/* ---------- searchable, user-first center guides ---------- */
.explore-strip { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(230px, 100%), 1fr)); gap: 14px; align-items: stretch; }
.explore-card { display: flex; min-width: 0; min-height: 104px; flex-direction: column; justify-content: center; gap: 8px; padding: 18px; border: 1px solid var(--border); border-radius: 16px; background: var(--surface, rgba(255,255,255,.72)); color: var(--text); box-shadow: 0 8px 22px rgba(42, 30, 80, .05); transition: transform .16s ease, border-color .16s ease, box-shadow .16s ease; }
.explore-card:hover, .explore-card:focus-visible { transform: translateY(-2px); border-color: var(--primary); box-shadow: var(--shadow-lg); }
.explore-card strong { display: block; font-size: 1.02rem; line-height: 1.45; overflow-wrap: anywhere; }
.explore-card span { display: block; color: var(--text-muted); font-size: .9rem; line-height: 1.6; overflow-wrap: anywhere; }

/* The horizontally scrollable top navigation clipped its absolute submenu on mobile. */
.nav-toggle { display: none; }
@media (max-width: 720px) {
  .nav-toggle { display: inline-flex; }
  .topnav { position: absolute; inset-block-start: calc(100% + 8px); inset-inline: 12px; z-index: 120; display: none; flex-direction: column; gap: 3px; max-height: calc(100dvh - 76px - env(safe-area-inset-top)); overflow-y: auto; overscroll-behavior: contain; margin: 0; padding: 8px; border: 1px solid var(--border); border-radius: 16px; background: var(--surface-solid); box-shadow: var(--shadow-lg); }
  .topnav.open { display: flex; }
  .topnav > a, .topnav-group > summary { display: flex; align-items: center; min-height: 44px; padding: 9px 12px; }
  .topnav-group > div { position: static; display: grid; min-width: 0; max-height: none; overflow: visible; padding: 2px 8px 8px 18px; border: 0; border-radius: 10px; background: transparent; box-shadow: none; }
  .topnav-group > div a { min-height: 44px; display: flex; align-items: center; white-space: normal; }
  .explore-strip { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .explore-card { min-height: 116px; padding: 14px 12px; }
}
@media (max-width: 380px) { .explore-strip { grid-template-columns: 1fr; } }

.hub-guide { max-width: 920px; margin: 34px auto 40px; line-height: 1.82; }
.hub-guide-intro { padding: 16px 18px; border-inline-start: 4px solid var(--primary); border-radius: 12px; background: var(--grad-soft); font-size: 1.05rem; }
.hub-guide h2 { margin: 28px 0 10px; font-size: clamp(1.2rem, 2.5vw, 1.55rem); line-height: 1.4; }
.hub-steps { display: grid; gap: 10px; padding-inline-start: 1.55rem; }
.hub-steps li { padding-inline-start: 5px; }
.hub-guide-section p { color: var(--text-muted); }
.hub-faq { margin-top: 30px; }
.hub-faq details { margin: 9px 0; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); }
.hub-faq summary { padding: 13px 16px; cursor: pointer; font-weight: 700; }
.hub-faq details[open] summary { color: var(--primary); border-bottom: 1px solid var(--border); }
.hub-faq details p { margin: 0; padding: 12px 16px 16px; color: var(--text-muted); }
.operation-note { max-width: 980px; margin: 12px auto; padding: 11px 14px; border-inline-start: 3px solid var(--warning, #c98b16); border-radius: 9px; background: color-mix(in srgb, var(--warning, #f59e0b) 10%, var(--surface-solid, #fff)); color: var(--text-muted); font-size: .92rem; line-height: 1.65; }

