:root {
  --bg: #08111f;
  --bg-alt: #101c30;
  --panel: rgba(10, 20, 36, 0.9);
  --panel-strong: #132540;
  --border: rgba(149, 186, 255, 0.18);
  --text: #eff5ff;
  --muted: #9db0cb;
  --accent: #5ae4c8;
  --accent-strong: #15b79e;
  --warm: #ffb347;
  --danger: #ff6b6b;
  --success: #54d2a5;
  --shadow: 0 18px 48px rgba(2, 10, 21, 0.35);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Space Grotesk", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(90, 228, 200, 0.12), transparent 30%),
    radial-gradient(circle at top right, rgba(255, 179, 71, 0.12), transparent 28%),
    linear-gradient(180deg, #08111f 0%, #0d1728 48%, #08111f 100%);
}

button,
select,
input {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

.app-shell {
  width: min(1120px, calc(100% - 24px));
  margin: 0 auto;
  padding: 20px 0 48px;
}

.topbar {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 22px;
}

.brand-button {
  padding: 0;
  background: none;
  color: inherit;
  text-align: left;
}

.brand-kicker {
  display: block;
  font-size: 1.15rem;
  font-weight: 700;
}

.brand-subtitle {
  display: block;
  color: var(--muted);
  margin-top: 4px;
}

.topbar-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.nav-link {
  color: var(--text);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  padding: 10px 15px;
  border-radius: 999px;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible,
.primary-button:hover,
.secondary-button:hover,
.danger-button:hover,
.answer-option:hover {
  transform: translateY(-1px);
}

.main-content {
  display: grid;
}

.screen {
  display: none;
}

.screen.active {
  display: block;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.hero {
  display: grid;
  gap: 20px;
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.eyebrow,
.mode-kicker {
  margin: 0 0 8px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-size: 0.76rem;
}

.hero h1,
.section-header h2,
.practice-topbar h2 {
  margin: 0;
  line-height: 1.05;
}

.hero h1 {
  font-size: clamp(2rem, 5.6vw, 3.35rem);
  max-width: 11ch;
}

.hero-subhead {
  margin: 14px 0 0;
  color: #cfe1ff;
  font-size: clamp(1.1rem, 2vw, 1.45rem);
  font-weight: 600;
  line-height: 1.2;
}

.hero-spark-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.spark-chip {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(149, 186, 255, 0.18);
  background: rgba(255, 255, 255, 0.03);
  color: #d7e7ff;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.78rem;
  text-transform: lowercase;
}

.hero-text,
.mode-card p,
.quick-play-card p,
.detail-card p,
.reset-card p {
  color: var(--muted);
  line-height: 1.55;
}

.hero-actions,
.challenge-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.hero-panel,
.mini-stat,
.stats-grid,
.stats-detail-grid,
.mode-grid,
.help-grid {
  display: grid;
  gap: 16px;
}

.hero-panel {
  grid-template-columns: repeat(1, minmax(0, 1fr));
}

.crew-caption {
  margin: 0;
  color: #dbe7ff;
  font-size: 0.9rem;
  font-weight: 600;
}

.cta-mascot-row {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-top: 18px;
}

.cta-copy {
  display: grid;
  gap: 8px;
  padding-top: 4px;
}

.cta-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.micro-chip {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(90, 228, 200, 0.18);
  background: rgba(90, 228, 200, 0.08);
  color: #cffff1;
  font-size: 0.78rem;
}

.cta-mascot {
  position: relative;
  width: 48px;
  height: 60px;
  flex: 0 0 auto;
  animation: bob 3.2s ease-in-out infinite;
}

.cta-mascot .char-head,
.cta-mascot .char-body {
  position: absolute;
  display: block;
}

.cta-mascot .char-head {
  top: 0;
  left: 50%;
  width: 30px;
  height: 24px;
  transform: translateX(-50%);
  border-radius: 15px;
  background: linear-gradient(180deg, #dff5ff, #98b9d7);
  box-shadow: inset 0 -2px 0 rgba(0, 0, 0, 0.12);
}

