:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --ink: #17202a;
  --muted: #687684;
  --line: #d9e0e7;
  --panel: #ffffff;
  --panel-soft: #eef4f8;
  --accent: #116149;
  --accent-2: #1f8a70;
  --danger: #bd312b;
  --danger-soft: #fde8e6;
  --ok-soft: #e4f5ee;
  --shadow: 0 18px 55px rgba(34, 51, 68, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(180deg, rgba(17, 97, 73, 0.08), transparent 34rem),
    var(--bg);
  color: var(--ink);
  font-family:
    "Noto Sans JP", "Yu Gothic UI", "Hiragino Kaku Gothic ProN", Meiryo,
    system-ui, sans-serif;
  letter-spacing: 0;
}

button {
  font: inherit;
}

.app-shell {
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem clamp(1rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.mark {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 8px;
  background: var(--accent);
  color: white;
  font-weight: 800;
  box-shadow: 0 8px 18px rgba(17, 97, 73, 0.22);
}

.eyebrow,
.panel-label {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}

h1 {
  margin: 0.1rem 0 0;
  font-size: clamp(1.15rem, 2.8vw, 1.65rem);
  line-height: 1.2;
}

.header-actions,
.bottom-actions,
.result-actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.icon-button,
.primary-button,
.secondary-button {
  min-height: 2.75rem;
  border: 0;
  border-radius: 8px;
  cursor: pointer;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background 160ms ease;
}

.icon-button:hover,
.primary-button:hover,
.secondary-button:hover {
  transform: translateY(-1px);
}

.icon-button {
  width: 2.75rem;
  background: var(--panel-soft);
  color: var(--ink);
  font-size: 1.2rem;
}

.primary-button,
.secondary-button {
  padding: 0 1.05rem;
  font-weight: 800;
}

.primary-button {
  background: var(--accent);
  color: white;
  box-shadow: 0 10px 22px rgba(17, 97, 73, 0.22);
}

.secondary-button {
  background: white;
  color: var(--ink);
  border: 1px solid var(--line);
}

.primary-button:disabled,
.secondary-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
  transform: none;
  box-shadow: none;
}

.exam-layout {
  display: grid;
  grid-template-columns: minmax(15rem, 19rem) minmax(0, 1fr);
  gap: clamp(1rem, 3vw, 2rem);
  width: min(1180px, calc(100% - 2rem));
  margin: clamp(1rem, 3vw, 2.5rem) auto;
  overflow: hidden;
}

.status-panel {
  align-self: start;
  display: grid;
  gap: 1rem;
  position: sticky;
  top: 5.8rem;
}

.timer-box,
.score-grid > div,
.mode-card,
.source-note,
.question-stage {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.timer-box,
.score-grid > div,
.mode-card,
.source-note {
  padding: 1rem;
}

.timer-box strong {
  display: block;
  margin-top: 0.3rem;
  font-size: 2rem;
  font-variant-numeric: tabular-nums;
}

.score-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.score-grid strong {
  display: block;
  margin-top: 0.25rem;
  font-size: 1.85rem;
}

.ok {
  color: var(--accent-2);
}

.bad {
  color: var(--danger);
}

.mode-card strong {
  display: block;
  margin: 0.35rem 0 0.55rem;
  font-size: 1.05rem;
}

.mode-card p,
.source-note p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
  font-size: 0.92rem;
}

.source-note {
  box-shadow: none;
  background: rgba(255, 255, 255, 0.68);
}

.home-view {
  width: min(1180px, calc(100% - 2rem));
  margin: clamp(1rem, 3vw, 2.5rem) auto 4rem;
  display: grid;
  gap: clamp(1rem, 3vw, 2rem);
}

.home-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(10rem, 14rem);
  gap: 1.5rem;
  align-items: stretch;
  min-height: 18rem;
  padding: clamp(1.25rem, 4vw, 3rem);
  border-radius: 8px;
  color: white;
  background:
    linear-gradient(90deg, rgba(11, 58, 49, 0.92), rgba(17, 97, 73, 0.72)),
    url("https://images.unsplash.com/photo-1555396273-367ea4eb4db5?auto=format&fit=crop&w=1600&q=80") center / cover;
  box-shadow: var(--shadow);
}

.home-hero h2 {
  max-width: 47rem;
  margin: 0.35rem 0 0.85rem;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1.16;
}

.home-hero p:not(.eyebrow) {
  max-width: 42rem;
  margin: 0;
  color: rgba(255, 255, 255, 0.86);
  line-height: 1.8;
  font-weight: 650;
}

.home-hero .eyebrow {
  color: rgba(255, 255, 255, 0.72);
}

.home-stats {
  align-self: end;
  display: grid;
  justify-items: end;
  gap: 0.15rem;
  padding: 1rem;
  border-left: 1px solid rgba(255, 255, 255, 0.32);
}

.home-stats span {
  font-weight: 800;
  color: rgba(255, 255, 255, 0.78);
}

.home-stats strong {
  font-size: clamp(3rem, 8vw, 5.5rem);
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.picker-section {
  display: grid;
  gap: 1rem;
}

.section-heading h3 {
  margin: 0.2rem 0 0;
  font-size: clamp(1.2rem, 3vw, 1.75rem);
}

.exam-card-grid,
.mode-grid {
  display: grid;
  gap: 1rem;
}

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

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

.exam-card,
.mode-select {
  min-height: 10.5rem;
  min-width: 0;
  padding: 1rem;
  border: 2px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
  cursor: pointer;
  text-align: left;
}

