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

/* ── Theme tokens: dark (default) ── */
body {
  --bg:                 #111111;
  --card-bg:            #1a1a1a;
  --card-border:        #2a2a2a;
  --text:               #f0ece4;
  --text-muted:         #b0aa9f;
  --text-subtle:        #888;
  --label:              #9a9490;
  --input-bg:           #242424;
  --input-border:       #3a3a3a;
  --input-text:         #f0ece4;
  --input-focus-border: #f9a823;
  --divider:            #2e2e2e;
  --preview-border:     #2e2e2e;
  --btn-bg:             #f9a823;
  --btn-border:         #f9a823;
  --btn-text:           #1a1a1a;
  --btn-hover-bg:       #e6961a;
  --hint:               #9a9490;
  --shadow:             rgba(0, 0, 0, 0.4);
  --toggle-track:       #555;
  --toggle-active:      #f9a823;
}

/* ── Theme tokens: light ── */
body.light {
  --bg:                 #f4f1eb;
  --card-bg:            #fff;
  --card-border:        #e0dcd4;
  --text:               #333;
  --text-muted:         #888;
  --text-subtle:        #555;
  --label:              #aaa;
  --input-bg:           #faf9f7;
  --input-border:       #e0dcd4;
  --input-text:         #333;
  --input-focus-border: #1a3a6b;
  --divider:            #e8e4dd;
  --preview-border:     #f0ece6;
  --btn-bg:             #f9a823;
  --btn-border:         #f9a823;
  --btn-text:           #1a1a1a;
  --btn-hover-bg:       #e6961a;
  --hint:               #aaa;
  --shadow:             rgba(0, 0, 0, 0.06);
  --toggle-track:       #ccc;
  --toggle-active:      #1a3a6b;
}

body {
  font-family: 'Georgia', serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  transition: background 0.2s, color 0.2s;
}

/* ── Page header ── */
.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 680px;
  width: 100%;
  margin-bottom: 1.5rem;
}

.page-title {
  font-family: 'Courier New', monospace;
  font-size: 16px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* ── Pill toggle switch ── */
.theme-switch {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  user-select: none;
}

.theme-switch input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.theme-switch-track {
  position: relative;
  width: 40px;
  height: 22px;
  border-radius: 11px;
  background: var(--toggle-track);
  flex-shrink: 0;
  transition: background 0.2s;
}

.theme-switch input:checked + .theme-switch-track {
  background: var(--toggle-active);
}

.theme-switch-thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
  transition: transform 0.2s;
}

.theme-switch input:checked + .theme-switch-track .theme-switch-thumb {
  transform: translateX(18px);
}

.theme-switch-label {
  font-family: 'Courier New', monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 4px;
  padding: 2.5rem;
  max-width: 680px;
  width: 100%;
  box-shadow: 0 2px 12px var(--shadow);
  transition: background 0.2s, border-color 0.2s;
}

.section-label {
  font-family: 'Courier New', monospace;
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--label);
  margin-bottom: 1rem;
}

/* ── Signature preview wrapper ── */
#signature-preview {
  padding: 1.25rem 0.75rem;
  border: 1px solid var(--preview-border);
  border-radius: 3px;
  margin-bottom: 1.75rem;
  background: #ffffff;
}

.divider {
  border: none;
  border-top: 1px solid var(--divider);
  margin: 1.75rem 0;
}

.instructions {
  font-family: 'Courier New', monospace;
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.instructions strong {
  color: var(--text-subtle);
  font-weight: normal;
}

.btn-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

button {
  font-family: 'Courier New', monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 10px 20px;
  border-radius: 3px;
  cursor: pointer;
  border: 1px solid var(--btn-border);
  background: var(--btn-bg);
  color: var(--btn-text);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

button:hover:not(:disabled) {
  background: var(--btn-hover-bg);
  border-color: var(--text-muted);
}

button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

button.primary {
  background: var(--btn-bg);
  color: var(--btn-text);
  border-color: var(--btn-border);
}

button.primary:hover:not(:disabled) {
  background: var(--btn-hover-bg);
  border-color: var(--btn-hover-bg);
}

#form-hint {
  font-family: 'Courier New', monospace;
  font-size: 14px;
  color: var(--hint);
  margin-top: 0.6rem;
  min-height: 16px;
}

#copy-status {
  font-family: 'Courier New', monospace;
  font-size: 11px;
  color: #4a90d9;
  margin-top: 0.75rem;
  min-height: 18px;
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 20px;
  margin-bottom: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.form-group label {
  font-family: 'Courier New', monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--label);
}

.form-group input {
  font-family: 'Courier New', monospace;
  font-size: 12px;
  padding: 7px 10px;
  border: 1px solid var(--input-border);
  border-radius: 3px;
  color: var(--input-text);
  background: var(--input-bg);
  outline: none;
  transition: border-color 0.15s, background 0.15s;
}

.form-group input:focus {
  border-color: var(--input-focus-border);
  background: var(--card-bg);
}

.form-group.wide {
  grid-column: 1 / -1;
}

.form-group input.invalid {
  border-color: #c0392b;
  background: rgba(192, 57, 43, 0.1);
}

.form-group input.invalid:focus {
  border-color: #c0392b;
}

.field-error {
  font-family: 'Courier New', monospace;
  font-size: 10px;
  color: #c0392b;
  display: none;
}

.field-error.visible {
  display: block;
}