:root {
  color-scheme: dark;
  --dos-green: #33ff66;
  --dos-dim: #159b3a;
  --dos-black: #020702;
}

* { box-sizing: border-box; }

html, body {
  min-height: 100%;
  margin: 0;
}

body {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 24px;
  overflow: hidden;
  background: #071407;
  color: var(--dos-green);
  font: 16px/1.6 "Courier New", monospace;
  text-shadow: 0 0 5px rgba(51, 255, 102, 0.65);
}

.dos-window {
  width: min(760px, 100%);
  border: 2px solid var(--dos-green);
  background: var(--dos-black);
  box-shadow: 0 0 0 5px #0a260f, 0 0 35px rgba(51, 255, 102, 0.2);
}

.dos-title {
  padding: 3px 12px;
  overflow: hidden;
  background: var(--dos-green);
  color: var(--dos-black);
  font-weight: 700;
  text-shadow: none;
  white-space: nowrap;
}

.dos-screen { padding: 26px clamp(18px, 5vw, 48px) 34px; }
.dos-screen p { margin: 0 0 8px; }
.blank { height: 16px; }
.cursor { animation: blink 1s steps(2, start) infinite; }

.progress {
  height: 18px;
  margin: 22px 0 18px;
  border: 1px solid var(--dos-dim);
  padding: 2px;
}

.progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--dos-green);
  box-shadow: 0 0 8px var(--dos-green);
  transition: width 1s linear;
}

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.dos-button {
  border: 1px solid var(--dos-green);
  padding: 8px 12px;
  background: var(--dos-black);
  color: var(--dos-green);
  font: inherit;
  text-decoration: none;
  cursor: pointer;
  text-shadow: inherit;
}
.dos-button:hover, .dos-button:focus-visible { background: var(--dos-green); color: var(--dos-black); text-shadow: none; }
.primary { background: var(--dos-dim); }

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

@media (max-width: 520px) {
  body { padding: 12px; font-size: 14px; }
  .dos-screen { padding: 20px 14px 24px; }
  .actions { flex-direction: column; }
  .dos-button { text-align: center; }
}