:root {
  --background: #ffffff;
  --foreground: #09090b;
  --card: #ffffff;
  --card-foreground: #09090b;
  --popover: #ffffff;
  --popover-foreground: #09090b;
  --primary: #18181b;
  --primary-foreground: #fafafa;
  --secondary: #f4f4f5;
  --secondary-foreground: #18181b;
  --muted: #f4f4f5;
  --muted-foreground: #71717a;
  --accent: #f4f4f5;
  --accent-foreground: #18181b;
  --destructive: #ef4444;
  --destructive-foreground: #fafafa;
  --border: #e4e4e7;
  --input: #e4e4e7;
  --ring: #18181b;
  --radius: 0.5rem;

  --success-bg: #dcfce7;
  --success-text: #166534;
  --error-bg: #fee2e2;
  --error-text: #991b1b;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--background);
  color: var(--foreground);
  font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  line-height: 1.5;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  margin-bottom: 0.5rem;
}

p {
  margin-bottom: 1rem;
}

.text-muted {
  color: var(--muted-foreground);
  font-size: 0.875rem;
}

.app-shell {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 2rem 1rem;
}

.shell {
  width: 100%;
  max-width: 32rem;
  margin: 0 auto;
}

.workspace-stack, .share-stage {
  width: 100%;
}

.panel {
  background-color: var(--card);
  color: var(--card-foreground);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

.form-deck {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.section-heading {
  margin-bottom: 1.5rem;
}

.section-heading-compact {
  margin-bottom: 1.5rem;
  text-align: center;
}

.switcher {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.switcher-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  background-color: var(--secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--card-foreground);
  font-weight: 500;
  font-size: 0.875rem;
}

.switcher-btn:hover {
  background-color: #e4e4e7;
}

.switcher-btn.active {
  border-color: var(--primary);
  background-color: var(--accent);
}

.switcher-label {
  font-weight: 500;
  font-size: 0.875rem;
}

.switcher-meta {
  font-size: 0.75rem;
  color: var(--muted-foreground);
}

.algorithm-panel {
  display: none;
}

.algorithm-panel.is-active {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.field span {
  font-size: 0.875rem;
  font-weight: 500;
  display: block;
  margin-bottom: 0.5rem;
}

input[type="text"] {
  display: flex;
  height: 2.5rem;
  width: 100%;
  border-radius: var(--radius);
  border: 2px solid var(--input);
  background-color: transparent;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  color: var(--foreground);
  transition: border-color 0.2s ease;
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--background), 0 0 0 4px var(--ring);
}

input[type="text"]::placeholder {
  color: var(--muted-foreground);
}

.inline-note {
  margin-top: 0.25rem;
  margin-bottom: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 500;
  height: 3rem;
  padding: 0 1.5rem;
  cursor: pointer;
  transition: background-color 0.2s;
  border: 2px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--primary-foreground);
  border-color: var(--primary);
}

.btn-primary:hover {
  background-color: #27272a;
  border-color: #27272a;
}

.btn-secondary {
  background-color: var(--secondary);
  color: var(--secondary-foreground);
  border-color: var(--border);
}

.btn-secondary:hover {
  background-color: #e4e4e7;
}

.w-full {
  width: 100%;
}

.submit-row {
  display: flex;
  justify-content: flex-end;
  margin-top: 0.5rem;
}

.code-stage {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.code-frame {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 2.5rem 1rem;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background-color: var(--card);
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

.code-frame:hover {
  border-color: var(--primary);
}

.code-frame.is-urgent {
  border-color: #fca5a5;
  box-shadow: 0 10px 15px -3px rgb(239 68 68 / 0.1), 0 4px 6px -4px rgb(239 68 68 / 0.1);
}

.code-frame.is-urgent:hover {
  border-color: var(--destructive);
}

.code-countdown {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background-color: var(--secondary);
  color: var(--secondary-foreground);
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius);
  border: 2px solid var(--border);
}

.code-frame.is-urgent .code-countdown {
  background-color: var(--error-bg);
  color: var(--error-text);
  border-color: #fca5a5;
}

.otp-code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--foreground);
}

.code-frame.is-urgent .otp-code {
  color: var(--destructive);
}

.pulse-strip {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--muted-foreground);
}

.pulse-dot {
  width: 0.5rem;
  height: 0.5rem;
  background-color: #22c55e;
  border-radius: 50%;
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: .5;
  }
}

.share-actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

#share-url {
  text-align: center;
  background-color: var(--secondary);
  border-color: var(--border);
  border-width: 2px;
  margin-bottom: 0.25rem;
}

.feedback {
  font-size: 0.875rem;
  min-height: 1.25rem;
  text-align: center;
  margin-top: 0.5rem;
}

.feedback.error {
  color: var(--destructive);
}

.toast {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1.25rem;
  background-color: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  z-index: 50;
  transition: opacity 0.3s ease;
  opacity: 0;
  pointer-events: none;
}

.toast:not([hidden]) {
  opacity: 1;
}

.toast[data-tone="success"] {
  background-color: var(--success-bg);
  border-color: #86efac;
  color: var(--success-text);
}

.toast[data-tone="error"] {
  background-color: var(--error-bg);
  border-color: #fca5a5;
  color: var(--error-text);
}

.toast-symbol {
  font-weight: bold;
}

.toast[hidden] {
  display: none !important;
}

.toast.is-visible {
  opacity: 1;
}

@media (max-width: 480px) {
  .switcher {
    grid-template-columns: 1fr;
  }
  .otp-code {
    font-size: 2.25rem;
  }
  .panel {
    padding: 1.5rem;
  }
}