/* Unified file workbench used by PDF, image, conversion and standalone tools. */
.hub-drop { display: grid; place-items: center; gap: 9px; min-height: 150px; margin: 12px 0 18px; padding: 26px 20px; text-align: center; color: var(--text); background: color-mix(in srgb, var(--primary) 3%, var(--surface-solid)); border: 2px dashed var(--border-strong); border-radius: 18px; cursor: pointer; transition: border-color .18s, background .18s, transform .18s; }
.hub-drop:hover, .hub-drop:focus-visible, .hub-drop.drag { border-color: var(--primary); background: var(--grad-soft); }
.hub-drop.drag { transform: scale(1.005); }
.hub-drop p { margin: 0; max-width: 620px; font-weight: 700; }
.hub-browse-hint { color: var(--text-muted); font-size: 12.5px; }
.hub-drop-icon { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 14px; background: var(--grad-soft); color: var(--primary); font-size: 25px; }
.hub-files, .hub-actions, .wb-result { margin: 16px 0; padding: 16px; border: 1px solid var(--border); border-radius: 15px; background: var(--surface, rgba(255,255,255,.72)); }
.hub-files h3, .hub-actions h3 { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: 0 0 12px; font-size: 16px; }
.wb-file-help { margin: -4px 0 10px; color: var(--text-muted); font-size: 13px; }
.hub-filelist { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.hub-filelist li { display: flex; align-items: center; gap: 10px; padding: 9px 10px; border: 1px solid var(--border); border-radius: 11px; background: var(--surface-solid); }
.hub-file-index { display: grid; place-items: center; flex: 0 0 28px; width: 28px; height: 28px; border-radius: 9px; background: var(--grad-soft); color: var(--primary); font-weight: 800; }
.hub-file-name { flex: 1; overflow-wrap: anywhere; font-weight: 650; }
.hub-file-name small { display: block; color: var(--text-muted); font-weight: 500; }
.wb-file-controls { display: flex; flex: 0 0 auto; gap: 4px; }
.hub-actions .hub-quality, .wb-opts { display: flex; flex-wrap: wrap; align-items: end; gap: 12px; margin: 0 0 14px; }
.wb-opt { display: grid; gap: 5px; min-width: min(190px, 100%); color: var(--text-muted); font-size: 13px; font-weight: 650; }
.wb-opt input:not([type="checkbox"]), .wb-opt select, .wb-opt textarea, .wb-input-text textarea, .wb-result textarea { width: 100%; padding: 9px 11px; border: 1px solid var(--border-strong); border-radius: 10px; background: var(--surface-solid); color: var(--text); font: inherit; }
.wb-opt input[type="range"] { accent-color: var(--primary); padding-inline: 0; }
.wb-opt.wb-wide { flex: 1 1 100%; }
.wb-opt.wb-check { display: flex; align-items: center; min-width: 0; }
.wb-input-text { display: grid; gap: 7px; margin: 14px 0; color: var(--text-muted); font-size: 13px; font-weight: 700; }
.wb-input-text textarea { min-height: 130px; resize: vertical; }
.action-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(190px, 100%), 1fr)); gap: 9px; }
.action-grid .hub-act { min-height: 44px; text-align: start; justify-content: flex-start; }
.wb-run-host { display: flex; justify-content: flex-start; margin-top: 14px; }
.wb-result { display: grid; gap: 10px; }
.wb-result label { font-weight: 750; }
.wb-result textarea { min-height: 130px; resize: vertical; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.hub-status { min-height: 28px; margin: 12px 2px; color: var(--text-muted); font-size: 14px; font-weight: 650; overflow-wrap: anywhere; }
.workspace .disclosure { margin-top: 14px; }
@media (max-width: 600px) {
  .hub-drop { min-height: 132px; padding: 20px 14px; }
  .hub-files, .hub-actions, .wb-result { padding: 12px; }
  .hub-filelist li { align-items: flex-start; flex-wrap: wrap; }
  .wb-file-controls { margin-inline-start: auto; }
  .action-grid { grid-template-columns: 1fr; }
  .wb-opt { min-width: 100%; }
}
@media (max-width: 640px) { .hub-guide { margin: 24px auto; } .hub-guide-intro { padding: 13px 14px; } }