/* Tech9Pros — site styles. No external fonts or frameworks (fast, private, CSP-friendly). */
:root {
  --paper: #eef1f5;
  --surface: #ffffff;
  --ink: #172033;
  --ink-soft: #4a5568;
  --line: #d5dbe4;
  --action: #2f45e0;
  --action-ink: #ffffff;
  --mark: #ffe25a;
  --bar-bg: #e3e8ef;
  --bar: #172033;
  --error: #b42318;
  --focus: #2f45e0;
  --radius-lg: 18px;
  --radius-sm: 8px;
  --wrap: 1080px;
  --text: 1.0625rem;
  --font: ui-sans-serif, "Segoe UI Variable", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0f1522;
    --surface: #182033;
    --ink: #e9edf5;
    --ink-soft: #a7b1c2;
    --line: #2b3550;
    --action: #6f7fff;
    --action-ink: #0f1522;
    --mark: #f5d33b;
    --bar-bg: #26304a;
    --bar: #e9edf5;
    --error: #ff8a80;
    --focus: #8f9bff;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 var(--text)/1.6 var(--font);
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
a { color: var(--action); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 4px; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip { position: absolute; left: 16px; top: -48px; background: var(--surface); padding: 8px 12px; z-index: 10; }
.skip:focus { top: 12px; }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 28px; } }

/* Header */
.site-header { border-bottom: 1px solid var(--line); background: var(--paper); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; min-height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 750; font-size: 1.125rem; letter-spacing: -0.01em; }
.brand svg { flex: none; }
.nav { display: flex; gap: 22px; }
.nav a { color: var(--ink); text-decoration: none; font-weight: 550; font-size: 0.975rem; }
.nav a:hover, .nav a[aria-current="page"] { text-decoration: underline; }
.menu { display: none; }
@media (max-width: 640px) {
  .nav { display: none; }
  .menu { display: block; position: relative; }
  .menu summary { list-style: none; cursor: pointer; padding: 8px 12px; border: 1px solid var(--line); border-radius: var(--radius-sm); font-weight: 600; font-size: 0.95rem; }
  .menu summary::-webkit-details-marker { display: none; }
  .menu nav { position: absolute; right: 0; top: calc(100% + 8px); background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 8px; min-width: 210px; z-index: 5; display: grid; }
  .menu nav a { padding: 10px 12px; color: var(--ink); text-decoration: none; border-radius: 6px; }
  .menu nav a:hover { background: var(--paper); }
}

/* Page intro */
.crumbs { font-size: 0.875rem; color: var(--ink-soft); margin: 22px 0 0; padding: 0; list-style: none; display: flex; flex-wrap: wrap; gap: 6px; }
.crumbs li + li::before { content: "/"; margin-right: 6px; color: var(--line); }
.crumbs a { color: var(--ink-soft); }
.intro { padding: 18px 0 22px; max-width: 46rem; }
h1 {
  font-size: clamp(2rem, 1.3rem + 3.2vw, 3.25rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
  font-weight: 800;
  margin: 0 0 14px;
}
.lead { font-size: 1.1875rem; color: var(--ink-soft); margin: 0; max-width: 40rem; }

/* Tool */
.tool { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 14px; }
@media (min-width: 720px) { .tool { padding: 20px; } }
.drop {
  display: grid; place-items: center; text-align: center; gap: 10px;
  min-height: 210px; padding: 28px 16px;
  border: 2px dashed var(--line); border-radius: 12px; cursor: pointer;
  background: repeating-linear-gradient(135deg, transparent 0 14px, color-mix(in srgb, var(--line) 22%, transparent) 14px 15px);
  transition: border-color .15s, background-color .15s;
}
.drop:hover, .drop.is-over { border-color: var(--action); background-color: color-mix(in srgb, var(--action) 6%, transparent); }
.drop:focus-within { outline: 3px solid var(--focus); outline-offset: 3px; }
.drop-title { font-size: 1.25rem; font-weight: 700; margin: 0; }
.drop-sub { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }
.drop .btn { pointer-events: none; }
.privacy-note { display: inline-flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 6px; font-size: 0.875rem; color: var(--ink-soft); margin: 0; text-wrap: balance; }
.privacy-note svg { flex: none; }

.settings { display: grid; gap: 14px; margin-top: 16px; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); }
.field { display: grid; gap: 6px; align-content: start; }
.field label, .field .label { font-size: 0.875rem; font-weight: 650; display: flex; justify-content: space-between; }
.field output { font-variant-numeric: tabular-nums; color: var(--ink-soft); font-weight: 600; }
.field select, .field input[type=number] {
  font: inherit; font-size: 1rem; color: var(--ink); background: var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 9px 10px; width: 100%;
}
.field input[type=range] { width: 100%; accent-color: var(--action); }
.field .hint { font-size: 0.8125rem; color: var(--ink-soft); margin: 0; }
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
[hidden] { display: none !important; }

.tool-msg { margin: 12px 0 0; font-size: 0.95rem; min-height: 0; }
.tool-msg:empty { display: none; }
.tool-msg.is-error { color: var(--error); font-weight: 600; }

