/* ============================================================
   Kemu One — landing page
   Direction: Chinese road-signage system.
   Palette, type and shapes are taken from the subject itself:
   asphalt, lane markings, blue mandatory discs, yellow warning
   triangles, red prohibitory rings, green guide panels.
   ============================================================ */

:root {
  /* Signage palette */
  --asphalt:      #14181F;
  --asphalt-2:    #1D2430;
  --marking:      #F7F8FA;   /* white lane paint */
  --sign-blue:    #0B4EA2;   /* mandatory / information disc */
  --sign-blue-lo: #093C7E;
  --sign-red:     #D92B2B;   /* prohibitory ring */
  --sign-yellow:  #F5C518;   /* warning triangle */
  --sign-green:   #0F6B45;   /* guide panel */
  --ink:          #10141C;
  --muted:        #5B6474;
  --line:         #E3E7EE;
  --paper:        #FFFFFF;
  --page:         #F4F6FA;

  /* Type */
  --display: 'Saira', 'Noto Sans SC', system-ui, sans-serif;
  --cjk: 'Noto Sans SC', 'Saira', system-ui, sans-serif;
  --body: 'IBM Plex Sans', system-ui, -apple-system, sans-serif;
  --data: 'IBM Plex Mono', ui-monospace, SFMono-Regular, monospace;

  --radius: 14px;
  --shadow: 0 18px 44px rgba(16, 20, 28, 0.14);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--sign-yellow);
  outline-offset: 3px;
  border-radius: 4px;
}

.shell { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* The signature: a painted centre line. Used as section floor + hero edge. */
.lane {
  height: 10px;
  background:
    repeating-linear-gradient(to right,
      rgba(247, 248, 250, 0.85) 0 46px,
      transparent 46px 84px);
}
.lane--on-paper {
  background:
    repeating-linear-gradient(to right,
      var(--line) 0 46px,
      transparent 46px 84px);
}

/* ---------------- Top bar ---------------- */

.bar {
  background: var(--asphalt);
  border-bottom: 1px solid rgba(247, 248, 250, 0.12);
}
.bar-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 18px; padding: 16px 0;
}
.brand {
  font-family: var(--display);
  font-weight: 800;
  font-size: 1.18rem;
  letter-spacing: -0.02em;
  color: var(--marking);
  text-decoration: none;
}
.brand .k { color: var(--sign-yellow); }
.bar-right { display: flex; align-items: center; gap: 20px; }
.bar-right a.plain {
  color: rgba(247, 248, 250, 0.78);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}
.bar-right a.plain:hover { color: #fff; }

.btn {
  display: inline-block;
  font-family: var(--body);
  font-weight: 600;
  text-decoration: none;
  border-radius: 10px;
  padding: 12px 24px;
  font-size: 1rem;
  transition: transform 0.12s ease, background 0.15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn--yellow { background: var(--sign-yellow); color: #17140A; }
.btn--yellow:hover { background: #FFD43F; }
.btn--blue { background: var(--sign-blue); color: #fff; }
.btn--blue:hover { background: var(--sign-blue-lo); }
.btn--ghost {
  color: var(--marking);
  border: 1px solid rgba(247, 248, 250, 0.35);
  padding: 11px 22px;
}
.btn--ghost:hover { border-color: var(--marking); }
.btn--sm { padding: 9px 18px; font-size: 0.93rem; }

/* ---------------- Hero ---------------- */

.hero {
  background: var(--asphalt);
  color: var(--marking);
  position: relative;
  overflow: hidden;
}
.hero::before {
  /* faint lane texture behind the headline */
  content: "";
  position: absolute; inset: 0;
  background:
    repeating-linear-gradient(115deg,
      rgba(247,248,250,0.035) 0 2px,
      transparent 2px 26px);
  pointer-events: none;
}
.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 54px;
  align-items: center;
  padding: 68px 0 62px;
}
.eyebrow {
  font-family: var(--data);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sign-yellow);
  margin: 0 0 18px;
}
.eyebrow .cjk { font-family: var(--cjk); letter-spacing: 0.1em; }

h1 {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(2.3rem, 5.4vw, 3.9rem);
  line-height: 1.04;
  letter-spacing: -0.035em;
  margin: 0 0 20px;
  text-wrap: balance;
}
h1 .cjk {
  font-family: var(--cjk);
  font-weight: 800;
  color: var(--sign-yellow);
  letter-spacing: -0.01em;
}
.hero p.lede {
  font-size: 1.09rem;
  color: rgba(247, 248, 250, 0.82);
  margin: 0 0 28px;
  max-width: 34em;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.hero-fine {
  font-family: var(--data);
  font-size: 0.8rem;
  color: rgba(247, 248, 250, 0.62);
  margin: 20px 0 0;
}
.hero-floor { position: relative; }

