/* ============================================================
   Paper to MD — UI/UX Upgrade Layer (v2)
   Loaded AFTER base styles. Only enhances / overrides.
   ============================================================ */

/* ---------- 0. Reduced motion first ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 1. Enhanced design tokens ---------- */
:root {
  /* refined brand */
  --ember: #FF5B2E;
  --ember-2: #FF7A4D;
  --ember-3: #FF9A6D;
  --ember-deep: #E04418;

  /* surface elevation */
  --elev-1: 0 1px 2px rgba(0,0,0,.25), 0 1px 1px rgba(0,0,0,.18);
  --elev-2: 0 4px 12px rgba(0,0,0,.35), 0 2px 4px rgba(0,0,0,.25);
  --elev-3: 0 16px 48px rgba(0,0,0,.55), 0 4px 12px rgba(0,0,0,.35);
  --elev-glow: 0 0 0 1px var(--ember-soft), 0 12px 40px var(--ember-glow);

  /* glass */
  --glass-bg: rgba(19,17,16,.72);
  --glass-border: rgba(255,255,255,.08);
  --glass-blur: blur(18px) saturate(140%);

  /* radii scale */
  --r-xs: 6px;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;
  --r-xl: 22px;
  --r-pill: 999px;

  /* motion */
  --ease-out-expo: cubic-bezier(.16,1,.3,1);
  --ease-spring: cubic-bezier(.34,1.56,.64,1);
  --dur-1: .18s;
  --dur-2: .32s;
  --dur-3: .55s;
  --dur-4: .8s;

  /* layout */
  --container: 1200px;
  --container-wide: 1320px;
  --nav-h: 68px;
}

/* ---------- 2. Base typography & selection ---------- */
html { -webkit-tap-highlight-color: transparent; }
body {
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(255,91,46,.07), transparent 60%),
    radial-gradient(900px 500px at -10% 20%, rgba(123,174,111,.05), transparent 55%),
    var(--ink);
  background-attachment: fixed;
}
::selection { background: rgba(255,91,46,.28); color: #fff; }

/* refined focus ring globally */
:focus-visible {
  outline: 2px solid var(--focus-ring, #4D9FFF);
  outline-offset: 2px;
  border-radius: 4px;
}
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible {
  outline: 2px solid var(--focus-ring, #4D9FFF);
  outline-offset: 2px;
}

/* ---------- 3. Scrollbar ---------- */
* { scrollbar-width: thin; scrollbar-color: var(--line-3) transparent; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: linear-gradient(var(--line-2), var(--line-3));
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--ember); background-clip: padding-box; }

/* ---------- 4. Navigation ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-2) var(--ease-out-expo),
              background var(--dur-2) var(--ease-out-expo),
              box-shadow var(--dur-2) var(--ease-out-expo);
}
.nav.scrolled {
  border-bottom-color: var(--glass-border);
  box-shadow: 0 8px 30px rgba(0,0,0,.35);
}
.nav-inner {
  max-width: var(--container-wide);
  height: var(--nav-h);
  padding: 0 28px;
  margin: 0 auto;
  display: flex; align-items: center; gap: 24px;
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-mark {
  font-size: 26px;
  transition: transform var(--dur-2) var(--ease-spring);
}
.brand:hover .brand-mark { transform: rotate(-6deg) scale(1.06); }
.nav-links { display: flex; gap: 4px; margin-left: 8px; }
.nav-links a {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .06em;
  padding: 8px 14px;
  border-radius: var(--r-pill);
  position: relative;
  overflow: hidden;
}
.nav-links a::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(255,91,46,.14), rgba(255,91,46,.04));
  opacity: 0;
  transition: opacity var(--dur-1) var(--ease-out-expo);
}
.nav-links a:hover::before, .nav-links a.active::before { opacity: 1; }
.nav-links a.active { color: var(--paper); }
.nav-spacer { flex: 1; }
.nav-actions { display: flex; align-items: center; gap: 10px; }

