/* ============================================================
   Design tokens — single source of truth (spacing/type/radius/color)
   ============================================================ */
:root {
  /* spacing scale */
  --sp-1: 4px; --sp-2: 8px; --sp-3: 12px; --sp-4: 16px; --sp-5: 24px; --sp-6: 32px;
  /* type scale */
  --fs-xs: 12px; --fs-sm: 14px; --fs-md: 16px; --fs-lg: 18px; --fs-xl: 22px;
  /* radius */
  --r-sm: 8px; --r-md: 12px; --r-lg: 16px; --r-full: 999px;
  /* color */
  --accent: #0f766e;
  --accent-soft: #14b8a6;
  --ox: #b91c1c;
  --lm: #1d4ed8;
  --bg: #f4f5f7;
  --surface: #ffffff;
  --text: #1f2937;
  --text-2: #6b7280;
  --border: #e5e7eb;
  --shadow-1: 0 1px 3px rgba(0,0,0,.08);
  --shadow-2: 0 8px 24px rgba(0,0,0,.14);
  /* layout */
  --topbar-h: 52px;
  --touch: 44px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101317;
    --surface: #1a1e26;
    --text: #e7eaee;
    --text-2: #9aa3af;
    --border: #2b313c;
    --accent: #2dd4bf;
    --accent-soft: #0f766e;
    --shadow-1: 0 1px 3px rgba(0,0,0,.4);
    --shadow-2: 0 8px 24px rgba(0,0,0,.5);
  }
}

/* ============================================================ base */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  font-size: var(--fs-md);
  line-height: 1.5;
  background: var(--bg);
  color: var(--text);
  -webkit-text-size-adjust: 100%;
}
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.hidden { display: none !important; }
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

/* ============================================================ topbar */
.topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; justify-content: space-between;
  padding: calc(var(--sp-2) + env(safe-area-inset-top)) var(--sp-4) var(--sp-2);
  min-height: var(--topbar-h);
  background: var(--accent-soft);
  color: #fff;
}
.brand { display: flex; align-items: center; gap: var(--sp-2); }
.brand img { border-radius: var(--r-sm); }
.brand h1 { font-size: var(--fs-lg); margin: 0; font-weight: 700; letter-spacing: -.01em; }
.brand .plus { opacity: .75; font-weight: 500; }
.topbar-actions { display: flex; gap: var(--sp-2); }
.icon-btn {
  width: 36px; height: 36px; border-radius: var(--r-full);
  border: 1px solid rgba(255,255,255,.45); background: rgba(255,255,255,.08);
  color: #fff; font-size: var(--fs-md); cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background .15s;
}
.icon-btn:hover { background: rgba(255,255,255,.22); }

main { max-width: 1400px; margin: 0 auto; padding: 0 var(--sp-3) var(--sp-6); }

/* ============================================================ search */
.search-wrap {
  position: sticky; top: var(--topbar-h); z-index: 20;
  padding: var(--sp-3) 0 var(--sp-1);
  background: var(--bg);
}
.search-box {
  display: flex; align-items: center; gap: var(--sp-1);
  background: var(--surface);
  border: 1.5px solid var(--border); border-radius: var(--r-md);
  padding: 0 var(--sp-1) 0 var(--sp-3);
  box-shadow: var(--shadow-1);
  transition: border-color .15s;
}
.search-box:focus-within { border-color: var(--accent); }
.search-icon { color: var(--text-2); flex: 0 0 auto; }
#search-input {
  flex: 1; min-width: 0;
  font-size: var(--fs-md); padding: var(--sp-3) var(--sp-1);
  border: none; background: transparent; color: var(--text);
  outline: none;
}
#search-input::placeholder { color: var(--text-2); }
#search-input::-webkit-search-cancel-button { display: none; }
.btn-clear {
  width: 32px; height: 32px; border: none; border-radius: var(--r-full);
  background: var(--bg); color: var(--text-2); font-size: var(--fs-md);
  cursor: pointer; flex: 0 0 auto;
}
.btn-search {
  height: 40px; padding: 0 var(--sp-4);
  border: none; border-radius: var(--r-sm);
  background: var(--accent); color: #fff; cursor: pointer;
  font-weight: 600;
}
@media (prefers-color-scheme: dark) { .btn-search { color: #06251f; } }