.cta-mascot .char-head::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 6px;
  width: 18px;
  height: 6px;
  border-radius: 999px;
  background: #0e2037;
  box-shadow: 0 0 0 2px rgba(90, 228, 200, 0.16);
}

.cta-mascot .char-head::after {
  content: "";
  position: absolute;
  top: -6px;
  left: 50%;
  width: 3px;
  height: 9px;
  transform: translateX(-50%);
  background: #89a8c6;
  box-shadow: 0 -3px 0 3px #5ae4c8;
}

.cta-mascot .char-body {
  left: 50%;
  bottom: 0;
  width: 34px;
  height: 34px;
  transform: translateX(-50%);
  border-radius: 14px 14px 12px 12px;
  background: linear-gradient(180deg, #ffffff, #d9e8ff);
  box-shadow: inset 0 -12px 0 #15b79e;
}

.cta-mascot .char-body::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 50%;
  width: 16px;
  height: 4px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: rgba(29, 43, 63, 0.28);
}

.stage-character {
  position: relative;
  width: 74px;
  height: 94px;
  animation: bob 3.2s ease-in-out infinite;
}

.stage-character .char-head,
.stage-character .char-body {
  position: absolute;
  display: block;
}

.stage-character .char-head {
  top: 0;
  left: 50%;
  width: 44px;
  height: 38px;
  transform: translateX(-50%);
  border-radius: 20px;
}

.stage-character .char-body {
  left: 50%;
  bottom: 0;
  width: 48px;
  height: 50px;
  transform: translateX(-50%);
  border-radius: 18px 18px 16px 16px;
}

.sensei-bot .char-head {
  background: linear-gradient(180deg, #dff5ff, #98b9d7);
  box-shadow: inset 0 -2px 0 rgba(0, 0, 0, 0.12);
}

.sensei-bot .char-head::before {
  content: "";
  position: absolute;
  top: 12px;
  left: 9px;
  width: 26px;
  height: 9px;
  border-radius: 999px;
  background: #0e2037;
  box-shadow: 0 0 0 2px rgba(90, 228, 200, 0.16);
}

.sensei-bot .char-head::after {
  content: "";
  position: absolute;
  top: -8px;
  left: 50%;
  width: 3px;
  height: 10px;
  transform: translateX(-50%);
  background: #89a8c6;
  box-shadow: 0 -3px 0 3px #5ae4c8;
}

.sensei-bot .char-body {
  background: linear-gradient(180deg, #5ae4c8, #239c87);
}

.sensei-bot .char-body::before {
  content: "";
  position: absolute;
  inset: 14px 10px auto;
  height: 6px;
  background: rgba(6, 31, 26, 0.28);
  border-radius: 999px;
}

.snake-student .char-head {
  background: linear-gradient(180deg, #ffe18b, #e5b748);
  border-radius: 22px 22px 17px 17px;
}

.snake-student .char-head::before {
  content: "";
  position: absolute;
  top: 13px;
  left: 8px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #12233c;
  box-shadow: 20px 0 0 #12233c;
}

.snake-student .char-head::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 50%;
  width: 14px;
  height: 10px;
  transform: translateX(-50%);
  border-radius: 0 0 8px 8px;
  background: #ff7f7f;
}

.snake-student .char-body {
  background: linear-gradient(180deg, #4fc89e, #287d68);
  border-radius: 20px 20px 24px 24px;
}

.snake-student .char-body::before {
  content: "";
  position: absolute;
  inset: 13px 10px auto;
  height: 15px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.2);
}

.mini-stat,
.stat-card {
  padding: 16px 18px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.mini-stat-copy {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.45;
}

.hero-orbit {
  position: relative;
  min-height: 240px;
  border-radius: var(--radius-md);
  border: 1px dashed rgba(149, 186, 255, 0.16);
  background:
    radial-gradient(circle at 50% 62%, rgba(90, 228, 200, 0.24), transparent 38%),
    radial-gradient(circle at center, rgba(255, 179, 71, 0.1), transparent 56%),
    rgba(255, 255, 255, 0.02);
  box-shadow: inset 0 0 0 1px rgba(149, 186, 255, 0.06), 0 12px 30px rgba(3, 14, 28, 0.18);
  overflow: hidden;
}