/* language button */
.btn-lang {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--mono); font-size: 11px; font-weight: 600;
  letter-spacing: .08em; text-transform: uppercase;
  color: var(--paper-2);
  padding: 8px 12px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-pill);
  background: rgba(255,255,255,.02);
  transition: all var(--dur-1) var(--ease-out-expo);
}
.btn-lang:hover {
  color: var(--paper);
  border-color: var(--line-3);
  background: rgba(255,255,255,.05);
}
.btn-lang svg { width: 14px; height: 14px; }

/* magnetic / primary buttons */
.btn-nav, .btn-primary, .btn-secondary, .dropzone-btn {
  position: relative;
  overflow: hidden;
  will-change: transform;
  transition: transform var(--dur-1) var(--ease-spring),
              box-shadow var(--dur-2) var(--ease-out-expo),
              background var(--dur-2) var(--ease-out-expo),
              border-color var(--dur-1) var(--ease-out-expo);
}
.btn-nav { border-radius: var(--r-pill); padding: 10px 20px; }
.btn-primary {
  border-radius: var(--r-pill);
  padding: 14px 30px;
  background: linear-gradient(135deg, var(--ember), var(--ember-deep));
  box-shadow: 0 8px 24px var(--ember-glow), inset 0 1px 0 rgba(255,255,255,.18);
}
.btn-primary::after {
  content: '';
  position: absolute; top: 0; left: -120%;
  width: 60%; height: 100%;
  background: linear-gradient(110deg, transparent, rgba(255,255,255,.35), transparent);
  transform: skewX(-20deg);
  transition: left .7s var(--ease-out-expo);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 36px var(--ember-glow-2), inset 0 1px 0 rgba(255,255,255,.22);
}
.btn-primary:hover::after { left: 130%; }
.btn-primary:active { transform: translateY(0) scale(.98); }
.btn-secondary {
  border-radius: var(--r-pill);
  padding: 14px 26px;
  background: rgba(255,255,255,.03);
  border: 1px solid var(--line-2);
}
.btn-secondary:hover {
  border-color: var(--ember);
  color: var(--paper);
  background: rgba(255,91,46,.06);
  transform: translateY(-1px);
}
.btn-secondary:active { transform: translateY(0) scale(.98); }

/* ---------- 5. Container / layout ---------- */
.container, .wrap, main > section {
  max-width: var(--container);
  margin-left: auto;
  margin-right: auto;
  padding-left: 28px;
  padding-right: 28px;
}
main { display: block; }

/* ---------- 6. Hero ---------- */
.hero {
  position: relative;
  padding: 72px 0 40px;
  text-align: center;
}
.hero-eyebrow {
  display: inline-flex !important; align-items: center; gap: 8px;
  padding: 6px 14px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-pill);
  background: rgba(255,91,46,.05);
  margin-bottom: 24px;
}
.hero-eyebrow::before {
  content: ''; width: 6px; height: 6px; border-radius: 50%;
  background: var(--ember); box-shadow: 0 0 10px var(--ember-glow);
  animation: dotPulse 2s ease-in-out infinite;
}
@keyframes dotPulse {
  0%,100% { opacity: 1; transform: scale(1); }
  50% { opacity: .5; transform: scale(1.3); }
}
.hero h1 {
  font-size: clamp(38px, 6vw, 68px);
  line-height: 1.02;
  letter-spacing: -.035em;
  background: linear-gradient(180deg, var(--paper) 30%, var(--paper-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero h1 em {
  font-style: italic;
  color: var(--ember);
  -webkit-text-fill-color: var(--ember);
  background: none;
}
.hero p.lead {
  font-size: clamp(15px, 1.4vw, 18px);
  max-width: 620px;
  margin: 22px auto 0;
  color: var(--paper-3);
}
.hero-meta { margin-top: 28px; gap: 28px; }
.hero-meta span { display: inline-flex; align-items: center; gap: 8px; }

/* entry animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--dur-3) var(--ease-out-expo),
              transform var(--dur-3) var(--ease-out-expo);
}
.reveal.in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .08s; }
.reveal[data-delay="2"] { transition-delay: .16s; }
.reveal[data-delay="3"] { transition-delay: .24s; }
.reveal[data-delay="4"] { transition-delay: .32s; }
.reveal[data-delay="5"] { transition-delay: .40s; }

