.auth-screen {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  grid-template-columns: minmax(260px, 1fr) minmax(360px, 520px);
  align-items: center;
  gap: clamp(30px, 8vw, 130px);
  padding: clamp(30px, 7vw, 110px);
  background:
    linear-gradient(90deg, rgba(7,17,30,.45), #07111e 70%),
    radial-gradient(circle at 18% 44%, #21486c, transparent 32rem),
    #07111e;
}

.auth-brand { display: flex; align-items: center; gap: 16px; font: 28px Impact, sans-serif; letter-spacing: .08em; }
.auth-brand .brand-mark { width: 62px; height: 68px; font-size: 34px; }
.auth-card { background: rgba(16,33,53,.96); border: 1px solid #2b4159; border-radius: 24px; padding: clamp(26px,5vw,46px); box-shadow: 0 30px 80px #0008; }
.auth-card h1 { margin: 0; font: 52px/1 Impact, sans-serif; text-transform: uppercase; letter-spacing: .025em; }
.auth-card>p:not(.eyebrow):not(.auth-message) { color: var(--muted); margin: 12px 0 28px; }
.auth-tabs { display: grid; grid-template-columns: 1fr 1fr; border-bottom: 1px solid var(--line); margin-bottom: 22px; }
.auth-tab { border: 0; border-bottom: 3px solid transparent; padding: 12px; background: transparent; color: var(--muted); font-weight: 850; }
.auth-tab.active { color: white; border-color: var(--red); }
#authForm { display: grid; gap: 15px; }
#authForm label { color: #cbd4df; font-size: 12px; font-weight: 800; }
#authForm input { width: 100%; margin-top: 7px; border: 1px solid var(--line); background: #091625; color: white; border-radius: 12px; padding: 14px; outline: none; }
#authForm input:focus { border-color: var(--blue); box-shadow: 0 0 0 3px #54a8ff22; }
#authSubmit { width: 100%; margin-top: 6px; }
.auth-message { min-height: 22px; font-size: 13px; color: var(--gold); text-align: center; }
.demo-link { display: block; border: 0; background: transparent; color: var(--muted); text-decoration: underline; margin: 6px auto 0; font-size: 12px; }
.week-controls { display: flex; align-items: center; gap: 12px; }
.phase-select { border: 1px solid var(--line); background: var(--card); color: white; border-radius: 11px; padding: 11px 13px; }
.sync-button { margin: 8px 0 16px; }

@media (max-width: 760px) {
  .auth-screen { display: block; overflow-y: auto; padding: 28px 20px; }
  .auth-brand { justify-content: center; margin-bottom: 28px; font-size: 20px; }
  .auth-brand .brand-mark { width: 44px; height: 49px; font-size: 25px; }
  .auth-card { max-width: 480px; margin: auto; }
  .auth-card h1 { font-size: 42px; }
  .week-controls { align-items: flex-end; flex-direction: column; }
  .phase-select { max-width: 180px; }
}