/* ---- Hero: a real question, rendered as HTML (not a screenshot) ---- */

.mock {
  background: var(--paper);
  color: var(--ink);
  border-radius: 18px;
  box-shadow: var(--shadow);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.5);
}
.mock-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
  padding: 13px 18px;
  background: var(--sign-blue);
  color: #fff;
}
.mock-head .topic {
  font-family: var(--data);
  font-size: 0.68rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}
.mock-head .time {
  font-family: var(--data);
  font-size: 0.78rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.16);
  padding: 2px 9px;
  border-radius: 6px;
}
.mock-body { padding: 20px 20px 8px; display: flex; gap: 18px; align-items: flex-start; }
.mock-sign {
  flex: 0 0 96px;
  width: 96px; height: 96px;
  object-fit: contain;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 6px;
}
.mock-q {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.14rem;
  line-height: 1.3;
  letter-spacing: -0.015em;
  margin: 4px 0 12px;
}
.mock-opts { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.mock-opts li {
  display: flex; align-items: center; gap: 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 9px 13px;
  font-size: 0.95rem;
}
.mock-opts li .key {
  font-family: var(--data);
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--muted);
  width: 14px;
}
.mock-opts li.correct {
  border-color: var(--sign-green);
  background: rgba(15, 107, 69, 0.07);
  font-weight: 600;
}
.mock-opts li.correct .key { color: var(--sign-green); }
.mock-opts li.correct::after {
  content: "✓";
  margin-left: auto;
  color: var(--sign-green);
  font-weight: 700;
}
.mock-note {
  border-top: 1px dashed var(--line);
  margin: 14px 0 0;
  padding: 14px 20px 18px;
  font-size: 0.88rem;
  color: var(--muted);
}
.mock-note b { color: var(--ink); font-weight: 600; }
.mock-note .std {
  display: inline-block;
  font-family: var(--data);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--sign-blue);
  background: rgba(11, 78, 162, 0.09);
  padding: 2px 7px;
  border-radius: 5px;
  margin-left: 6px;
  vertical-align: 1px;
}

/* ---------------- Sign stats (the signature) ---------------- */

.signs {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 22px;
  padding: 52px 0 8px;
}
.sign { display: flex; gap: 16px; align-items: center; }
.sign-mark {
  flex: 0 0 auto;
  display: grid; place-items: center;
  width: 74px; height: 74px;
  font-family: var(--display);
  font-weight: 800;
  font-size: 1.28rem;
  letter-spacing: -0.03em;
  line-height: 1;
  text-align: center;
}
/* blue mandatory disc: 100 questions */
.mark-disc {
  border-radius: 50%;
  background: var(--sign-blue);
  color: #fff;
  box-shadow: inset 0 0 0 4px #fff, 0 0 0 3px var(--sign-blue);
}
/* yellow warning triangle: 45 minutes */
.mark-tri {
  position: relative;
  width: 74px; height: 68px;
  background: var(--sign-yellow);
  clip-path: polygon(50% 0%, 100% 100%, 0% 100%);
}
.mark-tri span {
  position: absolute;
  left: 0; right: 0; bottom: 8px;
  font-family: var(--display);
  font-weight: 800;
  font-size: 1.05rem;
  color: #17140A;
  text-align: center;
  line-height: 1;
}
/* red prohibitory ring: 12-point system */
.mark-ring {
  border-radius: 50%;
  background: #fff;
  color: var(--sign-red);
  box-shadow: inset 0 0 0 7px var(--sign-red);
}
/* green guide panel: question bank */
.mark-guide {
  border-radius: 8px;
  background: var(--sign-green);
  color: #fff;
  box-shadow: inset 0 0 0 3px #fff, 0 0 0 2px var(--sign-green);
  font-size: 1.12rem;
}
.sign-label { min-width: 0; }
.sign-label b {
  display: block;
  font-family: var(--body);
  font-weight: 600;
  font-size: 0.98rem;
  line-height: 1.3;
}
.sign-label span {
  display: block;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.45;
}

/* ---------------- Sections ---------------- */

.section { padding: 64px 0; }
.section--paper { background: var(--paper); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.kicker {
  font-family: var(--data);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sign-blue);
  margin: 0 0 10px;
}
h2 {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(1.6rem, 3.4vw, 2.3rem);
  letter-spacing: -0.03em;
  line-height: 1.12;
  margin: 0 0 10px;
}
.section-intro { color: var(--muted); margin: 0 0 34px; max-width: 46em; }

/* What's inside */
.features {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 2px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.feature { background: var(--paper); padding: 26px 24px; }
.feature h3 {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.06rem;
  letter-spacing: -0.015em;
  margin: 0 0 8px;
  display: flex; align-items: center; gap: 9px;
}
.feature h3::before {
  content: "";
  width: 11px; height: 11px;
  border-radius: 50%;
  background: var(--sign-blue);
  flex: 0 0 auto;
}
.feature:nth-child(3n+2) h3::before { background: var(--sign-yellow); border-radius: 2px; transform: rotate(45deg); }
.feature:nth-child(3n) h3::before { background: var(--sign-red); }
.feature p { margin: 0; font-size: 0.94rem; color: var(--muted); }