/* ---------- 7. Section titles ---------- */
.sec-eyebrow {
  display: inline-block !important;
  padding: 4px 12px;
  background: var(--ember-soft);
  border: 1px solid rgba(255,91,46,.2);
  border-radius: var(--r-pill);
  color: var(--ember-2);
}
.sec-title {
  font-size: clamp(30px, 4vw, 44px);
  letter-spacing: -.025em;
  background: linear-gradient(180deg, var(--paper), var(--paper-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.sec-title em { font-style: italic; color: var(--ember); -webkit-text-fill-color: var(--ember); background: none; }

/* ---------- 8. Format cards ---------- */
.fmt-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 14px;
  margin-top: 28px;
}
.fmt-card {
  position: relative;
  padding: 22px 16px 18px;
  border-radius: var(--r-md);
  background:
    linear-gradient(180deg, rgba(255,255,255,.025), rgba(255,255,255,0)) ,
    var(--ink-2);
  border: 1px solid var(--line-2);
  cursor: pointer;
  text-align: center;
  transition: transform var(--dur-2) var(--ease-spring),
              border-color var(--dur-2) var(--ease-out-expo),
              box-shadow var(--dur-2) var(--ease-out-expo),
              background var(--dur-2) var(--ease-out-expo);
  overflow: hidden;
}
.fmt-card::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(180px 80px at 50% 0%, rgba(255,91,46,.18), transparent 70%);
  opacity: 0;
  transition: opacity var(--dur-2) var(--ease-out-expo);
  pointer-events: none;
}
.fmt-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-3);
  box-shadow: var(--elev-2);
}
.fmt-card:hover::before { opacity: 1; }
.fmt-card.active {
  border-color: var(--ember);
  background: linear-gradient(180deg, rgba(255,91,46,.08), var(--ink-2));
  box-shadow: var(--elev-glow), var(--elev-2);
}
.fmt-card .fmt-check {
  top: 10px; right: 10px;
  width: 20px; height: 20px;
  background: var(--ember);
  border-color: var(--ember);
  color: var(--ink);
  box-shadow: 0 0 12px var(--ember-glow);
  transform: scale(0);
}
.fmt-card.active .fmt-check { transform: scale(1); }
.fmt-card .fmt-name {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--paper);
  margin-top: 8px;
}
.fmt-card .fmt-ext {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--paper-4);
  margin-top: 2px;
}

/* ---------- 9. Dropzone ---------- */
.dropzone {
  position: relative;
  border-radius: var(--r-xl);
  border: 1.5px dashed var(--line-3);
  background:
    radial-gradient(600px 240px at 50% 0%, rgba(255,91,46,.06), transparent 70%),
    linear-gradient(180deg, var(--ink-2), var(--ink));
  padding: 56px 32px;
  transition: border-color var(--dur-2) var(--ease-out-expo),
              background var(--dur-2) var(--ease-out-expo),
              box-shadow var(--dur-2) var(--ease-out-expo),
              transform var(--dur-2) var(--ease-out-expo);
}
.dropzone.dragover {
  border-color: var(--ember);
  border-style: solid;
  background: linear-gradient(180deg, var(--ink-3), var(--ink-2));
  box-shadow: 0 0 0 4px var(--ember-soft), 0 24px 60px var(--ember-glow);
  transform: scale(1.005);
}
.dropzone.has-file {
  border-style: solid;
  border-color: rgba(123,174,111,.5);
  background: linear-gradient(180deg, rgba(123,174,111,.05), var(--ink-2));
}
.dropzone-title { font-size: 26px; }
.dropzone-btn {
  border-radius: var(--r-pill);
  padding: 13px 30px;
  background: linear-gradient(135deg, var(--ember), var(--ember-deep));
  box-shadow: 0 8px 24px var(--ember-glow);
}
.dropzone-btn:hover { transform: translateY(-2px); box-shadow: 0 14px 32px var(--ember-glow-2); }

