:root {
  --paper: #f4eee4;
  --paper-2: #ebe3d4;
  --ink: #1c1712;
  --ink-soft: #5c5348;
  --line: rgba(28, 23, 18, 0.12);
  --card: rgba(255, 252, 247, 0.86);
  --a: #2f6fad;
  --i: #2f8a5b;
  --u: #4d4a86;
  --e: #c49212;
  --o: #c45c28;
  --suffix: #c2302a;
  --euphony: #6d4ea8;
  --drop: #9a3412;
  --shadow: 0 18px 40px rgba(60, 42, 20, 0.08);
  --radius: 18px;
  --sans: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
  --serif: "Fraunces", "Iowan Old Style", serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--sans);
  background: var(--paper);
}

.page-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(900px 420px at 8% -10%, rgba(47, 111, 173, 0.16), transparent 60%),
    radial-gradient(700px 380px at 100% 0%, rgba(196, 92, 40, 0.12), transparent 55%),
    radial-gradient(600px 300px at 70% 100%, rgba(47, 138, 91, 0.1), transparent 50%),
    linear-gradient(180deg, #f7f1e7 0%, #efe6d8 100%);
}

.page-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='.18'/%3E%3C/svg%3E");
  pointer-events: none;
}

.site-header,
.group-select,
.verb-bar,
.stage,
.site-footer,
.status {
  width: min(1180px, calc(100% - 32px));
  margin-left: auto;
  margin-right: auto;
}

.site-header {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 28px;
  padding: 42px 0 18px;
  align-items: end;
}

.brand-kana {
  margin: 0 0 6px;
  letter-spacing: 0.28em;
  font-size: 0.78rem;
  color: var(--o);
}

h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(2rem, 4vw, 3.15rem);
  font-weight: 680;
  letter-spacing: -0.03em;
  line-height: 1.05;
}

.lede {
  margin: 12px 0 0;
  max-width: 46ch;
  color: var(--ink-soft);
  line-height: 1.55;
}

.header-tools {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 12px;
}

.script-toggle {
  display: inline-flex;
  padding: 4px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
}

.script-toggle button,
.group-btn,
.chip,
.stem-head,
.form-head,
.te-toggle,
.path-card,
.irregular-tab {
  font: inherit;
  cursor: pointer;
}

.script-toggle button {
  border: 0;
  background: transparent;
  color: var(--ink-soft);
  padding: 8px 14px;
  border-radius: 999px;
}

.script-toggle button.is-active {
  background: var(--ink);
  color: #f7f1e8;
}

.color-key {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 12px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.75rem;
  color: var(--ink-soft);
}

.swatch {
  display: inline-block;
  width: 0.7rem;
  height: 0.7rem;
  margin-right: 5px;
  border-radius: 999px;
  vertical-align: -1px;
}

.swatch-a { background: var(--a); }
.swatch-i { background: var(--i); }
.swatch-u { background: var(--u); }
.swatch-e { background: var(--e); }
.swatch-o { background: var(--o); }
.swatch-s { background: var(--suffix); }
.swatch-te { background: var(--euphony); }

.group-select {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 10px;
}

.group-btn {
  text-align: left;
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px 18px;
  box-shadow: var(--shadow);
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.group-btn:hover {
  transform: translateY(-1px);
}

.group-btn.is-active {
  border-color: transparent;
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

.group-btn[data-group="godan"].is-active { background: linear-gradient(180deg, #edf4fb, #fffaf3); }
.group-btn[data-group="ichidan"].is-active { background: linear-gradient(180deg, #eef8f1, #fffaf3); }
.group-btn[data-group="irregular"].is-active { background: linear-gradient(180deg, #f8eee8, #fffaf3); }

.group-en {
  display: block;
  font-family: var(--serif);
  font-size: 1.2rem;
}

.group-jp {
  display: block;
  margin-top: 2px;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.group-hint {
  display: block;
  margin-top: 10px;
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  color: var(--ink-soft);
}

