/* ABOUTME: VTT styling. Shell chrome follows the CertKraken design system; the terminal
   ABOUTME: stays authentically 3270, because the subject is a green screen. */

/* rbanffy/3270font, BSD-3-Clause and OFL-1.1-RFN. It descends from the x3270 font, which
   was hand-copied from a physical IBM 3270, so it is the cheapest large jump in
   authenticity available. License text is in fonts/LICENSE-3270font.txt. */
@font-face {
  font-family: "3270";
  src: url("./fonts/3270-Regular.woff") format("woff");
  font-weight: normal;
  font-style: normal;
  font-display: swap;
}

:root {
  /* CertKraken design system. Values taken from the brand guidelines and the site's own
     tailwind config, so this course reads as part of the same family of properties. */
  --purple: #5b2c91;
  --purple-dark: #4a2373;
  --purple-light: #7d3fbf;
  --cyan: #00d9ff;
  --cyan-dark: #00b8db;
  --cyan-light: #33e4ff;
  --navy: #1a1642;
  --navy-light: #2d2558;
  --offwhite: #f8f9fa;

  --ink: #1f2937;
  --mid: #5f6975;
  --line: #e5e7eb;
  --paper: #ffffff;
  --panel: #f5f0fa;

  /* Phosphor palettes for the terminal itself. Green is the default; amber is the
     alternate a learner can pick. These are deliberately NOT brand colours: a 3270 was
     green or amber, and the subject matter outranks the palette here. */
  --screen-bg: #0b1207;
  --screen-fg: #33ff66;
  --screen-dim: #1f9c40;
  --screen-glow: rgba(51, 255, 102, 0.16);
}

body.amber {
  --screen-bg: #140d02;
  --screen-fg: #ffb000;
  --screen-dim: #a86f00;
  --screen-glow: rgba(255, 176, 0, 0.16);
}

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  background: var(--offwhite);
  color: var(--ink);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* ---- header ---- */
header {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 11px 18px;
  background: linear-gradient(100deg, var(--navy) 0%, var(--purple-dark) 62%, var(--purple) 100%);
  color: #fff;
}
header .brand { display: flex; align-items: baseline; gap: 10px; }
header .wordmark { font-weight: 800; font-size: 17px; letter-spacing: -0.01em; }
header .sub { font-weight: 500; opacity: 0.62; font-size: 12.5px; }

/* A small terminal glyph rather than a mascot. This course is language training, not
   certification prep, so it carries the design system without the product identity. */
header .mark {
  width: 15px; height: 12px; border-radius: 2px;
  border: 2px solid var(--cyan);
  box-shadow: 0 0 9px rgba(0, 217, 255, 0.55);
  align-self: center;
}

.spacer { flex: 1; }

.progresswrap { display: flex; align-items: center; gap: 9px; }
.progressbar {
  width: 116px; height: 6px; border-radius: 999px;
  background: rgba(255, 255, 255, 0.16); overflow: hidden;
}
.progressfill {
  height: 100%; width: 0%; border-radius: 999px;
  background: linear-gradient(90deg, var(--cyan-dark), var(--cyan));
  transition: width 0.35s ease;
}
.progresstext { font-size: 11.5px; font-variant-numeric: tabular-nums; opacity: 0.78; }

.lessonpick { display: flex; align-items: center; gap: 8px; font-size: 13px; }
.lessonpick label { opacity: 0.66; }
.lessonpick select {
  font: inherit; font-size: 13px; padding: 5px 9px; border-radius: 7px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08); color: #fff;
}
.lessonpick select option { color: var(--ink); }

.split { flex: 1; display: flex; min-height: 0; }

/* ---- left: the lesson ---- */
.guide {
  width: 42%; min-width: 340px; max-width: 620px;
  overflow: auto; padding: 22px 24px;
  background: var(--paper);
  border-right: 1px solid var(--line);
}
.guide h1 { font-size: 21px; margin: 0 0 6px; color: var(--navy); }
.guide .lede { color: var(--mid); font-size: 14px; margin: 0 0 18px; line-height: 1.55; }
.guide .foot { color: var(--mid); font-size: 12px; margin-top: 22px; line-height: 1.5; }