/* file card */
.file-card {
  display: flex; align-items: center; gap: 16px;
  padding: 18px 22px;
  background: var(--ink-3);
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  margin: 0 auto;
  max-width: 520px;
  animation: fileIn .5s var(--ease-spring);
}
@keyframes fileIn {
  from { opacity: 0; transform: translateY(12px) scale(.98); }
  to { opacity: 1; transform: none; }
}
.file-icon {
  width: 44px; height: 44px; flex: none;
  border-radius: var(--r-sm);
  background: var(--ember-soft);
  border: 1px solid rgba(255,91,46,.25);
  display: flex; align-items: center; justify-content: center;
  color: var(--ember);
}

/* ---------- 10. Toolbar / controls ---------- */
.toolbar {
  border-radius: var(--r-lg);
  padding: 20px 24px;
  background:
    linear-gradient(180deg, rgba(255,255,255,.02), transparent),
    var(--ink-2);
  border: 1px solid var(--line);
  box-shadow: var(--elev-1);
}
.control select, .control input[type="text"] {
  background: var(--ink-3);
  border: 1px solid var(--line-2);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 10px 14px;
  border-radius: var(--r-sm);
  transition: border-color var(--dur-1) var(--ease-out-expo),
              box-shadow var(--dur-1) var(--ease-out-expo);
  min-width: 160px;
}
.control select {
  appearance: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238A8275' stroke-width='2.5'><polyline points='6 9 12 15 18 9'/></svg>");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 32px;
}
.control select:focus, .control input[type="text"]:focus {
  border-color: var(--ember);
  box-shadow: 0 0 0 3px var(--ember-soft);
  outline: none;
}
.toggle-row { user-select: none; }
.toggle-row .tb {
  width: 38px; height: 22px;
  background: var(--line-2);
  transition: background var(--dur-2) var(--ease-out-expo);
}
.toggle-row .tb::after {
  width: 16px; height: 16px; top: 3px; left: 3px;
  box-shadow: 0 2px 4px rgba(0,0,0,.4);
}
.toggle-row input:checked + .tb { background: linear-gradient(135deg, var(--ember), var(--ember-deep)); }
.toggle-row input:checked + .tb::after { left: 19px; background: #fff; }
.toolbar-actions .btn-primary, .toolbar-actions .btn-secondary {
  padding: 12px 24px;
}

/* ---------- 11. Progress ---------- */
.progress-wrap {
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
  border: 1px solid var(--line);
  box-shadow: var(--elev-2);
}
.progress-status { color: var(--ember-2); }
.progress-bar {
  height: 8px;
  background: var(--ink-4);
  border-radius: var(--r-pill);
  position: relative;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--ember), var(--ember-2), var(--ember-3));
  background-size: 200% 100%;
  border-radius: var(--r-pill);
  box-shadow: 0 0 12px var(--ember-glow);
  animation: progressShimmer 2s linear infinite;
}
@keyframes progressShimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
.ps { gap: 8px; }
.ps .ps-dot { width: 9px; height: 9px; }

/* ---------- 12. Result split / preview ---------- */
.result-split {
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  box-shadow: var(--elev-2);
  height: 72vh;
  min-height: 540px;
  background: var(--ink-2);
}
.result-split.fullscreen {
  position: fixed;
  inset: 0;
  z-index: 9999;
  border-radius: 0;
  border: none;
  height: 100dvh;
  min-height: 100dvh;
  width: 100vw;
  max-width: 100vw;
  margin: 0;
  background: var(--ink);
  box-shadow: none;
}
.result-split.fullscreen .pane-body { min-height: 0; }
.result-split.fullscreen .preview-pane { min-height: 0; }
.result-split.fullscreen .pane-splitter { width: 8px; }
/* Kill any transform/filter on ancestors so fixed positioning anchors to viewport */
.result-wrap.is-fullscreen {
  transform: none !important;
  opacity: 1 !important;
  filter: none !important;
  perspective: none !important;
  contain: none !important;
}
.preview-pane { background: var(--ink); }
.pane-header {
  padding: 14px 20px;
  background: linear-gradient(180deg, var(--ink-3), var(--ink-2));
  border-bottom: 1px solid var(--line);
}
.pane-title {
  font-size: 11px;
  letter-spacing: .12em;
  font-weight: 600;
  color: var(--paper-3);
}
.pane-body {
  background:
    radial-gradient(circle at 50% 0%, rgba(255,91,46,.04), transparent 60%),
    var(--code-bg);
  scroll-behavior: smooth;
}
.pane-body.is-rendered {
  background: linear-gradient(180deg, #fff, #faf7f2);
  padding: 40px 48px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.6);
}
.pane-splitter {
  width: 8px;
  background:
    linear-gradient(var(--line), var(--line-2));
  position: relative;
}
.pane-splitter::before {
  content: '';
  position: absolute; inset: 0;
  background: var(--ember);
  opacity: 0;
  transition: opacity var(--dur-1) var(--ease-out-expo);
}
.pane-splitter:hover::before, .pane-splitter.dragging::before { opacity: 1; }
.pane-splitter::after {
  width: 4px; height: 32px;
  background: var(--paper-5);
  border-radius: 2px;
  transition: background var(--dur-1);
}
.pane-splitter:hover::after { background: var(--paper); }

