font-face {
  font-family: "IBM VGA 8x16";
  src: url("/fonts/WebPlus_IBM_VGA_8x16.woff") format("woff");
  font-display: block;
}

:root {
  /* the sixteen colours of the text mode palette that the app uses */
  --black:       #000000;
  --blue:        #0000aa;
  --green:       #00aa00;
  --cyan:        #00aaaa;
  --red:         #aa0000;
  --light-grey:  #aaaaaa;
  --dark-grey:   #555555;
  --light-green: #55ff55;
  --light-cyan:  #55ffff;
  --yellow:      #ffff55;
  --white:       #ffffff;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
}

body {
  /* the part cells left over at the edge of the browser window blend in
     with the menu bar and the status line */
  background: var(--light-grey);
  display: flex;
  align-items: center;
  justify-content: center;
}

#screen {
  position: relative;
  flex: none;
  overflow: hidden;
  font-family: "IBM VGA 8x16", monospace;
  font-size: 16px;
  line-height: 1;
  font-weight: normal;
  font-style: normal;
  font-variant-ligatures: none;
  white-space: nowrap;
  color: var(--black);
  background: var(--light-grey);
  cursor: default;
  user-select: none;
}

.tv-hot {
  color: var(--red);
}

/* menu bar */

#menubar {
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  height: 1em;
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  z-index: 30;
}

.tv-menu {
  position: relative;
}

.tv-menu-title {
  display: block;
  padding: 0 0.5em;
}

.tv-menu.tv-selected > .tv-menu-title,
.tv-menu-items li.tv-selected > a {
  background: var(--green);
}

.tv-menu-items {
  display: none;
  position: absolute;
  left: 0;
  top: 1em;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--light-grey);
}

.tv-menu.tv-open > .tv-menu-items {
  display: block;
}

.tv-menu-items li:not(.tv-shadow) {
  display: flex;
  height: 1em;
  white-space: pre;
}

.tv-menu-items a {
  flex: 1;
  display: flex;
  justify-content: space-between;
  padding: 0 0.5em;
  color: inherit;
  text-decoration: none;
  cursor: default;
  outline: none;
}

.tv-menu-label {
  margin-right: 0.5em;
}

.tv-menu-shortcut {
  margin-left: 1em;
}

#clock {
  position: absolute;
  top: 0;
  right: 0;
  height: 1em;
  z-index: 31;
}

/* status line */

#statusline {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1em;
  display: flex;
  z-index: 30;
}

#statusline a {
  padding: 0 0.5em;
  color: inherit;
  text-decoration: none;
  cursor: default;
  outline: none;
}

#statusline a:active {
  background: var(--green);
}

/* desktop */

#desktop {
  position: absolute;
  left: 0;
  right: 0;
  top: 1em;
  bottom: 1em;
  overflow: hidden;
}

#desktop-pattern {
  position: absolute;
  inset: 0;
  overflow: hidden;
  white-space: pre;
  color: var(--blue);
}

/* windows and dialogs: the frame is drawn in the cells around the edge */

.tv-window,
.tv-dialog {
  position: absolute;
}

.tv-window {
  background: var(--blue);
  color: var(--light-grey);
  z-index: 10;
}

.tv-dialog {
  background: var(--light-grey);
  color: var(--black);
  padding: 1em 0.5em;
  z-index: 20;
}

.tv-frame {
  position: absolute;
  overflow: hidden;
  white-space: pre;
  color: var(--white);
}

.tv-inactive > .tv-frame {
  color: var(--light-grey);
}

.tv-frame-top,
.tv-frame-bottom {
  left: 0;
  right: 0;
  height: 1em;
  display: flex;
}

.tv-frame-top {
  top: 0;
}

.tv-frame-bottom {
  bottom: 0;
}

.tv-frame-left,
.tv-frame-right {
  top: 1em;
  bottom: 1em;
  width: 0.5em;
}

.tv-frame-left {
  left: 0;
}

.tv-frame-right {
  right: 0;
}

.tv-fill {
  flex: 1 1 0;
  min-width: 0;
  overflow: hidden;
}

.tv-frame .tv-title {
  flex: 0 1 auto;
  min-width: 0;
  padding: 0 0.5em;
  overflow: hidden;
}

.tv-icon > span {
  color: var(--light-green);
}

.tv-inactive .tv-icon,
.tv-inactive .tv-scrollbar,
.tv-window:not(.tv-inactive) .tv-frame-right > .tv-side {
  display: none;
}

.tv-resize {
  cursor: nwse-resize;
}

/* the shadow a window casts over what is two columns right and a row down */

.tv-shadow {
  position: absolute;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: grayscale(1);
  pointer-events: none;
}

.tv-shadow-right {
  left: 100%;
  top: 1em;
  width: 1em;
  height: 100%;
}

.tv-shadow-bottom {
  left: 1em;
  top: 100%;
  width: calc(100% - 1em);
  height: 1em;
}