.icon-inline {
  width: 32px; height: 32px; flex: 0 0 auto;
  border: none; border-radius: var(--r-full);
  background: transparent; color: var(--text-2);
  font-size: var(--fs-md); cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background .15s, color .15s;
}
.icon-inline:hover:not(:disabled) { background: var(--bg); color: var(--text); }
.icon-inline:disabled { opacity: .4; cursor: default; }
.icon-inline.is-saved { color: #d97706; }

/* ============================================================ topbar vocab badge */
.badge {
  position: absolute; top: -2px; right: -2px;
  min-width: 16px; height: 16px; padding: 0 3px;
  border-radius: var(--r-full); background: #dc2626; color: #fff;
  font-size: 10px; font-weight: 700; line-height: 16px; text-align: center;
}
#btn-vocab { position: relative; }

/* ============================================================ storage banner */
.storage-banner {
  display: flex; align-items: center; gap: var(--sp-3);
  margin-top: var(--sp-2);
  padding: var(--sp-3) var(--sp-4);
  background: #fef3c7; color: #78350f;
  border: 1px solid #fcd34d; border-radius: var(--r-md);
  font-size: var(--fs-sm); line-height: 1.5;
}
@media (prefers-color-scheme: dark) {
  .storage-banner { background: #451a03; color: #fde68a; border-color: #92400e; }
}
.storage-banner span:first-child { flex: 1; }
.storage-banner button {
  flex: 0 0 auto; border: none; background: transparent; color: inherit;
  font-size: var(--fs-lg); line-height: 1; cursor: pointer; padding: var(--sp-1);
}

/* ============================================================ saved words / SRS list */
#vocab-list { display: flex; flex-direction: column; gap: var(--sp-2); margin-top: var(--sp-3); }
.vocab-row {
  display: flex; align-items: center; flex-wrap: wrap; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--border); border-radius: var(--r-md);
}
.vocab-word {
  border: none; background: transparent; color: var(--accent);
  font-weight: 700; font-size: var(--fs-sm); cursor: pointer; padding: 0;
}
.vocab-meta { font-size: var(--fs-xs); color: var(--text-2); flex: 1; }
.vocab-actions { display: flex; gap: var(--sp-1); flex: 0 0 auto; }
.vocab-actions button {
  min-height: 30px; padding: 0 var(--sp-2); border-radius: var(--r-sm);
  font-size: var(--fs-xs); cursor: pointer; border: 1px solid var(--border);
  background: var(--surface); color: var(--text);
}
.vocab-actions button:disabled { opacity: .4; cursor: default; }
.btn-vocab-ok:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.btn-vocab-bad:not(:disabled) { border-color: #dc2626; color: #dc2626; }
.btn-vocab-del { color: var(--text-2); }

.suggestions {
  position: absolute; left: 0; right: 0; margin-top: var(--sp-1);
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-md); overflow: hidden;
  box-shadow: var(--shadow-2);
}
.suggestions div {
  padding: var(--sp-3) var(--sp-4); cursor: pointer;
  border-bottom: 1px solid var(--border);
}
.suggestions div:last-child { border-bottom: none; }
.suggestions div:hover, .suggestions div.active { background: var(--bg); }
.suggestions .sug-more {
  color: var(--accent); font-weight: 600; font-size: var(--fs-sm);
  text-align: center;
}

/* ============================================================ history */
.history { display: flex; align-items: center; gap: var(--sp-2); padding: var(--sp-2) 0 0; flex-wrap: wrap; }
.hist-label { font-size: var(--fs-xs); color: var(--text-2); }
#history-chips { display: flex; gap: var(--sp-1); flex-wrap: wrap; }
#history-chips button {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  border-radius: var(--r-full); padding: var(--sp-1) var(--sp-3);
  font-size: var(--fs-xs); cursor: pointer; min-height: 28px;
}
#history-chips button:hover { border-color: var(--accent); color: var(--accent); }

/* ============================================================ view switch (mobile) */
.view-switch { display: none; }

/* Mobile "Both" scroll cue — hidden on desktop, toggled by setView() */
.both-hint { display: none; text-align: center; }

