/* ============================================================
   MAINFRAME PRACTICE TERMINAL
   Design: 3270-style green-phosphor console.
   Grounded in the real visual world of mainframe terminals --
   monospace type, scanlines, command-line chrome, blocky cursors.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600;700&display=swap');

:root {
  --bg:        #04140a;
  --bg-raised: #06200f;
  --bg-field:  #02110a;
  --green:     #3df58a;
  --green-dim: #1f9b5c;
  --green-deep:#0e5e36;
  --amber:     #ffb627;
  --cyan:      #5be7d4;
  --magenta:   #ff7ad9;
  --red:       #ff5d5d;
  --white:     #d8ffe9;
  --border:    #1f6b42;
  --shadow-glow: 0 0 6px rgba(61, 245, 138, 0.35);
  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--green);
  font-family: var(--font-mono);
  min-height: 100vh;
}

body {
  position: relative;
  overflow-x: hidden;
}

/* Scanline / CRT texture overlay */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  background: repeating-linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0) 0px,
    rgba(0, 0, 0, 0) 2px,
    rgba(0, 20, 10, 0.18) 3px
  );
  mix-blend-mode: multiply;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9998;
  background: radial-gradient(ellipse at center, rgba(0,0,0,0) 60%, rgba(0,0,0,0.45) 100%);
}

a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection { background: var(--green); color: var(--bg); }

/* ---------- layout shell ---------- */

.screen {
  max-width: 880px;
  margin: 0 auto;
  padding: 28px 24px 60px;
  position: relative;
  z-index: 1;
}

.term-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 1px solid var(--border);
  padding-bottom: 12px;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 8px;
}

.term-header .sysid {
  font-size: 12px;
  color: var(--green-dim);
  letter-spacing: 0.05em;
}

.term-title {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-shadow: var(--shadow-glow);
  margin: 0;
}

.term-title .blink {
  display: inline-block;
  width: 10px;
  background: var(--green);
  margin-left: 6px;
  animation: blink 1.1s steps(1) infinite;
}

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

.breadcrumb {
  font-size: 12px;
  color: var(--green-dim);
  margin-bottom: 18px;
}

.breadcrumb span.current { color: var(--white); }

/* ---------- panel / card ---------- */

.panel {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 20px 22px;
  margin-bottom: 20px;
  box-shadow: inset 0 0 24px rgba(0, 0, 0, 0.4);
}

.panel-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--green-dim);
  margin: 0 0 10px;
}

/* ---------- topic grid (home) ---------- */

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 14px;
  margin-bottom: 28px;
}

.topic-card {
  display: block;
  background: var(--bg-field);
  border: 1px solid var(--border);
  padding: 18px 16px;
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.1s;
  position: relative;
}

.topic-card:hover, .topic-card:focus-visible {
  border-color: var(--green);
  box-shadow: var(--shadow-glow);
  transform: translateY(-1px);
  outline: none;
}

.topic-card .idx {
  font-size: 11px;
  color: var(--green-dim);
}

.topic-card .name {
  font-size: 22px;
  font-weight: 700;
  margin: 4px 0 2px;
  letter-spacing: 0.02em;
}

.topic-card .full {
  font-size: 11px;
  color: var(--green-dim);
  line-height: 1.4;
}

.topic-card .stats {
  margin-top: 12px;
  font-size: 11px;
  color: var(--white);
  border-top: 1px dashed var(--border);
  padding-top: 8px;
}

.topic-card.c-amber  .name { color: var(--amber); }
.topic-card.c-green  .name { color: var(--green); }
.topic-card.c-cyan   .name { color: var(--cyan); }
.topic-card.c-magenta .name { color: var(--magenta); }
.topic-card.c-white  .name { color: var(--white); }

.topic-card.c-amber:hover    { border-color: var(--amber); box-shadow: 0 0 6px rgba(255,182,39,0.35); }
.topic-card.c-cyan:hover     { border-color: var(--cyan); box-shadow: 0 0 6px rgba(91,231,212,0.35); }
.topic-card.c-magenta:hover  { border-color: var(--magenta); box-shadow: 0 0 6px rgba(255,122,217,0.35); }
.topic-card.c-white:hover    { border-color: var(--white); box-shadow: 0 0 6px rgba(216,255,233,0.35); }

/* ---------- module list (per topic) ---------- */

.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
  margin: 18px 0;
}

.module-btn {
  background: var(--bg-field);
  border: 1px solid var(--border);
  color: var(--green);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 12px 10px;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.module-btn:hover, .module-btn:focus-visible {
  border-color: var(--green);
  box-shadow: var(--shadow-glow);
  outline: none;
}

.module-btn .m-range {
  display: block;
  font-weight: 600;
  margin-bottom: 4px;
}

.module-btn .m-score {
  display: block;
  font-size: 11px;
  color: var(--green-dim);
}

.module-btn .m-score.attempted { color: var(--amber); }
.module-btn .m-score.perfect { color: var(--green); }

