:root {
  --canvas: #f4f8fb;
  --paper: #ffffff;
  --ink: #1c2731;
  --muted: #667482;
  --subtle: #9aaab6;
  --line: #dce6ed;
  --line-strong: #c7d8e3;
  --green: #287cad;
  --green-dark: #155a82;
  --green-soft: #e6f3fb;
  --amber: #a75e14;
  --amber-soft: #fff4e5;
  --red: #a74432;
  --red-soft: #fff0ec;
  --serif: Iowan Old Style, Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--canvas); color: var(--ink); font-family: var(--sans); font-size: 15px; line-height: 1.55; }
button, select { font: inherit; }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }

.topbar { width: min(1180px, calc(100% - 48px)); height: 76px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 15px; font-weight: 760; letter-spacing: -0.03em; }
.brand-mark { display: grid; width: 25px; height: 25px; place-items: center; border-radius: 7px; background: var(--ink); color: white; font-size: 16px; line-height: 1; }
nav { display: flex; align-items: center; gap: 26px; color: var(--muted); font-size: 13px; }
nav a:hover { color: var(--ink); }
.nav-action { padding: 8px 13px; border: 1px solid var(--ink); border-radius: 7px; color: var(--ink); font-weight: 650; }

main { width: min(1180px, calc(100% - 48px)); margin: 0 auto; }
.intro { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(360px, .85fr); gap: 86px; padding: 76px 0 66px; align-items: end; }
.eyebrow, .section-label { margin: 0 0 10px; color: var(--green); font-size: 11px; font-weight: 790; letter-spacing: .105em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 20px; font-family: var(--serif); font-size: clamp(44px, 5.25vw, 68px); font-weight: 500; line-height: 1.01; letter-spacing: -.055em; }
.intro-text { width: min(520px, 100%); margin-bottom: 20px; color: #4f5651; font-size: 17px; line-height: 1.65; }
.intro-points { display: flex; flex-wrap: wrap; gap: 7px; }
.intro-points span, .format-list span { padding: 5px 9px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255,255,255,.48); color: #515852; font-size: 12px; }
.steps { display: grid; gap: 1px; margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line-strong); }
.steps li { display: grid; grid-template-columns: 37px 1fr; gap: 13px; align-items: center; padding: 15px 0; border-bottom: 1px solid var(--line); }
.steps li > span { color: var(--green); font-size: 11px; font-weight: 800; letter-spacing: .06em; }
.steps strong, .steps small { display: block; }
.steps strong { font-size: 14px; }
.steps small { color: var(--muted); font-size: 12px; }

.tool-area { scroll-margin-top: 24px; padding-bottom: 62px; }
.tool-topline { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 20px; }
.tool-topline .section-label { margin-bottom: 5px; }
.tool-topline h2 { margin: 0; font-family: var(--serif); font-size: 30px; font-weight: 520; letter-spacing: -.035em; }
.privacy-line { margin: 0 0 3px; color: var(--muted); font-size: 12px; }
.privacy-line span { color: #4fa9dc; font-size: 11px; }

.tool-shell { overflow: hidden; border: 1px solid var(--line-strong); border-radius: 13px; background: var(--paper); box-shadow: 0 14px 32px rgba(35, 45, 37, .055); }
.tool-head { display: flex; align-items: center; justify-content: space-between; min-height: 68px; padding: 13px 20px; border-bottom: 1px solid var(--line); background: #fcfcfb; }
.tool-head-title, .file-info { display: flex; align-items: center; gap: 11px; }
.tool-head-title strong, .file-info strong { display: block; font-size: 13px; letter-spacing: -.015em; }
.tool-head-title small, .file-info span { display: block; color: var(--muted); font-size: 11px; }
.file-glyph { display: inline-grid; width: 35px; height: 35px; place-items: center; border: 1px solid #bcd8e8; border-radius: 8px; background: var(--green-soft); color: var(--green); font-size: 10px; font-weight: 830; letter-spacing: .03em; }
.local-pill { padding: 4px 7px; border: 1px solid #cde2ef; border-radius: 999px; color: var(--green); background: #f2f9fd; font-size: 10px; font-weight: 800; letter-spacing: .08em; }

