/* KakoNote — dark long-form guide */

:root{
  --bg:#0e1013;
  --bg2:#15181d;
  --panel:#191d23;
  --line:#262c35;
  --txt:#e6e9ee;
  --muted:#98a1ad;
  --accent:#ff6b35;
  --accent2:#ffb020;
  --radius:10px;
}

*{box-sizing:border-box}

html{-webkit-text-size-adjust:100%}

body{
  margin:0;
  background:var(--bg);
  color:var(--txt);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;
  font-size:17px;
  line-height:1.72;
  -webkit-font-smoothing:antialiased;
}

.wrap{
  max-width:820px;
  margin:0 auto;
  padding:0 22px;
}

/* ---------- top bar ---------- */

.topbar{
  position:sticky;
  top:0;
  z-index:20;
  background:rgba(14,16,19,.88);
  backdrop-filter:saturate(160%) blur(10px);
  -webkit-backdrop-filter:saturate(160%) blur(10px);
  border-bottom:1px solid var(--line);
}

.bar-in{
  display:flex;
  align-items:center;
  justify-content:space-between;
  height:56px;
}

.brand{
  font-weight:800;
  letter-spacing:-.02em;
  font-size:18px;
  color:inherit;
  text-decoration:none;
}
.brand:hover{text-decoration:none}
.brand span{color:var(--accent)}

/* ---------- headings ---------- */

main{padding:34px 0 10px}

h1{
  font-size:clamp(28px,4.6vw,42px);
  line-height:1.18;
  letter-spacing:-.025em;
  margin:6px 0 18px;
  font-weight:800;
}

h2{
  font-size:clamp(21px,2.9vw,27px);
  line-height:1.28;
  letter-spacing:-.018em;
  margin:52px 0 14px;
  padding-top:22px;
  border-top:1px solid var(--line);
  font-weight:750;
  scroll-margin-top:72px;
}

h3{
  font-size:17px;
  margin:0 0 6px;
  font-weight:700;
  letter-spacing:-.01em;
}

p{margin:0 0 17px}

a{color:var(--accent2);text-decoration:none}
a:hover{text-decoration:underline}

strong{color:#fff;font-weight:650}

.lead{
  font-size:19px;
  color:#cfd6df;
  margin-bottom:22px;
}

.note{
  background:var(--panel);
  border:1px solid var(--line);
  border-left:3px solid var(--accent);
  border-radius:var(--radius);
  padding:15px 18px;
  font-size:15.5px;
  color:var(--muted);
  margin:0 0 26px;
}
.note strong{color:var(--txt)}

.fineprint{
  font-size:13.5px;
  color:#7d8794;
  line-height:1.6;
}

/* ---------- lists ---------- */

ul,ol{padding-left:22px;margin:0 0 18px}
li{margin:0 0 9px}

.steps{list-style:none;padding-left:0;counter-reset:s}
.steps li{
  position:relative;
  padding-left:44px;
  margin-bottom:15px;
  counter-increment:s;
}
.steps li::before{
  content:counter(s);
  position:absolute;
  left:0;
  top:2px;
  width:28px;height:28px;
  display:flex;align-items:center;justify-content:center;
  background:var(--bg2);
  border:1px solid var(--line);
  color:var(--accent);
  border-radius:50%;
  font-size:14px;
  font-weight:700;
}

/* ---------- cards ---------- */

.cards{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:14px;
  margin:8px 0 24px;
}

.card{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px 17px;
}
.card p{margin:0;font-size:15.5px;color:var(--muted)}

