:root {
  --mint-50: #f7fffc;
  --mint-100: #effffa;
  --mint-200: #cff7e7;
  --mint-300: #b8f2e6;
  --mint-400: #9be7d8;
  --mint-500: #74dccb;
  --mint-600: #4cc9b0;
  --ink: #1e2b2a;
  --muted: #5f7370;
  --surface: rgba(255, 255, 255, 0.76);
  --surface-strong: rgba(255, 255, 255, 0.93);
  --line: rgba(30, 43, 42, 0.1);
  --shadow: 0 24px 70px rgba(37, 150, 133, 0.16);
  --danger: #e76f8a;
  --warning: #f5b85c;
  --radius: 24px;
  --radius-sm: 16px;
  --max: 1180px;
  --font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

html[data-theme="dark"] {
  --mint-50: #071311;
  --mint-100: #0d1d1a;
  --mint-200: #14332f;
  --mint-300: #1d4d45;
  --mint-400: #2d7066;
  --mint-500: #54bfae;
  --mint-600: #83ead8;
  --ink: #effffa;
  --muted: #b4cbc7;
  --surface: rgba(13, 29, 26, 0.76);
  --surface-strong: rgba(13, 29, 26, 0.94);
  --line: rgba(239, 255, 250, 0.13);
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
}

* {
  box-sizing: border-box;
}

body {
  overflow-x: hidden;
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  font-family: var(--font);
  background:
    radial-gradient(circle at 10% 6%, rgba(116, 220, 203, 0.36), transparent 28rem),
    radial-gradient(circle at 92% 18%, rgba(155, 231, 216, 0.32), transparent 30rem),
    linear-gradient(135deg, var(--mint-50), var(--mint-100) 45%, #ffffff);
  transition: background 0.3s ease, color 0.3s ease;
}

html[data-theme="dark"] body {
  background:
    radial-gradient(circle at 10% 6%, rgba(76, 201, 176, 0.18), transparent 28rem),
    radial-gradient(circle at 92% 18%, rgba(116, 220, 203, 0.14), transparent 30rem),
    linear-gradient(135deg, #071311, #0d1d1a 54%, #102622);
}

button,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: clamp(10px, 2.4vw, 18px);
}

.topbar,
.layout,
.user-card,
.onboarding,
.lesson-view,
.learning-card,
.finish-card {
  border: 1px solid var(--line);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(22px);
}

.topbar {
  position: sticky;
  top: 12px;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 12px;
  border-radius: var(--radius);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  border-radius: 16px;
  color: #07352e;
  font-weight: 900;
  background: linear-gradient(135deg, var(--mint-300), var(--mint-600));
  box-shadow: 0 12px 30px rgba(76, 201, 176, 0.34);
}

.brand strong,
.brand small {
  display: block;
  overflow-wrap: anywhere;
}

.brand small,
.eyebrow,
.muted {
  color: var(--muted);
}

.top-actions,
.lesson-controls,
.section-heading,
.lesson-head,
.score-grid {
  display: flex;
  align-items: center;
}

.top-actions {
  gap: 8px;
  min-width: 0;
}

.select,
.icon-button,
.primary-button,
.secondary-button,
.text-button,
.answer-button {
  border: 0;
  border-radius: 16px;
  min-height: 44px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.select,
.icon-button,
.secondary-button,
.answer-button {
  color: var(--ink);
  background: var(--surface-strong);
  border: 1px solid var(--line);
}

.select {
  width: 100%;
  min-width: 0;
  padding: 0 12px;
}

.icon-button {
  width: 46px;
  font-size: 1.25rem;
}

.primary-button,
.secondary-button {
  padding: 0 22px;
  font-weight: 800;
}

.primary-button {
  color: #07352e;
  background: linear-gradient(135deg, var(--mint-300), var(--mint-600));
  box-shadow: 0 12px 28px rgba(76, 201, 176, 0.3);
}

.secondary-button {
  color: var(--ink);
}

.text-button {
  min-height: 34px;
  padding: 0 10px;
  color: var(--muted);
  background: transparent;
}

button:hover {
  transform: translateY(-1px);
}

button:focus-visible,
select:focus-visible {
  outline: 3px solid rgba(76, 201, 176, 0.42);
  outline-offset: 2px;
}

.layout {
  display: grid;
  grid-template-columns: minmax(280px, 330px) minmax(0, 1fr);
  gap: 18px;
  margin-top: 18px;
  padding: clamp(10px, 2.2vw, 18px);
  border-radius: 32px;
  background: rgba(255, 255, 255, 0.36);
}

html[data-theme="dark"] .layout {
  background: rgba(13, 29, 26, 0.42);
}

.sidebar {
  display: grid;
  align-content: start;
  gap: 18px;
  min-width: 0;
}