.drop-zone { min-height: 338px; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 42px 24px; border: 1px dashed transparent; outline: none; text-align: center; transition: background .18s ease, border-color .18s ease; }
.drop-zone:hover, .drop-zone:focus-visible, .drop-zone.dragging { border-color: #82b9d9; background: #f5fbff; }
.drop-icon { display: grid; width: 47px; height: 47px; margin-bottom: 15px; place-items: center; border-radius: 50%; background: var(--green); color: white; font-size: 26px; line-height: 1; }
.drop-zone h3 { margin-bottom: 3px; font-size: 17px; letter-spacing: -.025em; }
.drop-zone p { margin-bottom: 7px; color: var(--muted); font-size: 13px; }
.drop-zone small { color: var(--subtle); font-size: 11px; }
.text-button { margin: 0; padding: 0; border: 0; border-bottom: 1px solid var(--green); background: none; color: var(--green); font-size: inherit; font-weight: 700; }
.sample-button { margin-top: 20px; padding: 7px 10px; border: 0; border-radius: 6px; background: transparent; color: var(--muted); font-size: 12px; text-decoration: underline; text-underline-offset: 3px; }
.sample-button:hover { color: var(--ink); }
.hidden { display: none !important; }

.workbench { padding: 21px; }
.file-row { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.quiet-button { padding: 7px 10px; border: 1px solid var(--line-strong); border-radius: 7px; background: white; color: #4f5751; font-size: 12px; font-weight: 650; }
.quiet-button:hover { border-color: #99a69d; color: var(--ink); }
.inspection-grid { display: grid; grid-template-columns: minmax(0, .86fr) minmax(0, 1.14fr); gap: 13px; margin-top: 18px; }
.detection-card, .settings-card, .preview-card { border: 1px solid var(--line); border-radius: 9px; background: #fff; }
.detection-card, .settings-card { padding: 17px; }
.card-heading { display: flex; align-items: start; justify-content: space-between; gap: 12px; }
.card-heading.compact { margin-bottom: 12px; }
.card-heading .section-label { margin-bottom: 3px; }
.card-heading h3, .preview-head h3 { margin: 0; font-size: 15px; letter-spacing: -.025em; }
.confidence { flex: none; padding: 3px 7px; border-radius: 999px; background: var(--green-soft); color: var(--green); font-size: 10px; font-weight: 800; }
.detection-value { margin-top: 19px; font-size: 21px; font-weight: 760; letter-spacing: -.04em; }
.detection-reason { min-height: 38px; margin: 5px 0 12px; color: var(--muted); font-size: 12px; line-height: 1.5; }
.candidate-list { display: flex; flex-wrap: wrap; gap: 5px; }
.candidate-list span { padding: 3px 6px; border: 1px solid var(--line); border-radius: 5px; color: #5f6760; background: #fafbf9; font-size: 10px; }
.candidate-list span:first-child { border-color: #b8d9eb; background: #f1f9fd; color: var(--green-dark); font-weight: 700; }

.settings-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 14px; }
.control-field { display: grid; gap: 5px; color: #525a53; font-size: 11px; font-weight: 700; }
.control-field select { width: 100%; min-width: 0; padding: 8px 27px 8px 9px; border: 1px solid #cfd3cd; border-radius: 6px; outline: none; background: #fff; color: var(--ink); font-size: 12px; font-weight: 520; }
.control-field select:focus { border-color: #5d9ec6; box-shadow: 0 0 0 3px rgba(71, 147, 194, .14); }

.diagnosis-row { display: flex; align-items: center; gap: 10px; margin-top: 14px; padding: 11px 13px; border: 1px solid #cce4f1; border-radius: 8px; background: #f2f9fd; color: #2b6387; }
.diagnosis-row.is-warning { border-color: #f1cfab; background: var(--amber-soft); color: #8b4d10; }
.diagnosis-icon { display: grid; flex: none; width: 19px; height: 19px; place-items: center; border-radius: 50%; background: var(--green); color: white; font-size: 12px; font-weight: 800; }
.is-warning .diagnosis-icon { background: var(--amber); }
.diagnosis-row div { display: flex; align-items: baseline; gap: 8px; min-width: 0; }
.diagnosis-row strong { flex: none; font-size: 12px; }
.diagnosis-row div span { overflow: hidden; color: inherit; font-size: 11px; opacity: .86; text-overflow: ellipsis; white-space: nowrap; }

