:root {
  --bg: #0f1115;
  --card: rgba(20, 22, 28, 0.78);
  --card-border: rgba(255, 255, 255, 0.08);
  --text: #e8eaed;
  --text-dim: rgba(255, 255, 255, 0.6);
  --text-faint: rgba(255, 255, 255, 0.35);
  --accent: #5b8def;
  --accent-2: #8b5cf6;
  --err: #f87171;
  --ok: #4ade80;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', sans-serif;
  overflow: hidden;
}

#bg-layer {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
#bg-layer .bg-gradient {
  position: absolute;
  inset: -10%;
  background:
    radial-gradient(60vmax 60vmax at 25% 30%, rgba(91, 141, 239, 0.25), transparent 70%),
    radial-gradient(60vmax 60vmax at 75% 70%, rgba(139, 92, 246, 0.22), transparent 70%),
    linear-gradient(180deg, #0a0c10 0%, #0f1115 100%);
  animation: bgshift 24s ease-in-out infinite alternate;
}
@keyframes bgshift {
  from { transform: scale(1) translate(0, 0); }
  to { transform: scale(1.08) translate(-3%, 2%); }
}
#bg-layer video,
#bg-layer img {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  width: 100vw;
  height: 100vh;
  object-fit: cover;
  object-position: center center;
  opacity: 0;
  transition: opacity 0.8s ease;
  will-change: opacity;
  transform: translate3d(0, 0, 0);
}
#bg-layer.has-media video,
#bg-layer.has-media img {
  opacity: 1;
}
#bg-layer.has-media::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(120vmax 120vmax at 50% 50%, transparent 0%, rgba(15, 17, 21, 0.55) 60%, rgba(15, 17, 21, 0.85) 100%),
    linear-gradient(180deg, rgba(0,0,0,0.35) 0%, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.6) 100%);
  pointer-events: none;
}

.card {
  position: relative;
  z-index: 1;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card-inner {
  width: 100%;
  max-width: 420px;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 32px 28px;
  backdrop-filter: blur(28px) saturate(140%);
  -webkit-backdrop-filter: blur(28px) saturate(140%);
  box-shadow:
    0 32px 80px rgba(0, 0, 0, 0.55),
    0 8px 24px rgba(0, 0, 0, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
  animation: card-in 0.5s cubic-bezier(0.2, 0.9, 0.3, 1.2);
}
@keyframes card-in {
  from { opacity: 0; transform: translateY(16px) scale(0.96); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 28px;
}
.brand h1 {
  margin: 0;
  font-size: 22px;
  letter-spacing: 0.2px;
}
.brand-sub {
  margin: 2px 0 0;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.4px;
  color: var(--text-faint);
}
.brand-logo {
  filter: drop-shadow(0 6px 16px rgba(91, 141, 239, 0.35));
}

.prompt {
  margin: 0 0 16px;
  font-size: 13px;
  color: var(--text-dim);
}

.otp-row {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
  margin-bottom: 18px;
}
.otp {
  width: 100%;
  height: 54px;
  text-align: center;
  font-size: 22px;
  font-family: ui-monospace, SF Mono, Menlo, monospace;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.15s ease, background 0.15s ease, transform 0.1s ease;
}
.otp:focus {
  border-color: var(--accent);
  background: rgba(91, 141, 239, 0.08);
  box-shadow: 0 0 0 3px rgba(91, 141, 239, 0.18);
}
.otp.filled { background: rgba(91, 141, 239, 0.12); border-color: rgba(91, 141, 239, 0.5); }
.otp.error { border-color: var(--err); background: rgba(248, 113, 113, 0.08); animation: shake 0.4s ease; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  20% { transform: translateX(-4px); }
  40% { transform: translateX(4px); }
  60% { transform: translateX(-2px); }
  80% { transform: translateX(2px); }
}

#submit {
  position: relative;
  width: 100%;
  padding: 13px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  border: 0;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.2px;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.2s ease, opacity 0.15s ease;
}
#submit:hover { box-shadow: 0 8px 24px rgba(91, 141, 239, 0.4); }
#submit:active { transform: scale(0.99); }
#submit[disabled] { opacity: 0.6; cursor: not-allowed; }
#submit.loading .label { opacity: 0; }
#submit .spinner {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  opacity: 0;
  animation: spin 0.7s linear infinite;
}
#submit.loading .spinner { opacity: 1; }
@keyframes spin { to { transform: rotate(360deg); } }

.error {
  margin-top: 12px;
  font-size: 12px;
  color: var(--err);
  min-height: 16px;
  text-align: center;
  opacity: 0;
  transition: opacity 0.15s ease;
}
.error.visible { opacity: 1; }

footer {
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.4px;
  color: var(--text-faint);
}
.muted { opacity: 0.5; }