:root {
  color-scheme: light;
  --bg: #f4f5f7;
  --card-bg: #ffffff;
  --text: #1a1d23;
  --text-muted: #6b7280;
  --border: #e3e5e9;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-contrast: #ffffff;
  --success-bg: #ecfdf3;
  --success-text: #067647;
  --success-border: #abefc6;
  --error-bg: #fef3f2;
  --error-text: #b42318;
  --error-border: #fecdca;
  --radius: 12px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.page {
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 32px 16px;
}

.card {
  width: 100%;
  max-width: 480px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.card__header h1 {
  margin: 0 0 4px;
  font-size: 1.5rem;
}

.subtitle {
  margin: 0 0 20px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.signup-form {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.signup-form input {
  flex: 1 1 200px;
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  color: var(--text);
  background: var(--card-bg);
}

.signup-form input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.signup-form button {
  padding: 10px 18px;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-contrast);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease;
  flex: 0 0 auto;
}

.signup-form button:hover:not(:disabled) {
  background: var(--accent-hover);
}

.signup-form button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.form-message {
  min-height: 1.25em;
  margin: 10px 0 0;
  font-size: 0.9rem;
}

.form-message[data-state="error"] {
  color: var(--error-text);
}

.form-message[data-state="success"] {
  color: var(--success-text);
}

.roster {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.roster__header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.roster__header h2 {
  margin: 0;
  font-size: 1.05rem;
}

.roster__count {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.roster-status {
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.roster-status[data-state="error"] {
  color: var(--error-text);
}

.roster-list {
  list-style: none;
  margin: 10px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.roster-list li {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fafafa;
  font-size: 0.95rem;
  word-break: break-word;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 380px) {
  .signup-form {
    flex-direction: column;
  }

  .signup-form input {
    flex: 0 1 auto;
    width: 100%;
  }

  .signup-form button {
    flex: 0 1 auto;
    width: 100%;
  }
}

.demo-banner {
  margin: 0 0 16px;
  padding: 8px 12px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.875rem;
}