:root {
  --blue: #1a4894;
  --blue-deep: #0f1f3d;
  --green: #5cb344;
  --accent: #ff7a3d;
  --bg: #fbfbfd;
  --bg-soft: #f3f5f9;
  --card: #ffffff;
  --text: #0f1f3d;
  --text-2: #4a5168;
  --dim: #8a90a3;
  --line: #e3e6ec;
  --line-soft: #eef0f4;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { background: var(--bg); color: var(--text); }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", Helvetica, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre, kbd { font-family: "SF Mono", Menlo, Consolas, monospace; }
svg.ic {
  width: 16px; height: 16px; flex-shrink: 0;
  fill: none; stroke: currentColor; stroke-width: 2;
  stroke-linecap: round; stroke-linejoin: round;
}

/* HERO */
.hero {
  background:
    radial-gradient(ellipse at top, rgba(92,179,68,0.18), transparent 60%),
    linear-gradient(135deg, #0a1530 0%, #1a4894 100%);
  color: #fff;
  padding: 5rem 1.5rem 5.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(255,255,255,0.06) 1px, transparent 1px),
    radial-gradient(circle at 60% 70%, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 30px 30px, 50px 50px;
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; }
.hero-h1 { margin: 0; line-height: 0; font-weight: inherit; }
.hero-logo {
  max-width: 320px; width: 70%;
  height: auto; opacity: 0.95;
  filter: drop-shadow(0 4px 20px rgba(0,0,0,0.3));
}
.hero .tagline {
  font-size: 18px; opacity: 0.82; margin-top: 1rem;
  font-weight: 300; letter-spacing: 0.3px;
}
.hero .meta-row {
  margin-top: 1rem;
  display: flex; gap: 1.4rem; align-items: center;
  justify-content: center;
  font-size: 12.5px; opacity: 0.7;
  flex-wrap: nowrap; white-space: nowrap;
  max-width: 100%; overflow-x: auto;
}
.hero .meta-row span {
  display: inline-flex; align-items: center; gap: 0.35rem;
  white-space: nowrap; flex-shrink: 0;
}
.dl-cta {
  display: flex; justify-content: center;
  margin-top: 2.5rem;
}
.download-count {
  margin-top: 0.5rem; font-size: 12.5px; opacity: 0.7;
  display: flex; justify-content: center; align-items: center; gap: 0.4rem;
}
.download-count strong {
  color: var(--accent); font-weight: 700; opacity: 1;
  font-size: 14px;
}
.download-btn {
  display: inline-flex; align-items: center; gap: 0.6rem;
  background: var(--accent);
  color: #fff; font-weight: 700; font-size: 16px;
  padding: 1rem 2.6rem; border-radius: 12px;
  box-shadow: 0 8px 30px rgba(255,122,61,0.45);
  transition: transform 0.15s, box-shadow 0.15s;
}
.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(255,122,61,0.55);
  text-decoration: none;
}
.download-btn svg { stroke: currentColor; }
.download-sub {
  margin-top: 0.8rem; font-size: 12.5px; opacity: 0.6;
}
.help-link {
  margin-top: 0.9rem; font-size: 14.5px;
  display: flex; justify-content: center;
}
.help-link a {
  color: #fff; opacity: 0.75; text-decoration: none;
  font-weight: 600;
  padding: 0.3rem 0.7rem; border-radius: 6px;
  border: 1px solid rgba(255,255,255,0.18);
  display: inline-flex; align-items: center; gap: 0.4rem;
  transition: opacity 0.15s, border-color 0.15s, background 0.15s;
}
.help-link a:hover {
  opacity: 1; border-color: var(--green);
  background: rgba(92,179,68,0.15);
  text-decoration: none;
}

