:root {
  --bg: #0d3b3e;
  --cream: #f4efe6;
  --ink: #1d2b2c;
  --muted: #5b6e70;
  --coral: #e76f51;
  --sand: #f4a261;
  --teal: #2a9d8f;
  --shadow: 0 18px 40px rgba(6, 22, 24, 0.28);
  --radius: 22px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

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

body {
  font-family: "Nunito", "Segoe UI", system-ui, sans-serif;
  background: radial-gradient(1200px 700px at 10% -10%, #1a6a6e 0%, transparent 55%),
    radial-gradient(900px 500px at 110% 10%, #e76f5133 0%, transparent 50%),
    var(--bg);
  color: var(--cream);
  min-height: 100dvh;
}

.bg-glow {
  position: fixed;
  inset: auto -80px -120px auto;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: #f4a26144;
  filter: blur(30px);
  pointer-events: none;
}

.app {
  width: min(440px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 36px;
}

.screen {
  display: none;
}

.screen.is-active {
  display: block;
}

.eyebrow {
  margin: 0 0 8px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.75rem;
  font-weight: 800;
  color: var(--sand);
}

.logo {
  font-family: "Fraunces", Georgia, serif;
  font-size: clamp(3rem, 12vw, 4.4rem);
  line-height: 0.95;
  margin: 0 0 14px;
}

.tagline {
  margin: 0 0 32px;
  font-size: 1.12rem;
  line-height: 1.45;
  color: #d7ebe8;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.user-list {
  display: grid;
  gap: 8px;
  margin-bottom: 22px;
}

.user-btn {
  appearance: none;
  width: 100%;
  text-align: left;
  border: 1px solid rgba(244, 239, 230, 0.18);
  background: rgba(244, 239, 230, 0.1);
  color: var(--cream);
  border-radius: 16px;
  padding: 12px 16px;
  font: inherit;
  cursor: pointer;
}

.user-btn:hover,
.user-btn:focus-visible {
  background: rgba(244, 239, 230, 0.18);
}

.user-btn strong {
  display: block;
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.25rem;
}

.user-btn span {
  display: block;
  margin-top: 2px;
  font-size: 0.82rem;
  color: #b7d4d1;
}

.login-form {
  display: grid;
  gap: 10px;
}

.name-input {
  width: 100%;
  border: 1px solid rgba(244, 239, 230, 0.28);
  background: rgba(244, 239, 230, 0.1);
  color: var(--cream);
  border-radius: 16px;
  padding: 14px 16px;
  font: inherit;
  font-size: 1.1rem;
  font-weight: 800;
}

.name-input::placeholder {
  color: #9bbfbb;
  font-weight: 700;
}

.name-input:focus {
  outline: 2px solid var(--sand);
  outline-offset: 2px;
}

.home-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 28px;
}

.home-stats div {
  background: rgba(244, 239, 230, 0.1);
  border: 1px solid rgba(244, 239, 230, 0.14);
  border-radius: 16px;
  padding: 14px 10px;
  text-align: center;
}

.stat-label {
  display: block;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #b7d4d1;
  margin-bottom: 4px;
}

.home-stats strong {
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.6rem;
}

.home-actions {
  display: grid;
  gap: 10px;
}

.btn {
  appearance: none;
  border: 0;
  border-radius: 999px;
  padding: 14px 22px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.btn-primary {
  background: var(--sand);
  color: var(--ink);
}

.btn-primary:hover {
  filter: brightness(1.05);
}

.btn-ghost {
  background: transparent;
  color: var(--cream);
  border: 1px solid rgba(244, 239, 230, 0.28);
}

.play-top {
  display: grid;
  grid-template-columns: 96px 1fr 96px;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.play-tools {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.icon-btn {
  width: 44px;
  height: 44px;
  border: 1px solid rgba(244, 239, 230, 0.22);
  background: rgba(244, 239, 230, 0.08);
  color: var(--cream);
  border-radius: 14px;
  font: inherit;
  font-size: 1.1rem;
  cursor: pointer;
}

.level-meta {
  text-align: center;
}

.level-kicker {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 800;
  color: var(--sand);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.level-name {
  margin: 2px 0 0;
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.25rem;
}

