:root{
  --bg: #ffffff;
  --bg-elev: rgba(255,255,255,.72);
  --text: #0b1220;
  --muted: rgba(11,18,32,.68);
  --border: rgba(11,18,32,.10);
  --shadow: 0 10px 30px rgba(11,18,32,.10);
  --shadow-soft: 0 6px 18px rgba(11,18,32,.08);
  --accent: #2b6cff;
  --accent-2: #1bb3a6;
  --ring: 0 0 0 3px rgba(43,108,255,.18);
  --radius: 18px;
  --radius-sm: 14px;
  --container: 1120px;
  --font: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC",
    Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

html[data-theme="dark"]{
  --bg: #070a12;
  --bg-elev: rgba(10,14,24,.68);
  --text: rgba(255,255,255,.92);
  --muted: rgba(255,255,255,.68);
  --border: rgba(255,255,255,.12);
  --shadow: 0 18px 44px rgba(0,0,0,.55);
  --shadow-soft: 0 10px 24px rgba(0,0,0,.38);
  --accent: #6aa4ff;
  --accent-2: #3be7d6;
  --ring: 0 0 0 3px rgba(106,164,255,.22);
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  color: var(--text);
  background: radial-gradient(900px 500px at 15% 0%, rgba(27,179,166,.10), transparent 60%),
              radial-gradient(800px 500px at 80% 10%, rgba(43,108,255,.10), transparent 55%),
              var(--bg);
  font-family: var(--font);
  letter-spacing: .2px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a{ color: inherit; }
img{ max-width: 100%; display: block; }

.container{
  width: min(var(--container), calc(100% - 40px));
  margin: 0 auto;
}

.skip-link{
  position: absolute;
  left: -999px;
  top: 8px;
  padding: 10px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow-soft);
  z-index: 1000;
}
.skip-link:focus{ left: 12px; outline: none; box-shadow: var(--shadow-soft), var(--ring); }

.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: linear-gradient(to bottom, var(--bg-elev), rgba(255,255,255,0));
  border-bottom: 1px solid rgba(255,255,255,0);
}
html[data-theme="dark"] .site-header{
  background: linear-gradient(to bottom, var(--bg-elev), rgba(0,0,0,0));
}

.header-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 0;
}

.brand{
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  min-width: 220px;
}
.brand-mark{
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(43,108,255,.16), rgba(27,179,166,.16));
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
  font-weight: 700;
  letter-spacing: .6px;
}
.brand-text{ display: grid; }
.brand-title{ font-size: 15px; font-weight: 700; line-height: 1.1; }
.brand-subtitle{ font-size: 12px; color: var(--muted); margin-top: 2px; }

.nav{
  display: flex;
  gap: 14px;
  align-items: center;
}
.nav-link{
  text-decoration: none;
  font-size: 13px;
  color: var(--muted);
  padding: 8px 10px;
  border-radius: 12px;
  border: 1px solid transparent;
  transition: all .18s ease;
}
.nav-link:hover{
  color: var(--text);
  border-color: var(--border);
  background: rgba(255,255,255,.42);
}
html[data-theme="dark"] .nav-link:hover{ background: rgba(255,255,255,.06); }
.nav-link.is-active{
  color: var(--text);
  border-color: var(--border);
  background: rgba(43,108,255,.10);
}

.header-actions{
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn{
  appearance: none;
  border: 1px solid rgba(255,255,255,0);
  background: linear-gradient(135deg, rgba(43,108,255,.95), rgba(27,179,166,.92));
  color: #fff;
  border-radius: 14px;
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 650;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-soft);
  transition: transform .12s ease, box-shadow .12s ease, filter .12s ease;
}
.btn:hover{ filter: brightness(1.02); transform: translateY(-1px); }
.btn:active{ transform: translateY(0px); }
.btn:focus{ outline: none; box-shadow: var(--shadow-soft), var(--ring); }
.btn-ghost{
  background: rgba(255,255,255,.50);
  color: var(--text);
  border-color: var(--border);
  box-shadow: none;
}
html[data-theme="dark"] .btn-ghost{ background: rgba(255,255,255,.06); }
.btn-icon{ font-size: 14px; opacity: .9; }
.btn-text{ font-size: 13px; }

.hero{
  padding: 46px 0 18px;
}
.hero-grid{
  display: grid;
  grid-template-columns: 1.25fr .75fr;
  gap: 26px;
  align-items: start;
}
.kicker{
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.48);
  color: var(--muted);
  font-size: 13px;
}
html[data-theme="dark"] .kicker{ background: rgba(255,255,255,.06); }
.hero-title{
  margin: 14px 0 10px;
  font-size: clamp(30px, 3.6vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.6px;
}
.hero-desc{
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}
.hero-actions{
  display: flex;
  gap: 12px;
  margin-top: 18px;
}
.hero-metrics{
  list-style: none;
  padding: 0;
  margin: 18px 0 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}
.metric{
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,.50);
}
html[data-theme="dark"] .metric{ background: rgba(255,255,255,.06); }
.metric-title{ font-weight: 700; font-size: 13px; }
.metric-desc{ display: block; margin-top: 4px; color: var(--muted); font-size: 13px; line-height: 1.6; }

