:root {
  --bg: #f4efde;
  --panel: rgba(255, 252, 245, 0.86);
  --panel-strong: rgba(255, 252, 245, 0.96);
  --line: rgba(45, 39, 30, 0.12);
  --ink: #1e1a17;
  --muted: #5d544d;
  --accent: #b2522d;
  --accent-soft: #f6dccf;
  --forest: #1f665d;
  --forest-soft: #d8ebe7;
  --gold: #c89f47;
  --shadow: 0 24px 68px rgba(54, 40, 22, 0.12);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(178, 82, 45, 0.16), transparent 28%),
    radial-gradient(circle at bottom right, rgba(31, 102, 93, 0.15), transparent 30%),
    linear-gradient(180deg, #f8f2e7 0%, #f2ead6 100%);
  color: var(--ink);
  font-family: "Space Grotesk", sans-serif;
  line-height: 1.45;
  padding: max(16px, env(safe-area-inset-top)) 16px max(24px, env(safe-area-inset-bottom));
}

button,
select {
  font: inherit;
}

.backdrop {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 0;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(28px);
  opacity: 0.72;
}

.orb-a {
  width: 22rem;
  height: 22rem;
  background: rgba(178, 82, 45, 0.18);
  top: -7rem;
  left: -3rem;
}

.orb-b {
  width: 19rem;
  height: 19rem;
  background: rgba(31, 102, 93, 0.14);
  right: -3rem;
  bottom: 5rem;
}

.grid-wash {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(45, 39, 30, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(45, 39, 30, 0.04) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.72), transparent 88%);
}

.app-shell {
  position: relative;
  z-index: 1;
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  gap: 18px;
  animation: rise-in 520ms ease both;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.hero,
.practice-panel,
.reference-card {
  padding: clamp(20px, 4vw, 30px);
}

.eyebrow,
.section-kicker,
.sidebar-kicker,
.settings-label {
  margin: 0 0 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.74rem;
  color: var(--accent);
}

.hero {
  display: grid;
  gap: 20px;
}

.hero h1,
.panel-heading h2,
.reference-card h2,
.settings-summary-row h2 {
  margin: 0;
  line-height: 1;
  letter-spacing: -0.03em;
}

.hero h1 {
  font-size: clamp(2.4rem, 8vw, 4.8rem);
}

.hero h1 span {
  display: block;
  margin-top: 0.4rem;
  color: var(--forest);
  font-family: "Literata", serif;
  font-size: 0.62em;
  line-height: 1.1;
}

.lede,
.prompt-gloss,
.prompt-direction,
.hint-text,
.feedback-body,
.reference-list,
.settings-note {
  color: var(--muted);
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 1rem;
}

.ghost-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0.75rem 1rem;
  border-radius: 999px;
  border: 1px solid rgba(45, 39, 30, 0.1);
  background: rgba(255, 252, 245, 0.7);
  color: var(--ink);
  text-decoration: none;
}

.hero-metrics {
  display: grid;
  gap: 12px;
}

.metric-card {
  background: var(--panel-strong);
  border: 1px solid rgba(45, 39, 30, 0.08);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: grid;
  gap: 0.3rem;
}

.metric-card span,
.metric-footer span {
  color: var(--muted);
}

.metric-card strong {
  font-size: 1.5rem;
}

.metric-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: rgba(31, 102, 93, 0.09);
  color: var(--forest);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
}

.metric-footer strong {
  font-size: 1.1rem;
}

.ghost-button,
.primary-button,
.option-button {
  border: 0;
  min-height: 48px;
  border-radius: 16px;
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease, color 160ms ease, box-shadow 160ms ease;
}

.ghost-button,
.settings-select {
  background: rgba(45, 39, 30, 0.05);
  color: var(--ink);
}

.ghost-button {
  padding: 0.9rem 1rem;
}

.primary-button {
  background: var(--ink);
  color: #fffaf4;
  padding: 0.95rem 1.2rem;
  box-shadow: 0 12px 24px rgba(30, 26, 23, 0.18);
}