/* ---------- tables ---------- */

.tablewrap{
  overflow-x:auto;
  margin:0 0 24px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:var(--panel);
}

table{
  width:100%;
  border-collapse:collapse;
  font-size:15.5px;
}

th,td{
  text-align:left;
  padding:12px 15px;
  border-bottom:1px solid var(--line);
  vertical-align:top;
}

thead th{
  background:var(--bg2);
  font-size:13px;
  letter-spacing:.04em;
  text-transform:uppercase;
  color:var(--muted);
  font-weight:600;
}

tbody tr:last-child td,
tbody tr:last-child th{border-bottom:none}

tbody th{
  color:var(--muted);
  font-weight:600;
  width:38%;
}

/* ---------- FAQ ---------- */

.faq{margin:6px 0 26px}

.faq details{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  margin-bottom:10px;
  overflow:hidden;
}

.faq summary{
  cursor:pointer;
  padding:14px 17px;
  font-weight:650;
  font-size:16px;
  list-style:none;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";
  float:right;
  color:var(--accent);
  font-weight:700;
}
.faq details[open] summary::after{content:"\2013"}

.faq details p{
  margin:0;
  padding:0 17px 16px;
  color:var(--muted);
  font-size:15.5px;
}

/* ---------- buttons ---------- */

.btn{
  display:inline-block;
  background:var(--accent);
  color:#140b05;
  font-weight:700;
  font-size:16px;
  padding:13px 22px;
  border-radius:var(--radius);
  text-decoration:none;
  border:none;
  transition:transform .12s ease, filter .12s ease;
}
.btn:hover{filter:brightness(1.08);text-decoration:none;transform:translateY(-1px)}

.btn-sm{
  font-size:14px;
  padding:9px 15px;
}

.cta{
  margin:26px 0 34px;
  padding:20px;
  background:linear-gradient(180deg,#1c2129,#171b21);
  border:1px solid var(--line);
  border-radius:var(--radius);
  text-align:center;
}
.cta-end{margin-top:38px}
.cta-end .fineprint{margin:16px 0 0}

/* ---------- footer ---------- */

.legal{
  margin-top:56px;
  padding:26px 0 40px;
  border-top:1px solid var(--line);
  background:var(--bg2);
  color:var(--muted);
  font-size:15px;
}
.legal p{margin:0 0 8px}

/* ---------- on this page ---------- */

.toc{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px 18px 18px;
  margin:0 0 28px;
}

.toc-h{
  margin:0 0 10px;
  font-size:13px;
  letter-spacing:.06em;
  text-transform:uppercase;
  color:var(--muted);
  font-weight:700;
}

.toc-grid{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:5px 20px;
}

.toc-grid a{
  position:relative;
  font-size:15px;
  line-height:1.45;
  color:var(--txt);
  padding:3px 0 3px 15px;
}

.toc-grid a::before{
  content:"\203A";
  position:absolute;
  left:0;
  top:2px;
  color:var(--accent);
  font-weight:700;
}

.toc-grid a:hover{color:var(--accent2);text-decoration:none}

/* ---------- category wall ---------- */

.catwall{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:10px;
  margin:10px 0 30px;
}

.catbtn{
  display:flex;
  align-items:center;
  justify-content:center;
  text-align:center;
  min-height:58px;
  padding:12px 14px;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  color:var(--txt);
  font-size:15.5px;
  font-weight:600;
  line-height:1.3;
  cursor:pointer;
  text-decoration:none;
  transition:border-color .12s ease, color .12s ease, background .12s ease, transform .12s ease;
}

.catbtn:hover{
  border-color:var(--accent);
  color:var(--accent2);
  background:#1f242c;
  text-decoration:none;
  transform:translateY(-1px);
}

/* 链接没填 → 变灰、点不动 */
.catbtn.is-empty{
  opacity:.4;
  cursor:not-allowed;
  pointer-events:none;
  border-style:dashed;
}

/* ---------- responsive ---------- */

@media (max-width:640px){
  body{font-size:16.5px}
  .cards{grid-template-columns:1fr}
  .catwall{grid-template-columns:repeat(2,1fr)}
  .toc-grid{grid-template-columns:1fr}
  tbody th{width:auto}
  .brand{font-size:16px}
  h2{margin-top:40px}
}