:root {
  --bso-paper: #f3eee4;
  --bso-paper-deep: #e7dfd0;
  --bso-surface: #fffdf8;
  --bso-ink: #1c2430;
  --bso-ink-soft: #5b6573;
  --bso-sage: #2f6f5e;
  --bso-sage-deep: #245748;
  --bso-terracotta: #b85c38;
  --bso-highlight: #f4d35e;
  --bso-line: #d8cfbe;
  --bso-danger: #9b2c2c;
  --bso-pen: #1c2430;
  --bso-shadow-sm: 0 4px 12px rgba(28, 36, 48, 0.05);
  --bso-shadow-md: 0 10px 25px rgba(28, 36, 48, 0.06);
  --bso-radius: 10px;
  --bso-space-1: 8px;
  --bso-space-2: 16px;
  --bso-space-3: 24px;
  --bso-space-4: 32px;
  --bso-z-base: 10;
  --bso-z-bar: 50;
  --bso-z-modal: 100;
  --bso-z-toast: 9999;
  --bso-font: "Segoe UI", "Helvetica Neue", system-ui, sans-serif;
  --bso-serif: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, serif;
}

[data-theme="dark"] {
  --bso-paper: #161b22;
  --bso-paper-deep: #10141a;
  --bso-surface: #1e252f;
  --bso-ink: #f3eee4;
  --bso-ink-soft: #b7c0cc;
  --bso-sage: #7dbaa6;
  --bso-sage-deep: #5e9a88;
  --bso-terracotta: #e08a66;
  --bso-highlight: #e6c04a;
  --bso-line: #2c3542;
  --bso-danger: #e07070;
  --bso-pen: #f3eee4;
  --bso-shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.18);
  --bso-shadow-md: 0 10px 25px rgba(0, 0, 0, 0.22);
}

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

html,
body {
  margin: 0;
  min-height: 100%;
  min-height: 100dvh;
  min-height: -webkit-fill-available;
  background: var(--bso-paper);
  color: var(--bso-ink);
  font-family: var(--bso-font);
  font-size: clamp(16px, 1.35vw, 18px);
  line-height: 1.55;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

button,
input {
  font: inherit;
}

button {
  min-height: 48px;
  min-width: 48px;
  cursor: pointer;
  touch-action: manipulation;
}

:focus-visible {
  outline: 2px solid var(--bso-sage);
  outline-offset: 2px;
}

.bso-app {
  min-height: 100dvh;
}

.bso-login {
  display: grid;
  place-items: center;
  min-height: 100dvh;
  padding: var(--bso-space-3);
  background:
    radial-gradient(1200px 500px at 10% -10%, rgba(47, 111, 94, 0.08), transparent 55%),
    var(--bso-paper);
}

.bso-login__card {
  width: min(420px, 100%);
  background: var(--bso-surface);
  border: 1px solid var(--bso-line);
  border-radius: var(--bso-radius);
  box-shadow: var(--bso-shadow-md);
  padding: var(--bso-space-4);
  display: grid;
  gap: var(--bso-space-2);
}

.bso-login__kicker {
  margin: 0;
  color: var(--bso-sage);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.72rem;
  font-weight: 700;
}

.bso-login__title {
  margin: 0;
  font-family: var(--bso-serif);
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.2;
}

.bso-login__lead {
  margin: 0;
  color: var(--bso-ink-soft);
}

.bso-field {
  display: grid;
  gap: 8px;
}

.bso-field__label {
  font-size: 0.85rem;
  font-weight: 600;
}

.bso-field__input {
  height: 48px;
  border: 1px solid var(--bso-line);
  border-radius: 8px;
  padding: 0 var(--bso-space-2);
  background: var(--bso-paper);
  color: var(--bso-ink);
}

.bso-field__input:focus {
  border-color: var(--bso-sage);
}

@media (hover: hover) {
  .bso-field__input:hover {
    border-color: var(--bso-sage);
  }
}

.bso-btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0 var(--bso-space-2);
  background: var(--bso-sage);
  color: #fffdf8;
  font-weight: 600;
  transition: all 0.2s ease-in-out;
}

.bso-btn:focus {
  background: var(--bso-sage-deep);
  box-shadow: var(--bso-shadow-sm);
}

@media (hover: hover) {
  .bso-btn:hover {
    background: var(--bso-sage-deep);
    box-shadow: var(--bso-shadow-sm);
  }

  .bso-btn--ghost:hover {
    background: var(--bso-paper-deep);
    border-color: var(--bso-sage);
  }

  .bso-btn--danger:hover {
    border-color: var(--bso-danger);
  }
}

.bso-btn--ghost {
  background: transparent;
  color: var(--bso-ink);
  border-color: var(--bso-line);
}

.bso-btn--danger {
  background: transparent;
  color: var(--bso-danger);
  border-color: var(--bso-line);
}

.bso-btn--icon {
  width: 48px;
  padding: 0;
}

.bso-btn.is-active {
  border-color: var(--bso-sage);
  box-shadow: var(--bso-shadow-sm);
}