.step {
  border: 1px solid var(--line); border-radius: 11px;
  margin-bottom: 13px; overflow: hidden;
}
.step .h {
  display: flex; align-items: center; gap: 11px;
  padding: 11px 13px; background: var(--panel); cursor: pointer;
}
.step .num {
  width: 25px; height: 25px; flex: 0 0 25px; border-radius: 50%;
  background: var(--purple); color: #fff; font-weight: 800;
  display: grid; place-items: center; font-size: 12.5px;
}
.step.done .num { background: #1a7f37; }
.step .t { font-weight: 700; font-size: 14.5px; color: var(--navy); }
.step .chev { margin-left: auto; color: var(--mid); font-size: 12px; }
.step .b { display: none; padding: 12px 13px; font-size: 14px; line-height: 1.6; }
.step.open .b { display: block; }
.step .b p { margin: 0 0 10px; }
.step .b p:last-child { margin-bottom: 0; }

code.inl {
  background: var(--panel); color: var(--purple-dark);
  border-radius: 5px; padding: 1px 6px;
  font-family: "3270", ui-monospace, Menlo, Consolas, monospace; font-size: 12.5px;
}

/* A runnable code block. Clicking loads it into the editor and runs it. */
.cmd {
  position: relative; display: block; white-space: pre;
  background: var(--navy); color: #d6deeb; border-radius: 9px;
  padding: 11px 74px 11px 13px; margin: 9px 0;
  font-family: "3270", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px; line-height: 1.45; cursor: pointer; overflow-x: auto;
}
.cmd:hover { outline: 2px solid var(--cyan); }
.cmd .go {
  position: absolute; top: 8px; right: 8px;
  font: inherit; font-size: 11px; font-weight: 700;
  background: var(--cyan); color: var(--navy); border: 0; border-radius: 6px;
  padding: 4px 9px; cursor: pointer;
}
.cmd.sent .go { background: #57d98a; }

.tip {
  background: #edf9fc; border: 1px solid #b6e8f4; border-radius: 9px;
  padding: 10px 12px; font-size: 13px; color: #0f5666; margin: 9px 0; line-height: 1.55;
}
.warn {
  background: #fff8e6; border: 1px solid #f0dda4; border-radius: 9px;
  padding: 10px 12px; font-size: 13px; color: #6b4c00; margin: 9px 0; line-height: 1.55;
}

/* An exercise: the learner writes the code, and the check runs against what it did. */
.exercise {
  border: 1px solid var(--purple-light); border-radius: 10px;
  background: #faf7fe; padding: 12px 13px; margin: 11px 0;
}
.exercise .xh {
  display: flex; align-items: center; gap: 8px;
  font-weight: 800; font-size: 12px; letter-spacing: 0.08em;
  color: var(--purple); text-transform: uppercase; margin-bottom: 7px;
}
.exercise .xtask { font-size: 13.5px; line-height: 1.55; margin: 0 0 10px; }
.exercise .xact { display: flex; gap: 8px; align-items: center; }
.exercise button {
  font: inherit; font-size: 12.5px; font-weight: 700;
  border: 0; border-radius: 7px; padding: 6px 13px; cursor: pointer;
}
.exercise .load { background: var(--purple); color: #fff; }
.exercise .check { background: var(--cyan); color: var(--navy); }
.exercise button:hover { filter: brightness(1.09); }
.xresult { font-size: 13px; margin-top: 9px; line-height: 1.5; display: none; }
.xresult.show { display: block; }
.xresult.pass { color: #1a7f37; font-weight: 600; }
.xresult.fail { color: #b3261e; }

/* ---- right: editor and terminal ---- */
.termcol { flex: 1; min-width: 0; display: flex; flex-direction: column; background: #05080c; }

.termbar {
  flex: 0 0 auto; display: flex; align-items: center; gap: 8px;
  padding: 7px 10px; background: #0a0f16; border-bottom: 1px solid #141c26;
}
.tab {
  font: inherit; font-size: 11px; font-weight: 800; letter-spacing: 0.12em;
  background: transparent; color: #6e7d90; border: 0;
  border-bottom: 2px solid transparent; padding: 5px 10px; cursor: pointer;
}
.tab.active { color: var(--cyan); border-bottom-color: var(--cyan); }
.tab:hover { color: #b9c6d4; }