/* Steps — a real sequence, so numbering earns its place */
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 0; counter-reset: s; }
.steps li {
  counter-increment: s;
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 26px 0;
  border-top: 1px dashed var(--line);
}
.steps li:last-child { border-bottom: 1px dashed var(--line); }
.steps li::before {
  content: counter(s, decimal-leading-zero);
  font-family: var(--data);
  font-size: 1.7rem;
  font-weight: 600;
  color: var(--sign-blue);
  line-height: 1;
}
.steps h3 {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.14rem;
  letter-spacing: -0.02em;
  margin: 0 0 6px;
}
.steps p { margin: 0; color: var(--muted); max-width: 52em; }

/* Pricing */
.prices { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.plan {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  position: relative;
}
.plan--featured {
  border-color: var(--sign-blue);
  box-shadow: 0 14px 34px rgba(11, 78, 162, 0.16);
}
.plan-tag {
  position: absolute; top: -11px; left: 50%; transform: translateX(-50%);
  background: var(--sign-blue); color: #fff;
  font-family: var(--data); font-size: 0.66rem; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase;
  padding: 4px 11px; border-radius: 999px; white-space: nowrap;
}
.plan .name {
  font-family: var(--data);
  font-size: 0.74rem; font-weight: 600;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--muted);
}
.plan .amount {
  font-family: var(--display);
  font-weight: 800;
  font-size: 2.35rem;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin: 8px 0 2px;
}
.plan .per { font-size: 0.85rem; color: var(--muted); }
.plan .detail { font-size: 0.85rem; color: var(--muted); margin-top: 12px; line-height: 1.5; }
.price-note {
  font-family: var(--data);
  font-size: 0.82rem;
  color: var(--muted);
  margin: 22px 0 0;
}

/* FAQ teasers */
.faq-list { display: grid; gap: 10px; }
.faq-list a {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 4px solid var(--sign-blue);
  border-radius: 10px;
  padding: 16px 20px;
  text-decoration: none;
  color: var(--ink);
  font-weight: 600;
  font-size: 1rem;
}
.faq-list a:hover { border-left-color: var(--sign-yellow); background: #fff; }
.faq-list a .arrow { color: var(--sign-blue); font-family: var(--data); }
.faq-more { margin-top: 18px; }
.faq-more a { color: var(--sign-blue); font-weight: 600; text-decoration: none; }
.faq-more a:hover { text-decoration: underline; }

/* Final CTA */
.final {
  background: var(--asphalt);
  color: var(--marking);
  position: relative;
  padding: 64px 0 58px;
  text-align: center;
}
.final h2 { color: #fff; }
.final p { color: rgba(247, 248, 250, 0.78); margin: 0 auto 26px; max-width: 40em; }

/* Footer */
.foot {
  background: var(--asphalt-2);
  color: rgba(247, 248, 250, 0.68);
  padding: 30px 0;
  font-size: 0.88rem;
}
.foot-inner { display: flex; flex-wrap: wrap; gap: 18px; justify-content: space-between; align-items: center; }
.foot nav { display: flex; gap: 18px; flex-wrap: wrap; }
.foot a { color: var(--sign-yellow); text-decoration: none; font-weight: 600; }
.foot a:hover { text-decoration: underline; }

/* ---------------- Responsive ---------------- */

@media (max-width: 1000px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; padding: 52px 0 48px; }
  .signs { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px 22px; }
  .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .prices { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 620px) {
  .shell { padding: 0 18px; }
  .signs { grid-template-columns: 1fr; }
  .features { grid-template-columns: 1fr; }
  .prices { grid-template-columns: 1fr; }
  .mock-body { flex-direction: column; }
  .mock-sign { width: 88px; height: 88px; flex-basis: 88px; }
  .steps li { grid-template-columns: 54px minmax(0, 1fr); gap: 14px; }
  .bar-right a.plain { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .btn { transition: none; }
  .btn:hover { transform: none; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --page: #0E1117;
    --paper: #151A24;
    --ink: #EEF1F7;
    --muted: #A2ABC0;
    --line: #262C3A;
    --shadow: 0 18px 44px rgba(0, 0, 0, 0.5);
  }
  .section--paper { background: var(--paper); border-color: var(--line); }
  .feature { background: var(--paper); }
  .faq-list a { background: var(--paper); }
  .mock { background: #fff; color: #10141C; }
  .mock .mock-q, .mock .mock-opts li { color: #10141C; }
  .mark-ring { background: var(--paper); }
}