:root {
  --navy: #15356c;
  --blue: #1765d9;
  --cyan: #07a8c3;
  --ink: #17233d;
  --muted: #607188;
  --line: #d8e3f0;
  --surface: #fff;
  --bg: #f3f7fc;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}
main {
  width: min(1180px, calc(100% - 40px));
  margin: auto;
  padding: 64px 0 54px;
}
.personal-home-link,
.stage-nav a {
  color: var(--blue);
  font-weight: 800;
  text-decoration: none;
}
.eyebrow {
  margin: 20px 0 10px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0.12em;
}
h1 {
  margin: 0;
  color: var(--navy);
  font-size: clamp(38px, 6vw, 62px);
  line-height: 1.2;
}
.lead {
  max-width: 880px;
  margin: 18px 0 28px;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.7;
}
.stage-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}
.stage-nav a {
  padding: 9px 14px;
  border: 1px solid #bad4ee;
  border-radius: 999px;
  background: #fff;
}
.knowledge-map-entry {
  display: grid;
  grid-template-columns: 160px 1fr auto;
  gap: 24px;
  align-items: center;
  margin-bottom: 34px;
  padding: 24px 26px;
  border: 1px solid #bdd5ec;
  border-left: 7px solid var(--blue);
  border-radius: 18px;
  background: linear-gradient(135deg, #fff, #edf7ff);
  box-shadow: 0 10px 26px rgba(31, 65, 112, 0.09);
  color: inherit;
  text-decoration: none;
  transition: 0.2s ease;
}
.knowledge-map-entry:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
  box-shadow: 0 14px 30px rgba(31, 65, 112, 0.13);
}
.knowledge-map-entry > span {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.11em;
}
.knowledge-map-entry h2 {
  margin: 0 0 5px;
  color: var(--navy);
  font-size: 24px;
}
.knowledge-map-entry p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.55;
}
.knowledge-map-entry strong {
  color: var(--blue);
  white-space: nowrap;
}
.course-stage {
  margin: 34px 0;
}
.course-stage > header {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
  align-items: end;
  margin-bottom: 16px;
}
.course-stage header span {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
}
.course-stage h2 {
  margin: 5px 0 0;
  color: var(--navy);
  font-size: 28px;
}
.course-stage header p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.lesson-card {
  display: block;
  padding: 23px 24px;
  border: 1px solid var(--line);
  border-radius: 17px;
  background: linear-gradient(135deg, #fff, #f6fbff);
  box-shadow: 0 8px 22px rgba(31, 65, 112, 0.07);
  color: inherit;
  text-decoration: none;
  transition: 0.2s ease;
}
.lesson-card:hover {
  transform: translateY(-3px);
  border-color: var(--cyan);
  box-shadow: 0 12px 28px rgba(31, 65, 112, 0.12);
}
.lesson-card > span {
  color: var(--blue);
  font-size: 13px;
  font-weight: 900;
}
.lesson-card h3 {
  margin: 7px 0;
  color: var(--navy);
  font-size: 22px;
  line-height: 1.4;
}
.lesson-card p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.55;
}
.lesson-card small {
  color: #73849a;
}
.usage {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
  margin-top: 38px;
}
.usage article {
  padding: 19px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
}
.usage strong {
  color: var(--navy);
  font-size: 17px;
}
.usage p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}
footer {
  margin-top: 42px;
  color: #74849a;
  font-size: 14px;
}
@media (max-width: 760px) {
  main {
    width: min(100% - 28px, 1180px);
    padding-top: 42px;
  }
  .knowledge-map-entry {
    grid-template-columns: 1fr;
    gap: 10px;
    padding: 21px;
  }
  .knowledge-map-entry strong {
    white-space: normal;
  }
  .course-stage > header,
  .lesson-grid,
  .usage {
    grid-template-columns: 1fr;
  }
  .lead {
    font-size: 17px;
  }
  .lesson-card h3 {
    font-size: 20px;
  }
}