/* scroll bar, in place of the right hand edge of the frame */

.tv-scrollbar {
  height: 100%;
  display: flex;
  flex-direction: column;
  background: var(--cyan);
  color: var(--blue);
}

.tv-scrollbar-track {
  flex: 1;
  position: relative;
  overflow: hidden;
}

.tv-scrollbar-thumb {
  position: absolute;
  left: 0;
  top: 0;
}

/* the document inside the window */

.tv-window > .tv-content {
  position: absolute;
  inset: 1em 0.5em;
  overflow: hidden;
  padding: 0 1em;
  white-space: normal;
  overflow-wrap: break-word;
  cursor: auto;
  user-select: text;
}

/* a blank row above and below the document */
.tv-window > .tv-content::before,
.tv-window > .tv-content::after {
  content: "";
  display: block;
  height: 1em;
}

.tv-content ::selection {
  background: var(--light-grey);
  color: var(--blue);
}

.tv-content :is(h2, h3, h4, h5, h6) {
  margin: 1em 0;
  font: inherit;
  color: var(--white);
}

.tv-content h2 {
  text-transform: uppercase;
}

.tv-content :is(p, ul, ol, pre, table, blockquote, hr) {
  margin: 1em 0;
}

.tv-window > .tv-content > :first-child {
  margin-top: 0;
}

.tv-window > .tv-content > :last-child {
  margin-bottom: 0;
}

.tv-content :is(ul, ol) :is(ul, ol) {
  margin: 0;
}

.tv-content ul {
  padding-left: 1em;
  list-style: none;
}

.tv-content ul > li {
  position: relative;
}

.tv-content ul > li::before {
  content: "\25A0";
  position: absolute;
  left: -1em;
  color: var(--cyan);
}

.tv-content ol {
  padding-left: 2em;
}

.tv-content li > p {
  margin: 0;
}

.tv-window a {
  color: var(--yellow);
  text-decoration: none;
  outline: none;
}

.tv-window a:hover,
.tv-window a:focus-visible {
  background: var(--cyan);
  color: var(--black);
}

.tv-content strong {
  font-weight: normal;
  color: var(--white);
}

.tv-content em {
  font-style: normal;
  color: var(--light-green);
}

.tv-content code {
  font: inherit;
  color: var(--light-cyan);
}

.tv-content pre {
  padding: 0 0.5em;
  background: var(--black);
  color: var(--light-grey);
  font: inherit;
  white-space: pre-wrap;
}

.tv-content pre code {
  color: inherit;
}

.tv-content blockquote {
  padding-left: 1em;
  color: var(--light-cyan);
}

.tv-content table {
  border-collapse: collapse;
}

.tv-content :is(th, td) {
  padding: 0 1em 0 0;
  text-align: left;
  vertical-align: top;
  font-weight: normal;
}

.tv-content th {
  color: var(--white);
}

.tv-content hr {
  height: 1em;
  border: 0;
  overflow: hidden;
  white-space: nowrap;
}

.tv-content hr::before {
  content: "\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500\2500";
}

.tv-content img {
  max-width: 100%;
}

/* dialog */

.tv-dialog {
  width: 27em;
}

.tv-dialog > .tv-content {
  padding: 0 0.5em;
  white-space: normal;
  text-align: center;
}

.tv-button {
  position: relative;
  margin: 0 0 1em;
  padding: 0 1.5em;
  border: 0;
  border-radius: 0;
  font: inherit;
  line-height: 1;
  background: var(--green);
  color: var(--white);
  cursor: default;
  outline: none;
}

.tv-button .tv-hot {
  color: var(--yellow);
}

.tv-button::before,
.tv-button::after {
  position: absolute;
  color: var(--black);
  overflow: hidden;
  white-space: nowrap;
}

.tv-button::before {
  content: "\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580\2580";
  left: 0.5em;
  top: 1em;
  width: 100%;
  text-align: left;
}

.tv-button::after {
  content: "\2584";
  left: 100%;
  top: 0;
}

/* a pressed button moves into the space its shadow took */
.tv-button:active {
  left: 0.5em;
}

.tv-button:active::before,
.tv-button:active::after {
  display: none;
}

/* what is left after exit */

#dos {
  position: absolute;
  inset: 0;
  z-index: 100;
  background: var(--black);
  color: var(--light-grey);
  overflow: hidden;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  cursor: none;
}

/* an empty line of output is still a line */
#dos div {
  min-height: 1em;
}

body.tv-dos {
  background: var(--black);
  align-items: flex-start;
  justify-content: flex-start;
}

.tv-cursor {
  animation: tv-blink 1s step-end infinite;
}

@keyframes tv-blink {
  50% { opacity: 0; }
}