.act {
  font: inherit; font-size: 12.5px; font-weight: 700;
  background: var(--cyan); color: var(--navy); border: 0; border-radius: 7px;
  padding: 6px 13px; cursor: pointer;
}
.act.ghost { background: #1c2531; color: #b9c6d4; }
.act:hover { filter: brightness(1.12); }

.pane { flex: 1; min-height: 0; display: flex; }
.pane[hidden] { display: none; }

/* The source editor, with a line-number gutter because Natural diagnostics name lines. */
.editorpane { background: #0d1117; }
.gutter {
  flex: 0 0 auto; padding: 12px 8px 12px 12px;
  font-family: "3270", ui-monospace, Menlo, Consolas, monospace;
  font-size: 14px; line-height: 1.5; color: #3d4a5c;
  text-align: right; user-select: none; white-space: pre;
  border-right: 1px solid #1b2430; background: #0a0e14;
}
#editor {
  flex: 1; min-width: 0; resize: none; border: 0; outline: 0;
  padding: 12px 14px; background: transparent; color: #d6deeb;
  font-family: "3270", ui-monospace, Menlo, Consolas, monospace;
  font-size: 14px; line-height: 1.5; tab-size: 2;
  overflow: auto; caret-color: var(--cyan);
}

.termpane { flex-direction: column; }

/* A real 3270 does not scroll or reflow, so the grid is a fixed panel anchored to the top
   rather than stretched to the pane. */
.screenwrap {
  flex: 1; min-height: 0; position: relative;
  display: grid; place-items: start center; padding: 16px 14px;
  background: var(--screen-bg); overflow: hidden;
}
.screen { position: relative; z-index: 1; }
.screen .xterm { padding: 0; }

/* Subtle CRT treatment, self-authored: scanlines plus a phosphor glow. Deliberately
   understated so it never impedes reading. cool-retro-term-renderer is GPL-3.0 and is
   not vendored. */
.crt {
  position: absolute; inset: 0; z-index: 2; pointer-events: none;
  background:
    repeating-linear-gradient(
      to bottom,
      rgba(0, 0, 0, 0) 0px,
      rgba(0, 0, 0, 0) 2px,
      rgba(0, 0, 0, 0.16) 3px,
      rgba(0, 0, 0, 0.16) 4px
    ),
    radial-gradient(ellipse at center, var(--screen-glow) 0%, rgba(0, 0, 0, 0) 72%);
}

/* The AID key bar, shown only while a map is on screen. */
.aidbar {
  flex: 0 0 auto; display: none; align-items: center; gap: 7px;
  padding: 6px 12px; background: #0a0f16; border-top: 1px solid #141c26;
}
.aidlabel {
  font-size: 10.5px; font-weight: 800; letter-spacing: 0.12em; color: #6e7d90;
  margin-right: 4px;
}
.aidbar button {
  font: inherit; font-size: 12px; font-weight: 700;
  background: #1c2531; color: var(--screen-fg); border: 1px solid var(--screen-dim);
  border-radius: 6px; padding: 4px 12px; cursor: pointer;
  font-family: "3270", ui-monospace, Menlo, Consolas, monospace;
}
.aidbar button:hover { background: #26313f; }

/* The Operator Information Area: the strip a 3270 uses to tell you what it is doing. */
.oia {
  flex: 0 0 auto; display: flex; align-items: center; gap: 14px;
  padding: 5px 12px;
  border-top: 2px solid var(--screen-dim);
  background: var(--screen-bg); color: var(--screen-fg);
  font-family: "3270", ui-monospace, Menlo, Consolas, monospace;
  font-size: 12.5px; letter-spacing: 0.04em;
}
.oia-msg { font-weight: 700; }
.oia-pos { opacity: 0.72; }

@media (max-width: 900px) {
  body { overflow: auto; height: auto; }
  .split { flex-direction: column; }
  .guide { width: 100%; max-width: none; border-right: 0; border-bottom: 1px solid var(--line); }
  .termcol { min-height: 76vh; }
  .progresswrap { display: none; }
}