:root{
  --bg:#0b0f1a;
  --panel:#11182a;
  --panel2:#0e1526;
  --text:#e8eefc;
  --muted:#a9b4d0;
  --brand:#7aa2ff;
  --border: rgba(255,255,255,.08);
  --shadow: 0 10px 30px rgba(0,0,0,.35);
  --radius: 16px;
  --max: 1120px;
  --codebg: rgba(255,255,255,.06);
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Noto Sans", "Helvetica Neue", sans-serif;
  background:
    radial-gradient(1200px 600px at 30% -10%, rgba(122,162,255,.25), transparent 60%),
    radial-gradient(900px 500px at 90% 10%, rgba(127,255,212,.10), transparent 55%),
    var(--bg);
  color:var(--text);
}

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

/* ===== TOP BAR ===== */
.topbar{
  position: sticky;
  top:0;
  z-index: 5;
  backdrop-filter: blur(10px);
  background: rgba(11,15,26,.55);
  border-bottom: 1px solid var(--border);
}
.topbar-inner{
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 16px;
  display:flex;
  align-items:center;
  gap:12px;
}
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  font-weight: 700;
  letter-spacing:.2px;
}
.logo{
  width:34px;
  height:34px;
  border-radius: 8px;
  background: url("../assets/logo.jpg") center / contain no-repeat;
  box-shadow: var(--shadow);
}
.brand small{
  display:block;
  font-weight: 500;
  color: var(--muted);
  margin-top:2px;
}

/* ===== LAYOUT ===== */
.shell{
  max-width: var(--max);
  margin: 0 auto;
  padding: 18px 16px 40px;
  display:grid;
  grid-template-columns: 320px 1fr;
  gap:16px;
}

.sidebar{
  background: rgba(17,24,42,.72);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 14px;
  position: sticky;
  top: 74px;
  align-self:start;
}

.content{
  background: rgba(17,24,42,.55);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px 22px 26px;
}

/* ===== NAV ===== */
.nav-title{
  font-size: 13px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .12em;
  margin: 6px 6px 10px;
}
.nav-group{
  border-radius: 14px;
  background: rgba(255,255,255,.03);
  border: 1px solid var(--border);
  overflow:hidden;
}
.nav-item, .nav-subitem{
  display:flex;
  gap:10px;
  align-items:center;
  padding: 12px 12px;
  border-top: 1px solid var(--border);
  color: var(--text);
}
.nav-item:first-child{border-top:none}
.nav-item:hover, .nav-subitem:hover{
  background: rgba(122,162,255,.08);
  text-decoration:none;
}
.nav-item.active, .nav-subitem.active{
  background: rgba(122,162,255,.16);
  border-left: 3px solid var(--brand);
  padding-left: 9px;
}
.nav-sublist{
  padding: 6px 6px 10px 18px;
}
.nav-subitem{
  padding: 10px 10px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,.06);
  background: rgba(255,255,255,.02);
}
.nav-subitem + .nav-subitem{margin-top:6px}

/* ===== TEXT ===== */
.breadcrumbs{
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 10px;
}
.breadcrumbs a{color: var(--muted)}
.breadcrumbs a:hover{color: var(--text); text-decoration:none}

h1{margin: 6px 0 12px; font-size: 30px}
h2{margin: 22px 0 10px; font-size: 20px}
p{color: var(--text); line-height: 1.6}
ul,ol{color: var(--text); line-height:1.7}

.note{
  margin: 14px 0;
  padding: 14px 14px;
  border-radius: 14px;
  border: 1px solid rgba(122,162,255,.22);
  background: rgba(122,162,255,.08);
}
.note strong{display:block; margin-bottom: 6px}

.card-grid{
  display:grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap:12px;
  margin-top: 14px;
}
.card{
  border: 1px solid var(--border);
  background: rgba(255,255,255,.03);
  border-radius: 16px;
  padding: 14px;
}
.card h3{margin:0 0 6px; font-size: 16px}
.card p{margin:0; color: var(--muted); font-size: 14px}

.btnrow{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin: 14px 0 0;
}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid rgba(122,162,255,.25);
  background: rgba(122,162,255,.10);
  color: var(--text);
  text-decoration:none;
}
.btn:hover{
  background: rgba(122,162,255,.16);
  text-decoration:none;
}

/* ===== STEPS ===== */
.steps{
  display:grid;
  gap:12px;
  margin-top: 12px;
}
.step{
  border: 1px solid var(--border);
  background: rgba(255,255,255,.02);
  border-radius: 16px;
  padding: 14px;
  display:grid;
  grid-template-columns: 190px 1fr;
  gap:14px;
  align-items:start;
}
.step img{
  width:100%;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,.25);
  cursor: zoom-in;
}
.step h4{margin:0 0 6px; font-size: 16px}
.step p{margin:0; color: var(--muted)}

.footer{
  margin-top: 26px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 13px;
  display:flex;
  justify-content:space-between;
  gap:12px;
  flex-wrap:wrap;
}

/* ===== Mobile fix: always image first ===== */
@media (max-width: 980px){
  .shell{grid-template-columns: 1fr}
  .sidebar{position: relative; top:0}
  .card-grid{grid-template-columns: 1fr}

  .step{
    display:flex;
    flex-direction: column;
  }
  .step img{
    width:100%;
    margin-bottom: 10px;
  }
}

/* ===== Lightbox ===== */
.lightbox{
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 18px;
  background: rgba(0,0,0,.78);
  backdrop-filter: blur(6px);
}
.lightbox.open{ display:flex; }
.lightbox-inner{
  position: relative;
  max-width: min(1100px, 96vw);
  max-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.lightbox-img{
  max-width: 100%;
  max-height: 92vh;
  border-radius: 16px;
  border: 1px solid rgba(255,255,255,.12);
  box-shadow: 0 18px 60px rgba(0,0,0,.55);
  background: rgba(0,0,0,.25);
}
.lightbox-close{
  position: absolute;
  top: -12px;
  right: -12px;
  width: 40px;
  height: 40px;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,.16);
  background: rgba(15,20,35,.85);
  color: #fff;
  font-size: 20px;
  line-height: 40px;
  text-align: center;
  cursor: pointer;
  user-select: none;
}
.lightbox-hint{
  position: fixed;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  color: rgba(255,255,255,.75);
  font-size: 13px;
  background: rgba(0,0,0,.35);
  border: 1px solid rgba(255,255,255,.10);
  padding: 8px 10px;
  border-radius: 12px;
}