/* QR Studio — minimal professional UI */

:root {
  --bg: #f8fafc;
  --bg-elevated: #ffffff;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --danger: #b91c1c;
  --warn-bg: #fffbeb;
  --warn-border: #f59e0b;
  --warn-text: #78350f;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 24px rgba(15, 23, 42, 0.08);
  --font: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Monaco, "Cascadia Code", monospace;
  --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.45);
  --page-gradient-top: #eef2ff;
  --header-bg: rgba(255, 255, 255, 0.85);
  --input-bg: #ffffff;
  --input-focus-border: #93c5fd;
  --surface-muted: #f8fafc;
  --surface-sunken: #f1f5f9;
  --brand-mark-bg: #eff6ff;
  --brand-mark-border: #bfdbfe;
  --btn-primary-fg: #ffffff;
  --btn-secondary-bg: #ffffff;
  --btn-secondary-hover-bg: #f1f5f9;
  --btn-secondary-hover-border: #cbd5e1;
  --btn-ghost-hover-bg: #f1f5f9;
  --btn-pressed-bg: #eff6ff;
  --btn-pressed-border: #93c5fd;
  --value-badge-bg: #f1f5f9;
  --preview-wrap-bg: #f8fafc;
  --history-bg: #ffffff;
  --history-row-border: #f1f5f9;
  --history-btn-bg: #ffffff;
  --history-btn-hover: #f8fafc;
  --trust-bg: #ffffff;
  --code-bg: #f1f5f9;
  --theme-toggle-bg: #f1f5f9;
  --theme-toggle-pressed-shadow: var(--shadow);
}

html[data-site-theme="dark"] {
  color-scheme: dark;
  --bg: #0c1222;
  --bg-elevated: #141b2d;
  --text: #e8edf5;
  --text-muted: #94a3b8;
  --border: #2d3a52;
  --accent: #3b82f6;
  --accent-hover: #60a5fa;
  --danger: #f87171;
  --warn-bg: #2a2410;
  --warn-border: #ca8a04;
  --warn-text: #fcd34d;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.45);
  --shadow-md: 0 4px 24px rgba(0, 0, 0, 0.4);
  --focus-ring: 0 0 0 3px rgba(59, 130, 246, 0.45);
  --page-gradient-top: #15192e;
  --header-bg: rgba(12, 18, 34, 0.92);
  --input-bg: #1a2235;
  --input-focus-border: #60a5fa;
  --surface-muted: #0f1628;
  --surface-sunken: #1a2438;
  --brand-mark-bg: rgba(59, 130, 246, 0.12);
  --brand-mark-border: rgba(96, 165, 250, 0.35);
  --btn-primary-fg: #ffffff;
  --btn-secondary-bg: #1a2235;
  --btn-secondary-hover-bg: #243049;
  --btn-secondary-hover-border: #475569;
  --btn-ghost-hover-bg: #1a2438;
  --btn-pressed-bg: rgba(59, 130, 246, 0.18);
  --btn-pressed-border: #3b82f6;
  --value-badge-bg: #1a2438;
  --preview-wrap-bg: #0f172a;
  --history-bg: #141b2d;
  --history-row-border: #243049;
  --history-btn-bg: #1a2235;
  --history-btn-hover: #243049;
  --trust-bg: #141b2d;
  --code-bg: #1a2438;
  --theme-toggle-bg: #1a2438;
  --theme-toggle-pressed-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--text);
  background: linear-gradient(180deg, var(--page-gradient-top) 0%, var(--bg) 32%);
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0.5rem;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  text-decoration: none;
}

.skip-link:focus {
  left: 0.5rem;
  outline: none;
  box-shadow: var(--focus-ring);
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--header-bg);
  backdrop-filter: blur(8px);
}

.site-header__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
}

.site-header__bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.brand__mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  font-size: 1.25rem;
  color: var(--accent);
  background: var(--brand-mark-bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--brand-mark-border);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem;
  gap: 0.15rem;
  background: var(--theme-toggle-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.theme-toggle__btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: none;
  background: transparent;
  cursor: pointer;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  padding: 0.4rem 0.65rem;
  border-radius: 999px;
  opacity: 0.72;
  transition: opacity 0.15s, background 0.15s, color 0.15s, box-shadow 0.15s;
}

.theme-toggle__btn:hover {
  opacity: 1;
  color: var(--text);
}

.theme-toggle__btn[aria-pressed="true"] {
  opacity: 1;
  color: var(--text);
  background: var(--bg-elevated);
  box-shadow: var(--theme-toggle-pressed-shadow);
}

.theme-toggle__icon {
  font-size: 1.1rem;
  line-height: 1;
}

@media (max-width: 420px) {
  .theme-toggle__label {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }

  .theme-toggle__btn {
    padding: 0.45rem 0.55rem;
  }
}

.brand__title {
  margin: 0;
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand__tagline {
  margin: 0.15rem 0 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem;
}

.layout__grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}

@media (min-width: 900px) {
  .layout__grid {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }

  .panel--preview {
    grid-column: 1 / -1;
  }
}

@media (min-width: 1100px) {
  .layout__grid {
    grid-template-columns: 1fr 1fr 1.05fr;
  }