.orbit-node {
  position: absolute;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-family: "JetBrains Mono", monospace;
}

.orbit-node {
  min-height: 30px;
  padding: 4px 10px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(149, 186, 255, 0.16);
  color: #dce8ff;
  font-size: 0.8rem;
}

.orbit-node-a {
  top: 18px;
  left: 18px;
}

.orbit-node-b {
  top: 22px;
  right: 20px;
}

.orbit-node-c {
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
}

.dojo-stage {
  position: absolute;
  inset: 0;
}

.stage-ring {
  position: absolute;
  left: 50%;
  bottom: 18px;
  width: 232px;
  height: 120px;
  transform: translateX(-50%);
  border-radius: 50%;
  background:
    radial-gradient(circle at center, rgba(90, 228, 200, 0.34), rgba(90, 228, 200, 0.08) 54%, transparent 66%),
    radial-gradient(circle at center, rgba(255, 179, 71, 0.12), transparent 74%);
  box-shadow: inset 0 0 0 1px rgba(149, 186, 255, 0.09);
}

.sensei-bot {
  position: absolute;
  left: calc(50% - 70px);
  bottom: 54px;
}

.snake-student {
  position: absolute;
  left: calc(50% + 18px);
  bottom: 42px;
  animation-delay: 0.5s;
}

.sensei-bot .char-body {
  background: linear-gradient(180deg, #e8f1ff, #b8c8da);
  box-shadow: inset 0 -16px 0 #15b79e;
}

.snake-student .char-body {
  background: linear-gradient(180deg, #64d6ac, #2c9076);
}

.sensei-bot::before,
.snake-student::before {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 16px;
  width: 28px;
  height: 4px;
  transform-origin: center;
  background: rgba(225, 236, 255, 0.9);
  border-radius: 999px;
}

.sensei-bot::before {
  transform: translateX(-75%) rotate(-28deg);
}

.snake-student::before {
  transform: translateX(-25%) rotate(22deg);
  background: rgba(255, 220, 128, 0.9);
}

@keyframes bob {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-4px);
  }
}

.mini-label {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 8px;
}

.mode-grid,
.stats-grid,
.stats-detail-grid,
.help-grid {
  margin-top: 20px;
}

.mode-card,
.detail-card,
.quick-play-card,
.filters-card,
.reset-card,
.challenge-card,
.practice-topbar {
  padding: 20px;
}

.mode-card,
.quick-play-card,
.reset-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mode-card-meta,
.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.mini-badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(149, 186, 255, 0.14);
  color: #d6e5ff;
  font-size: 0.8rem;
}

.preset-row {
  margin-top: 20px;
}

.preset-button {
  min-height: 42px;
}

.practice-position {
  margin: 8px 0 0;
  color: var(--muted);
}

.progress-card {
  padding: 14px 18px;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

.progress-track {
  margin-top: 10px;
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
  overflow: hidden;
}

.progress-fill {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), #82ffc1);
  transition: width 0.2s ease;
}

.session-complete-card {
  padding: 22px;
  border: 1px solid rgba(90, 228, 200, 0.2);
  background:
    radial-gradient(circle at top left, rgba(90, 228, 200, 0.12), transparent 28%),
    rgba(255, 255, 255, 0.03);
}

.session-complete-badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(90, 228, 200, 0.12);
  border: 1px solid rgba(90, 228, 200, 0.24);
  color: #caffef;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.session-complete-card h3 {
  margin: 14px 0 8px;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
}

.session-complete-copy {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.session-complete-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.session-complete-stat {
  padding: 14px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(149, 186, 255, 0.12);
}

.session-complete-stat strong {
  display: block;
  font-size: 1.2rem;
}

.section-header {
  margin-bottom: 12px;
}

.filters-card {
  display: grid;
  gap: 14px;
}

.filter-group {
  display: grid;
  gap: 8px;
}

.filter-group label {
  color: var(--muted);
  font-size: 0.9rem;
}

select,
.patch-input {
  width: 100%;
  padding: 13px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: #091526;
  color: var(--text);
}