.preview-card { margin-top: 14px; overflow: hidden; }
.preview-head { display: flex; align-items: end; justify-content: space-between; gap: 18px; padding: 15px 16px 12px; border-bottom: 1px solid var(--line); }
.preview-head .section-label { margin-bottom: 3px; }
.row-count { color: var(--muted); font-size: 11px; white-space: nowrap; }
.preview-shell { min-height: 166px; position: relative; }
.table-scroll { overflow: auto; max-height: 320px; }
table { width: 100%; border-collapse: collapse; font-size: 12px; }
th, td { min-width: 125px; max-width: 320px; padding: 9px 12px; border-bottom: 1px solid #eceeea; overflow: hidden; text-align: left; text-overflow: ellipsis; white-space: nowrap; }
th { position: sticky; top: 0; background: #fafbf9; color: #596159; font-size: 11px; font-weight: 760; z-index: 1; }
td { color: #303631; }
tbody tr:last-child td { border-bottom: 0; }
.preview-empty { padding: 58px 20px; color: var(--muted); text-align: center; font-size: 12px; }
.warning-row { display: flex; gap: 9px; align-items: start; margin-top: 13px; padding: 11px 13px; border: 1px solid #efc7bd; border-radius: 8px; background: var(--red-soft); color: #8d4335; }
.warning-row > span { display: grid; flex: none; width: 18px; height: 18px; place-items: center; border-radius: 50%; background: var(--red); color: white; font-size: 12px; font-weight: 800; }
.warning-row p { margin: 0; font-size: 12px; line-height: 1.5; }

.download-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-top: 17px; padding-top: 17px; border-top: 1px solid var(--line); }
.download-row p { display: grid; gap: 1px; margin: 0; }
.download-row strong { font-size: 13px; }
.download-row p span { color: var(--muted); font-size: 11px; }
.download-button { flex: none; padding: 10px 13px; border: 1px solid var(--green); border-radius: 7px; background: var(--green); color: white; font-size: 12px; font-weight: 760; transition: background .15s ease, transform .15s ease; }
.download-button:hover { background: var(--green-dark); transform: translateY(-1px); }