.user-card {
  display: grid;
  gap: 18px;
  padding: 20px;
  border-radius: var(--radius);
}

h1,
h2,
h3,
p {
  max-width: 100%;
  margin-top: 0;
  overflow-wrap: anywhere;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(1.7rem, 4vw, 2.55rem);
  line-height: 1.05;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.45rem, 3vw, 2.2rem);
  line-height: 1.08;
}

h3 {
  margin-bottom: 12px;
  font-size: 1.25rem;
}

p,
li {
  font-size: 1.06rem;
  line-height: 1.65;
}

.eyebrow {
  display: inline-flex;
  margin-bottom: 8px;
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.score-grid {
  gap: 10px;
}

.score-grid > div {
  flex: 1;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface-strong);
}

.score-grid strong,
.score-grid span {
  display: block;
}

.score-grid strong {
  font-size: 1.55rem;
}

.score-grid span {
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 700;
}

.overall-progress,
.lesson-meter div {
  overflow: hidden;
  height: 12px;
  border-radius: 999px;
  background: rgba(116, 220, 203, 0.22);
}

.overall-progress span,
.lesson-meter span + div span {
  display: block;
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--mint-500), var(--mint-600));
  transition: width 0.35s ease;
}

.section-heading {
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.section-heading h2 {
  font-size: 1.05rem;
}

.lesson-list {
  display: grid;
  gap: 10px;
  min-width: 0;
}

.lesson-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) minmax(38px, auto);
  align-items: center;
  gap: 12px;
  width: 100%;
  min-width: 0;
  padding: 12px;
  color: var(--ink);
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface-strong);
}

.lesson-item.is-active {
  border-color: rgba(76, 201, 176, 0.75);
  box-shadow: 0 0 0 4px rgba(76, 201, 176, 0.14);
}

.lesson-item.is-locked {
  opacity: 0.58;
}

.lesson-icon {
  display: grid;
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 16px;
  color: #07352e;
  font-weight: 900;
  background: var(--mint-300);
}

.lesson-item > span:nth-child(2) {
  min-width: 0;
}

.lesson-title {
  display: -webkit-box;
  overflow: hidden;
  font-weight: 850;
  line-height: 1.22;
  overflow-wrap: anywhere;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.lesson-meta {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.lesson-check {
  justify-self: end;
  min-width: 0;
  color: var(--mint-600);
  font-weight: 900;
  overflow-wrap: anywhere;
}

.stage {
  min-width: 0;
  max-width: 100%;
}

.onboarding,
.lesson-view {
  min-height: 610px;
  border-radius: 30px;
}

.onboarding {
  display: grid;
  grid-template-columns: minmax(220px, 0.8fr) minmax(0, 1fr);
  align-items: center;
  gap: 28px;
  overflow: hidden;
  padding: clamp(22px, 5vw, 42px);
}

.onboarding p {
  max-width: 56ch;
  color: var(--muted);
}

.hero-visual {
  position: relative;
  overflow: hidden;
  min-height: 360px;
  border-radius: 24px;
}

.hero-visual span {
  position: absolute;
  display: block;
  border-radius: 28px;
  background: linear-gradient(135deg, var(--mint-200), var(--mint-600));
  box-shadow: 0 28px 70px rgba(76, 201, 176, 0.24);
  animation: floaty 5s ease-in-out infinite;
}

.hero-visual span:nth-child(1) {
  inset: 18% 20% auto auto;
  width: 150px;
  height: 150px;
}

.hero-visual span:nth-child(2) {
  inset: 42% auto auto 12%;
  width: 190px;
  height: 130px;
  animation-delay: -1.2s;
}

.hero-visual span:nth-child(3) {
  inset: auto 8% 10% auto;
  width: 110px;
  height: 110px;
  border-radius: 999px;
  animation-delay: -2s;
}

.lesson-view {
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 18px;
  padding: clamp(18px, 4vw, 28px);
}

.lesson-head {
  justify-content: space-between;
  gap: 18px;
}

.lesson-meter {
  display: grid;
  gap: 8px;
  width: min(210px, 34vw);
  color: var(--muted);
  font-weight: 900;
  text-align: right;
}

.card-canvas {
  display: grid;
  align-items: stretch;
  min-height: clamp(320px, 48vh, 420px);
  min-width: 0;
}

.learning-card,
.finish-card {
  display: grid;
  align-content: center;
  gap: 18px;
  min-width: 0;
  padding: clamp(22px, 5vw, 44px);
  border-radius: 30px;
  animation: cardIn 0.32s ease both;
}

.learning-card * {
  min-width: 0;
}

.learning-card blockquote {
  margin: 0;
  padding: 18px 20px;
  border-left: 5px solid var(--mint-600);
  border-radius: 18px;
  background: rgba(116, 220, 203, 0.16);
  color: var(--ink);
  font-weight: 700;
}

.learning-card figure {
  margin: 0;
}

.learning-card img {
  display: block;
  width: 100%;
  max-height: 340px;
  object-fit: contain;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface-strong);
}