  .panel--preview {
    grid-column: auto;
  }
}

.panel {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  box-shadow: var(--shadow);
}

.panel__title {
  margin: 0 0 1rem;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.subsection-title {
  margin: 1.25rem 0 0.65rem;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.field {
  margin-bottom: 0.85rem;
}

.field--row {
  display: grid;
  gap: 0.75rem;
}

@media (min-width: 520px) {
  .field--row {
    grid-template-columns: 1fr 1fr;
  }
}

.field--align-end {
  align-items: end;
}

.field label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--text);
}

.optional {
  font-weight: 400;
  color: var(--text-muted);
}

.field__hint {
  margin: 0.35rem 0 0;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.field__hint--tight {
  margin-top: 0.2rem;
  margin-bottom: 0.5rem;
}

.field--checkbox {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.field--checkbox label {
  margin: 0;
  font-weight: 500;
}

input[type="text"],
input[type="url"],
input[type="email"],
input[type="tel"],
input[type="number"],
input[type="password"],
input[type="file"],
select,
textarea {
  width: 100%;
  padding: 0.5rem 0.65rem;
  font-family: inherit;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--input-bg);
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}

textarea {
  resize: vertical;
  min-height: 4rem;
}

input:focus,
select:focus,
textarea:focus,
button:focus-visible {
  outline: none;
  border-color: var(--input-focus-border);
  box-shadow: var(--focus-ring);
}

input[type="color"] {
  height: 2.5rem;
  padding: 0.2rem;
  cursor: pointer;
}

input[type="range"] {
  width: 100%;
}

fieldset.fieldset {
  margin: 1rem 0;
  padding: 0.75rem 1rem 1rem;
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
}

fieldset.fieldset legend {
  padding: 0 0.35rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.button-group--wrap {
  gap: 0.45rem;
}

.button-group--export {
  margin-top: 0.75rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.55rem 0.9rem;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--btn-primary-fg);
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.05s;
}

.button:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.button:active {
  transform: translateY(1px);
}

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

.button--secondary:hover {
  background: var(--btn-secondary-hover-bg);
  border-color: var(--btn-secondary-hover-border);
}

.button--ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: transparent;
  font-weight: 500;
}

.button--ghost:hover {
  background: var(--btn-ghost-hover-bg);
  color: var(--text);
}

.button[aria-pressed="true"] {
  background: var(--btn-pressed-bg);
  border-color: var(--btn-pressed-border);
  color: var(--accent);
}

.content-panel.is-hidden {
  display: none;
}

.color-row {
  display: grid;
  gap: 0.75rem;
}

@media (min-width: 520px) {
  .color-row {
    grid-template-columns: repeat(3, 1fr);
  }
}

.value-badge {
  display: inline-block;
  min-width: 2.5rem;
  padding: 0.15rem 0.4rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  background: var(--value-badge-bg);
  border-radius: 4px;
  text-align: center;
}

.preview-wrap {
  display: flex;
  justify-content: center;
  padding: 1rem;
  background: var(--preview-wrap-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  min-height: 200px;
}

.qr-container {
  display: flex;
  align-items: center;
  justify-content: center;
}

.qr-container canvas,
.qr-container svg {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}

.qr-container .placeholder {
  margin: 0;
  max-width: 22rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.status-banner {
  min-height: 1.25rem;
  margin-bottom: 0.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.alert {
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
  border: 1px solid transparent;
}

.alert--warn {
  background: var(--warn-bg);
  border-color: var(--warn-border);
  color: var(--warn-text);
}

.alert.is-hidden {
  display: none;
}

.meta-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin: 1rem 0 0;
  padding: 0;
}

.meta-list dt {
  margin: 0;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.meta-list dd {
  margin: 0.15rem 0 0;
  font-family: var(--mono);
  font-size: 0.85rem;
}

.history-list {
  list-style: none;
  margin: 0 0 0.75rem;
  padding: 0;
  max-height: 200px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--history-bg);
}

.history-list li {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.5rem 0.65rem;
  font-size: 0.8rem;
  border-bottom: 1px solid var(--history-row-border);
}

.history-list li:last-child {
  border-bottom: none;
}

.history-list button {
  flex-shrink: 0;
  font: inherit;
  font-size: 0.75rem;
  padding: 0.2rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--history-btn-bg);
  color: var(--text);
  cursor: pointer;
}

.history-list button:hover {
  background: var(--history-btn-hover);
}

.history-list .snippet {
  word-break: break-all;
  color: var(--text-muted);
}

.trust {
  margin-top: 2rem;
  padding: 1.25rem 1.35rem;
  background: var(--trust-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
}

.trust h2 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
}

.trust__list {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.trust__list li {
  margin-bottom: 0.5rem;
}

.trust__list strong {
  color: var(--text);
}

.trust code {
  font-family: var(--mono);
  font-size: 0.82rem;
  background: var(--code-bg);
  padding: 0.1rem 0.3rem;
  border-radius: 4px;
}

.site-footer {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1.5rem 2rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
  }
}