.hero-card .card{
  position: sticky;
  top: 86px;
}

.section{
  padding: 46px 0;
}
.section-alt{
  background: linear-gradient(to bottom, rgba(255,255,255,.35), rgba(255,255,255,0));
  border-top: 1px solid rgba(255,255,255,0);
  border-bottom: 1px solid rgba(255,255,255,0);
}
html[data-theme="dark"] .section-alt{
  background: linear-gradient(to bottom, rgba(255,255,255,.05), rgba(255,255,255,0));
}
.section-head{
  display: grid;
  gap: 10px;
  margin-bottom: 18px;
}
.section-title{
  margin: 0;
  font-size: 22px;
  letter-spacing: -0.2px;
}
.section-desc{
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
  font-size: 14px;
}

.grid{
  display: grid;
  gap: 14px;
}
.grid-5{ grid-template-columns: repeat(5, 1fr); }
.grid-3{ grid-template-columns: repeat(3, 1fr); }
.grid-2{ grid-template-columns: repeat(2, 1fr); }

.card{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(255,255,255,.62);
  box-shadow: var(--shadow-soft);
}
html[data-theme="dark"] .card{ background: rgba(255,255,255,.06); }

.card-badge{
  display: inline-flex;
  font-size: 12px;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 10px;
  background: rgba(255,255,255,.45);
}
html[data-theme="dark"] .card-badge{ background: rgba(255,255,255,.06); }
.card-title{
  margin: 12px 0 10px;
  font-size: 18px;
  letter-spacing: -0.2px;
}
.card-text{
  margin: 0;
  color: var(--muted);
  line-height: 1.9;
  font-size: 14px;
}
.card-actions{ margin-top: 12px; }
.card-footnote{
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--border);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.feature{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  background: rgba(255,255,255,.52);
  min-height: 200px;
}
html[data-theme="dark"] .feature{ background: rgba(255,255,255,.05); }
.feature-title{ margin: 0 0 8px; font-size: 16px; }
.feature-text{ margin: 0; color: var(--muted); line-height: 1.8; font-size: 13px; }

.mini-list{
  margin: 12px 0 0;
  padding: 0 0 0 16px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}

.post{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(255,255,255,.58);
  box-shadow: var(--shadow-soft);
}
html[data-theme="dark"] .post{ background: rgba(255,255,255,.06); }
.post-meta{
  font-size: 12px;
  color: var(--muted);
  letter-spacing: .4px;
}
.post-title{
  margin: 10px 0 8px;
  font-size: 17px;
  letter-spacing: -0.2px;
}
.post-excerpt{
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}
.post-list{
  margin: 12px 0 0;
  padding-left: 16px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}

.checklist-list{
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  color: var(--muted);
  font-size: 14px;
}
.checklist-list li{
  display: flex;
  align-items: flex-start;
  gap: 10px;
  line-height: 1.6;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(255,255,255,.45);
}
html[data-theme="dark"] .checklist-list li{ background: rgba(255,255,255,.05); }
.checklist-list input{
  width: 18px;
  height: 18px;
  margin-top: 2px;
  accent-color: var(--accent);
}

.tool .card-title{ margin-top: 0; }
.copy-btn{ width: fit-content; }

.subscribe{
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 16px;
  align-items: start;
}
.subscribe-form{
  display: grid;
  gap: 12px;
}
.field{ display: grid; gap: 8px; }
.field-label{ font-size: 12px; color: var(--muted); }
.input{
  width: 100%;
  border-radius: 14px;
  padding: 12px 12px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.65);
  color: var(--text);
  font-size: 14px;
}
html[data-theme="dark"] .input{ background: rgba(255,255,255,.06); }
.input:focus{ outline: none; box-shadow: var(--ring); }

.muted{ color: var(--muted); }
.small{ font-size: 12px; line-height: 1.6; }

.link{
  color: var(--accent);
  text-decoration: none;
  font-weight: 650;
}
.link:hover{ text-decoration: underline; }

.site-footer{
  padding: 26px 0 40px;
}
.footer-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}
.footer-links{
  display: flex;
  gap: 12px;
}

.back-to-top{
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 44px;
  height: 44px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.70);
  color: var(--text);
  box-shadow: var(--shadow-soft);
  cursor: pointer;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: all .16s ease;
}
html[data-theme="dark"] .back-to-top{ background: rgba(255,255,255,.08); }
.back-to-top.is-visible{
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:focus{ outline: none; box-shadow: var(--shadow-soft), var(--ring); }

@media (max-width: 980px){
  .hero-grid{ grid-template-columns: 1fr; }
  .hero-card .card{ position: relative; top: 0; }
  .grid-5{ grid-template-columns: repeat(2, 1fr); }
  .grid-3{ grid-template-columns: repeat(2, 1fr); }
  .subscribe{ grid-template-columns: 1fr; }
  .nav{ display: none; }
}
@media (max-width: 560px){
  .grid-3, .grid-2, .grid-5{ grid-template-columns: 1fr; }
  .header-inner{ gap: 10px; }
  .brand{ min-width: unset; }
  .header-actions .btn-text{ display: none; }
}