/* PDF page styling */
.pdf-page-wrap {
  border-radius: var(--r-sm);
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0,0,0,.5);
  margin-bottom: 18px;
}

/* result tabs */
.result-tab {
  padding: 12px 20px;
  border-radius: var(--r-sm) var(--r-sm) 0 0;
  font-weight: 600;
  transition: color var(--dur-1), background var(--dur-1);
}
.result-tab:hover { color: var(--paper); background: rgba(255,255,255,.03); }
.result-tab.active {
  color: var(--paper);
  background: var(--ink-2);
}
.result-tab.active::after {
  height: 2px;
  background: linear-gradient(90deg, var(--ember), var(--ember-2));
  box-shadow: 0 0 8px var(--ember-glow);
}
.pv-tool {
  border-radius: var(--r-sm);
  padding: 8px 14px;
  font-size: 10.5px;
  transition: all var(--dur-1) var(--ease-out-expo);
}
.pv-tool:hover {
  color: var(--paper);
  border-color: var(--ember);
  background: rgba(255,91,46,.08);
  transform: translateY(-1px);
}

/* markdown rendered */
.result-body .rendered h1,
.pane-body.is-rendered h1 {
  letter-spacing: -.02em;
}
.result-body .rendered a,
.pane-body.is-rendered a {
  color: var(--ember);
  text-underline-offset: 3px;
  transition: color var(--dur-1);
}
.result-body .rendered a:hover { color: var(--ember-2); }

/* ---------- 13. History ---------- */
.history-section { padding: 72px 0; }
.history-container {
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
  box-shadow: var(--elev-2);
  overflow: hidden;
}
.history-header {
  padding: 18px 24px;
  background: linear-gradient(180deg, var(--ink-3), var(--ink-2));
  border-bottom: 1px solid var(--line);
}
.hist-item {
  padding: 16px 24px;
  transition: background var(--dur-1) var(--ease-out-expo),
              transform var(--dur-1) var(--ease-out-expo);
  position: relative;
}
.hist-item::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--ember);
  transform: scaleY(0);
  transform-origin: center;
  transition: transform var(--dur-2) var(--ease-out-expo);
}
.hist-item:hover {
  background: rgba(255,91,46,.05);
  padding-left: 28px;
}
.hist-item:hover::before { transform: scaleY(1); }
.hist-icon {
  width: 40px; height: 40px;
  border-radius: var(--r-sm);
  transition: transform var(--dur-2) var(--ease-spring);
}
.hist-item:hover .hist-icon { transform: scale(1.08) rotate(-4deg); }
.hist-name { font-size: 13.5px; color: var(--paper); }
.hist-fmt {
  border-radius: var(--r-xs);
  padding: 2px 8px;
  background: var(--ink-4);
  transition: all var(--dur-1);
}
.hist-item:hover .hist-fmt {
  background: var(--ember-soft);
  color: var(--ember-2);
  border-color: rgba(255,91,46,.25);
}
.hist-del {
  width: 32px; height: 32px;
  border-radius: var(--r-sm);
  opacity: 0;
  transform: translateX(4px);
  transition: all var(--dur-1) var(--ease-out-expo);
}
.hist-item:hover .hist-del { opacity: 1; transform: none; }
.history-empty {
  padding: 56px 24px;
  text-align: center;
  color: var(--paper-5);
}

