:root {
  --bg: #f5f3ee;
  --bg-quiet: #ece9e1;
  --surface: rgba(255, 254, 250, 0.94);
  --surface-plain: #fffefa;
  --surface-muted: #f4f0e7;
  --surface-ink: #202722;
  --text-main: #202722;
  --text-muted: #68726b;
  --brand: #24725f;
  --brand-strong: #155341;
  --brand-soft: rgba(36, 114, 95, 0.11);
  --accent: #b86a3c;
  --accent-soft: rgba(184, 106, 60, 0.12);
  --danger: #b3382e;
  --line: rgba(32, 39, 34, 0.12);
  --line-strong: rgba(32, 39, 34, 0.2);
  --shadow-sm: 0 2px 10px rgba(32, 39, 34, 0.06);
  --shadow: 0 16px 40px rgba(32, 39, 34, 0.1);
  --shadow-lg: 0 28px 70px rgba(32, 39, 34, 0.16);
  --radius-xl: 24px;
  --radius-lg: 16px;
  --radius-md: 10px;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html { background: var(--bg); color: var(--text-main); }

body {
  margin: 0;
  height: 100vh;
  overflow: hidden;
  color: var(--text-main);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    linear-gradient(90deg, rgba(32, 39, 34, 0.035) 1px, transparent 1px),
    linear-gradient(0deg, rgba(32, 39, 34, 0.03) 1px, transparent 1px),
    linear-gradient(135deg, #f7f5ef 0%, #ece8dd 48%, #f5f2e9 100%);
  background-size: 36px 36px, 36px 36px, auto;
  padding: 20px 16px 10px;
}

button, input, textarea, select { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: 0.62; }
img { display: block; max-width: 100%; }
a { color: var(--brand); }

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

:where(button, a, input, textarea, select, [tabindex]):focus-visible {
  outline: 3px solid #d2783f;
  outline-offset: 3px;
  box-shadow: 0 0 0 2px var(--surface-plain);
}

.ambient { display: none; }

.eyebrow {
  margin: 0 0 8px;
  color: var(--brand);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.subtitle {
  margin: 6px 0 0;
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.65;
}

.small-label,
.panel-meta,
.mini-line {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.84rem;
  line-height: 1.55;
}

.rich-text {
  overflow-wrap: anywhere;
  white-space: pre-wrap;
  line-height: 1.7;
}

.katex-display {
  margin: 0.2em 0;
  overflow-x: auto;
  overflow-y: hidden;
}

.primary-button,
.ghost-button,
.chip,
.nav-item,
.review-btn {
  min-height: 40px;
  border-radius: 999px;
  transition:
    color 180ms var(--ease-out),
    background 180ms var(--ease-out),
    border-color 180ms var(--ease-out),
    box-shadow 180ms var(--ease-out),
    transform 140ms var(--ease-out);
}

.primary-button {
  border: 1px solid var(--brand-strong);
  padding: 10px 18px;
  color: #fffefa;
  font-weight: 800;
  background: var(--brand-strong);
  box-shadow: 0 10px 24px rgba(21, 83, 65, 0.18);
}

.primary-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px rgba(21, 83, 65, 0.22);
}

.ghost-button,
.chip,
.nav-item {
  border: 1px solid var(--line);
  padding: 9px 15px;
  color: var(--brand-strong);
  background: rgba(255, 254, 250, 0.72);
}

.ghost-button:hover,
.chip:hover {
  border-color: var(--line-strong);
  background: var(--surface-plain);
  transform: translateY(-1px);
}

.danger-button {
  color: var(--danger);
  border-color: rgba(179, 56, 46, 0.26);
  background: rgba(179, 56, 46, 0.07);
}

.badge {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  min-height: 26px;
  border: 1px solid rgba(36, 114, 95, 0.14);
  border-radius: 999px;
  padding: 4px 10px;
  color: var(--brand-strong);
  font-size: 0.78rem;
  font-weight: 700;
  background: var(--brand-soft);
}

.badge.soft {
  color: var(--text-muted);
  border-color: var(--line);
  background: rgba(255, 254, 250, 0.68);
}

.badge.warn,
.badge.danger {
  color: var(--danger);
  border-color: rgba(179, 56, 46, 0.22);
  background: rgba(179, 56, 46, 0.08);
}

.toolbar,
.card-actions,
.settings-actions,
.review-actions,
.badge-row,
.pager-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  min-width: 0;
}

.panel,
.upload-card,
.auth-card,
.section-block,
.mistake-card,
.review-card,
.stats-card,
.flash-card {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.panel,
.upload-card {
  padding: 16px;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  min-width: 0;
}

.panel-header h2,
.panel-header h3,
.detail-modal-header h2 {
  margin: 0;
  color: var(--surface-ink);
  letter-spacing: 0;
}

.empty-state {
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--text-muted);
}

.settings-form,
.edit-form,
.auth-form {
  display: grid;
  gap: 14px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.settings-form label,
.edit-form label,
.auth-form label {
  display: grid;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.settings-form input,
.edit-form input,
.edit-form textarea,
.edit-form select,
.auth-form input,
.editable-control,
.prompt-input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 12px;
  color: var(--text-main);
  background: var(--surface-plain);
}

.settings-form input:focus,
.edit-form input:focus,
.edit-form textarea:focus,
.edit-form select:focus,
.auth-form input:focus,
.editable-control:focus,
.prompt-input:focus {
  outline: none;
  border-color: rgba(36, 114, 95, 0.7);
  box-shadow: 0 0 0 3px rgba(36, 114, 95, 0.12);
}

.edit-form textarea { min-height: 86px; resize: vertical; }

.auth-code-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
}

.auth-card {
  width: min(420px, 100%);
  margin: 0 auto;
  padding: 30px 26px 24px;
  display: grid;
  gap: 20px;
}

.auth-header { text-align: center; }
.auth-header h1 { margin: 0 0 8px; color: var(--brand-strong); font-size: 1.55rem; }
.auth-form .primary-button { width: 100%; min-height: 44px; }

.auth-code-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
}

.auth-code-row input {
  text-align: center;
  letter-spacing: 0.26em;
  font-size: 1.08rem;
}

.auth-switch,
.auth-msg {
  margin: 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.86rem;
}

.auth-msg {
  padding: 8px 12px;
  border-radius: 10px;
  background: rgba(32, 39, 34, 0.04);
}

.link-button {
  border: 0;
  background: none;
  color: var(--brand);
  text-decoration: underline;
}

@media (max-width: 640px) {
  body {
    height: auto;
    min-height: 100vh;
    overflow: auto;
    padding: max(10px, env(safe-area-inset-top)) max(8px, env(safe-area-inset-right)) calc(148px + env(safe-area-inset-bottom)) max(8px, env(safe-area-inset-left));
  }

  .panel,
  .upload-card,
  .section-block,
  .mistake-card,
  .review-card,
  .stats-card,
  .flash-card {
    border-radius: var(--radius-md);
  }

  .form-grid { grid-template-columns: 1fr; }
  .auth-card { padding: 24px 18px 18px; }
}


@media (pointer: coarse) {
  :where(button, .upload-mode-tab, .folder-more, .folder-context-menu button) {
    min-width: 44px;
    min-height: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}