:root {
  --background: #f7f9fb;
  --surface: #ffffff;
  --surface-low: #f2f4f6;
  --surface-container: #eceef0;
  --surface-high: #e6e8ea;
  --text: #191c1e;
  --muted: #44474d;
  --outline: #75777d;
  --outline-soft: #c4c6cd;
  --primary: #05162b;
  --result: #1b2b41;
  --blue: #0058be;
  --blue-hover: #2170e4;
  --blue-soft: #d8e2ff;
  --error: #ba1a1a;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  --shadow-result: 0 10px 25px rgba(5, 22, 43, 0.12);
  --container: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--background);
  color: var(--text);
  font-family: Inter, "Noto Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button { color: inherit; }
.container { width: min(calc(100% - 48px), var(--container)); margin-inline: auto; }
.hidden { display: none !important; }
.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 999;
  padding: 9px 12px;
  background: var(--primary);
  color: #fff;
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  border-bottom: 1px solid #e0e3e5;
  background: rgba(236, 238, 240, 0.96);
  backdrop-filter: blur(10px);
}
.nav-shell {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  min-height: 72px;
  align-items: center;
  gap: 24px;
}
.brand {
  justify-self: start;
  color: var(--primary);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.035em;
}
.brand-mark { display: none; }
.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
}
.site-nav a {
  position: relative;
  padding: 24px 0 21px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
}
.site-nav a:hover,
.site-nav a[aria-current="page"] { color: var(--blue); }
.site-nav a[aria-current="page"]::after {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 2px;
  background: var(--blue);
  content: "";
}
.header-actions { justify-self: end; display: none; }

.page-main {
  min-height: calc(100vh - 218px);
  padding: 56px 0 72px;
}
.page-heading { max-width: 820px; margin-bottom: 40px; }
.page-heading h1 {
  margin: 0 0 8px;
  color: var(--primary);
  font-size: clamp(28px, 3vw, 36px);
  line-height: 1.3;
  letter-spacing: -0.025em;
}
.page-heading p { margin: 0; color: var(--muted); font-size: 17px; }
.breadcrumb { display: none; }

.home-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 36px;
}
.home-heading .page-heading { margin: 0; }
.search-box { position: relative; width: min(100%, 360px); }
.search-box input {
  width: 100%;
  height: 56px;
  padding: 0 18px 0 46px;
  border: 1px solid var(--outline-soft);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  outline: none;
  box-shadow: var(--shadow);
}
.search-box input:focus { border: 2px solid var(--blue); }
.search-icon { position: absolute; top: 50%; left: 17px; color: var(--outline); transform: translateY(-50%); }
.tool-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.tool-card {
  display: flex;
  min-height: 292px;
  flex-direction: column;
  padding: 26px;
  border: 1px solid var(--outline-soft);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
  transition: border-color 0.16s ease, transform 0.16s ease;
}
.tool-card:hover { transform: translateY(-2px); border-color: var(--blue); }
.tool-card.is-disabled { opacity: 0.55; pointer-events: none; }
.tool-icon {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  margin-bottom: 24px;
  border-radius: 8px;
  background: var(--blue-soft);
  color: var(--primary);
  font-size: 18px;
  font-weight: 700;
}
.tool-card h2 { margin: 0 0 8px; color: var(--primary); font-size: 23px; line-height: 1.35; letter-spacing: -0.02em; }
.tool-card p { margin: 0 0 24px; color: var(--muted); font-size: 15px; }
.tool-link { margin-top: auto; color: var(--blue); font-size: 14px; font-weight: 600; }
.tool-badge { display: inline-flex; width: fit-content; margin-top: auto; padding: 5px 8px; background: var(--surface-low); color: var(--outline); font-size: 12px; }
.feature-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 36px; }
.tip-card,
.trust-card { min-height: 250px; padding: 32px; border-radius: 8px; }
.tip-card { background: var(--result); color: #fff; box-shadow: var(--shadow-result); }
.tip-label { color: #b7c7e4; font-size: 12px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; }
.tip-card h3 { margin: 16px 0 10px; font-size: 24px; }
.tip-card p { margin: 0; color: #b7c7e4; font-size: 16px; }
.tip-card a { display: inline-flex; margin-top: 24px; padding: 11px 16px; border: 1px solid #b7c7e4; border-radius: 4px; font-size: 13px; font-weight: 600; }
.trust-card { border: 1px solid var(--outline-soft); background: var(--surface); box-shadow: var(--shadow); }
.trust-card h3 { margin: 0 0 12px; color: var(--primary); font-size: 23px; }
.trust-card p,
.trust-card li { color: var(--muted); font-size: 15px; }
.trust-card ul { margin: 20px 0 0; padding: 0; list-style: none; }
.trust-card li { margin-top: 8px; }

