/* ============================================================
   Drillspress.com — screen styles
   ============================================================ */
:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --ink: #1d2733;
  --muted: #5c6572;
  --line: #dfe4ee;
  --brand: #2f5bd8;
  --brand-dark: #2347ab;
  --brand-soft: #e8eefc;
  --correct: #1f9d61;
  --correct-soft: #e4f5ec;
  --wrong: #d64545;
  --wrong-soft: #fdeaea;
  --warn: #b7791f;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(24, 39, 75, .08), 0 6px 18px rgba(24, 39, 75, .06);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}
img { max-width: 100%; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(1120px, 92%); margin: 0 auto; }

/* ---------- header / nav ---------- */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 50;
}
.nav-wrap { display: flex; align-items: center; gap: 18px; height: 60px; }
.brand {
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -.02em;
  color: var(--ink);
  white-space: nowrap;
}
.brand span { color: var(--brand); }
.brand:hover { text-decoration: none; }
.site-nav { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.site-nav a {
  color: var(--ink);
  font-size: .92rem;
  font-weight: 600;
  padding: 7px 11px;
  border-radius: 8px;
}
.site-nav a:hover { background: var(--brand-soft); text-decoration: none; color: var(--brand-dark); }
.nav-toggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 1.2rem;
  line-height: 1;
  padding: 6px 11px;
  cursor: pointer;
}

/* ---------- layout / hero ---------- */
main { flex: 1; padding: 26px 0 56px; }
.hero {
  background: linear-gradient(135deg, #1e3f9e 0%, var(--brand) 55%, #4a7bff 100%);
  color: #fff;
  border-radius: 18px;
  padding: 44px 40px;
  margin: 10px 0 30px;
}
.hero h1 { margin: 0 0 10px; font-size: clamp(1.7rem, 3.6vw, 2.6rem); line-height: 1.2; letter-spacing: -.02em; }
.hero p { margin: 0 auto; max-width: 640px; color: #e3eaff; font-size: 1.06rem; }
.hero .btn { margin-top: 20px; }
.page-head { margin-bottom: 22px; }
.page-head h1 { margin: 6px 0 8px; font-size: clamp(1.5rem, 2.6vw, 2.05rem); line-height: 1.25; letter-spacing: -.01em; }
.page-head .lede { color: var(--muted); margin: 0; max-width: 720px; }
.level-chip {
  display: inline-block;
  background: var(--brand-soft);
  color: var(--brand-dark);
  font-weight: 700;
  font-size: .78rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 999px;
}

.breadcrumb { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 10px; padding: 0; font-size: .84rem; color: var(--muted); }
.breadcrumb li + li::before { content: "›"; margin-right: 6px; color: #b3bac8; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--brand); }

/* ---------- cards / grids ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; list-style: none; padding: 0; margin: 0; }
.grid li { margin: 0; }
.card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  height: 100%;
  box-shadow: var(--shadow);
  transition: transform .12s ease, box-shadow .12s ease, border-color .12s ease;
}
a.card:hover { text-decoration: none; transform: translateY(-2px); border-color: #c3cfe9; box-shadow: 0 10px 24px rgba(24, 39, 75, .10); }
.card h3 { margin: 6px 0 4px; font-size: 1.05rem; color: var(--ink); }
.card p { margin: 0; font-size: .86rem; color: var(--muted); }
.card .level-chip { margin-bottom: 8px; }
.feature-cards .card { display: flex; flex-direction: column; gap: 6px; }

.section-title { font-size: 1.35rem; margin: 34px 0 14px; }
.section-title small { color: var(--muted); font-weight: 500; }

/* ---------- buttons ---------- */
.btn {
  display: inline-block;
  background: var(--brand);
  color: #fff;
  border: 0;
  border-radius: 10px;
  font: inherit;
  font-weight: 700;
  padding: 11px 22px;
  cursor: pointer;
  transition: background .12s ease;
}
.btn:hover { background: var(--brand-dark); text-decoration: none; color: #fff; }
.btn.ghost { background: var(--surface); color: var(--brand-dark); border: 1.5px solid #c6d3f0; }
.btn.ghost:hover { background: var(--brand-soft); }
.btn.success { background: var(--correct); }
.btn.success:hover { background: #177e4c; }
.btn.small { padding: 7px 14px; font-size: .88rem; }
.btn:disabled { opacity: .55; cursor: not-allowed; }