/* ---------- 14. Formats available (bento) ---------- */
.formats-avail { margin-top: 72px; }
.fa-grid {
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}
.fa-card {
  border-radius: var(--r-lg);
  padding: 26px 22px;
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
  border: 1px solid var(--line);
  position: relative;
  overflow: hidden;
  transition: transform var(--dur-2) var(--ease-spring),
              border-color var(--dur-2),
              box-shadow var(--dur-2);
}
.fa-card::after {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(200px 120px at 100% 0%, rgba(255,91,46,.12), transparent 60%);
  opacity: 0;
  transition: opacity var(--dur-2);
  pointer-events: none;
}
.fa-card:hover {
  transform: translateY(-6px);
  border-color: var(--line-3);
  box-shadow: var(--elev-3);
}
.fa-card:hover::after { opacity: 1; }
.fa-icon {
  width: 48px; height: 48px;
  border-radius: var(--r-md);
  margin-bottom: 18px;
  transition: transform var(--dur-2) var(--ease-spring);
}
.fa-card:hover .fa-icon { transform: scale(1.1) rotate(-6deg); }

/* ---------- 15. CTA ---------- */
.bottom-cta {
  border-radius: var(--r-xl);
  padding: 64px 40px;
  background:
    radial-gradient(600px 300px at 50% 0%, rgba(255,91,46,.18), transparent 70%),
    linear-gradient(180deg, var(--ink-3), var(--ink));
  border: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}
.bottom-cta::before {
  content: '';
  position: absolute; inset: -1px;
  background: linear-gradient(135deg, transparent 40%, rgba(255,91,46,.2), transparent 60%);
  opacity: 0;
  transition: opacity var(--dur-3);
  pointer-events: none;
}
.bottom-cta:hover::before { opacity: 1; }
.bottom-cta h2 { font-size: clamp(28px, 3.5vw, 38px); }

/* ---------- 16. Footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  padding: 48px 0 32px;
  margin-top: 64px;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,.2));
}
.foot-inner { max-width: var(--container); }
.foot-links a {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  position: relative;
}
.foot-links a::after {
  content: '';
  position: absolute; left: 0; bottom: -2px;
  width: 0; height: 1px;
  background: var(--ember);
  transition: width var(--dur-2) var(--ease-out-expo);
}
.foot-links a:hover { color: var(--ember); }
.foot-links a:hover::after { width: 100%; }

/* ---------- 18. Toast ---------- */
.toast {
  bottom: 32px;
  padding: 14px 20px;
  border-radius: var(--r-pill);
  background: rgba(28,25,22,.92);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border: 1px solid var(--line-2);
  box-shadow: var(--elev-3);
}
.toast.success { border-color: rgba(123,174,111,.3); }
.toast.error { border-color: rgba(255,91,46,.3); }
.toast.info { border-color: rgba(77,159,255,.3); }

/* ---------- 19. Click spark ---------- */
.spark {
  position: fixed;
  pointer-events: none;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ember);
  z-index: 9999;
  animation: sparkFly .6s var(--ease-out-expo) forwards;
}
@keyframes sparkFly {
  0% { transform: translate(-50%,-50%) scale(1); opacity: 1; }
  100% { transform: translate(var(--tx), var(--ty)) scale(0); opacity: 0; }
}

/* spinner ring for loading/retry states */
.spinner-ring {
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 2.5px solid var(--line-2);
  border-top-color: var(--ember);
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- 20. Utility / no-select for buttons ---------- */
.btn-primary, .btn-secondary, .btn-nav, .dropzone-btn,
.fmt-card, .toggle-row, .pv-tool, .auth-tab {
  -webkit-user-select: none; user-select: none;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

/* Large desktop */
@media (min-width: 1440px) {
  :root { --container: 1280px; }
  .container, .wrap, main > section { max-width: var(--container); }
}

