:root{
  /* Dark theme defaults */
  --bg1:#0b1220;
  --bg2:#0f1b33;
  --card:#0f172aee;
  --card2:#0b1220cc;
  --text:#e6edf6;
  --muted:#94a3b8;
  --border:#23314f;
  --accent:#60a5fa;
  --danger:#ef4444;
  --shadow: 0 18px 60px rgba(0,0,0,.45);
  --radius: 16px;

  --pad: 24px;
  --gap: 22px;
  --font: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
}

/* System mode: follow OS */
html[data-theme="system"]{ color-scheme: light dark; }
@media (prefers-color-scheme: light){
  html[data-theme="system"]{
    --bg1:#f6f8fc;
    --bg2:#edf2ff;
    --card:#ffffffee;
    --card2:#ffffffcc;
    --text:#0b1220;
    --muted:#52627a;
    --border:#d7e0f0;
    --accent:#2563eb;
    --danger:#dc2626;
    --shadow: 0 18px 60px rgba(15,23,42,.14);
  }
}

/* Manual overrides */
html[data-theme="light"]{
  color-scheme: light;
  --bg1:#f6f8fc;
  --bg2:#edf2ff;
  --card:#ffffffee;
  --card2:#ffffffcc;
  --text:#0b1220;
  --muted:#52627a;
  --border:#d7e0f0;
  --accent:#2563eb;
  --danger:#dc2626;
  --shadow: 0 18px 60px rgba(15,23,42,.14);
}
html[data-theme="dark"]{
  color-scheme: dark;
}

*{ box-sizing:border-box; }
html,body{ height:100%; }
body{
  margin:0;
  font-family: var(--font);
  color:var(--text);
  background:
    radial-gradient(1200px 800px at 20% 10%, rgba(96,165,250,.22), transparent 55%),
    radial-gradient(900px 700px at 85% 35%, rgba(34,197,94,.16), transparent 55%),
    linear-gradient(180deg, var(--bg1), var(--bg2));
  display:flex;
  align-items:center;
  justify-content:center;
  padding: var(--pad);
}

.shell{
  width:min(980px, 100%);
  display:grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--gap);
  align-items:stretch;
}

.hero, .card{
  border:1px solid var(--border);
  background: linear-gradient(180deg, var(--card), var(--card2));
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero{
  padding: 28px;
  position:relative;
  overflow:hidden;
}
.hero:before{
  content:"";
  position:absolute;
  inset:-2px;
  background:
    radial-gradient(600px 240px at 25% 0%, rgba(96,165,250,.18), transparent 60%),
    radial-gradient(420px 260px at 70% 30%, rgba(34,197,94,.14), transparent 60%);
  pointer-events:none;
}

.brand{
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:12px;
  margin-bottom:18px;
}

.brand-left{
  display:flex;
  align-items:center;
  gap:12px;
  min-width: 0;
}

.mark{
  width:38px;height:38px;border-radius:12px;
  background: linear-gradient(135deg, rgba(96,165,250,.95), rgba(34,197,94,.85));
  box-shadow: 0 10px 28px rgba(37,99,235,.18);
  position:relative;
  flex:0 0 auto;
}
.mark:after{
  content:"";
  position:absolute;
  inset:10px;
  border-radius:10px;
  border:1px solid rgba(255,255,255,.55);
  transform: rotate(8deg);
}

.brand h1{
  font-size:16px;
  letter-spacing:.2px;
  margin:0;
  font-weight:650;
}
.brand p{
  margin:2px 0 0 0;
  color:var(--muted);
  font-size:12.5px;
}

.theme-btn{
  border:1px solid var(--border);
  background: rgba(255,255,255,.03);
  color: var(--muted);
  font-size:12.5px;
  padding:8px 10px;
  border-radius: 12px;
  cursor:pointer;
}
.theme-btn:hover{ color: var(--text); }

.headline{
  margin:14px 0 10px;
  font-size:28px;
  line-height:1.15;
  letter-spacing:-.3px;
  font-weight:750;
}

.sub{
  margin:0 0 18px;
  color:var(--muted);
  font-size:14.5px;
  line-height:1.5;
  max-width: 62ch;
}

.bullets{
  display:grid;
  grid-template-columns: 1fr 1fr;
  gap:10px;
  margin-top:14px;
}