/* ---------- buttons ---------- */

.btn {
  display: inline-block;
  background: transparent;
  border: 1px solid var(--green);
  color: var(--green);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.03em;
  padding: 10px 18px;
  cursor: pointer;
  text-transform: uppercase;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}

.btn:hover, .btn:focus-visible {
  background: var(--green);
  color: var(--bg);
  box-shadow: var(--shadow-glow);
  outline: none;
}

.btn.btn-ghost {
  border-color: var(--border);
  color: var(--green-dim);
}
.btn.btn-ghost:hover { background: var(--border); color: var(--white); }

.btn.btn-danger { border-color: var(--red); color: var(--red); }
.btn.btn-danger:hover { background: var(--red); color: var(--bg); }

.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }

/* ---------- quiz screen ---------- */

.quiz-meta {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--green-dim);
  margin-bottom: 10px;
  flex-wrap: wrap;
  gap: 6px;
}

.progress-bar {
  height: 6px;
  background: var(--bg-field);
  border: 1px solid var(--border);
  margin-bottom: 20px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--green);
  box-shadow: var(--shadow-glow);
  transition: width 0.25s;
}

.q-number {
  font-size: 12px;
  color: var(--green-dim);
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.q-text {
  font-size: 17px;
  color: var(--white);
  line-height: 1.55;
  margin: 0 0 18px;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 18px;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--bg-field);
  border: 1px solid var(--border);
  padding: 12px 14px;
  cursor: pointer;
  font-size: 14px;
  line-height: 1.5;
  text-align: left;
  color: var(--green);
  transition: border-color 0.12s, background 0.12s;
}

.option:hover:not(.locked) {
  border-color: var(--green);
}

.option .letter {
  flex-shrink: 0;
  width: 20px;
  font-weight: 700;
  color: var(--green-dim);
}

.option.selected-correct {
  border-color: var(--green);
  background: rgba(61, 245, 138, 0.08);
  box-shadow: var(--shadow-glow);
}
.option.selected-correct .letter { color: var(--green); }

.option.selected-wrong {
  border-color: var(--red);
  background: rgba(255, 93, 93, 0.08);
}
.option.selected-wrong .letter { color: var(--red); }

.option.reveal-correct {
  border-color: var(--green);
}
.option.reveal-correct .letter { color: var(--green); }

.option.locked { cursor: default; }

.explain-box {
  border-left: 3px solid var(--cyan);
  background: var(--bg-field);
  padding: 12px 14px;
  font-size: 13px;
  color: var(--white);
  line-height: 1.6;
  margin-bottom: 18px;
}

.explain-box .tag {
  display: inline-block;
  color: var(--cyan);
  font-weight: 600;
  margin-right: 6px;
}

/* ---------- result screen ---------- */

.score-display {
  text-align: center;
  padding: 30px 10px;
}

.score-display .big-score {
  font-size: 56px;
  font-weight: 700;
  color: var(--green);
  text-shadow: var(--shadow-glow);
  line-height: 1;
}

.score-display .of-total {
  font-size: 16px;
  color: var(--green-dim);
  margin-top: 6px;
}

.score-display .pct {
  font-size: 14px;
  margin-top: 12px;
  letter-spacing: 0.05em;
}

.pct.good { color: var(--green); }
.pct.mid  { color: var(--amber); }
.pct.bad  { color: var(--red); }

.review-list {
  margin-top: 10px;
}

.review-item {
  border: 1px solid var(--border);
  border-left: 3px solid var(--border);
  padding: 10px 14px;
  margin-bottom: 8px;
  font-size: 13px;
}

.review-item.right { border-left-color: var(--green); }
.review-item.wrong { border-left-color: var(--red); }

.review-item .rq { color: var(--white); margin-bottom: 4px; }
.review-item .ra { color: var(--green-dim); font-size: 12px; }
.review-item .ra.wrong-answer { color: var(--red); }

/* ---------- upload / data manager screen ---------- */

.upload-zone {
  border: 1px dashed var(--border);
  padding: 24px;
  text-align: center;
  color: var(--green-dim);
  font-size: 13px;
  margin-bottom: 16px;
}

.file-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
  font-size: 13px;
}

.file-row:last-child { border-bottom: none; }

.tag-ok { color: var(--green); }
.tag-bad { color: var(--red); }

input[type="file"] {
  font-family: var(--font-mono);
  color: var(--green);
  font-size: 12px;
}

/* ---------- footer ---------- */

.term-footer {
  margin-top: 30px;
  font-size: 11px;
  color: var(--green-deep);
  text-align: center;
  letter-spacing: 0.05em;
}

/* ---------- responsive ---------- */

@media (max-width: 600px) {
  .screen { padding: 18px 14px 50px; }
  .term-title { font-size: 17px; }
  .score-display .big-score { font-size: 42px; }
}

/* ---------- accessibility ---------- */

:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .term-title .blink { animation: none; }
  * { transition: none !important; }
}