:root {
  --base-font-size: 36px;
  --body-bg: #f5f7fb;
  --card-bg: #ffffff;
  --line-color: #d9deea;
  --primary: #2d6cdf;
}

* {
  box-sizing: border-box;
}

html {
  font-size: var(--base-font-size);
}

body {
  font-family: "Yu Gothic UI", "Meiryo", Arial, sans-serif;
  background: var(--body-bg);
  color: #222;
  margin: 0;
  padding: 0 0 72px;
  font-size: 1rem;
  line-height: 1.7;
}

body.login-page {
  min-height: 100vh;
}

.font-scale-toolbar {
  position: fixed;
  top: 78px;
  right: 12px;
  z-index: 1100;
  display: flex;
  gap: 8px;
}

.font-scale-toolbar button {
  margin-top: 0;
  padding: 8px 14px;
  border-radius: 10px;
  border: 1px solid #bfd0fb;
  background: #ffffff;
  color: #24427f;
  font-size: 20px;
  cursor: pointer;
  box-shadow: 0 1px 6px rgba(0,0,0,0.08);
}

.font-scale-toolbar button:hover {
  background: #eef3ff;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 1050;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  align-items: center;
  padding: 18px 28px;
  background: #ffffff;
  border-bottom: 1px solid var(--line-color);
}

.nav a {
  color: #1f3f8f;
  text-decoration: none;
  font-weight: 700;
}

.nav .nav-user {
  margin-left: auto;
  color: #666;
  font-size: 0.72rem;
}

.container {
  max-width: 1200px;
  margin: 30px auto;
  background: var(--card-bg);
  padding: 28px;
  border-radius: 16px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

.auth-center {
  min-height: calc(100vh - 220px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.auth-card,
.card,
.question-card,
.result-box,
.passage-box,
.explanation-box,
.summary-box,
.control-box,
.message-box {
  margin-top: 20px;
  padding: 20px;
  border: 1px solid var(--line-color);
  border-radius: 14px;
  background: #fafcff;
}

.auth-card {
  width: min(100%, 760px);
  margin-top: 0;
  background: #fff;
}

h1 { font-size: 1.3rem; margin: 0 0 18px; }
h2 { font-size: 1.15rem; margin: 0 0 16px; }
h3 { font-size: 1rem; margin: 0 0 14px; }
p, li, label, span, td, th, a, div { font-size: 1rem; }

input,
select,
button,
textarea {
  font: inherit;
}

input[type="text"],
input[type="password"],
input[type="email"],
input[type="number"],
select,
textarea {
  width: 100%;
  max-width: 100%;
  padding: 14px 16px;
  border: 1px solid #c5cede;
  border-radius: 10px;
  background: #fff;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 0.78rem;
  color: #555;
}

.question-text,
.question-card h2,
.question-card h3 {
  font-size: 1.1rem;
  margin-bottom: 16px;
}

.choices {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.choice-item {
  display: block;
  padding: 14px 18px;
  border: 1px solid #ccd4e0;
  border-radius: 12px;
  background: white;
  cursor: pointer;
}

.choice-item:hover {
  background: #f0f7ff;
}

.choice-item input[type="radio"] {
  transform: scale(1.5);
  margin-right: 14px;
}

button,
.btn,
a.btn {
  display: inline-block;
  margin-top: 16px;
  padding: 14px 22px;
  border: none;
  border-radius: 12px;
  background: var(--primary);
  color: white;
  cursor: pointer;
  text-decoration: none;
}

button:hover,
.btn:hover,
a.btn:hover {
  background: #1f57b8;
}

.secondary-btn {
  background: #eef3ff;
  color: #24427f;
  border: 1px solid #bfd0fb;
}

.secondary-btn:hover {
  background: #dfe9ff;
}

.ok { color: #0a8a2a; }
.ng, .error { color: #c62828; }
.success { color: #0a8a2a; }

.exp-block {
  margin-bottom: 14px;
}

.exp-block strong {
  display: inline-block;
  margin-bottom: 4px;
}

.actions, .control-box {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  align-items: end;
}

.control-box label {
  flex: 1 1 220px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.version-badge {
  position: fixed;
  right: 16px;
  bottom: 12px;
  z-index: 1000;
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid #d5dceb;
  background: rgba(255, 255, 255, 0.96);
  color: #4a5a7a;
  font-size: 18px;
  box-shadow: 0 1px 6px rgba(0,0,0,0.08);
}

.analysis-panel {
  margin-top: 18px;
}

.analysis-panel[hidden] {
  display: none !important;
}

@media (max-width: 900px) {
  :root {
    --base-font-size: 24px;
  }

  .font-scale-toolbar {
    top: 10px;
    right: 10px;
    gap: 6px;
  }

  .font-scale-toolbar button {
    padding: 6px 10px;
    font-size: 16px;
  }

  .container {
    margin: 16px;
    padding: 18px;
  }

  .nav {
    padding: 14px 16px;
  }
}


.practice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 32px;
}

.practice-card {
  background: #fff;
  border: 1px solid #dfe6ee;
  border-radius: 20px;
  padding: 28px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.practice-card h2 {
  margin-top: 0;
  margin-bottom: 16px;
}

.practice-card p {
  margin-bottom: 24px;
}


.audio-box {
  margin: 18px 0;
  padding: 18px;
  border: 1px solid #cfd8ea;
  border-radius: 14px;
  background: #f8fbff;
}

.audio-box h3 {
  margin: 0 0 10px;
}

.audio-note {
  margin: 0 0 10px;
  color: #44516a;
}

.listening-audio {
  width: 100%;
  margin-top: 8px;
}

.audio-transcript {
  margin-top: 12px;
}

.audio-transcript summary {
  cursor: pointer;
  font-weight: 700;
}

.audio-missing {
  background: #fff8f8;
  border-color: #efc4c4;
}