.calculator-grid {
  display: grid;
  grid-template-columns: minmax(360px, 5fr) minmax(0, 7fr);
  gap: 40px;
  align-items: start;
}
.tax-grid { grid-template-columns: minmax(0, 7fr) minmax(360px, 5fr); }
.stack { display: grid; gap: 24px; }
.card {
  border: 1px solid var(--outline-soft);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.form-card { padding: 30px; }
.card-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid #e0e3e5;
  color: var(--primary);
  font-size: 24px;
}
.card-title-icon { color: var(--blue); font-size: 18px; }
.form-section + .form-section { margin-top: 28px; padding-top: 28px; border-top: 1px solid #eceef0; }
.form-section h3 { margin: 0 0 16px; color: var(--primary); font-size: 16px; }
.field-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.field-grid.one-column { grid-template-columns: 1fr; }
.field-full { grid-column: 1 / -1; }
.field label,
.field-label { display: flex; align-items: center; gap: 5px; margin-bottom: 8px; color: var(--text); font-size: 14px; font-weight: 500; }
.required { color: var(--error); }
.input-wrap { position: relative; }
input[type="text"],
input[type="number"],
input[type="date"],
select {
  width: 100%;
  min-height: 56px;
  padding: 12px 14px;
  border: 1px solid var(--outline-soft);
  border-radius: 4px;
  background: var(--background);
  color: var(--text);
  outline: none;
  font-size: 16px;
  transition: border-color 0.14s ease, box-shadow 0.14s ease;
}
input.has-suffix { padding-right: 54px; }
input:focus,
select:focus { border: 2px solid var(--blue); box-shadow: 0 0 0 2px rgba(0, 88, 190, 0.1); }
input[aria-invalid="true"] { border-color: var(--error); }
.input-suffix { position: absolute; top: 50%; right: 14px; color: var(--outline); font-size: 14px; transform: translateY(-50%); pointer-events: none; }
.field-help,
.validation-message { margin: 6px 0 0; font-size: 12px; }
.field-help { color: var(--muted); }
.validation-message { min-height: 18px; color: var(--error); font-weight: 500; }
.choice-group { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-bottom: 18px; }
.choice-card {
  position: relative;
  display: flex;
  min-height: 52px;
  align-items: center;
  padding: 10px 12px;
  border: 1px solid var(--outline-soft);
  border-radius: 4px;
  background: var(--surface);
  cursor: pointer;
}
.choice-card input { position: absolute; opacity: 0; }
.choice-card:has(input:checked) { border: 2px solid var(--blue); background: rgba(216, 226, 255, 0.55); color: var(--blue); }
.choice-card strong { display: block; font-size: 13px; }
.choice-card span span { display: block; margin-top: 2px; color: var(--muted); font-size: 11px; }
.check-card { display: flex; gap: 10px; align-items: flex-start; padding: 14px; border: 1px solid var(--outline-soft); border-radius: 4px; background: var(--surface-low); cursor: pointer; }
.check-card input { width: 17px; height: 17px; margin-top: 2px; accent-color: var(--blue); }
.advanced-block { margin-top: 20px; border: 1px solid var(--outline-soft); border-radius: 4px; background: var(--surface-low); }
.advanced-block summary { padding: 14px 16px; cursor: pointer; color: var(--primary); font-size: 13px; font-weight: 600; }
.advanced-inner { padding: 0 16px 16px; }
.period-table-wrap { overflow-x: auto; margin-top: 12px; }
.period-table { width: 100%; min-width: 620px; border-collapse: collapse; font-size: 12px; }
.period-table th,
.period-table td { padding: 10px; border: 1px solid #e0e3e5; text-align: left; }
.period-table th { background: var(--surface-low); color: var(--muted); }
.period-table input { min-height: 40px; }
.info-box { padding: 12px 14px; border-radius: 4px; font-size: 12px; }
.info-box strong { display: block; margin-bottom: 3px; }
.info-primary { background: #eaf2ff; color: #234a78; }
.info-warning { background: #fff5df; color: #755211; }
.info-danger { background: #ffdad6; color: #93000a; }
.form-actions { display: flex; gap: 12px; margin-top: 28px; }
.btn {
  display: inline-flex;
  min-height: 52px;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 4px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
}
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-hover); }
.btn-secondary { border-color: var(--primary); background: transparent; color: var(--primary); }
.btn-secondary:hover { background: var(--surface-low); }
.form-actions .btn-primary { flex: 1; }