.learning-card ul {
  display: grid;
  gap: 9px;
  padding-left: 24px;
}

.practice-card {
  border-color: rgba(76, 201, 176, 0.45);
}

.answers {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.answer-button {
  min-height: 64px;
  padding: 14px 16px;
  font-weight: 850;
  text-align: left;
  overflow-wrap: anywhere;
}

.answer-button.is-correct {
  background: rgba(116, 220, 203, 0.32);
  box-shadow: 0 0 0 4px rgba(76, 201, 176, 0.16);
}

.answer-button.is-wrong {
  background: rgba(231, 111, 138, 0.16);
  animation: shake 0.3s ease;
}

.feedback {
  min-height: 54px;
  padding: 14px 16px;
  border-radius: 18px;
  color: var(--muted);
  background: var(--surface-strong);
}

.lesson-controls {
  justify-content: space-between;
  gap: 12px;
}

.finish-card {
  justify-items: center;
  text-align: center;
}

.award {
  display: grid;
  width: 118px;
  height: 118px;
  place-items: center;
  border-radius: 32px;
  color: #07352e;
  font-size: 2.5rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--mint-300), var(--warning));
  box-shadow: 0 20px 55px rgba(245, 184, 92, 0.25);
}

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

.badge {
  padding: 10px 14px;
  border-radius: 999px;
  color: #07352e;
  font-weight: 900;
  background: var(--mint-300);
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 10;
  max-width: min(360px, calc(100vw - 36px));
  padding: 14px 18px;
  border: 1px solid var(--line);
  border-radius: 18px;
  color: var(--ink);
  background: var(--surface-strong);
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.confetti {
  position: fixed;
  inset: 0;
  z-index: 9;
  pointer-events: none;
}

.confetti i {
  position: absolute;
  width: 9px;
  height: 14px;
  border-radius: 4px;
  background: var(--mint-600);
  animation: confettiDrop 850ms ease-out forwards;
}

.is-hidden {
  display: none !important;
}

@keyframes floaty {
  0%,
  100% {
    transform: translateY(0) rotate(0deg);
  }
  50% {
    transform: translateY(-16px) rotate(4deg);
  }
}

@keyframes cardIn {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.985);
    filter: blur(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
    filter: blur(0);
  }
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  30% {
    transform: translateX(-8px);
  }
  60% {
    transform: translateX(8px);
  }
}

@keyframes confettiDrop {
  from {
    opacity: 1;
    transform: translateY(-10vh) rotate(0deg);
  }
  to {
    opacity: 0;
    transform: translateY(70vh) rotate(240deg);
  }
}

@media (max-width: 940px) {
  .layout,
  .onboarding {
    grid-template-columns: 1fr;
  }

  .sidebar {
    order: 2;
  }

  .stage {
    order: 1;
  }

  .onboarding,
  .lesson-view {
    min-height: auto;
  }

  .hero-visual {
    min-height: 170px;
  }

  .lesson-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-visual span:nth-child(1) {
    inset: 12% 14% auto auto;
    width: min(110px, 32vw);
    height: min(110px, 32vw);
  }

  .hero-visual span:nth-child(2) {
    inset: 36% auto auto 8%;
    width: min(150px, 44vw);
    height: min(96px, 28vw);
  }

  .hero-visual span:nth-child(3) {
    inset: auto 10% 8% auto;
    width: min(94px, 28vw);
    height: min(94px, 28vw);
  }
}

@media (max-width: 680px) {
  h1 {
    font-size: 1.65rem;
  }

  h2 {
    font-size: 1.45rem;
  }

  p,
  li {
    font-size: 1rem;
  }

  .lesson-list,
  .answers {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .topbar,
  .lesson-head,
  .lesson-controls {
    align-items: stretch;
  }

  .topbar,
  .lesson-head {
    flex-direction: column;
  }

  .top-actions,
  .lesson-controls,
  .answers {
    grid-template-columns: 1fr;
  }

  .top-actions {
    display: grid;
    grid-template-columns: 1fr 46px;
  }

  .brand-mark,
  .lesson-icon,
  .icon-button {
    width: 42px;
    height: 42px;
  }

  .lesson-item {
    grid-template-columns: 42px minmax(0, 1fr) minmax(34px, auto);
    gap: 10px;
    padding: 10px;
    border-radius: 18px;
  }

  .lesson-title {
    -webkit-line-clamp: 3;
  }

  .score-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .lesson-meter {
    width: 100%;
    text-align: left;
  }

  .answers {
    display: grid;
  }

  .learning-card,
  .finish-card {
    padding: 18px;
    border-radius: 24px;
  }

  .onboarding,
  .lesson-view {
    border-radius: 24px;
  }

  .onboarding {
    padding: 18px;
  }
}

@media (max-width: 390px) {
  .topbar,
  .layout {
    border-radius: 20px;
  }

  .lesson-item {
    grid-template-columns: 1fr auto;
  }

  .lesson-icon {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}