:root {
  --bg: #ffffff;
  --fg: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --soft: #f1f5f9;
  --primary: #2563eb;
  --primary-fg: #ffffff;
  --good: #16a34a;
  --warn: #d97706;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --fg: #e2e8f0;
    --muted: #94a3b8;
    --border: #1e293b;
    --soft: #111827;
    --primary: #3b82f6;
    --good: #4ade80;
    --warn: #fbbf24;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.6 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.wrap { max-width: 860px; margin: 0 auto; padding: 32px 16px 48px; display: grid; gap: 20px; }
.content { display: grid; grid-template-columns: minmax(0, 1fr); gap: 16px; }
h1 { margin: 0; font-size: 26px; line-height: 1.25; }
a { color: var(--primary); }
.muted { color: var(--muted); }
.small { font-size: 12.5px; }
.top { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; }
.top p { margin: 4px 0 0; }
.top-actions { display: flex; gap: 4px; flex-shrink: 0; }
button, select, .ghost { font: inherit; color: inherit; cursor: pointer; }
.ghost {
  background: none; border: 0; border-radius: 999px; padding: 6px 10px;
  font-size: 13px; font-weight: 600; text-decoration: none; color: var(--fg);
}
.ghost:hover { background: var(--soft); }
.drop {
  width: 100%; display: flex; flex-direction: column; align-items: center; gap: 6px; text-align: center;
  padding: 36px 16px; border: 2px dashed var(--border); border-radius: 14px; background: none;
  transition: background .15s, border-color .15s;
}
.drop svg { color: var(--muted); }
.drop:hover, .drop.over { background: var(--soft); border-color: var(--primary); }
.panel { border: 1px solid var(--border); border-radius: 14px; padding: 16px; }
.settings { display: grid; gap: 14px; }
@media (max-width: 640px) { .settings { grid-template-columns: 1fr; } }
.field { display: grid; gap: 6px; }
.label { font-size: 12.5px; color: var(--muted); }
.label b { color: var(--fg); }
.seg { display: flex; gap: 4px; }
.seg button {
  flex: 1; padding: 6px 4px; border: 1px solid var(--border); border-radius: 8px; background: none;
  font-size: 12px; font-weight: 600;
}
.seg button.active { background: var(--primary); border-color: var(--primary); color: var(--primary-fg); }
input[type="range"] { width: 100%; accent-color: var(--primary); }
input[type="range"]:disabled { opacity: .4; }
select { width: 100%; padding: 6px 8px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); }
.bar { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 8px; }
.bar p { margin: 0; }
.actions { display: flex; gap: 8px; }
.primary, .outline {
  height: 32px; padding: 0 12px; border-radius: 8px; font-size: 13px; font-weight: 600; border: 1px solid var(--primary);
}
.primary { background: var(--primary); color: var(--primary-fg); }
.outline { background: none; border-color: var(--border); }
.primary:disabled, .outline:disabled { opacity: .5; cursor: default; }
.good { color: var(--good); }
.warn { color: var(--warn); }
#list { list-style: none; margin: 12px 0 0; padding: 0; display: grid; gap: 8px; }
#list li { display: flex; align-items: center; gap: 12px; border: 1px solid var(--border); border-radius: 12px; padding: 8px; }
#list img { width: 56px; height: 56px; object-fit: cover; border-radius: 8px; border: 1px solid var(--border); flex-shrink: 0; }
#list .info { flex: 1; min-width: 0; font-size: 13.5px; }
#list .name { font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#list .meta { font-size: 12.5px; color: var(--muted); }
footer { text-align: center; padding-top: 8px; }

/* List */
.row-actions { display: flex; gap: 6px; flex-shrink: 0; }
.icon { width: 30px; height: 30px; border: 1px solid var(--border); border-radius: 8px; background: none; color: var(--muted); }
.icon:hover { color: var(--warn); }

[hidden] { display: none !important; }

/* List actions: same-size buttons on one row */
.row-actions { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }
.btn-sm {
  height: 32px; min-width: 32px; padding: 0 12px; display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  border: 1px solid var(--border); border-radius: 8px; background: none; font-size: 13px; font-weight: 600;
}
.btn-sm:hover:not(:disabled) { background: var(--soft); }
.btn-sm:disabled { opacity: .5; cursor: default; }
.btn-icon { width: 32px; padding: 0; color: var(--muted); font-size: 14px; }
.btn-icon:hover { color: var(--warn); }
@media (max-width: 640px) {
  .btn-sm span { display: none; }
  .btn-sm { padding: 0; width: 32px; }
}

/* Convert bar */
.convert { display: grid; gap: 10px; border: 1px solid var(--border); border-radius: 14px; padding: 14px 16px; }
.convert .seg { max-width: 420px; }
.convert .seg button { padding: 8px 4px; font-size: 13px; }
.convert #quality { max-width: 560px; }
.drop { padding: 48px 16px; }
.seg button:disabled { opacity: .4; cursor: not-allowed; }

/* Quality: default in the middle, lighter left, sharper right */
.seg-q button { padding: 8px 4px; }
.seg-q b { font-size: 13px; }

/* Brand */
.top { align-items: center; }
.brand { flex-shrink: 0; display: block; line-height: 0; }
.top-text { flex: 1; min-width: 0; }