.ghost-button:hover,
.primary-button:hover,
.option-button:hover,
.ghost-link:hover {
  transform: translateY(-1px);
}

.panel-heading,
.hint-row,
.action-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.phase-status {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.65rem;
}

.status-pill,
.mode-badge,
.timer-chip,
.settings-summary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 0.42rem 0.82rem;
  border-radius: 999px;
  font-size: 0.84rem;
}

.status-pill {
  background: rgba(31, 102, 93, 0.12);
  color: var(--forest);
}

.mode-badge {
  background: rgba(178, 82, 45, 0.12);
  color: var(--accent);
}

.timer-chip {
  background: rgba(200, 159, 71, 0.14);
  color: #7e5a15;
  font-weight: 700;
}

.phase-progress {
  color: var(--muted);
}

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

.practice-grid {
  margin-top: 1.5rem;
}

.prompt-card,
.sidebar-card {
  background: var(--panel-strong);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(45, 39, 30, 0.08);
  padding: 18px;
}

.prompt-card,
.sidebar-stack,
.pattern-grid,
.weak-list,
.practice-options,
.prompt-body {
  display: grid;
  gap: 0.7rem;
}

.prompt-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.prompt-label {
  margin: 0 0 0.45rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.7rem;
  color: var(--accent);
}

.prompt-word,
.inline-ru {
  font-family: "Literata", serif;
}

.prompt-word {
  font-size: clamp(2.2rem, 7vw, 3.4rem);
  line-height: 1.05;
}

.prompt-base {
  padding-top: 1rem;
  border-top: 1px solid rgba(45, 39, 30, 0.08);
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  gap: 0.2rem 0.75rem;
}

.prompt-base .prompt-label,
.prompt-base .prompt-direction {
  width: 100%;
}

.prompt-base .prompt-label {
  margin-bottom: 0;
}

.prompt-base .prompt-word {
  font-size: clamp(1.5rem, 4vw, 2rem);
}

.prompt-base .prompt-gloss,
.prompt-base .prompt-direction {
  margin: 0;
}

.sentence-text,
.feedback-sentence {
  margin: 0;
  font-family: "Literata", serif;
}

.sentence-text {
  font-size: clamp(1.45rem, 5vw, 2rem);
  line-height: 1.35;
}

.sentence-note {
  margin: 0;
  color: var(--muted);
  max-width: 40ch;
  font-size: 0.96rem;
}

.sentence-blank,
.sentence-fill {
  display: inline-block;
  min-width: 5.4ch;
  padding: 0 0.15em 0.02em;
  text-align: center;
}

.sentence-blank {
  border-bottom: 2px solid rgba(45, 39, 30, 0.3);
}

.sentence-fill {
  border-radius: 10px;
  background: rgba(31, 102, 93, 0.12);
  color: #154c45;
}

.prompt-gloss,
.prompt-direction {
  margin: 0.45rem 0 0;
  font-size: 1rem;
}

.hint-row {
  align-items: flex-start;
}

.hint-text {
  display: block;
  max-width: 40ch;
}

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

.option-button {
  padding: 1rem 0.9rem;
  background: #fffaf2;
  border: 1px solid rgba(45, 39, 30, 0.08);
  color: var(--ink);
  font-family: "Literata", serif;
  font-size: 1.22rem;
  box-shadow: 0 8px 18px rgba(45, 39, 30, 0.06);
}

.option-button.is-selected {
  outline: 2px solid rgba(178, 82, 45, 0.28);
}

.option-button.is-correct {
  background: var(--forest-soft);
  color: #154c45;
}

.option-button.is-wrong {
  background: var(--accent-soft);
  color: #913d20;
}

.option-button:disabled,
.primary-button:disabled,
.ghost-button:disabled {
  cursor: default;
}

.feedback-card {
  padding: 1rem 1.05rem;
  border-radius: var(--radius-md);
  background: rgba(45, 39, 30, 0.04);
  border: 1px solid rgba(45, 39, 30, 0.08);
}

