*{margin:0;padding:0;box-sizing:border-box}
:root{
  --brand:#009fe3;
  --brand-2:#00b4ff;
  --ink:#1f2d3d;
  --muted:#7a8ca2;
  --card:#ffffff;
  --bg:#0ea5e9;
}

html,body{height:100%}
body{
  min-height:100vh;
  background: linear-gradient(180deg,var(--brand-2),var(--brand));
  display:flex;align-items:center;justify-content:center;
  color:var(--ink);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'Apple Color Emoji','Segoe UI Emoji', sans-serif;
  overflow-x:hidden;
}

/* floating skyline footer effect */
.footer-silhouette{
  position:fixed;left:0;right:0;bottom:0;height:110px;
  background: radial-gradient(1200px 120px at 50% 100%, rgba(255,255,255,.18), transparent 70%);
  pointer-events:none;
  filter: blur(0.3px);
}

/* container */
.wrapper{
  width:min(1200px,96vw);
  margin:24px;
  position:relative;
}
.card{
  display:grid;
  grid-template-columns: 1.15fr 0.85fr;
  background:var(--card);
  border-radius:16px;
  box-shadow: 0 24px 60px rgba(2,32,71,.25);
  overflow:hidden;
}

/* left form panel */
.form-pane{
  padding:42px clamp(24px,5vw,56px);
  position:relative;
}
.brand-row{display:flex;align-items:center;gap:12px;margin-bottom:18px}
.brand-row img{width:34px;height:34px}
.brand-title{font-weight:800;letter-spacing:.4px;color:var(--brand);font-size:22px;text-shadow:0 1px 2px rgba(0,0,0,.06)}

h1{font-size:26px;margin:6px 0 18px 0}
.helper{color:var(--muted);font-size:14px;margin-bottom:18px}

.form-group{margin-top:14px}
label{display:block;font-weight:600;font-size:14px;margin-bottom:6px}
.input{
  width:100%;
  border:1px solid #d6e3f0;
  background:#fbfdff;
  padding:12px 14px;
  border-radius:10px;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
.input:hover{border-color:#b9d2ea}
.input:focus{
  outline:none;
  border-color:var(--brand);
  box-shadow:0 0 0 4px rgba(0,159,227,.15);
}

/* visited example */
a:visited{color:#0b74b8}

.row{display:flex;gap:12px;align-items:center;justify-content:space-between;margin-top:10px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}

.btn{
  width:100%;padding:12px 16px;border:none;border-radius:10px;
  background: linear-gradient(90deg,var(--brand),var(--brand-2));
  color:white;font-weight:700;letter-spacing:.5px;cursor:pointer;
  transition: transform .15s ease, box-shadow .2s ease, filter .2s ease;
  box-shadow:0 10px 18px rgba(0,159,227,.35);
}
.btn:hover{transform:translateY(-1px) scale(1.02)}
.btn:active{transform:translateY(0) scale(.98);filter:brightness(.98)}

.divider{height:1px;background:#e6eef6;margin:16px 0;position:relative}
.divider::before{content:'or sign in with';position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);background:#fff;padding:0 10px;color:#90a4b7;font-size:12px}

.sso{display:grid;gap:10px}
.sso button{
  background:#fff;border:1px solid #d6e3f0;color:#2b3b4c;font-weight:600;
  padding:10px 14px;border-radius:10px;cursor:pointer;transition:transform .15s, box-shadow .2s;
}
.sso button:hover{transform:translateY(-1px);box-shadow:0 6px 12px rgba(2,32,71,.08)}

/* right promo panel */
.promo{
  position:relative;display:flex;align-items:center;justify-content:center;
  background: radial-gradient(140% 140% at 100% -20%, rgba(255,255,255,.15), transparent 60%),
              radial-gradient(120% 120% at -10% 0%, rgba(255,255,255,.12), transparent 50%),
              linear-gradient(180deg,var(--brand),var(--brand-2));
}
.promo::before{
  content:"";position:absolute;inset:0;
  background:url('assets/planes.svg') center top/cover no-repeat;
  opacity:.55;pointer-events:none;
  animation: slide 16s linear infinite;
}
@keyframes slide{
  0%{background-position: -20% 0}
  100%{background-position: 120% 0}
}

.promo-inner{padding:28px;color:#fff;text-align:left;max-width:440px}
.promo h2{font-size:28px;line-height:1.25;margin-bottom:10px;text-shadow:0 2px 8px rgba(0,0,0,.2)}
.promo p{opacity:.95}
.hero{
  width:min(360px,70%);display:block;margin:12px auto 0;
  border-radius:16px;box-shadow:0 18px 40px rgba(0,0,0,.35);
  animation: float 5s ease-in-out infinite;
  filter: saturate(1.05) contrast(1.02);
}
@keyframes float{0%{transform:translateY(0)}50%{transform:translateY(-10px)}100%{transform:translateY(0)}}

/* error shake */
.alert{
  display:none;margin:8px 0 4px 0;padding:10px 12px;border-radius:10px;
  background:#ffe8e8;color:#9a1a1a;border:1px solid #f6b3b3;
}
.alert.show{display:block;animation:shake .35s ease}
@keyframes shake{
  10%,90%{transform:translateX(-2px)}
  20%,80%{transform:translateX(4px)}
  30%,50%,70%{transform:translateX(-6px)}
  40%,60%{transform:translateX(6px)}
}

/* responsiveness */
@media (max-width: 980px){
  .card{grid-template-columns: 1fr}
  .promo{order:-1;min-height:300px}
  .promo-inner{max-width:600px;text-align:center}
}
@media (max-width: 420px){
  .brand-title{font-size:20px}
  h1{font-size:22px}
}