.verb-bar {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
  margin-top: 22px;
  padding: 18px;
  border-radius: var(--radius);
  background: var(--card);
  border: 1px solid var(--line);
}

.verb-field {
  position: relative;
}

.verb-field label,
.picks-label {
  display: block;
  margin-bottom: 8px;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

#verb-input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  font: inherit;
  font-size: 1.15rem;
  background: #fffdf8;
  color: var(--ink);
}

#verb-input:focus {
  outline: 2px solid var(--a);
  outline-offset: 1px;
}

.verb-meta {
  min-height: 1.3em;
  margin: 8px 0 0;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.suggestions {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% - 8px);
  z-index: 5;
  margin: 0;
  padding: 6px;
  list-style: none;
  background: #fffdf8;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow);
  max-height: 240px;
  overflow: auto;
}

.suggestions button {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  border: 0;
  background: transparent;
  padding: 8px 10px;
  border-radius: 8px;
  text-align: left;
  font: inherit;
  cursor: pointer;
}

.suggestions button:hover,
.suggestions button.is-active {
  background: var(--paper-2);
}

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

.chip {
  border: 1px solid var(--line);
  background: #fffdf8;
  border-radius: 999px;
  padding: 7px 12px;
  color: var(--ink);
}

.chip small {
  margin-left: 6px;
  font-size: 0.75rem;
  opacity: 0.7;
}

.chip.is-active {
  background: var(--ink);
  color: #f7f1e8;
  border-color: var(--ink);
}

.status {
  margin-top: 14px;
  padding: 10px 14px;
  border-radius: 12px;
  background: #f8e4d8;
  color: #7a2d12;
}

.stage {
  margin-top: 28px;
  padding-bottom: 64px;
}

.flow-source,
.stem-card,
.form-card,
.te-panel,
.irregular-card,
.rule-banner {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.rule-banner {
  padding: 16px 18px;
  margin-bottom: 22px;
}

.rule-banner h2 {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: 1.4rem;
}

.rule-banner p {
  margin: 0;
  color: var(--ink-soft);
  line-height: 1.5;
}

.flow-source {
  width: min(420px, 100%);
  margin: 0 auto;
  text-align: center;
  padding: 18px 20px 16px;
  position: relative;
}

.source-label {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.source-verb {
  margin: 6px 0 2px;
  font-size: clamp(2rem, 5vw, 2.8rem);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.source-reading {
  margin: 0;
  color: var(--ink-soft);
}

.flow-tree {
  position: relative;
  margin-top: 8px;
}

.flow-tree::before {
  content: "";
  display: block;
  width: 2px;
  height: 28px;
  margin: 0 auto;
  background: var(--ink);
  opacity: 0.28;
}

.vowel-rail {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
  position: relative;
  padding-top: 22px;
}

.vowel-rail::before {
  content: "";
  position: absolute;
  top: 0;
  left: 8%;
  right: 8%;
  height: 2px;
  background: rgba(28, 23, 18, 0.22);
}

.stem-card {
  position: relative;
  min-width: 0;
  overflow: hidden;
}

.stem-card::before {
  content: "";
  position: absolute;
  top: -22px;
  left: 50%;
  width: 2px;
  height: 22px;
  background: rgba(28, 23, 18, 0.22);
}

.stem-card[data-stem="a"] { --stem: var(--a); }
.stem-card[data-stem="i"] { --stem: var(--i); }
.stem-card[data-stem="u"] { --stem: var(--u); }
.stem-card[data-stem="e"] { --stem: var(--e); }
.stem-card[data-stem="o"] { --stem: var(--o); }

.stem-card[data-stem="u"] {
  outline: 2px solid color-mix(in srgb, var(--u) 45%, transparent);
}

.stem-head {
  width: 100%;
  border: 0;
  background: transparent;
  text-align: left;
  padding: 14px 14px 12px;
  color: inherit;
  border-bottom: 3px solid var(--stem);
  position: relative;
}