.bso-error {
  margin: 0;
  color: var(--bso-danger);
  min-height: 1.4em;
}

.bso-shell {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100dvh;
}

.bso-topbar {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: var(--bso-space-2);
  padding: max(var(--bso-space-2), env(safe-area-inset-top)) var(--bso-space-3) var(--bso-space-2);
  background: var(--bso-surface);
  border-bottom: 1px solid var(--bso-line);
  z-index: var(--bso-z-bar);
  position: sticky;
  top: 0;
}

.bso-topbar__brand {
  display: grid;
  gap: 2px;
}

.bso-topbar__title {
  margin: 0;
  font-family: var(--bso-serif);
  font-size: 1.25rem;
}

.bso-topbar__meta {
  margin: 0;
  color: var(--bso-ink-soft);
  font-size: 0.85rem;
}

.bso-topbar__actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

.bso-library {
  padding: var(--bso-space-3);
  display: grid;
  gap: var(--bso-space-3);
  align-content: start;
}

.bso-library__head {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--bso-space-2);
  align-items: end;
}

.bso-library__intro h2 {
  margin: 0;
  font-family: var(--bso-serif);
  font-size: 1.7rem;
}

.bso-library__intro p {
  margin: 8px 0 0;
  color: var(--bso-ink-soft);
}

.bso-upload {
  position: relative;
  overflow: hidden;
}

.bso-upload input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.bso-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--bso-space-2);
}

@media (min-width: 1100px) {
  .bso-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.bso-card {
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 8px;
  background: var(--bso-surface);
  border: 1px solid var(--bso-line);
  border-radius: var(--bso-radius);
  box-shadow: var(--bso-shadow-sm);
  padding: var(--bso-space-2);
  min-height: 180px;
}

.bso-card__mark {
  width: 40px;
  height: 48px;
  border-radius: 4px 8px 8px 4px;
  background: linear-gradient(180deg, var(--bso-paper-deep), var(--bso-surface));
  border: 1px solid var(--bso-line);
  box-shadow: inset -8px 0 0 var(--bso-sage);
}

.bso-card__title {
  margin: 0;
  font-weight: 650;
  overflow-wrap: anywhere;
}

.bso-card__meta {
  margin: 0;
  color: var(--bso-ink-soft);
  font-size: 0.85rem;
}

.bso-card__actions {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
}

.bso-empty {
  grid-column: 1 / -1;
  padding: var(--bso-space-4);
  text-align: center;
  border: 1px dashed var(--bso-line);
  border-radius: var(--bso-radius);
  background: var(--bso-surface);
}

.bso-viewer {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100dvh;
  height: 100svh;
  max-height: -webkit-fill-available;
  background: var(--bso-paper-deep);
  overflow: hidden;
}

html.is-viewer,
html.is-viewer body {
  overflow: hidden;
  height: 100%;
  height: 100dvh;
}

.bso-toolbar {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
  padding: max(8px, env(safe-area-inset-top)) var(--bso-space-2) 8px;
  background: var(--bso-surface);
  border-bottom: 1px solid var(--bso-line);
  z-index: var(--bso-z-bar);
  min-height: 56px;
}

.bso-toolbar__group {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  min-width: 0;
}

.bso-toolbar__group::-webkit-scrollbar {
  display: none;
}

.bso-toolbar__status {
  color: var(--bso-ink-soft);
  font-size: 0.82rem;
  white-space: nowrap;
}

.bso-swatch {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  border: 2px solid var(--bso-line);
  padding: 0;
  touch-action: manipulation;
}

.bso-swatch.is-active {
  border-color: var(--bso-sage);
  box-shadow: var(--bso-shadow-sm);
}

.bso-swatch--ink { background: #1c2430; }
.bso-swatch--terra { background: #b85c38; }
.bso-swatch--sage { background: #2f6f5e; }
.bso-swatch--blue { background: #2b6cb0; }
.bso-swatch--red { background: #9b2c2c; }
.bso-swatch--yellow { background: #f4d35e; }

.bso-pages {
  overflow: auto;
  padding: var(--bso-space-2);
  padding-bottom: calc(var(--bso-space-3) + env(safe-area-inset-bottom));
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  touch-action: pan-y;
}

.bso-page {
  position: relative;
  margin: 0 auto var(--bso-space-2);
  background: #fff;
  box-shadow: var(--bso-shadow-md);
  width: min(100%, 1400px);
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
}

.bso-page canvas {
  display: block;
  width: 100%;
  height: auto;
  touch-action: none;
}

.bso-page__ink {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  touch-action: none;
}

.bso-toast {
  position: fixed;
  right: var(--bso-space-2);
  bottom: calc(var(--bso-space-2) + env(safe-area-inset-bottom));
  z-index: var(--bso-z-toast);
  background: var(--bso-ink);
  color: var(--bso-surface);
  padding: 10px 14px;
  border-radius: 8px;
  box-shadow: var(--bso-shadow-md);
}

.bso-range {
  width: 120px;
  height: 44px;
  accent-color: var(--bso-sage);
}

@media (max-width: 834px) {
  .bso-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 600px) {
  .bso-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .bso-library__head,
  .bso-topbar,
  .bso-toolbar {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (pointer: coarse) {
  .bso-login__card {
    width: min(480px, 100%);
    padding: var(--bso-space-4);
  }

  .bso-card {
    min-height: 200px;
    padding: var(--bso-space-3);
  }

  .bso-field__input {
    height: 52px;
    font-size: 16px;
  }
}