.progress-wrap {
  margin-bottom: 12px;
}

.progress-bar {
  height: 10px;
  background: rgba(244, 239, 230, 0.15);
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--teal), #8ad4c8);
  border-radius: inherit;
  transition: width 220ms ease;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
}

.progress-label {
  margin: 0;
  font-size: 0.82rem;
  color: #c5ddda;
}

.facts-wrap {
  position: relative;
  z-index: 4;
}

.facts-btn {
  appearance: none;
  border: 1px solid rgba(244, 239, 230, 0.28);
  background: rgba(244, 239, 230, 0.1);
  color: var(--cream);
  border-radius: 999px;
  padding: 4px 12px;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  cursor: pointer;
}

.facts-btn:hover,
.facts-wrap.is-open .facts-btn {
  background: rgba(244, 239, 230, 0.2);
}

.facts-pop {
  position: absolute;
  top: 100%;
  right: 0;
  width: min(92vw, 420px);
  background: var(--cream);
  color: var(--ink);
  border-radius: 18px;
  padding: 14px;
  margin-top: 6px;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition: opacity 140ms ease, transform 140ms ease, visibility 140ms ease;
}

.facts-pop::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 100%;
  height: 10px;
}

.facts-wrap.is-open .facts-pop,
.facts-wrap:focus-within .facts-pop {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

@media (hover: hover) {
  .facts-wrap:hover .facts-pop {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }
}

.facts-pop-head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 10px;
}

.facts-pop-title {
  margin: 0;
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.05rem;
}

.facts-legend {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--muted);
}

.swatch {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 3px;
  border: 1px solid rgba(29, 43, 44, 0.16);
}

.swatch-new {
  background: #fff;
}

.swatch-miss {
  background: var(--coral);
}

.swatch-solid {
  background: var(--teal);
}

.facts-maps {
  overflow: auto;
  max-height: min(62vh, 500px);
}

.fact-map + .fact-map {
  margin-top: 14px;
}

.fact-map-title {
  margin: 0 0 6px;
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.fact-table {
  display: grid;
  gap: 1px;
  background: rgba(29, 43, 44, 0.1);
  padding: 1px;
  border-radius: 8px;
  overflow: hidden;
}

.fact-cell {
  min-width: 0;
  aspect-ratio: 1;
  background: #fff;
}

.fact-cell.is-axis {
  aspect-ratio: auto;
  min-height: 0.9rem;
  display: grid;
  place-items: center;
  background: #efe9de;
  font-size: 0.55rem;
  font-weight: 800;
  color: var(--muted);
  line-height: 1;
}

.fact-cell.is-corner,
.fact-cell.is-blank {
  background: #efe9de;
}

.hud {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 16px;
  font-size: 0.92rem;
  color: #c5ddda;
}

.hud p {
  margin: 0;
}

.problem-card {
  background: var(--cream);
  color: var(--ink);
  border-radius: var(--radius);
  padding: 28px 18px 22px;
  box-shadow: var(--shadow);
  min-height: 168px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  transition: transform 160ms ease, background 160ms ease;
}

.problem-card.is-correct {
  background: #d8f3ee;
}

.problem-card.is-slow {
  background: #f8ead0;
}

.problem-card.is-wrong {
  background: #fde8e1;
  animation: shake 420ms ease;
}

.equation {
  margin: 0;
  font-family: "Fraunces", Georgia, serif;
  font-size: clamp(2.2rem, 10vw, 3.1rem);
  font-weight: 700;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: baseline;
  gap: 0.28em;
}

.equation span {
  transition: transform 120ms ease, background 120ms ease, box-shadow 120ms ease, color 120ms ease;
}

.op {
  color: var(--coral);
}

.answer-slot {
  min-width: 1.4em;
  padding: 0 0.12em;
  border-bottom: 4px solid var(--ink);
  text-align: center;
}

.answer-slot.is-empty {
  color: #9aa8aa;
}

.answer-slot.is-reveal {
  color: var(--teal);
  border-bottom-color: transparent;
}

.equation .is-lit {
  background: #f8ead0;
  border-radius: 10px;
  padding: 0.04em 0.18em;
  box-shadow: 0 0 0 3px var(--sand);
  transform: scale(1.08);
  color: var(--ink);
}