.stem-head .more {
  position: absolute;
  top: 12px;
  right: 12px;
  color: var(--ink-soft);
}

.vowel-glyph {
  display: block;
  font-size: 2rem;
  line-height: 1;
  color: var(--stem);
  font-weight: 700;
}

.stem-title {
  display: block;
  margin-top: 6px;
  font-size: 0.82rem;
  color: var(--ink-soft);
}

.stem-form {
  display: block;
  margin-top: 8px;
  font-size: 1.25rem;
  font-weight: 700;
}

.stem-rule {
  display: block;
  margin-top: 4px;
  font-size: 0.75rem;
  color: var(--ink-soft);
  line-height: 1.35;
}

.stem-body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.28s ease;
}

.stem-card.is-open .stem-body {
  grid-template-rows: 1fr;
}

.stem-body-inner {
  overflow: hidden;
}

.form-stack {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 10px;
}

.form-card {
  width: 100%;
  text-align: left;
  padding: 0;
  border-radius: 14px;
  background: #fffdf8;
  border: 1px solid var(--line);
}

.form-head {
  width: 100%;
  border: 0;
  background: transparent;
  text-align: left;
  padding: 10px 12px;
  color: inherit;
  font: inherit;
  cursor: pointer;
  border-radius: 14px;
}

.form-card:hover {
  box-shadow: 0 8px 18px rgba(60, 42, 20, 0.08);
}

.form-preview {
  margin: 6px 0 0;
  font-size: 0.75rem;
  line-height: 1.4;
  color: var(--ink-soft);
}

.form-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.more::before {
  content: "▸";
  font-size: 0.8rem;
}

.form-card.is-open .more::before,
.stem-card.is-open .more::before {
  content: "▾";
}

.form-card.is-open {
  outline: 2px solid color-mix(in srgb, var(--stem, var(--ink)) 55%, white);
}

.form-detail {
  display: none;
  margin: 0;
  padding: 0 12px 12px;
  border-top: 1px dashed var(--line);
  font-size: 0.86rem;
  line-height: 1.45;
  color: var(--ink-soft);
}

.form-card.is-open .form-detail {
  display: block;
  padding-top: 10px;
}

.chart {
  display: grid;
  gap: 6px;
  margin-top: 10px;
  align-items: stretch;
}

.chart.cols-1 {
  grid-template-columns: 4.4rem 1fr;
}

.chart.cols-2 {
  grid-template-columns: 4.4rem 1fr 1fr;
}

.chart-h {
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
  display: flex;
  align-items: center;
}

.paradigm-cell {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 6px 8px;
  min-width: 0;
}

.paradigm-cell.is-empty {
  color: var(--ink-soft);
  display: flex;
  align-items: center;
  justify-content: center;
}

.paradigm-cell .morph {
  font-size: 0.95rem;
  margin-top: 0;
}

.paradigm-cell .form-sub {
  font-size: 0.7rem;
}

.cell-label {
  display: block;
  font-size: 0.65rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.extra-label {
  margin: 12px 0 6px;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.extra-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.ichidan-grid .form-card.is-open,
.irregular-list .form-card.is-open,
.result-row .form-card.is-open {
  grid-column: 1 / -1;
}

.result-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.stem-card .chart.cols-2 {
  grid-template-columns: 3.4rem minmax(0, 1fr) minmax(0, 1fr);
}

.stem-card .paradigm-cell .morph {
  font-size: 0.8rem;
}

.stem-card .extra-grid {
  grid-template-columns: 1fr;
}

.morph {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  margin-top: 6px;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.source-verb.morph {
  margin-top: 6px;
  justify-content: center;
  font-size: clamp(2rem, 5vw, 2.8rem);
}