.result-panel { position: sticky; top: 104px; overflow: hidden; }
.result-empty { display: grid; min-height: 330px; place-items: center; padding: 32px; text-align: center; }
.result-empty-icon { display: grid; width: 52px; height: 52px; place-items: center; margin: 0 auto 14px; border-radius: 50%; background: var(--blue-soft); color: var(--blue); font-weight: 700; }
.result-empty strong { color: var(--primary); }
.result-empty p { margin: 5px 0 0; color: var(--muted); font-size: 13px; }
.result-content { display: none; }
.result-content.is-visible { display: block; }
.result-hero { padding: 36px; background: var(--result); color: #fff; }
.result-label { color: #b7c7e4; font-size: 12px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }
.result-amount { display: block; margin: 10px 0 20px; font-size: clamp(40px, 5vw, 58px); line-height: 1.15; letter-spacing: -0.035em; font-variant-numeric: tabular-nums; }
.result-status { margin: 0; color: #cbd4e2; font-size: 13px; }
.result-kpis { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 28px; padding-top: 22px; border-top: 1px solid rgba(255, 255, 255, 0.18); }
.result-kpis span { display: block; color: #aebbd0; font-size: 11px; }
.result-kpis strong { display: block; margin-top: 5px; font-size: 20px; font-variant-numeric: tabular-nums; }
.result-body { padding: 28px; }
.result-body h3 { margin: 0 0 18px; color: var(--primary); font-size: 20px; }
.result-list { margin: 0; }
.result-row { display: flex; justify-content: space-between; gap: 22px; padding: 13px 0; border-bottom: 1px solid #eceef0; font-size: 13px; }
.result-row dt { color: var(--muted); }
.result-row dd { margin: 0; color: var(--primary); font-weight: 600; font-variant-numeric: tabular-nums; }
.result-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 22px; }
.result-actions .btn:first-child { grid-column: 1 / -1; }
.breakdown-card { padding: 28px; }
.breakdown-card h3 { margin: 0 0 20px; color: var(--primary); font-size: 22px; }
.breakdown-bars { display: grid; gap: 15px; }
.breakdown-line { display: grid; grid-template-columns: 130px minmax(90px, 1fr) 110px; align-items: center; gap: 14px; font-size: 12px; }
.bar-track { height: 9px; overflow: hidden; border-radius: 999px; background: #e0e3e5; }
.bar-fill { height: 100%; border-radius: inherit; background: var(--blue); }
.bar-fill.muted { background: #8fa5c1; }
.rules-card { padding: 28px; background: var(--surface-low); }
.rules-card h3 { margin: 0 0 16px; color: var(--primary); font-size: 21px; }
.rule-list { display: grid; gap: 15px; margin: 0; padding: 0; list-style: none; }
.rule-list li { display: grid; grid-template-columns: 20px 1fr; gap: 10px; color: var(--muted); font-size: 13px; }
.rule-check { color: var(--blue); font-weight: 700; }
.rule-list strong { display: block; color: var(--text); font-size: 13px; }

.content-section { margin-top: 44px; padding-top: 32px; border-top: 1px solid var(--outline-soft); }
.content-section h2 { margin: 0 0 12px; color: var(--primary); font-size: 22px; }
.content-section p,
.content-section li { color: var(--muted); font-size: 14px; }
.faq-list { display: grid; gap: 8px; margin-top: 18px; }
.faq-list details { border: 1px solid var(--outline-soft); border-radius: 4px; background: var(--surface); }
.faq-list summary { padding: 14px 16px; cursor: pointer; color: var(--primary); font-size: 14px; font-weight: 600; }
.faq-list details p { margin: 0; padding: 0 16px 16px; }

.site-footer { margin-top: 24px; padding: 38px 0; background: var(--primary); color: #fff; }
.footer-grid { display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.footer-brand { font-size: 22px; font-weight: 700; }
.footer-copy { margin-top: 8px; color: #8fa0b7; font-size: 12px; }
.footer-links { display: flex; gap: 24px; color: #8fa0b7; font-size: 12px; }
.toast { position: fixed; right: 20px; bottom: 20px; z-index: 100; padding: 11px 14px; border-radius: 4px; background: var(--primary); color: #fff; font-size: 12px; box-shadow: var(--shadow-result); opacity: 0; transform: translateY(10px); pointer-events: none; transition: 0.18s ease; }
.toast.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  .nav-shell { grid-template-columns: auto 1fr; }
  .site-nav { justify-content: end; }
  .tool-grid { grid-template-columns: 1fr 1fr; }
  .calculator-grid,
  .tax-grid { grid-template-columns: 1fr; gap: 24px; }
  .result-panel { position: static; }
  .home-heading { align-items: stretch; flex-direction: column; }
  .search-box { width: 100%; }
}

@media (max-width: 640px) {
  .container { width: min(calc(100% - 40px), var(--container)); }
  .nav-shell { min-height: 64px; gap: 14px; }
  .brand { font-size: 18px; }
  .site-nav { gap: 14px; }
  .site-nav a { padding: 22px 0 19px; font-size: 12px; }
  .page-main { padding: 38px 0 52px; }
  .page-heading { margin-bottom: 28px; }
  .page-heading p { font-size: 15px; }
  .tool-grid,
  .feature-grid { grid-template-columns: 1fr; }
  .tool-card { min-height: 240px; }
  .field-grid,
  .choice-group { grid-template-columns: 1fr; }
  .form-card,
  .breakdown-card,
  .rules-card { padding: 22px; }
  .result-hero { padding: 28px 22px; }
  .result-body { padding: 22px; }
  .result-actions { grid-template-columns: 1fr; }
  .result-actions .btn:first-child { grid-column: auto; }
  .breakdown-line { grid-template-columns: 1fr; gap: 6px; }
  .footer-grid { align-items: flex-start; flex-direction: column; }
  .footer-links { flex-wrap: wrap; }
}