:root {
  --paper: #f6f0e3;
  --paper2: #efe5d3;
  --ink: #1b1b1b;
  --ink2: #2b2a28;
  --muted: #5b554a;
  --line: rgba(30, 25, 20, 0.18);
  --accent: #c0392b;
  --accent2: #1f7a8c;
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.16);
  --shadow2: 0 10px 26px rgba(0, 0, 0, 0.12);
  --radius: 20px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(1000px 700px at 15% 15%, rgba(192, 57, 43, 0.09), transparent 60%),
    radial-gradient(900px 650px at 85% 20%, rgba(31, 122, 140, 0.10), transparent 55%),
    radial-gradient(1100px 800px at 65% 88%, rgba(20, 20, 20, 0.08), transparent 60%),
    linear-gradient(180deg, var(--paper), var(--paper2));
  font-family: "Palatino", "Palatino Linotype", "Book Antiqua", "Georgia", serif;
  letter-spacing: 0.1px;
}

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  opacity: 0.14;
  mix-blend-mode: multiply;
  background:
    repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.06), rgba(0, 0, 0, 0.06) 1px, transparent 1px, transparent 2px),
    repeating-linear-gradient(90deg, rgba(0, 0, 0, 0.03), rgba(0, 0, 0, 0.03) 1px, transparent 1px, transparent 3px);
}

.top {
  padding: 18px 18px 6px;
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
}

.badge {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-family: "Courier New", Courier, monospace;
  font-weight: 700;
  background: linear-gradient(135deg, rgba(192, 57, 43, 0.18), rgba(31, 122, 140, 0.18));
  border: 1px solid rgba(0, 0, 0, 0.12);
  box-shadow: var(--shadow2);
}

.title .kicker {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--muted);
}

h1 {
  margin: 0;
  font-size: 22px;
  letter-spacing: 0.03em;
}

.nav {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.tab {
  border: 1px solid rgba(0, 0, 0, 0.14);
  background: rgba(255, 255, 255, 0.55);
  padding: 10px 12px;
  border-radius: 14px;
  cursor: pointer;
  font-family: "Courier New", Courier, monospace;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.06);
  transition: transform 120ms ease, background 120ms ease;
}

.tab:hover {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.75);
}

.tab.is-active {
  border-color: rgba(192, 57, 43, 0.35);
  background: rgba(192, 57, 43, 0.10);
}

.layout {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 18px;
  padding: 12px 18px 18px;
  align-items: start;
}

.panel {
  position: sticky;
  top: 10px;
  display: grid;
  gap: 12px;
}

.box {
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.52);
  border: 1px solid rgba(0, 0, 0, 0.12);
  box-shadow: var(--shadow2);
  padding: 14px 14px 12px;
}

.box h2 {
  margin: 0 0 10px;
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(0, 0, 0, 0.66);
  font-family: "Courier New", Courier, monospace;
}

.box h3 {
  margin: 0 0 10px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(0, 0, 0, 0.66);
  font-family: "Courier New", Courier, monospace;
}

.field {
  display: grid;
  gap: 6px;
  margin: 10px 0;
}

.field > span {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

input,
select,
textarea {
  border: 1px solid rgba(0, 0, 0, 0.14);
  border-radius: 14px;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.7);
  font-family: inherit;
  font-size: 14px;
  outline: none;
  transition: border-color 140ms ease, transform 120ms ease;
}

textarea {
  min-height: 210px;
  resize: vertical;
  line-height: 1.45;
}

input:focus,
select:focus,
textarea:focus {
  border-color: rgba(31, 122, 140, 0.45);
}

.row {
  display: flex;
  gap: 10px;
  align-items: center;
}

.row input[type="number"] {
  width: 120px;
}

.hr {
  height: 1px;
  background: var(--line);
  margin: 10px 0;
}

.hint {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.4;
}

.tools {
  display: grid;
  gap: 8px;
}

.btn {
  border: 1px solid rgba(0, 0, 0, 0.16);
  background: rgba(255, 255, 255, 0.65);
  padding: 10px 12px;
  border-radius: 14px;
  cursor: pointer;
  font-family: "Courier New", Courier, monospace;
  letter-spacing: 0.02em;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.06);
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}

.btn:hover {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.8);
}

.btn:active {
  transform: translateY(0px);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.35);
}

.btn-danger {
  border-color: rgba(192, 57, 43, 0.38);
  background: rgba(192, 57, 43, 0.10);
}

.stage {
  display: grid;
  gap: 12px;
  min-width: 0;
}

.view {
  display: none;
  animation: pop 240ms ease both;
}

.view.is-active {
  display: grid;
  gap: 12px;
}

@keyframes pop {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.stageHeader {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.stageHeader h2 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.02em;
}