/* How it works */
.howto { border: 1px solid var(--border); border-radius: 14px; padding: 0 16px; font-size: 14px; }
.howto summary { cursor: pointer; font-weight: 600; padding: 12px 0; }
.howto[open] summary { border-bottom: 1px solid var(--border); margin-bottom: 4px; }
.howto ol { padding-left: 20px; margin: 10px 0; }
.howto li { margin: 4px 0; }
.howto p { margin: 8px 0 12px; color: var(--muted); }
.howto p b { color: var(--fg); }
html[lang="vi"] .howto[lang="en"], html[lang="en"] .howto[lang="vi"] { display: none; }

/* Container like Tailwind's: full width with breakpoint max-widths */
.wrap { width: 100%; max-width: 1280px; padding: 32px 16px 48px; }
@media (min-width: 640px) { .wrap { padding-left: 24px; padding-right: 24px; gap: 40px; } }
@media (min-width: 1024px) { .wrap { padding-left: 32px; padding-right: 32px; gap: 60px; } }

/* File converter */
.badge {
  width: 56px; height: 56px; flex-shrink: 0; display: grid; place-items: center; border-radius: 8px;
  font-size: 11px; font-weight: 800; color: #fff; background: #64748b;
}
.badge.pdf { background: #dc2626; }
#detected { margin: 0; }
#detected b { color: var(--fg); }
.howto ul { margin: 4px 0; padding-left: 18px; }

/* Header: back link + mobile layout */
.top-actions { align-items: center; }
.back { color: var(--primary); }
@media (max-width: 640px) {
  .top { flex-wrap: wrap; align-items: flex-start; gap: 10px 12px; }
  .top-actions { order: -1; width: 100%; justify-content: flex-end; margin: -8px -10px 0 0; }
  .top-actions .back { margin-right: auto; margin-left: -10px; }
  .brand img { width: 36px; height: 36px; }
  h1 { font-size: 22px; }
  .top p { font-size: 13.5px; }
}

/* Option buttons: regular text weight */
.seg button, .seg button b, .seg-q b { font-weight: 400; }

/* Header: title only */
.top p[data-i18n="subtitle"] { display: none; }
.top { align-items: center; }

/* Minimal font weights: regular text everywhere, medium only for the title */
strong, b, button, .ghost, .primary, .outline, .btn-sm, .seg button, .seg button b,
summary, .howto summary, #list .name, .file-row .name, .page, label, .label b, #detected b { font-weight: 400; }
h1 { font-weight: 600; }
.badge { font-weight: 600; }

/* Image resizer */
.convert .seg { max-width: none; flex-wrap: wrap; }
.convert .seg button { flex: 0 1 auto; min-width: 72px; padding: 8px 14px; }
.inline { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.inline input[type="number"] {
  width: 110px; height: 36px; padding: 0 10px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg); color: var(--fg); font: inherit; font-size: 13px;
}
.inline input[type="number"]:focus { outline: none; border-color: var(--primary); }
#list img { object-fit: contain; background: repeating-conic-gradient(var(--soft) 0 25%, transparent 0 50%) 0 0 / 12px 12px; }

/* Lightbox preview */
.lb { position: fixed; inset: 0; z-index: 100; display: none; align-items: center; justify-content: center; padding: 48px 56px; background: rgba(2, 6, 23, .88); cursor: zoom-out; }
.lb.open { display: flex; animation: lb-in .15s ease-out; }
@keyframes lb-in { from { opacity: 0; } }
.lb figure { margin: 0; display: grid; gap: 10px; justify-items: center; max-width: 100%; max-height: 100%; }
.lb img { max-width: 100%; max-height: calc(100vh - 120px); object-fit: contain; border-radius: 8px; background: #fff; cursor: default; box-shadow: 0 20px 50px rgba(0,0,0,.4); }
.lb figcaption { color: #e2e8f0; font-size: 13px; text-align: center; }
.lb-btn { position: absolute; width: 40px; height: 40px; border: 0; border-radius: 999px; background: rgba(255,255,255,.14); color: #fff; font-size: 22px; line-height: 1; cursor: pointer; }
.lb-btn:hover { background: rgba(255,255,255,.26); }
.lb-close { top: 12px; right: 12px; font-size: 16px; }
.lb-prev { left: 10px; top: 50%; transform: translateY(-50%); }
.lb-next { right: 10px; top: 50%; transform: translateY(-50%); }
.lb-single .lb-prev, .lb-single .lb-next { display: none; }
@media (max-width: 640px) { .lb { padding: 56px 8px 24px; } .lb-prev, .lb-next { top: auto; bottom: 12px; transform: none; } }
.zoomable { cursor: zoom-in; }
#list li.zoomable { cursor: zoom-in; transition: border-color .15s, background .15s; }
#list li.zoomable:hover { border-color: color-mix(in srgb, var(--primary) 45%, var(--border)); background: var(--soft); }
#list li.zoomable .btn-sm { cursor: pointer; }

/* Mobile: 16px form text so iOS does not zoom in on focus */
@media (max-width: 640px) {
  input, select, textarea { font-size: 16px !important; }
}

/* Phones: one compact header bar across the full width, stuck to the top (same in every tool) */
@media (max-width: 639px) {
  .wrap { padding-top: 0; }
  .top { position: sticky; top: 0; z-index: 10; flex-wrap: nowrap; align-items: center; gap: 10px; margin: 0 -16px; padding: 10px 16px;
    background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
  .top-text { flex: 1; min-width: 0; }
  .brand img { width: 32px; height: 32px; }
  h1 { font-size: 18px; line-height: 1.3; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .back { padding: 6px 8px; font-size: 16px; }
  .back span { display: none; }
  .top-actions { order: 0; width: auto; flex: none; gap: 0; margin: 0; }
  .top-actions .back { margin: 0; }
  .top-actions .ghost { padding: 6px 8px; }
}