:root {
  color-scheme: light;
  --bg: #f6f4ef;
  --surface: #ffffff;
  --surface-strong: #f0faf6;
  --text: #1b1f24;
  --muted: #65717d;
  --line: #d9e0e7;
  --primary: #146c63;
  --primary-strong: #0d5049;
  --accent: #c44536;
  --focus: #2b72d6;
  --shadow: 0 18px 50px rgba(27, 31, 36, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(135deg, rgba(20, 108, 99, 0.10), transparent 36%),
    linear-gradient(315deg, rgba(196, 69, 54, 0.10), transparent 34%),
    var(--bg);
  color: var(--text);
  font-family: "Segoe UI", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  width: min(980px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: 28px;
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 26px;
}

.topbar {
  min-height: 74px;
  display: grid;
  grid-template-columns: 44px 1fr 44px;
  align-items: center;
  gap: 16px;
}

.eyebrow {
  margin: 0 0 3px;
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 800;
}

h1 {
  margin: 0;
  font-size: clamp(1.55rem, 2.7vw, 2.35rem);
  line-height: 1.18;
  letter-spacing: 0;
}

.icon-button {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  display: grid;
  place-items: center;
  box-shadow: 0 8px 22px rgba(27, 31, 36, 0.08);
}

.icon-button:hover,
.icon-button:focus-visible,
.choice-card:hover,
.choice-card:focus-visible,
.primary-button:hover,
.primary-button:focus-visible,
.secondary-button:hover,
.secondary-button:focus-visible {
  outline: 3px solid rgba(43, 114, 214, 0.22);
  outline-offset: 2px;
}

.view {
  min-height: calc(100vh - 156px);
  display: grid;
  align-content: center;
}

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

.list-grid,
.choice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

.file-card,
.choice-card {
  min-height: 112px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.92);
  color: var(--text);
  padding: 18px;
  text-align: left;
  box-shadow: var(--shadow);
}

.file-card {
  display: grid;
  align-content: space-between;
  gap: 12px;
}

.file-title,
.choice-title {
  display: block;
  font-size: 1.05rem;
  font-weight: 800;
  line-height: 1.35;
}

.file-meta,
.choice-meta {
  display: block;
  color: var(--muted);
  font-size: 0.91rem;
  line-height: 1.45;
}

.practice-layout,
.finish-panel {
  width: min(760px, 100%);
  margin: 0 auto;
  display: grid;
  justify-items: center;
  gap: 18px;
}

.progress-wrap {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  overflow: hidden;
  background: #dfe7e1;
}

.progress-bar {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--primary), #328b7e);
  transition: width 180ms ease;
}

.counter {
  margin: 0;
  color: var(--muted);
  font-weight: 700;
}

.question {
  min-height: 120px;
  margin: 0;
  display: grid;
  place-items: center;
  text-align: center;
  font-size: clamp(2rem, 7vw, 4.2rem);
  font-weight: 900;
  line-height: 1.2;
  word-break: keep-all;
  overflow-wrap: anywhere;
}

.answer-form {
  width: min(520px, 100%);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

input {
  min-width: 0;
  height: 48px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: 0 14px;
  color: var(--text);
}

input:focus {
  outline: 3px solid rgba(43, 114, 214, 0.25);
  border-color: var(--focus);
}

.primary-button,
.secondary-button {
  min-height: 44px;
  border-radius: 8px;
  border: 1px solid transparent;
  padding: 0 16px;
  font-weight: 800;
  white-space: nowrap;
}

.primary-button {
  background: var(--primary);
  color: #ffffff;
}

.primary-button:active {
  background: var(--primary-strong);
}

.secondary-button {
  background: var(--surface);
  border-color: var(--line);
  color: var(--text);
}

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

.result {
  min-height: 32px;
  margin: 0;
  color: var(--accent);
  font-weight: 900;
}

.result.is-correct {
  color: var(--primary);
}

.finish-score {
  margin: 0;
  text-align: center;
  font-size: clamp(2rem, 7vw, 4rem);
  font-weight: 900;
}

@media (max-width: 640px) {
  .app-shell {
    padding: 18px;
    gap: 16px;
  }

  .topbar {
    grid-template-columns: 40px 1fr 40px;
    gap: 10px;
  }

  .icon-button {
    width: 40px;
    height: 40px;
  }

  .view {
    min-height: calc(100vh - 122px);
  }

  .answer-form {
    grid-template-columns: 1fr;
  }
}