.answer-slot.is-lit {
  border-bottom-color: var(--sand);
  color: var(--ink);
}

.feedback {
  min-height: 1.3em;
  margin: 12px 0 0;
  font-weight: 800;
  color: var(--muted);
}

.pad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.pad button {
  height: 58px;
  border: 0;
  border-radius: 16px;
  background: rgba(244, 239, 230, 0.12);
  color: var(--cream);
  font: inherit;
  font-size: 1.35rem;
  font-weight: 800;
  cursor: pointer;
}

.pad button:active {
  transform: translateY(1px);
}

.pad-util {
  color: var(--sand) !important;
}

.pad-enter {
  background: var(--sand) !important;
  color: var(--ink) !important;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(6, 22, 24, 0.62);
  display: grid;
  place-items: center;
  padding: 24px;
  z-index: 5;
  overflow: auto;
}

.overlay-card {
  width: min(380px, 100%);
  background: var(--cream);
  color: var(--ink);
  border-radius: 24px;
  padding: 28px 24px;
  text-align: center;
  box-shadow: var(--shadow);
}

.overlay-card .eyebrow {
  color: var(--coral);
}

.overlay-card h2 {
  font-family: "Fraunces", Georgia, serif;
  margin: 0 0 8px;
}

.overlay-card p {
  margin: 0 0 22px;
}

.overlay-actions {
  display: grid;
  gap: 10px;
}

.overlay-card .overlay-stay-note {
  margin: 6px 0 2px;
  font-size: 0.92rem;
  line-height: 1.4;
  color: var(--muted);
}

.setting {
  text-align: left;
  margin-bottom: 22px;
}

.setting-label {
  display: block;
  font-weight: 800;
  margin-bottom: 4px;
}

.setting-label-sub {
  margin-top: 16px;
}

.overlay-card .setting-help {
  margin: 0 0 14px;
  font-size: 0.92rem;
  line-height: 1.4;
  color: var(--muted);
}

.slider-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  font-size: 0.82rem;
  font-weight: 800;
  color: var(--muted);
}

.slider-row input {
  width: 100%;
  accent-color: var(--teal);
}

.overlay-card .slider-value {
  margin: 10px 0 0;
  font-weight: 800;
  text-align: center;
}

.song-dropdown {
  position: relative;
  z-index: 1;
}

.song-dropdown-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-top: 2px;
  padding: 10px 12px;
  border: 1px solid rgba(29, 43, 44, 0.18);
  border-radius: 12px;
  font: inherit;
  font-weight: 800;
  color: var(--ink);
  background: #fff;
  text-align: left;
  cursor: pointer;
}

.song-dropdown-toggle::after {
  content: "▾";
  color: var(--muted);
  font-size: 0.9em;
}

.song-dropdown.is-open .song-dropdown-toggle::after {
  content: "▴";
}

.song-list {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 4px);
  z-index: 6;
  max-height: 220px;
  overflow: auto;
  padding: 6px;
  gap: 4px;
  border: 1px solid rgba(29, 43, 44, 0.18);
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 12px 28px rgba(6, 22, 24, 0.18);
}

.song-dropdown.is-open .song-list {
  display: grid;
}

.song-option {
  width: 100%;
  text-align: left;
  padding: 8px 12px;
  border: 0;
  border-radius: 10px;
  font: inherit;
  font-weight: 800;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
}

.song-option:hover {
  background: rgba(42, 157, 143, 0.12);
}

.song-option.is-selected {
  background: var(--teal);
  color: #fff;
}

.settings-credit {
  margin: 0 0 18px;
  font-size: 0.88rem;
  color: var(--muted);
}

.settings-credit a {
  color: var(--teal);
  font-weight: 800;
  text-decoration: none;
}

.settings-credit a:hover {
  text-decoration: underline;
}

.btn-quiet {
  background: transparent;
  color: var(--ink);
  border: 1px solid rgba(29, 43, 44, 0.18);
}

.btn-danger {
  background: var(--coral);
  color: #fff;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-6px);
  }
  75% {
    transform: translateX(6px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .progress-fill,
  .problem-card,
  .facts-pop {
    transition: none;
  }

  .problem-card.is-wrong {
    animation: none;
  }

  .equation .is-lit {
    transform: none;
  }

  .equation span {
    transition: none;
  }
}