:root {
  --bg: #0b1020;
  --card: #12182b;
  --muted: #98a2b3;
  --text: #e6e9f2;
  --primary: #4f46e5;
  --primary-2: #6366f1;
  --accent: #22c55e;
  --danger: #ef4444;
  --ring: rgba(99, 102, 241, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: radial-gradient(1200px 800px at 80% -10%, #1a2150 0%, transparent 60%),
              radial-gradient(900px 700px at -20% 120%, #0a5d7c 0%, transparent 60%),
              var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, 'Helvetica Neue', Arial;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 520px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.03));
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 24px 22px;
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.35);
}

.header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.logo {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
}

.title {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.sub {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 18px;
}

.otp-wrap {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin: 18px 0 10px;
}

.otp-input {
  width: 48px;
  height: 56px;
  text-align: center;
  font-size: 22px;
  font-weight: 700;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #0f1530;
  color: var(--text);
  outline: none;
  transition: all 0.18s ease;
}

.otp-input:focus {
  border-color: var(--primary-2);
  box-shadow: 0 0 0 4px var(--ring);
}

.prefix {
  user-select: none;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: #a5b4fc;
  background: #0f1530;
  border: 1px dashed rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  padding: 14px 10px;
  margin-right: 8px;
  align-self: center;
}

.actions {
  display: flex;
  gap: 10px;
  margin-top: 16px;
  justify-content: center;
}

.btn {
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #0f1530;
  color: var(--text);
  cursor: pointer;
  font-weight: 600;
  transition: 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.22);
}

.btn-primary {
  background: linear-gradient(90deg, var(--primary), var(--primary-2));
  border: none;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.muted {
  color: var(--muted);
  font-size: 13px;
  text-align: center;
  margin-top: 4px;
}
@media (max-width: 480px){
  .card{
    padding: clamp(16px, 4vw, 24px) clamp(12px, 4vw, 22px);
  }

  /* keep the row centered and inside the card */
  .otp-wrap{
    gap: clamp(6px, 1.5vw, 10px);
    max-width: 100%;
  }

  /* shrink boxes responsively so 6 of them + prefix always fit */
  .otp-input{
    width: clamp(36px, 10vw, 48px);   /* 36–48px depending on screen */
    height: clamp(44px, 11.5vw, 56px);
    font-size: clamp(18px, 5vw, 22px);
    border-radius: 10px;
  }

  /* slimmer prefix on phones */
  .prefix{
    margin-right: clamp(6px, 1.5vw, 8px);
    padding: clamp(8px, 2.5vw, 14px) clamp(8px, 2vw, 10px);
    font-size: clamp(12px, 3.6vw, 16px);
  }
}

/* as a last resort, prevent visual spill while typing (optional) */
.card { overflow: hidden; }

@media (max-width: 360px){
  .otp-input{ width: 36px; height: 44px; }
  .prefix{ padding: 8px 8px; }
}