/* ---------- Base ---------- */
* {
  box-sizing: border-box;
  margin: 0;
}

body {
  min-width: 320px;
  background: #09090b;
  color: #f8fafc;
  font-family: Poppins, sans-serif;
}

.backdrop {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 55% 55% at 75% 40%, #3b82f625, transparent),
    radial-gradient(ellipse 40% 38% at 18% 85%, #8b5cf61d, transparent),
    linear-gradient(#fff5 1px, transparent 1px),
    linear-gradient(90deg, #fff5 1px, transparent 1px);
  background-size: auto, auto, 42px 42px, 42px 42px;
}

header,
section {
  width: min(calc(100% - 48px), 1080px);
  margin-inline: auto;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 84px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: inherit;
  font-weight: 700;
  text-decoration: none;
}

.brand img {
  filter: drop-shadow(0 0 8px #3b82f680);
}

header > a:last-child {
  color: #94a3b8;
  font-size: 0.78rem;
  text-decoration: none;
}

section {
  display: grid;
  grid-template-columns: 0.82fr 1.18fr;
  align-items: center;
  gap: 75px;
  min-height: calc(100vh - 150px);
  margin-top: 20px;
  margin-bottom: 48px;
}

/* ---------- Introduction ---------- */
.intro > p,
.heading small,
.success small {
  color: #9bbefb;
  font: 10px "JetBrains Mono", monospace;
  letter-spacing: 0.12em;
}

.intro h1 {
  margin: 20px 0;
  font-size: clamp(2.8rem, 5vw, 4.4rem);
  letter-spacing: -0.07em;
  line-height: 1.08;
}

.intro h1 em {
  color: transparent;
  font-style: normal;
  background: linear-gradient(100deg, #60a5fa, #a78bfa);
  background-clip: text;
  -webkit-background-clip: text;
}

.intro > span {
  display: block;
  max-width: 330px;
  color: #94a3b8;
  font-size: 0.9rem;
  line-height: 1.8;
}

/* ---------- Form ---------- */
.card {
  padding: 39px;
  border: 1px solid #94a3b833;
  border-radius: 20px;
  background: linear-gradient(135deg, #fff1, #fff000);
  box-shadow: 0 30px 70px #0005;
}

.heading h2,
.success h2 {
  margin-top: 10px;
  font-size: 1.55rem;
  letter-spacing: -0.05em;
}

.heading p {
  margin-top: 5px;
  color: #94a3b8;
  font-size: 0.8rem;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-top: 29px;
}

.student-id {
  grid-column: span 2;
}

label {
  display: block;
  color: #dce5f4;
  font-size: 0.72rem;
  font-weight: 500;
}

label span {
  color: #758398;
  font-weight: 400;
}

input,
select,
textarea {
  display: block;
  width: 100%;
  margin-top: 7px;
  padding: 11px 12px;
  border: 1px solid #94a3b838;
  border-radius: 9px;
  outline: 0;
  background: #09090b99;
  color: #f8fafc;
  font: inherit;
  font-size: 0.78rem;
}

select option { background: #18181b; }
textarea { resize: vertical; }

input:focus,
select:focus,
textarea:focus {
  border-color: #5794f7;
  box-shadow: 0 0 0 3px #3b82f61a;
}

label i {
  display: block;
  min-height: 13px;
  margin-top: 4px;
  color: #758398;
  font: 9px "JetBrains Mono", monospace;
  font-style: normal;
}

.invalid input,
.invalid select { border-color: #fb7185; }
.invalid i { color: #fda4af; }
.full { margin-top: 18px; }

button,
.success a {
  display: block;
  width: 100%;
  margin-top: 25px;
  padding: 13px;
  border: 0;
  border-radius: 10px;
  background: linear-gradient(105deg, #3b82f6, #7462e4);
  box-shadow: 0 10px 24px #3b82f63b;
  color: #fff;
  font-size: 0.83rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}

.note {
  margin-top: 12px;
  color: #65738a;
  font-size: 0.65rem;
  text-align: center;
}

.success {
  padding: 42px 10px 12px;
  text-align: center;
}

.success[hidden] { display: none; }

.success > b {
  display: grid;
  place-items: center;
  width: 60px;
  height: 60px;
  margin: 0 auto 22px;
  border: 1px solid #4ade8088;
  border-radius: 50%;
  background: #22c55e22;
  color: #86efac;
  font-size: 27px;
}

.success > p {
  max-width: 330px;
  margin: 13px auto 20px;
  color: #94a3b8;
  font-size: 0.83rem;
  line-height: 1.75;
}

footer {
  padding: 22px;
  border-top: 1px solid #94a3b833;
  color: #65738a;
  font-size: 0.65rem;
  text-align: center;
}

@media (max-width: 800px) {
  section {
    max-width: 580px;
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .intro { text-align: center; }
  .intro > span { margin-inline: auto; }
}

@media (max-width: 520px) {
  header,
  section { width: calc(100% - 34px); }

  header { height: 70px; }
  .card { padding: 25px 18px; }
  .grid { grid-template-columns: 1fr; gap: 9px; }
  .student-id { grid-column: auto; }
  .full { margin-top: 9px; }
}