/* Tablet landscape and below */
@media (max-width: 1024px) {
  .fmt-grid { grid-template-columns: repeat(5, 1fr); gap: 10px; }
  .fa-grid { grid-template-columns: repeat(3, 1fr); }
  .hero { padding: 56px 0 32px; }
  .pane-body.is-rendered { padding: 32px 36px; }
}

/* Tablet */
@media (max-width: 900px) {
  .fmt-grid { grid-template-columns: repeat(3, 1fr); }
  .fa-grid { grid-template-columns: repeat(2, 1fr); }
  .result-split { height: 68vh; }
  .nav-inner { padding: 0 20px; gap: 16px; }
  .container, .wrap, main > section { padding-left: 20px; padding-right: 20px; }
}

/* Mobile */
@media (max-width: 768px) {
  :root { --nav-h: 60px; }
  .nav-inner { padding: 0 16px; }
  .container, .wrap, main > section { padding-left: 16px; padding-right: 16px; }

  .hero { padding: 40px 0 24px; }
  .hero h1 { font-size: clamp(32px, 9vw, 46px); }
  .hero p.lead { font-size: 15px; }
  .hero-meta { gap: 14px; font-size: 9.5px; }

  .fmt-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .fmt-card { padding: 18px 12px 14px; }

  .dropzone { padding: 40px 20px; border-radius: var(--r-lg); }
  .dropzone-title { font-size: 22px; }

  .toolbar {
    padding: 16px;
    border-radius: var(--r-md);
  }
  .toolbar-group { gap: 14px; }
  .control select, .control input[type="text"] {
    width: 100%; min-width: 0;
  }
  .toggle-list { gap: 14px; }
  .toolbar-actions { width: 100%; }
  .toolbar-actions .btn-primary,
  .toolbar-actions .btn-secondary {
    width: 100%; justify-content: center;
  }

  .result-split {
    flex-direction: column;
    height: auto;
    min-height: 0;
    max-height: none;
    border-radius: var(--r-md);
  }
  .preview-pane { min-height: 380px; }
  .pane-splitter { width: 100%; height: 8px; cursor: row-resize; }
  .pane-splitter::after { width: 32px; height: 4px; }
  .pane-body.is-rendered { padding: 24px 20px; font-size: 14.5px; }
  .result-pane { border-radius: 0 0 var(--r-md) var(--r-md); }
  .result-tab { padding: 10px 14px; font-size: 10.5px; }

  .history-section { padding: 48px 0; }
  .hist-item { padding: 14px 16px; }
  .hist-item:hover { padding-left: 20px; }
  .hist-del { opacity: 1; transform: none; }
  .hist-meta { font-size: 9.5px; }

  .formats-avail { margin-top: 56px; }
  .fa-grid { grid-template-columns: 1fr; }
  .fa-card { padding: 22px 20px; }

  .bottom-cta { padding: 44px 24px; border-radius: var(--r-lg); }
  .footer { padding: 36px 0 24px; margin-top: 48px; }
  .foot-inner { flex-direction: column; text-align: center; gap: 20px; }

  .auth-box { padding: 24px 20px; }
  .toast { bottom: 16px; left: 16px; right: 16px; transform: translateY(20px); max-width: none; }
  .toast.show { transform: translateY(0); }
}

/* Small phones */
@media (max-width: 420px) {
  .fmt-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-meta { flex-direction: column; gap: 8px; }
  .btn-primary, .btn-secondary { padding: 12px 22px; font-size: 11px; }
  .file-card { flex-direction: column; text-align: center; padding: 16px; }
  .file-meta { justify-content: center; flex-wrap: wrap; }
}

/* Safe area for notched phones */
@supports (padding: max(0px)) {
  .nav-inner { padding-left: max(28px, env(safe-area-inset-left)); padding-right: max(28px, env(safe-area-inset-right)); }
  .toast { bottom: max(28px, env(safe-area-inset-bottom)); }
  @media (max-width: 768px) {
    .nav-inner { padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)); }
  }
}

/* Print */
@media print {
  .nav, .toolbar, .result-tabs, .result-tools, .pane-splitter, .footer { display: none !important; }
  .result-split { height: auto; border: none; }
  .pane-body.is-rendered { padding: 0; background: #fff; }
}