.support-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong); }
.support-grid article { min-height: 216px; padding: 25px 26px 24px 0; border-right: 1px solid var(--line); }
.support-grid article + article { padding-left: 26px; }
.support-grid article:last-child { border-right: 0; }
.support-number { display: block; margin-bottom: 35px; color: var(--green); font-size: 11px; font-weight: 800; letter-spacing: .08em; }
.support-grid h2 { margin-bottom: 7px; font-family: var(--serif); font-size: 20px; font-weight: 550; letter-spacing: -.035em; }
.support-grid p { max-width: 285px; margin: 0; color: var(--muted); font-size: 12px; line-height: 1.65; }
.formats { display: flex; align-items: center; justify-content: space-between; gap: 56px; padding: 62px 0 77px; }
.formats .section-label { margin-bottom: 5px; }
.formats h2 { margin: 0; font-family: var(--serif); font-size: 29px; font-weight: 550; letter-spacing: -.04em; }
.format-list { display: flex; max-width: 490px; flex-wrap: wrap; justify-content: end; gap: 7px; }
.related-pages { display: grid; grid-template-columns: minmax(220px, .8fr) 1.2fr; gap: 48px; padding: 42px 0 24px; border-top: 1px solid var(--line); }
.related-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.related-links a { display: flex; min-height: 88px; flex-direction: column; justify-content: space-between; gap: 12px; padding: 16px 18px; border: 1px solid var(--line); border-radius: 12px; background: rgba(255, 255, 255, .58); color: var(--ink); text-decoration: none; transition: border-color .16s ease, background .16s ease, transform .16s ease; }
.related-links a:hover { border-color: var(--blue); background: #fff; transform: translateY(-2px); }
.related-links strong { font-size: 15px; font-weight: 650; }
.related-links span { color: var(--muted); font-size: 12px; line-height: 1.5; }
.seo-page { width: min(960px, calc(100% - 48px)); margin: 0 auto; }
.seo-hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(240px, .85fr); gap: 56px; align-items: end; padding: 92px 0 66px; }
.seo-hero h1 { max-width: 710px; margin: 0 0 20px; font-family: var(--serif); font-size: clamp(42px, 6vw, 74px); font-weight: 560; letter-spacing: -.065em; line-height: .98; }
.seo-hero .intro-text { max-width: 560px; margin: 0; }
.seo-aside { padding: 20px; border: 1px solid var(--line); border-radius: 14px; background: rgba(255, 255, 255, .65); }
.seo-aside strong { display: block; margin-bottom: 8px; font-size: 14px; }
.seo-aside p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.seo-cta { display: inline-flex; align-items: center; gap: 10px; margin-top: 26px; padding: 12px 15px; border-radius: 8px; background: var(--blue); color: white; font-size: 13px; font-weight: 750; text-decoration: none; }
.seo-cta:hover { background: var(--blue-dark); }
.seo-section { padding: 40px 0; border-top: 1px solid var(--line); }
.seo-section h2 { margin: 0 0 12px; font-family: var(--serif); font-size: 30px; font-weight: 550; letter-spacing: -.045em; }
.seo-section > p { max-width: 720px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.8; }
.seo-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 22px; }
.seo-card { padding: 19px; border: 1px solid var(--line); border-radius: 12px; background: rgba(255, 255, 255, .55); }
.seo-card strong { display: block; margin-bottom: 8px; font-size: 14px; }
.seo-card p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.seo-note { margin-top: 18px !important; padding: 14px 16px; border-left: 3px solid var(--blue); background: var(--blue-soft); color: var(--ink) !important; font-size: 13px !important; }
.seo-footer { display: flex; justify-content: space-between; gap: 18px; padding: 24px 0 46px; color: var(--muted); font-size: 12px; }
.seo-footer a { color: var(--blue-dark); text-decoration: none; }
.seo-footer a:hover { text-decoration: underline; }
footer { display: flex; width: min(1180px, calc(100% - 48px)); margin: 0 auto; justify-content: space-between; padding: 18px 0 24px; border-top: 1px solid var(--line); color: var(--muted); font-size: 11px; }

@media (max-width: 820px) {
  .topbar, main, footer { width: min(100% - 32px, 620px); }
  .topbar { height: 64px; }
  nav { gap: 14px; font-size: 12px; }
  nav a:not(.nav-action) { display: none; }
  .intro { grid-template-columns: 1fr; gap: 35px; padding: 54px 0 46px; }
  .steps { max-width: 480px; }
  .tool-topline { align-items: start; flex-direction: column; gap: 8px; }
  .inspection-grid { grid-template-columns: 1fr; }
  .support-grid { grid-template-columns: 1fr; }
  .support-grid article, .support-grid article + article { min-height: 0; padding: 24px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .support-grid article:last-child { border-bottom: 0; }
  .support-number { margin-bottom: 19px; }
  .formats { align-items: start; flex-direction: column; gap: 23px; padding: 48px 0; }
  .format-list { justify-content: start; }
  .related-pages { grid-template-columns: 1fr; gap: 20px; }
  .seo-hero { grid-template-columns: 1fr; gap: 28px; padding: 60px 0 46px; }
  .seo-grid { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .intro { padding-top: 43px; }
  h1 { font-size: 43px; }
  .tool-shell { margin: 0 -4px; }
  .tool-head { padding: 12px 14px; }
  .workbench { padding: 14px; }
  .file-row, .download-row { align-items: start; flex-direction: column; gap: 12px; }
  .settings-grid { grid-template-columns: 1fr; }
  .diagnosis-row div { display: grid; gap: 1px; }
  .diagnosis-row div span { overflow: visible; white-space: normal; }
  .download-button { width: 100%; }
  .formats h2, .tool-topline h2 { font-size: 26px; }
  .related-links { grid-template-columns: 1fr; }
  .seo-page { width: min(100% - 32px, 620px); }
  .seo-hero h1 { font-size: 45px; }
  .seo-footer { align-items: start; flex-direction: column; }
  footer { align-items: start; flex-direction: column; gap: 4px; }
}