/* SECTIONS */
section { max-width: 980px; margin: 0 auto; padding: 4.5rem 1.5rem 1rem; }
section:last-of-type { padding-bottom: 4rem; }
.sec-head {
  margin-bottom: 2rem;
}
.sec-head .eyebrow {
  display: inline-block;
  font-size: 11px; font-weight: 600; letter-spacing: 1.5px;
  color: var(--green); text-transform: uppercase;
  margin-bottom: 0.3rem;
}
.sec-head h2 {
  font-size: 30px; font-weight: 700; letter-spacing: -0.5px;
  color: var(--text);
}
.sec-head p {
  color: var(--text-2); font-size: 15px; margin-top: 0.4rem;
}

/* INSTALL STEPS */
.steps { display: flex; flex-direction: column; gap: 0.8rem; }
.step {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.1rem 1.3rem;
  display: flex; gap: 1.1rem; align-items: flex-start;
  transition: border-color 0.15s;
}
.step:hover { border-color: var(--blue); }
.step .step-num {
  flex-shrink: 0; width: 30px; height: 30px;
  border-radius: 50%;
  background: var(--blue); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 14px;
}
.step-body { flex: 1; min-width: 0; }
.step-title { font-weight: 600; margin-bottom: 0.2rem; color: var(--text); }
.step-desc { color: var(--text-2); font-size: 14px; }
.step pre {
  background: #0f1f3d; color: #c0caf5;
  padding: 0.8rem 1rem; border-radius: 8px;
  font-size: 12.5px; margin-top: 0.6rem;
  overflow-x: auto; position: relative;
}
.copy-btn {
  position: absolute; right: 8px; top: 8px;
  background: rgba(255,255,255,0.12); color: #fff;
  border: none; padding: 0.25rem 0.7rem; border-radius: 5px;
  font-size: 11px; cursor: pointer;
  display: inline-flex; align-items: center; gap: 0.3rem;
}
.copy-btn:hover { background: rgba(255,255,255,0.22); }
.warn {
  background: #fff8e6;
  border-left: 4px solid #f0b429;
  padding: 0.9rem 1rem; border-radius: 6px;
  font-size: 13.5px; color: #6b4a00;
  margin-top: 0.8rem;
  display: flex; gap: 0.6rem;
}
.warn svg { stroke: #f0b429; margin-top: 2px; flex-shrink: 0; }

/* FEATURES */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.9rem;
}
.feature {
  padding: 1.3rem 1.3rem 1.2rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
}
.feature:hover {
  transform: translateY(-2px);
  border-color: var(--blue);
  box-shadow: 0 8px 24px rgba(26,72,148,0.08);
}
.feature .ic-wrap {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px;
  border-radius: 9px;
  background: linear-gradient(135deg, rgba(92,179,68,0.12), rgba(26,72,148,0.12));
  color: var(--blue);
  margin-bottom: 0.7rem;
}
.feature .ic-wrap svg { width: 20px; height: 20px; }
.feature h3 {
  font-size: 15px; font-weight: 600; margin-bottom: 0.3rem; color: var(--text);
}
.feature p {
  font-size: 13px; color: var(--text-2); line-height: 1.6;
}

