/* ── Login button (header, right-justified) ─────────────── */
#login-btn {
  background: var(--color-orange);
  color: white;
  border-radius: var(--radius-btn);
  padding: 7px 14px;
  font-size: 11px;
  font-weight: var(--font-weight-medium);
  letter-spacing: 0.5px;
  opacity: 0;
  transition: opacity 0.6s ease 1s, background 0.15s;
  white-space: nowrap;
}

#login-btn.visible {
  opacity: 1;
}

#login-btn:hover {
  background: var(--color-orange-hover);
}

/* ── Auth modal overlay ─────────────────────────────────── */
#auth-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 15, 15, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

#auth-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

#auth-sheet {
  background: var(--color-surface);
  border-radius: 24px 24px 0 0;
  padding: 28px 24px max(32px, env(safe-area-inset-bottom));
  width: 100%;
  max-width: 480px;
  transform: translateY(24px);
  transition: transform 0.3s var(--ease-smooth);
  border-top: 1px solid var(--color-border-subtle);
}

#auth-overlay.open #auth-sheet {
  transform: translateY(0);
}

#auth-sheet-title {
  font-size: 18px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  margin-bottom: 6px;
}

#auth-sheet-subtitle {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 20px;
  line-height: 1.5;
}

#usms-input {
  width: 100%;
  background: var(--color-bg);
  border: 1px solid var(--color-border-subtle);
  border-radius: 12px;
  padding: 14px 16px;
  color: var(--color-text);
  font-size: 16px; /* 16px prevents iOS zoom on focus */
  letter-spacing: 1px;
  margin-bottom: 12px;
  transition: border-color 0.2s;
}

#usms-input:focus {
  border-color: rgba(42, 191, 191, 0.5);
}

#usms-input::placeholder {
  color: var(--color-text-placeholder);
  letter-spacing: 0;
}

#auth-submit-btn {
  width: 100%;
  background: var(--color-teal);
  color: white;
  border-radius: 12px;
  padding: 14px;
  font-size: 15px;
  font-weight: var(--font-weight-medium);
  transition: opacity 0.15s, background 0.15s;
}

#auth-submit-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#auth-error {
  font-size: 12px;
  color: #ff6b6b;
  margin-top: 8px;
  min-height: 18px;
}

#auth-close-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  color: var(--color-text-muted);
  font-size: 20px;
  padding: 4px 8px;
}

#auth-sheet {
  position: relative;
}