.results { margin-top: 18px; border-top: 1px solid var(--line); padding-top: 14px; }
.results-head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px; }
.results-summary { margin: 0; font-weight: 650; font-variant-numeric: tabular-nums; }
.results-actions { display: flex; gap: 8px; }
.results-list { list-style: none; margin: 12px 0 0; padding: 0; display: grid; gap: 8px; }
.row { display: grid; grid-template-columns: 56px 1fr auto; gap: 12px; align-items: center; padding: 10px; border-radius: 12px; background: var(--paper); }
.row.is-error .row-meta { color: var(--error); }
.row-thumb { width: 56px; height: 56px; object-fit: cover; border-radius: 8px; background: var(--bar-bg); }
.row-thumb.is-empty { animation: pulse 1.2s ease-in-out infinite; }
.row-main { min-width: 0; }
.row-name { margin: 0; font-weight: 600; font-size: 0.95rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.row-meta { margin: 2px 0 0; font-size: 0.9rem; font-variant-numeric: tabular-nums; display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: baseline; }
.row-note { margin: 4px 0 0; font-size: 0.8125rem; color: var(--ink-soft); }
.saved { background: var(--mark); color: #1b1b0f; padding: 0 6px; border-radius: 3px; font-weight: 700; }
.grew { color: var(--ink-soft); }
.dims { color: var(--ink-soft); }
.weight { height: 6px; background: var(--bar-bg); border-radius: 3px; margin-top: 7px; overflow: hidden; }
.weight span { display: block; height: 100%; background: var(--bar); border-radius: 3px; transition: width .5s ease-out; }
@media (max-width: 520px) {
  .row { grid-template-columns: 48px 1fr; }
  .row-thumb { width: 48px; height: 48px; }
  .row .btn { grid-column: 1 / -1; justify-self: stretch; text-align: center; }
}
@keyframes pulse { 50% { opacity: .45; } }

/* Buttons */
.btn {
  display: inline-block; font: inherit; font-weight: 650; font-size: 1rem; line-height: 1;
  padding: 13px 20px; border-radius: 999px; border: 1px solid var(--action);
  background: var(--action); color: var(--action-ink); text-decoration: none; cursor: pointer;
}
.btn:hover { filter: brightness(1.08); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-small { padding: 9px 14px; font-size: 0.9rem; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }

/* Ad slot (collapsed until ads are enabled) */
.ad-slot { margin: 28px 0 0; min-height: 120px; }

/* Content */
.content { display: grid; gap: 40px; padding: 44px 0 20px; }
@media (min-width: 900px) { .content { grid-template-columns: minmax(0, 1fr) 300px; align-items: start; } }
.prose { max-width: 42rem; }
.prose h2 { font-size: 1.5rem; letter-spacing: -0.02em; line-height: 1.2; margin: 36px 0 10px; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.0625rem; margin: 20px 0 4px; }
.prose p, .prose li { color: var(--ink); }
.prose ol { padding-left: 1.25rem; }
.prose ol li { margin-bottom: 6px; padding-left: 4px; }
.faq details { border-bottom: 1px solid var(--line); padding: 12px 0; }
.faq summary { cursor: pointer; font-weight: 650; }
.faq details p { margin: 8px 0 0; color: var(--ink-soft); }

.aside { display: grid; gap: 24px; }
@media (min-width: 900px) { .aside { position: sticky; top: 20px; } }
.aside h2 { font-size: 1rem; margin: 0 0 10px; }
.link-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.link-list a { display: block; padding: 8px 10px; border-radius: 8px; color: var(--ink); text-decoration: none; font-weight: 550; }
.link-list a:hover { background: var(--surface); }

/* Home + hub */
.home-hero { padding: 40px 0 26px; max-width: 48rem; }
.home-hero h1 { font-size: clamp(2.25rem, 1.4rem + 4vw, 4rem); }
.group { padding: 36px 0 8px; }
.group h2 { font-size: 1.375rem; letter-spacing: -0.02em; margin: 0 0 4px; }
.group > p { margin: 0 0 16px; color: var(--ink-soft); }
.tool-index { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); border-top: 1px solid var(--line); }
.tool-index li { border-bottom: 1px solid var(--line); }
.tool-index a { display: block; padding: 14px 4px 14px 0; text-decoration: none; color: var(--ink); }
.tool-index a strong { display: block; font-weight: 650; }
.tool-index a span { display: block; font-size: 0.875rem; color: var(--ink-soft); }
.tool-index a:hover strong { color: var(--action); text-decoration: underline; }
@media (min-width: 560px) { .tool-index li:nth-child(odd) a { padding-right: 20px; } }

.page-body { padding: 10px 0 40px; }

/* Footer */
.site-footer { margin-top: 56px; border-top: 1px solid var(--line); padding: 28px 0 40px; font-size: 0.9rem; color: var(--ink-soft); }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 18px; }
.site-footer a { color: var(--ink-soft); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}