:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --border: #e3e6ef;
  --text: #14172b;
  --text-muted: #6b7086;

  --brand-navy: #0d1b42;
  --brand-blue: #1f6bff;
  --brand-cyan: #22d3ee;
  --brand-purple: #7c3aed;
  --brand-gradient: linear-gradient(135deg, var(--brand-blue) 0%, var(--brand-purple) 100%);

  --accent: var(--brand-blue);
  --accent-hover: #1857d1;
  --danger: #d64545;
  --radius: 14px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0f1a;
    --surface: #171a2b;
    --border: #2a2e45;
    --text: #f1f2f8;
    --text-muted: #9598ad;
    --accent: #5b8bff;
    --accent-hover: #7ba0ff;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 20px 60px;
}

/* Topbar */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-icon {
  height: 30px;
  width: auto;
  display: block;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--brand-navy);
}

@media (prefers-color-scheme: dark) {
  .brand-name { color: var(--text); }
}

.accent {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lang-switch {
  display: flex;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 3px;
}

.lang-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  padding: 4px 6px;
  border-radius: 100px;
  cursor: pointer;
  opacity: .5;
  filter: grayscale(60%);
  transition: opacity .15s ease, filter .15s ease, background .15s ease;
}

.flag-icon {
  width: 22px;
  height: 15px;
  border-radius: 2px;
  display: block;
}

.lang-btn:hover {
  opacity: .8;
  filter: grayscale(0%);
}

.lang-btn.active {
  background: var(--surface-alt, rgba(127,127,127,.15));
  opacity: 1;
  filter: grayscale(0%);
}

/* Hero */

.hero {
  text-align: center;
  padding: 16px 0 36px;
}

.hero h1 {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -.02em;
  margin: 0 0 12px;
  background: linear-gradient(135deg, var(--brand-navy) 0%, var(--brand-blue) 55%, var(--brand-purple) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

@media (prefers-color-scheme: dark) {
  .hero h1 {
    background: linear-gradient(135deg, #ffffff 0%, var(--brand-cyan) 55%, var(--brand-purple) 100%);
    -webkit-background-clip: text;
    background-clip: text;
  }
}

.hero .subtitle {
  color: var(--text-muted);
  margin: 0 auto;
  max-width: 560px;
  font-size: 1.02rem;
  line-height: 1.5;
}

/* Tabs */

.tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 16px;
}

.tab-btn {
  padding: 9px 18px;
  border-radius: 10px 10px 0 0;
  border: 1px solid var(--border);
  border-bottom: none;
  background: var(--bg);
  color: var(--text-muted);
  font-size: .88rem;
  font-weight: 700;
  cursor: pointer;
  transition: color .15s ease, background .15s ease;
}

.tab-btn:hover { color: var(--text); }

.tab-btn.active {
  background: var(--surface);
  color: var(--accent);
}

/* Card */

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  box-shadow: 0 1px 2px rgba(16, 24, 60, .04), 0 12px 32px -16px rgba(16, 24, 60, .12);
}

@media (prefers-color-scheme: dark) {
  .card { box-shadow: 0 1px 2px rgba(0,0,0,.2), 0 12px 32px -16px rgba(0,0,0,.4); }
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 44px 20px;
  text-align: center;
  background: var(--bg);
  transition: border-color .15s ease, background .15s ease;
  cursor: pointer;
}

.dropzone.dragover {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, var(--bg));
}

.dropzone-content svg {
  color: var(--brand-blue);
  margin-bottom: 10px;
}

.dropzone p {
  margin: 0;
  color: var(--text-muted);
}

.link-btn {
  background: none;
  border: none;
  color: var(--accent);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  padding: 0;
  text-decoration: underline;
}

.controls {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 24px;
}

.controls.hidden, .hidden { display: none !important; }

.controls-left {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  align-items: flex-end;
}

.field {
  display: flex;
  flex-direction: column;
}

.field label {
  font-size: .75rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.field select {
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: .9rem;
}

.controls-right {
  display: flex;
  gap: 10px;
}

.btn {
  padding: 10px 20px;
  border-radius: 10px;
  border: none;
  font-size: .9rem;
  font-weight: 700;
  cursor: pointer;
  transition: background .15s ease, opacity .15s ease, transform .1s ease;
}

.btn-primary {
  background: var(--brand-gradient);
  color: #fff;
}

.btn-primary:hover:not(:disabled) { filter: brightness(1.08); }
.btn-primary:active:not(:disabled) { transform: translateY(1px); }

.btn-primary:disabled {
  opacity: .5;
  cursor: not-allowed;
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}