.exam-card {
  display: grid;
  gap: 0.55rem;
  align-content: start;
}

.exam-card strong,
.mode-select strong {
  display: block;
  font-size: 1.2rem;
  overflow-wrap: anywhere;
}

.exam-card small,
.mode-select span {
  color: var(--muted);
  line-height: 1.6;
  font-weight: 650;
  overflow-wrap: anywhere;
}

.exam-icon {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  border-radius: 8px;
  background: var(--panel-soft);
  color: var(--accent);
  font-size: 1.25rem;
  font-weight: 900;
}

.exam-card.selected,
.mode-select.selected {
  border-color: var(--accent);
  background: var(--ok-soft);
}

.exam-card.locked {
  cursor: not-allowed;
  opacity: 0.62;
  box-shadow: none;
}

.mode-select {
  display: grid;
  gap: 0.65rem;
  align-content: center;
}

.question-stage {
  min-height: 38rem;
  padding: clamp(1rem, 3vw, 2rem);
  min-width: 0;
  overflow: hidden;
}

.progress-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) max-content;
  gap: 0.8rem;
  align-items: center;
  margin-bottom: 1.6rem;
  min-width: 0;
}

.progress-track {
  display: grid;
  grid-template-columns: repeat(var(--count, 30), 1fr);
  gap: clamp(0.08rem, 0.35vw, 0.28rem);
  min-width: 0;
  overflow: hidden;
}

.progress-track.compact {
  display: block;
  height: 0.42rem;
  border-radius: 999px;
  background: #cbd5df;
  position: relative;
}

.progress-track.compact::before {
  content: "";
  display: block;
  width: var(--progress, 0%);
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
  transition: width 160ms ease;
}

.progress-segment {
  height: 0.42rem;
  border-radius: 999px;
  background: #cbd5df;
}

.progress-segment.current {
  background: var(--accent);
}

.progress-segment.correct {
  background: #22a06b;
}

.progress-segment.wrong {
  background: #d24b43;
}

.progress-count {
  min-width: 4.8rem;
  max-width: 6.25rem;
  color: var(--muted);
  font-weight: 800;
  text-align: right;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.question-area {
  display: grid;
  gap: 1.1rem;
  min-width: 0;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.question-meta span {
  border-radius: 999px;
  background: var(--panel-soft);
  color: var(--accent);
  padding: 0.35rem 0.7rem;
  font-weight: 800;
  font-size: 0.82rem;
}

h2 {
  margin: 0;
  font-size: clamp(1.3rem, 3vw, 2rem);
  line-height: 1.55;
}

.choices {
  display: grid;
  gap: 0.8rem;
}

.choice {
  display: grid;
  grid-template-columns: 2.1rem 1fr;
  gap: 0.85rem;
  align-items: start;
  min-height: 4.4rem;
  width: 100%;
  padding: 1rem;
  border: 2px solid transparent;
  border-radius: 8px;
  background: #f8fafc;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
}

.choice:hover {
  border-color: #9ab6c9;
  background: white;
}

.choice-letter {
  display: grid;
  place-items: center;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 8px;
  background: white;
  color: var(--muted);
  font-weight: 900;
}

.choice-text {
  line-height: 1.65;
  font-weight: 750;
}

.choice.correct {
  border-color: #22a06b;
  background: var(--ok-soft);
}

.choice.wrong {
  border-color: #d24b43;
  background: var(--danger-soft);
}

.choice[disabled] {
  cursor: default;
}

.explanation {
  border-left: 4px solid var(--accent);
  background: var(--panel-soft);
  padding: 1rem;
  border-radius: 0 8px 8px 0;
}

.explanation p {
  margin: 0;
  line-height: 1.75;
}

.result-line {
  margin-bottom: 0.35rem !important;
  font-weight: 900;
}

.bottom-actions {
  justify-content: space-between;
  margin-top: 1.6rem;
}

dialog {
  width: min(28rem, calc(100% - 2rem));
  border: 0;
  border-radius: 8px;
  padding: 0;
  box-shadow: 0 30px 90px rgba(23, 32, 42, 0.25);
}

dialog::backdrop {
  background: rgba(23, 32, 42, 0.48);
}

.result-dialog {
  padding: 1.5rem;
}

.result-dialog h2 {
  margin: 0.25rem 0 0.5rem;
}

.result-dialog p {
  line-height: 1.7;
}

.result-actions {
  justify-content: flex-end;
  margin-top: 1rem;
}

@media (max-width: 820px) {
  .topbar {
    align-items: flex-start;
  }

  .exam-layout {
    grid-template-columns: 1fr;
  }

  .home-hero {
    grid-template-columns: 1fr;
  }

  .home-stats {
    justify-items: start;
    border-left: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.32);
  }

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

  .status-panel {
    position: static;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mode-card,
  .source-note {
    grid-column: 1 / -1;
  }
}

@media (max-width: 560px) {
  .brand {
    align-items: flex-start;
  }

  .mark {
    width: 2.4rem;
    height: 2.4rem;
  }

  .header-actions {
    gap: 0.35rem;
  }

  .icon-button {
    width: 2.45rem;
    min-height: 2.45rem;
  }

  .status-panel {
    grid-template-columns: 1fr;
  }

  .exam-card-grid,
  .mode-grid {
    grid-template-columns: 1fr;
  }

  .progress-row {
    grid-template-columns: 1fr;
  }

  .progress-count {
    text-align: left;
  }

  .choice {
    grid-template-columns: 1.85rem 1fr;
    padding: 0.9rem;
  }

  .choice-letter {
    width: 1.85rem;
    height: 1.85rem;
  }

  .bottom-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
}