.bullet{
  border:1px solid var(--border);
  border-radius: 14px;
  padding:12px;
  background: rgba(255,255,255,.03);
}
.bullet strong{
  display:block;
  font-size:13px;
  margin-bottom:4px;
}
.bullet span{
  color:var(--muted);
  font-size:12.5px;
  line-height:1.35;
}

.card{
  padding: 22px;
}

.card-title{
  margin:0 0 6px;
  font-size:16px;
  font-weight:720;
  letter-spacing:.2px;
}

.hint{
  margin:0 0 14px;
  color:var(--muted);
  font-size:12.5px;
  line-height:1.45;
}

form{ margin-top:12px; }

label{
  display:block;
  font-size:12.5px;
  color:var(--muted);
  margin:10px 0 6px;
}

.field{
  display:flex;
  gap:8px;
  align-items:center;
  border:1px solid var(--border);
  border-radius: 14px;
  padding:10px 12px;
  background: rgba(255,255,255,.03);
}

input{
  width:100%;
  background: transparent;
  border:0;
  outline:none;
  color:var(--text);
  font-size:16px;
  padding:2px 0;
}

.icon{
  width:18px;height:18px;opacity:.85;flex:0 0 auto;
  color:var(--muted);
}

.row{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  margin-top:12px;
  flex-wrap:wrap;
}

.checkbox{
  display:flex;
  align-items:center;
  gap:8px;
  font-size:12.5px;
  color:var(--muted);
  user-select:none;
}
.checkbox input{ width:auto; }

.btn{
  width:100%;
  margin-top:14px;
  border:1px solid rgba(96,165,250,.35);
  background: linear-gradient(135deg, rgba(37,99,235,.95), rgba(96,165,250,.75));
  color:white;
  padding:11px 12px;
  border-radius: 14px;
  font-weight:700;
  letter-spacing:.2px;
  cursor:pointer;
  box-shadow: 0 12px 30px rgba(37,99,235,.22);
}
.btn:disabled{
  opacity:.6;
  cursor:not-allowed;
  box-shadow:none;
}

.links{
  margin-top:12px;
  display:flex;
  justify-content:space-between;
  gap:10px;
  flex-wrap:wrap;
  font-size:12.5px;
}

.link, a{
  color: var(--accent);
  text-decoration: none;
}
.link:hover, a:hover{ text-decoration: underline; }

.linkbtn{
  all:unset;
  cursor:pointer;
  padding:4px 2px;
  color:var(--muted);
  font-size:12.5px;
}

.alert{
  display:none;
  margin-top:12px;
  border:1px solid rgba(239,68,68,.35);
  background: rgba(239,68,68,.08);
  border-radius: 14px;
  padding:10px 12px;
  font-size:12.8px;
  line-height:1.35;
}
.alert.show{ display:block; }
.alert b{ color: var(--danger); }

.footer{
  margin-top:14px;
  color:var(--muted);
  font-size:11.5px;
  line-height:1.4;
}
.footer.small{ margin-top:12px; }

.kbd{
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 11.5px;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 2px 6px;
  border-radius: 8px;
  background: rgba(255,255,255,.03);
}

/* Theme menu: fixed portal above everything */
.theme-menu{
  position: fixed;
  z-index: 999999;
  display:none;

  min-width: 180px;
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 6px;

  background: rgba(10, 14, 24, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.theme-menu.show{ display:block; }

html[data-theme="light"] .theme-menu{
  background: rgba(255, 255, 255, 0.94);
}
@media (prefers-color-scheme: light){
  html[data-theme="system"] .theme-menu{
    background: rgba(255, 255, 255, 0.94);
  }
}

.theme-item{
  width:100%;
  text-align:left;
  border:0;
  background: transparent;
  color: var(--text);
  padding:10px 10px;
  border-radius: 10px;
  cursor:pointer;
  font-size:13px;
}
.theme-item:hover{ background: rgba(96,165,250,.12); }
.theme-item.active{
  outline: 1px solid rgba(96,165,250,.35);
  background: rgba(96,165,250,.10);
}

/* Mobile */
@media (max-width: 860px){
  body{ padding: 16px; align-items: stretch; }
  .shell{ grid-template-columns: 1fr; gap: 14px; }
  .hero{ padding: 18px; }
  .card{ padding: 18px; }
  .headline{ font-size: 24px; }
  .bullets{ grid-template-columns: 1fr; }
  .brand{ align-items: center; }
  .theme-btn{ padding:7px 9px; }
}