.stem-form.morph {
  margin-top: 8px;
  font-size: 1.25rem;
}

.morph span {
  padding: 1px 3px;
  border-radius: 6px;
}

.morph .root { color: var(--ink); }
.morph .stem-a { color: #fff; background: var(--a); }
.morph .stem-i { color: #fff; background: var(--i); }
.morph .stem-u { color: #fff; background: var(--u); }
.morph .stem-e { color: #fff; background: var(--e); }
.morph .stem-o { color: #fff; background: var(--o); }
.morph .suffix { color: #fff; background: var(--suffix); }
.morph .euphony { color: #fff; background: var(--euphony); }
.morph .drop {
  color: var(--drop);
  background: rgba(154, 52, 18, 0.12);
  text-decoration: line-through;
}

.form-sub {
  margin: 4px 0 0;
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.attach {
  display: inline-block;
  margin-bottom: 6px;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(194, 48, 42, 0.1);
  color: var(--suffix);
  font-size: 0.75rem;
}

.te-panel {
  margin-top: 22px;
}

.te-toggle {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  border: 0;
  background: transparent;
  padding: 16px 18px;
  text-align: left;
  color: inherit;
  border-bottom: 3px solid var(--euphony);
}

.te-toggle strong {
  display: block;
  font-family: var(--serif);
  font-size: 1.2rem;
}

.te-toggle span {
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.te-body {
  display: none;
  padding: 8px 14px 16px;
}

.te-panel.is-open .te-body {
  display: block;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
}

.path-card {
  border: 1px solid var(--line);
  background: #fffdf8;
  border-radius: 14px;
  padding: 12px;
  text-align: left;
  color: inherit;
}

.path-card.is-current {
  outline: 2px solid var(--euphony);
  background: #f4eefc;
}

.path-card small {
  display: block;
  color: var(--ink-soft);
  margin-top: 6px;
  line-height: 1.35;
}

.ichidan-flow {
  display: grid;
  justify-items: center;
  gap: 0;
}

.drop-arrow {
  width: 2px;
  height: 34px;
  background: rgba(28, 23, 18, 0.22);
  position: relative;
}

.drop-arrow::after {
  content: "drop る";
  position: absolute;
  left: 12px;
  top: 6px;
  white-space: nowrap;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--drop);
}

.stem-pill {
  padding: 12px 22px;
  border-radius: 999px;
  background: #eef8f1;
  border: 1px solid color-mix(in srgb, var(--i) 35%, white);
  font-size: 1.4rem;
  font-weight: 700;
}

.ichidan-grid {
  width: 100%;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
  margin-top: 22px;
}

.irregular-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.irregular-card {
  padding: 8px;
}

.irregular-card h2 {
  margin: 8px 16px 4px;
  font-family: var(--serif);
}

.irregular-card .lead {
  margin: 0 16px 12px;
  color: var(--ink-soft);
}

.irregular-list {
  display: grid;
  gap: 8px;
  padding: 0 8px 8px;
}

.caret {
  font-size: 0.85rem;
  opacity: 0.7;
}

.site-footer {
  padding: 0 0 48px;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.noscript {
  margin: 24px auto;
  width: min(720px, calc(100% - 32px));
  padding: 12px 16px;
  background: #f8e4d8;
}

.script-toggle button:focus-visible,
.group-btn:focus-visible,
.chip:focus-visible,
.form-head:focus-visible,
.stem-head:focus-visible,
.te-toggle:focus-visible,
#verb-input:focus-visible {
  outline: 2px solid var(--a);
  outline-offset: 2px;
}

@media (max-width: 980px) {
  .site-header,
  .verb-bar,
  .irregular-grid,
  .path-grid {
    grid-template-columns: 1fr;
  }

  .header-tools {
    align-items: flex-start;
  }

  .color-key {
    justify-content: flex-start;
  }

  .vowel-rail {
    grid-template-columns: 1fr;
    padding-top: 0;
  }

  .vowel-rail::before,
  .stem-card::before,
  .flow-tree::before {
    display: none;
  }
}

@media (max-width: 720px) {
  .group-select {
    grid-template-columns: 1fr;
  }

  .verb-bar {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .group-btn,
  .stem-body {
    transition: none;
  }
}