/* ============================================================ dict panels */
.dict-grid { display: grid; grid-template-columns: 1fr; gap: var(--sp-3); margin-top: var(--sp-3); }
@media (min-width: 900px) {
  .view-switch { display: none; }
  .dict-grid { grid-template-columns: 1fr 1fr; align-items: start; }
  .dict-panel.collapsed { display: none; }
}
@media (max-width: 899.5px) {
  .view-switch {
    display: grid; grid-template-columns: repeat(3, 1fr);
    margin-top: var(--sp-3);
    background: var(--surface); border: 1px solid var(--border);
    border-radius: var(--r-md); padding: 3px; gap: 3px;
  }
  .view-switch button {
    padding: var(--sp-2) var(--sp-1); min-height: 38px;
    border: none; border-radius: var(--r-sm);
    background: transparent; color: var(--text-2);
    cursor: pointer; font-size: var(--fs-sm); font-weight: 600;
  }
  .view-switch button.active { background: var(--accent); color: #fff; }
  @media (prefers-color-scheme: dark) { .view-switch button.active { color: #06251f; } }

  .dict-panel { max-height: 78vh; display: flex; flex-direction: column; }
  .dict-panel .entry-frame { overflow-y: auto; }
  .dict-panel.collapsed { display: none; }
  .both-hint { display: block; }

  /* Touch targets: minimum 44×44px on touch/mobile layouts */
  .icon-btn { width: 44px; height: 44px; }
  .icon-inline, .btn-clear { width: 44px; height: 44px; }
  .btn-search { height: 44px; }
  #search-input { padding: var(--sp-2) var(--sp-1); }
  .view-switch button { min-height: 44px; }
}

.dict-panel {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); overflow: hidden;
  box-shadow: var(--shadow-1);
}
.panel-head {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-3);
  color: #fff; font-weight: 600; font-size: var(--fs-sm);
}
.oxford-head { background: var(--ox); }
.longman-head { background: var(--lm); }
.dict-name {
  flex: 0 1 auto; min-width: 0;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  cursor: help; /* full name + source file shown in tooltip */
}
.dict-status {
  flex: 1 0 auto; font-size: var(--fs-sm); font-weight: 500; opacity: 1;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  text-align: right;
  text-shadow: 0 1px 2px rgba(0,0,0,.4); /* legibility on the red/blue headers */
}
.dict-status.loading::after {
  content: ""; display: inline-block; width: 12px; height: 12px;
  border: 2px solid rgba(255,255,255,.4); border-top-color: #fff;
  border-radius: 50%; margin-left: 6px; vertical-align: -2px;
  animation: spin .7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.panel-toggle, .panel-remove {
  background: transparent; border: none; color: #fff;
  font-size: var(--fs-md); cursor: pointer; padding: var(--sp-1) var(--sp-2);
}
.panel-remove { font-size: var(--fs-sm); opacity: .85; }
.panel-remove:hover { opacity: 1; }

.panel-loader { padding: var(--sp-3); }
.file-row { display: flex; gap: var(--sp-2); flex-wrap: wrap; }
.file-btn {
  display: inline-flex; align-items: center; gap: var(--sp-1);
  padding: var(--sp-2) var(--sp-3); min-height: var(--touch);
  border: 1.5px dashed var(--text-2); border-radius: var(--r-md);
  cursor: pointer; font-size: var(--fs-sm); color: var(--text);
  transition: border-color .15s;
}
.file-btn:hover { border-color: var(--accent); color: var(--accent); }
.file-btn small { color: var(--text-2); }
.hint { font-size: var(--fs-xs); color: var(--text-2); margin: var(--sp-2) 0 0; line-height: 1.5; }

/* Entry content always renders as "paper" (light background, dark text) —
   MDX entries are authored for light backgrounds, so readability is guaranteed
   in both light and dark app themes. */
.entry-frame iframe {
  width: 100%; border: none; display: block;
  min-height: 280px; height: 55vh;
  background: #fff;
  transition: height .12s ease-out;
}

/* ============================================================ full-screen reading view */
body.reading-mode .about,
body.reading-mode .foot,
body.reading-mode .history,
body.reading-mode .storage-banner { display: none; }
body.reading-mode .dict-grid { grid-template-columns: 1fr; }
body.reading-mode .dict-panel { display: none; }
/* Must stay a vertical stack: the panel was block-level in desktop view, and a
   bare `display:flex` here laid head and frame out side-by-side (the "narrow
   strip" bug). */
body.reading-mode .dict-panel.reading {
  display: flex;
  flex-direction: column;
  max-height: none;
  width: 100%;
}
body.reading-mode .dict-panel.reading .entry-frame { overflow-y: visible; width: 100%; }
body.reading-mode .dict-panel.reading .entry-frame iframe { height: calc(100vh - 140px); }