.btn-secondary:hover { border-color: var(--text-muted); }

.image-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 14px;
}

.image-item {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: grab;
  user-select: none;
}

.image-item.dragging {
  opacity: .4;
}

.image-item .thumb-wrap {
  aspect-ratio: 3/4;
  overflow: hidden;
  background: #00000010;
}

.image-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.image-item .page-num {
  position: absolute;
  top: 6px;
  left: 6px;
  background: rgba(13, 27, 66, .75);
  color: #fff;
  font-size: .7rem;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 100px;
}

.image-item .remove-btn {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: none;
  background: rgba(13, 27, 66, .75);
  color: #fff;
  font-size: .85rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-item .remove-btn:hover { background: var(--danger); }

.image-item .filename {
  padding: 6px 8px;
  font-size: .72rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Split PDF panel */

.pdf-status {
  margin: 20px 0 0;
  text-align: center;
  color: var(--text-muted);
  font-size: .88rem;
}

.split-info {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 20px;
  flex-wrap: wrap;
}

.pdf-file-name {
  font-weight: 700;
  color: var(--text);
}

.pdf-page-count {
  color: var(--text-muted);
  font-size: .85rem;
  flex: 1;
}

.range-rows {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 18px;
}

.range-row {
  display: flex;
  align-items: flex-end;
  gap: 14px;
  flex-wrap: wrap;
}

.range-row input[type="number"] {
  width: 90px;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: .9rem;
}

.remove-range-btn {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.remove-range-btn:hover {
  background: var(--danger);
  border-color: var(--danger);
  color: #fff;
}

.split-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 14px;
}

.range-error {
  margin: 10px 0 0;
  color: var(--danger);
  font-size: .82rem;
}

.section-title {
  font-size: .95rem;
  font-weight: 700;
  margin: 28px 0 0;
}

.pdf-page-item .thumb-wrap {
  aspect-ratio: unset;
  background: #00000010;
}

.pdf-page-item img {
  object-fit: contain;
}

.pdf-page-item.excluded {
  opacity: .3;
}

.split-results {
  margin-top: 24px;
}

.range-group + .range-group {
  margin-top: 24px;
}

.range-group-label {
  font-size: .8rem;
  font-weight: 700;
  color: var(--text-muted);
  margin: 0 0 10px;
}

.hint-text {
  margin: 10px 0 0;
  color: var(--text-muted);
  font-size: .82rem;
}

/* Crop Audio panel */

.waveform-wrap {
  position: relative;
  margin-top: 20px;
  height: 120px;
  touch-action: none;
  user-select: none;
  cursor: pointer;
}

/* Clips the waveform drawing/selection; kept separate from .waveform-wrap
   so the drag handles (positioned in the unclipped outer box) stay fully
   paintable and hit-testable even when parked at the very start/end. */
.waveform-inner {
  position: absolute;
  inset: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

.waveform-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.waveform-region {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 0;
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  border-left: 2px solid var(--accent);
  border-right: 2px solid var(--accent);
  pointer-events: none;
}

.waveform-playhead {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 2px;
  background: var(--danger);
  pointer-events: none;
}

.waveform-handle {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 18px;
  margin-left: -9px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: ew-resize;
}

.waveform-handle::before {
  content: '';
  width: 4px;
  height: 40px;
  border-radius: 3px;
  background: var(--accent);
  box-shadow: 0 0 0 2px var(--surface);
}

.waveform-handle:hover::before,
.waveform-handle:focus-visible::before,
.waveform-handle.dragging::before {
  background: var(--accent-hover);
}

.waveform-handle:focus-visible {
  outline: none;
}

.waveform-handle:focus-visible::before {
  box-shadow: 0 0 0 2px var(--surface), 0 0 0 4px var(--accent);
}

.audio-controls .split-info {
  margin-top: 20px;
}

.audio-time-fields {
  display: flex;
  align-items: flex-end;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 18px;
}

.audio-time-fields input[type="text"] {
  width: 84px;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: .9rem;
  text-align: center;
}

.selected-duration {
  color: var(--text-muted);
  font-size: .85rem;
  flex: 1;
}

/* Footer */

.footer {
  margin-top: 32px;
  text-align: center;
  color: var(--text-muted);
  font-size: .8rem;
}

.footer .credit {
  margin-top: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: inherit;
  text-decoration: none;
  transition: opacity .15s ease;
}

.footer .credit:hover {
  opacity: .75;
}

.footer-logo {
  height: 16px;
  width: auto;
  opacity: .85;
}

.footer-brand {
  font-size: .85rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--brand-navy);
}

@media (prefers-color-scheme: dark) {
  .footer-brand { color: var(--text); }
}