/* ---------- quiz engine ---------- */
.drill-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px 26px;
  margin-top: 18px;
}
.quiz-topbar { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 14px; }
.quiz-progress-text { font-weight: 700; }
.quiz-score { margin-left: auto; font-weight: 700; color: var(--brand-dark); background: var(--brand-soft); padding: 4px 12px; border-radius: 999px; font-size: .9rem; }
.quiz-progress { flex: 1 1 100%; height: 8px; background: #e8ecf5; border-radius: 999px; overflow: hidden; }
.quiz-progress-bar { height: 100%; width: 0; background: var(--brand); border-radius: 999px; transition: width .25s ease; }
.quiz-q { font-size: 1.22rem; font-weight: 700; line-height: 1.5; margin: 6px 0 4px; }
.blank { display: inline-block; min-width: 7ch; border-bottom: 2px solid currentColor; }
.q-num { color: var(--muted); font-size: .84rem; font-weight: 600; letter-spacing: .04em; }
.options { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 10px; }
.options li { margin: 0; }
.option {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  text-align: left;
  background: #f8fafd;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  padding: 11px 14px;
  font: inherit;
  cursor: pointer;
  transition: border-color .1s, background .1s;
}
.option:hover:not(:disabled) { border-color: #9db4e6; background: #eef3fd; }
.option:disabled { cursor: default; }
.option .letter {
  flex: 0 0 auto;
  width: 28px; height: 28px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 50%;
  background: var(--surface);
  border: 1.5px solid #c8d2e4;
  font-weight: 700; font-size: .86rem;
  color: var(--brand-dark);
}
.option .opt-text { flex: 1; }
.option.correct { border-color: var(--correct); background: var(--correct-soft); }
.option.correct .letter { background: var(--correct); border-color: var(--correct); color: #fff; }
.option.wrong { border-color: var(--wrong); background: var(--wrong-soft); }
.option.wrong .letter { background: var(--wrong); border-color: var(--wrong); color: #fff; }
.option .mark { font-weight: 800; }
.feedback {
  margin-top: 14px;
  border-left: 4px solid var(--brand);
  background: #f2f6ff;
  border-radius: 0 10px 10px 0;
  padding: 12px 16px;
}
.feedback.right { border-color: var(--correct); background: var(--correct-soft); }
.feedback.wrong { border-color: var(--wrong); background: var(--wrong-soft); }
.feedback .exp { font-weight: 700; margin: 0 0 4px; }
.feedback .example { margin: 0; font-style: italic; color: var(--muted); }
.quiz-actions { margin-top: 16px; display: flex; gap: 10px; flex-wrap: wrap; }
.quiz-actions .spacer { flex: 1; }

.results { text-align: center; padding: 18px 6px 8px; }
.results .big-score { font-size: 3rem; font-weight: 800; letter-spacing: -.02em; margin: 8px 0 2px; }
.results .big-score em { font-style: normal; color: var(--brand); }
.results .msg { color: var(--muted); margin: 0 0 18px; font-size: 1.05rem; }
.results .actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.best-line { display: inline-block; margin-top: 12px; background: #fdf6e3; color: #8a5a00; border-radius: 999px; padding: 6px 16px; font-weight: 700; font-size: .95rem; }
.timer-badge {
  font-variant-numeric: tabular-nums;
  background: #10233f; color: #7ff0b4;
  font-weight: 800; font-size: 1.15rem;
  padding: 5px 16px; border-radius: 999px;
}
.timer-badge.low { color: #ffb3a7; animation: blink 1s infinite; }
@keyframes blink { 50% { opacity: .5; } }

.generating {
  text-align: center;
  padding: 48px 20px;
  color: var(--muted);
}
.generating .hammer { font-size: 2.4rem; display: block; margin-bottom: 8px; }
.generating h2 { color: var(--ink); margin: 0 0 6px; }

/* ---------- verbs table ---------- */
.verbs-table-wrap { overflow-x: auto; margin-top: 10px; }
table.verbs { width: 100%; border-collapse: collapse; background: var(--surface); font-size: .95rem; }
table.verbs th, table.verbs td { border: 1px solid var(--line); padding: 8px 12px; text-align: left; }
table.verbs th { background: var(--brand-soft); color: var(--brand-dark); }
table.verbs tbody tr:nth-child(even) { background: #f8fafd; }
table.verbs td.v { font-weight: 700; }

/* ---------- static / content ---------- */
.prose { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 28px 32px; }
.prose h2 { margin-top: 26px; }
.prose ul { padding-left: 22px; }
.prose code { background: #eef1f7; padding: 1px 6px; border-radius: 6px; }
.prose .muted { color: var(--muted); }

.note { background: #fff8e8; border: 1px solid #f2ddae; color: #7a5b16; border-radius: 10px; padding: 12px 16px; font-size: .92rem; margin: 14px 0; }
.ad-slot { min-height: 90px; margin: 18px 0; }

/* ---------- footer ---------- */
#print-sheet { display: none; }
.quiz { scroll-margin-top: 84px; }
.site-footer { background: #14202f; color: #aab6c8; margin-top: 40px; }
.site-footer .container { padding: 34px 0 26px; }
.footer-grid { display: flex; gap: 30px; flex-wrap: wrap; justify-content: space-between; }
.site-footer h4 { color: #fff; margin: 0 0 10px; font-size: .95rem; }
.site-footer a { color: #b9c6da; }
.site-footer a:hover { color: #fff; text-decoration: none; }
.footer-links { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.footer-note { border-top: 1px solid #26374c; margin-top: 24px; padding-top: 16px; font-size: .84rem; color: #7f8da3; }

@media (max-width: 820px) {
  .nav-toggle { display: block; }
  .site-nav {
    display: none;
    position: absolute;
    top: 60px; left: 0; right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    padding: 10px 4% 16px;
    gap: 2px;
    box-shadow: 0 14px 24px rgba(24, 39, 75, .12);
  }
  .site-nav.open { display: flex; }
  .hero { padding: 34px 24px; }
  .drill-card { padding: 18px 16px; }
  .option { padding: 10px 12px; }
}