/* ============================================================ empty state */
.empty-state {
  margin-top: var(--sp-5); text-align: center;
  color: var(--text-2); font-size: var(--fs-sm); line-height: 1.7;
  display: flex; flex-direction: column; align-items: center; gap: var(--sp-2);
}
.empty-state strong { color: var(--text); }
.load-error {
  color: #b91c1c; font-weight: 600; max-width: 46ch; margin: 0;
}
@media (prefers-color-scheme: dark) { .load-error { color: #f87171; } }
.btn-secondary {
  padding: var(--sp-2) var(--sp-4); border-radius: var(--r-md);
  border: 1px solid var(--accent); background: transparent; color: var(--accent);
  font-size: var(--fs-sm); cursor: pointer; min-height: var(--touch);
}
.btn-primary {
  padding: var(--sp-3) var(--sp-5); border-radius: var(--r-md); border: none;
  background: var(--accent); color: #fff; font-size: var(--fs-md);
  cursor: pointer; font-weight: 600; min-height: var(--touch);
}
@media (prefers-color-scheme: dark) { .btn-primary { color: #06251f; } }
.btn-primary:disabled { opacity: .6; cursor: wait; }

/* ============================================================ about (SEO copy) */
.about {
  margin-top: var(--sp-6);
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: var(--sp-4);
  font-size: var(--fs-sm); color: var(--text-2); line-height: 1.7;
}
.about h2 { font-size: var(--fs-lg); margin: 0 0 var(--sp-2); color: var(--text); }
.about summary {
  cursor: pointer; color: var(--accent); font-weight: 600;
  padding: var(--sp-2) 0; min-height: var(--touch); display: flex; align-items: center;
}
.about p strong { color: var(--text); font-weight: 600; }
.about ul { padding-left: var(--sp-5); margin: var(--sp-2) 0 0; }
.about li { margin-bottom: var(--sp-1); }

/* ============================================================ footer */
.foot { text-align: center; margin-top: var(--sp-6); font-size: var(--fs-xs); color: var(--text-2); }
.foot p { margin: var(--sp-1) 0; }
.foot a { color: var(--text-2); }
.foot a:hover { color: var(--accent); }
.credits { line-height: 1.7; }

/* --- Buy Me a Coffee (footer, unobtrusive) --- */
.support { margin-top: var(--sp-2); }
.support-note { color: var(--text-2); margin-bottom: 0; }
.support [data-name="bmc-button"] { display: inline-block; }

/* ============================================================ dialog */
dialog {
  border: none; border-radius: var(--r-lg);
  max-width: 560px; width: 92vw; max-height: 84vh; overflow-y: auto;
  padding: var(--sp-5); color: var(--text); background: var(--surface);
}
dialog::backdrop { background: rgba(0,0,0,.5); }
dialog h2 { margin: 0 0 var(--sp-3); font-size: var(--fs-xl); }
dialog h3 { font-size: var(--fs-md); margin: var(--sp-4) 0 var(--sp-1); }
dialog ol, dialog ul { padding-left: var(--sp-5); }
dialog li { margin-bottom: var(--sp-2); line-height: 1.6; font-size: var(--fs-sm); }
dialog a { color: var(--accent); }
dialog code { background: var(--bg); padding: 1px 5px; border-radius: 4px; }

/* Sticky close button — stays visible at the top-right even in a long modal,
   so the user never has to scroll to the bottom to dismiss. */
.dialog-close {
  position: sticky; top: 0; float: right; z-index: 5;
  width: 44px; height: 44px;
  margin: calc(-1 * var(--sp-2)) calc(-1 * var(--sp-2)) 0 var(--sp-2);
  border: none; border-radius: var(--r-full);
  background: transparent; color: var(--text-2);
  font-size: var(--fs-lg); line-height: 1; cursor: pointer;
}
.dialog-close:hover { background: var(--bg); color: var(--text); }

/* Help modal: short quickstart first, long content collapsed */
dialog .quickstart li { font-size: var(--fs-md); margin-bottom: var(--sp-3); }
.help-more { margin-top: var(--sp-3); border-top: 1px solid var(--border); padding-top: var(--sp-2); }
.help-more summary {
  cursor: pointer; color: var(--accent); font-weight: 600;
  min-height: var(--touch); display: flex; align-items: center;
}

/* First-load gate */
.first-load-sizes { margin: 0; color: var(--text-2); text-align: left; }
.first-load-note { margin: 0; }
.license-note {
  font-size: var(--fs-xs); color: var(--text-2);
  background: var(--bg); border-radius: var(--r-sm);
  padding: var(--sp-3); line-height: 1.7;
}