.feedback-card.is-hidden,
.action-row.is-hidden {
  display: none;
}

.feedback-card.is-correct {
  background: rgba(31, 102, 93, 0.09);
  border-color: rgba(31, 102, 93, 0.15);
}

.feedback-card.is-wrong {
  background: rgba(178, 82, 45, 0.09);
  border-color: rgba(178, 82, 45, 0.15);
}

.feedback-title {
  margin: 0 0 0.4rem;
  font-weight: 700;
}

.feedback-sentence {
  margin: 0 0 0.55rem;
  font-size: 1.05rem;
}

.action-row {
  justify-content: flex-end;
}

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

.pattern-card,
.weak-item {
  background: rgba(45, 39, 30, 0.04);
  border: 1px solid rgba(45, 39, 30, 0.08);
  border-radius: var(--radius-md);
  padding: 0.95rem;
}

.pattern-card strong,
.weak-item strong {
  display: block;
}

.pattern-card strong {
  margin-bottom: 0.2rem;
}

.pattern-meta,
.weak-note {
  color: var(--muted);
  font-size: 0.9rem;
}

.mastery-track {
  width: 100%;
  height: 8px;
  border-radius: 999px;
  overflow: hidden;
  background: rgba(45, 39, 30, 0.08);
  margin: 0.55rem 0 0.4rem;
}

.mastery-fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--gold), var(--forest));
  border-radius: inherit;
  transition: width 220ms ease;
}

.weak-item {
  display: grid;
  gap: 0.25rem;
}

.weak-forms {
  font-family: "Literata", serif;
  font-size: 1.1rem;
}

.reference-card h2 {
  font-size: 1.6rem;
  margin-bottom: 0.85rem;
}

.reference-list {
  margin: 0;
  padding-left: 1.15rem;
}

.reference-list li {
  margin: 0.65rem 0;
}

.settings-panel {
  overflow: hidden;
  padding: 0;
}

.settings-summary-row {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 18px 22px;
  cursor: pointer;
}

.settings-summary-row::-webkit-details-marker {
  display: none;
}

.settings-summary-row h2 {
  font-size: 1.2rem;
}

.settings-summary {
  background: rgba(45, 39, 30, 0.05);
  color: var(--muted);
  white-space: nowrap;
}

.settings-body {
  display: grid;
  gap: 0.8rem;
  padding: 0 22px 22px;
}

.settings-note {
  margin: 0;
}

.settings-select {
  min-height: 48px;
  border-radius: 14px;
  border: 1px solid rgba(45, 39, 30, 0.12);
  padding: 0.75rem 0.9rem;
}

@media (min-width: 720px) {
  body {
    padding-left: 24px;
    padding-right: 24px;
  }

  .hero {
    grid-template-columns: 1.3fr 0.92fr;
    align-items: end;
  }

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

  .metric-footer,
  .hero-metrics > .ghost-button {
    grid-column: 1 / -1;
  }

  .practice-grid {
    grid-template-columns: 1.18fr 0.92fr;
    align-items: start;
  }

  .reference-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .settings-body {
    grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.8fr);
    align-items: end;
  }

  .settings-label {
    grid-column: 2;
  }

  .settings-select {
    grid-column: 2;
    grid-row: 2;
  }
}

@media (max-width: 719px) {
  .panel-heading,
  .hint-row,
  .action-row,
  .settings-summary-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .phase-status {
    justify-content: flex-start;
  }

  .hero h1 {
    max-width: none;
  }

  .prompt-card,
  .sidebar-card,
  .reference-card {
    padding: 16px;
  }

  .prompt-word {
    font-size: clamp(1.75rem, 9vw, 2.45rem);
  }

  .prompt-base .prompt-word {
    font-size: 1.45rem;
  }

  .options-grid {
    gap: 10px;
  }

  .sentence-text {
    font-size: clamp(1.25rem, 6vw, 1.65rem);
  }

  .option-button {
    font-size: 1.14rem;
    padding: 0.95rem 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto;
    animation: none;
    transition: none;
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}