/* CHANGELOG — TIMELINE */
.timeline {
  position: relative;
  padding-left: 28px;
}
.timeline::before {
  content: ""; position: absolute;
  left: 9px; top: 6px; bottom: 6px;
  width: 2px; background: linear-gradient(180deg, var(--green) 0%, var(--blue) 100%);
  border-radius: 1px;
}
.release {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.2rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.release:hover { border-color: var(--blue); box-shadow: 0 6px 20px rgba(26,72,148,0.06); }
.release::before {
  content: ""; position: absolute;
  left: -28px; top: 24px;
  width: 18px; height: 18px;
  background: #fff;
  border: 3px solid var(--green);
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--bg);
}
.release.current::before { border-color: var(--accent); }
.release-head {
  display: flex; align-items: baseline; gap: 0.8rem;
  flex-wrap: wrap;
  margin-bottom: 0.8rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--line-soft);
}
.release-head .ver {
  font-size: 22px; font-weight: 700;
  color: var(--blue);
  letter-spacing: -0.5px;
}
.release-head .date {
  font-size: 12.5px; color: var(--dim);
}
.release-head .badge {
  font-size: 10.5px; padding: 0.18rem 0.6rem;
  border-radius: 999px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.5px;
  margin-left: auto;
}
.release-head .badge.current {
  background: var(--accent); color: #fff;
}
/* 重大更新单独卡片 */
.major-list {
  display: flex; flex-direction: column; gap: 0.6rem;
  margin-bottom: 0.6rem;
}
.major {
  display: flex; gap: 0.9rem; align-items: flex-start;
  padding: 0.85rem 1rem;
  background: var(--bg-soft);
  border: 1px solid var(--line-soft);
  border-radius: 9px;
  transition: border-color 0.15s, background 0.15s;
}
.major:hover {
  border-color: var(--green);
  background: #f6faf3;
}
.major-ic {
  flex-shrink: 0;
  width: 36px; height: 36px;
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(92,179,68,0.18), rgba(26,72,148,0.18));
  color: var(--blue);
}
.major-ic svg.ic { width: 18px; height: 18px; }
.major-body { flex: 1; min-width: 0; }
.major-body h4 {
  font-size: 14.5px; font-weight: 600;
  color: var(--text); margin-bottom: 0.2rem;
}
.major-body p {
  font-size: 13px; color: var(--text-2);
  line-height: 1.55;
}

/* 折叠的「其余更新」 */
.more-changes {
  margin-top: 0.4rem;
  border-top: 1px dashed var(--line-soft);
  padding-top: 0.6rem;
}
.more-changes summary {
  cursor: pointer; user-select: none;
  font-size: 12.5px; color: var(--blue);
  font-weight: 500; list-style: none;
  display: inline-flex; align-items: center; gap: 0.3rem;
  padding: 0.3rem 0;
}
.more-changes summary::-webkit-details-marker { display: none; }
.more-changes summary .chev {
  width: 13px; height: 13px;
  transition: transform 0.2s;
}
.more-changes[open] summary .chev { transform: rotate(180deg); }
.release-notes {
  list-style: none; padding: 0.4rem 0 0;
  display: flex; flex-direction: column; gap: 0.4rem;
}
.release-notes li {
  font-size: 13px; line-height: 1.55;
  color: var(--text-2);
  display: flex; gap: 0.5rem; align-items: flex-start;
}
.release-notes li svg.ic {
  width: 15px; height: 15px;
  stroke: var(--green);
  margin-top: 2px;
  flex-shrink: 0;
}
.release-notes li strong {
  color: var(--text); font-weight: 600;
}

/* FOOTER */
footer {
  background: var(--blue-deep); color: #fff;
  padding: 3rem 1.5rem 2.5rem;
  text-align: center;
  margin-top: 2rem;
}
footer .ft-brand {
  max-width: 140px;
  margin: 0 auto 1rem;
  opacity: 0.9;
}
footer .ft-row { font-size: 13px; opacity: 0.7; margin-bottom: 0.3rem; }
footer .ft-links { display: flex; justify-content: center; gap: 0.5rem; }
footer .ft-sep { opacity: 0.4; }
footer a { color: var(--green); }
footer .copyright {
  margin-top: 1rem; opacity: 0.4; font-size: 12px;
}

/* RESPONSIVE */
@media (max-width: 640px) {
  .hero { padding: 3.5rem 1rem 4rem; }
  .hero-logo { width: 80%; }
  section { padding: 3rem 1rem 0; }
  .sec-head h2 { font-size: 24px; }
  .timeline { padding-left: 22px; }
  .timeline::before { left: 7px; }
  .release::before { left: -22px; top: 22px; width: 14px; height: 14px; }
  .release { padding: 1.1rem 1.2rem; }
}