.sub {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.pill {
  font-family: "Courier New", Courier, monospace;
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.14);
  background: rgba(255, 255, 255, 0.45);
}

.pill.is-accent {
  border-color: rgba(31, 122, 140, 0.32);
  background: rgba(31, 122, 140, 0.10);
}

.pill.is-selected {
  border-color: rgba(192, 57, 43, 0.38);
  background: rgba(192, 57, 43, 0.10);
}

.cardWrap {
  padding: 6px 0;
  display: grid;
  place-items: center;
}

.studyCard {
  width: min(860px, 100%);
  min-height: 360px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 420ms cubic-bezier(0.2, 0.8, 0.2, 1);
  border-radius: 26px;
  cursor: pointer;
  outline: none;
}

.studyCard.is-flipped {
  transform: rotateY(180deg);
}

.face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 26px;
  background:
    radial-gradient(1200px 450px at 30% 20%, rgba(31, 122, 140, 0.10), transparent 60%),
    radial-gradient(900px 480px at 70% 85%, rgba(192, 57, 43, 0.10), transparent 55%),
    rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(0, 0, 0, 0.14);
  box-shadow: var(--shadow);
  padding: 18px 18px 16px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 10px;
}

.face.back {
  transform: rotateY(180deg);
}

.label {
  font-family: "Courier New", Courier, monospace;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: rgba(0, 0, 0, 0.62);
}

.big {
  font-size: 22px;
  line-height: 1.25;
}

.micro {
  color: var(--muted);
  font-size: 12px;
}

.answer {
  margin: 0;
  white-space: pre-wrap;
  font-family: "Palatino", "Palatino Linotype", "Book Antiqua", "Georgia", serif;
  font-size: 16px;
  line-height: 1.45;
}

.answer.is-muted {
  color: rgba(0, 0, 0, 0.45);
}

.grading {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.grade[data-grade="again"] {
  border-color: rgba(192, 57, 43, 0.38);
  background: rgba(192, 57, 43, 0.10);
}

.grade[data-grade="easy"] {
  border-color: rgba(31, 122, 140, 0.35);
  background: rgba(31, 122, 140, 0.10);
}

.coach {
  width: min(860px, 100%);
  margin: 0 auto;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.45);
  border: 1px dashed rgba(0, 0, 0, 0.18);
  padding: 12px 14px;
}

.coachTitle {
  font-family: "Courier New", Courier, monospace;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  color: rgba(0, 0, 0, 0.66);
  margin-bottom: 6px;
}

.coachText {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

.quizGrid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 12px;
}

.quizBox {
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.52);
  border: 1px solid rgba(0, 0, 0, 0.12);
  box-shadow: var(--shadow2);
  padding: 14px;
  min-width: 0;
  display: grid;
  gap: 10px;
  align-content: start;
}

.tiny {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.4;
}

.mapShell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 12px;
  align-items: start;
}

#mapSvg {
  width: 100%;
  height: auto;
  border-radius: 26px;
  box-shadow: var(--shadow2);
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: rgba(255, 255, 255, 0.2);
  touch-action: pan-x pan-y pinch-zoom;
}

.node rect {
  fill: rgba(255, 255, 255, 0.50);
  stroke: rgba(0, 0, 0, 0.18);
  stroke-width: 1.2;
}

.node:hover rect {
  stroke: rgba(31, 122, 140, 0.45);
  fill: rgba(31, 122, 140, 0.08);
}

.node text {
  font-family: "Courier New", Courier, monospace;
  font-size: 14px;
  fill: rgba(0, 0, 0, 0.68);
  text-anchor: middle;
  dominant-baseline: middle;
  pointer-events: none;
}

.node text.b {
  font-size: 18px;
  letter-spacing: 0.06em;
  fill: rgba(0, 0, 0, 0.80);
}

.node.mini text.b {
  font-size: 16px;
}

.node {
  cursor: pointer;
}

.hintNode rect {
  stroke: rgba(192, 57, 43, 0.35);
  fill: rgba(192, 57, 43, 0.08);
}

.mapSide .list {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.45;
  font-size: 13px;
}

.mnemo {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  font-family: "Courier New", Courier, monospace;
  font-size: 12px;
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.14);
  background: rgba(255, 255, 255, 0.45);
}

.statsGrid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.statNum {
  font-family: "Courier New", Courier, monospace;
  font-size: 34px;
  letter-spacing: 0.02em;
}

.statLabel {
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.para {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
  font-size: 14px;
}

.foot {
  padding: 8px 18px 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: space-between;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }
  .panel {
    position: static;
  }
  .quizGrid {
    grid-template-columns: 1fr;
  }
  .mapShell {
    grid-template-columns: 1fr;
  }
  .statsGrid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}