.primary-button,
.secondary-button,
.danger-button {
  min-height: 48px;
  padding: 12px 16px;
  border-radius: 14px;
  font-weight: 700;
}

.primary-button {
  background: linear-gradient(135deg, var(--accent), #82ffc1);
  color: #062318;
}

.secondary-button {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border: 1px solid var(--border);
}

.danger-button {
  background: rgba(255, 107, 107, 0.12);
  color: #ffd8d8;
  border: 1px solid rgba(255, 107, 107, 0.28);
}

.practice-shell {
  display: grid;
  gap: 18px;
}

.practice-topbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
}

.session-badges,
.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.badge,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(90, 228, 200, 0.08);
  border: 1px solid rgba(90, 228, 200, 0.22);
  color: #bbfff2;
  font-size: 0.85rem;
}

.challenge-meta {
  display: grid;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  margin-bottom: 18px;
}

.challenge-label {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

#challenge-title {
  margin: 0;
  font-size: clamp(1.25rem, 2.5vw, 1.7rem);
}

.challenge-prompt {
  margin: 10px 0 0;
  color: #dbe7ff;
  font-size: 1.02rem;
  line-height: 1.55;
}

.code-shell,
.answer-shell {
  border-radius: var(--radius-md);
  border: 1px solid rgba(149, 186, 255, 0.12);
  background: rgba(255, 255, 255, 0.02);
  overflow: hidden;
}

.code-shell-top,
.answer-shell-top {
  display: flex;
  align-items: center;
  min-height: 42px;
  padding: 0 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  background: rgba(255, 255, 255, 0.025);
}

.code-shell-label {
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.code-block {
  margin: 0;
  padding: 18px;
  background: #06111e;
  overflow-x: auto;
}

.code-block code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.92rem;
  line-height: 1.6;
  white-space: pre;
}

.answer-area {
  display: grid;
  gap: 12px;
  padding: 14px;
}

.answer-option {
  width: 100%;
  padding: 15px 16px;
  text-align: left;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text);
}

.answer-option.selected {
  border-color: var(--accent);
  background: rgba(90, 228, 200, 0.1);
}

.answer-option.correct {
  border-color: rgba(84, 210, 165, 0.5);
  background: rgba(84, 210, 165, 0.14);
}

.answer-option.incorrect {
  border-color: rgba(255, 107, 107, 0.5);
  background: rgba(255, 107, 107, 0.12);
}

.patch-hint {
  color: var(--muted);
  margin: 0;
}

.feedback-panel {
  margin-top: 18px;
  padding: 16px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  animation: feedback-in 0.2s ease;
}

.feedback-answer {
  margin: 0 0 14px;
  padding: 14px;
  border-radius: var(--radius-sm);
  background: #06111e;
  border: 1px solid rgba(149, 186, 255, 0.16);
  overflow-x: auto;
}

.feedback-answer code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.9rem;
  line-height: 1.55;
  white-space: pre;
}

.feedback-status {
  font-weight: 700;
  margin-top: 0;
}

.feedback-panel.correct .feedback-status {
  color: var(--success);
}

.feedback-panel.incorrect .feedback-status {
  color: var(--danger);
}

.feedback-ai-context {
  color: #bfd5f6;
}

.takeaway {
  color: #dbe7ff;
  margin-bottom: 0;
}

@keyframes feedback-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.detail-list {
  display: grid;
  gap: 10px;
}

.coaching-grid {
  margin-top: 20px;
}

.coaching-card {
  display: grid;
  gap: 14px;
}

.coaching-summary {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.detail-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.detail-row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

@media (min-width: 720px) {
  .topbar {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .hero {
    grid-template-columns: 1.35fr 0.9fr;
    align-items: stretch;
    padding: 28px;
  }

  .mode-grid,
  .stats-grid,
  .stats-detail-grid,
  .help-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .stats-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .filters-card {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: end;
  }

  .challenge-meta {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: start;
  }
}