:root {
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --primary: #0f766e;
  --primary-dark: #115e59;
  --soft: #ecfeff;
  --soft-2: #f8fafc;
  --danger: #991b1b;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
  --radius: 18px;
  --max: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Arial, "Noto Sans KR", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

a {
  color: var(--primary-dark);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  width: min(100% - 32px, var(--max));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 72px;
}

.logo {
  font-size: 20px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}

.nav a {
  font-size: 14px;
  color: var(--text);
  font-weight: 600;
}

.hero {
  padding: 64px 0 36px;
  background:
    linear-gradient(180deg, #eefcf9 0%, #f7f8fb 100%);
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: 28px;
  align-items: stretch;
}

.hero-copy,
.hero-side {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
  padding: 32px;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 12px;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--primary-dark);
  font-size: 13px;
  font-weight: 700;
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(32px, 5vw, 50px);
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.hero-sub {
  margin: 0 0 14px;
  font-size: 19px;
  color: var(--text);
  font-weight: 700;
}

.hero-desc {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 12px;
  font-weight: 700;
  border: 1px solid transparent;
  transition: 0.2s ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
  text-decoration: none;
}

.btn-secondary {
  background: #fff;
  color: var(--text);
  border-color: var(--line);
}

.btn-secondary:hover {
  background: var(--soft-2);
  text-decoration: none;
}

.hero-side h2 {
  margin: 0 0 14px;
  font-size: 20px;
}

.hero-side ul {
  padding-left: 18px;
  margin: 0;
  color: var(--muted);
}

.hero-side li + li {
  margin-top: 10px;
}

.section {
  padding: 64px 0;
}

.section-header {
  margin-bottom: 24px;
}

.section-header h2 {
  margin: 0 0 10px;
  font-size: clamp(26px, 4vw, 34px);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.section-header p {
  margin: 0;
  color: var(--muted);
}

.grid-3,
.grid-2,
.grid-4 {
  display: grid;
  gap: 18px;
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
}

.card h3 {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.mini-note {
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.calculator-wrap {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 18px;
  align-items: start;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.field label {
  font-weight: 700;
  font-size: 14px;
}

.field input,
.field select {
  width: 100%;
  min-height: 48px;
  padding: 12px 14px;
  font-size: 15px;
  color: var(--text);
  border: 1px solid #d1d5db;
  border-radius: 12px;
  background: #fff;
}

.field input:focus,
.field select:focus {
  outline: 2px solid #99f6e4;
  border-color: var(--primary);
}

.field.full {
  grid-column: 1 / -1;
}

.calc-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 56px;
  padding: 0 18px;
  border-radius: 12px;
  font-weight: 800;
  font-size: 1.1rem;
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
  transition: 0.2s ease;
}

.calc-btn:hover {
  background: var(--primary-dark);
}

.result-grid {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.result-item {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 16px;
  border-radius: 12px;
  background: var(--soft-2);
  border: 1px solid var(--line);
}

.result-label {
  color: var(--muted);
  font-weight: 700;
  font-size: 14px;
}

.result-value {
  font-weight: 800;
  text-align: right;
}

.result-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px;
}

.warning-box {
  margin-top: 16px;
  padding: 16px 18px;
  border-radius: 14px;
  background: #fff7ed;
  border: 1px solid #fed7aa;
  color: #7c2d12;
  font-size: 14px;
}

.guide-link-list,
.source-list,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin-top: 14px;
}

.pill-link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-weight: 700;
  color: var(--text);
}

.pill-link:hover {
  background: var(--soft-2);
  text-decoration: none;
}

.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.faq-item details {
  padding: 0;
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 20px 22px;
  font-weight: 800;
  position: relative;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-answer {
  padding: 0 22px 22px;
  color: var(--muted);
}

.sources-box {
  background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.cta-panel {
  background: linear-gradient(135deg, #0f766e 0%, #134e4a 100%);
  color: #fff;
}

.cta-panel h2,
.cta-panel p,
.cta-panel a {
  color: #fff;
}

.cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

.cta-links a {
  border: 1px solid rgba(255,255,255,0.22);
  background: rgba(255,255,255,0.08);
  border-radius: 999px;
  padding: 10px 14px;
  font-weight: 700;
}

.cta-links a:hover {
  text-decoration: none;
  background: rgba(255,255,255,0.16);
}

footer {
  padding: 32px 0 60px;
  border-top: 1px solid var(--line);
  background: #fff;
}

.footer-desc {
  color: var(--muted);
  margin: 10px 0 0;
  max-width: 760px;
}

.footer-meta {
  margin-top: 14px;
  color: var(--muted);
  font-size: 14px;
}

.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;
}

.hidden {
    display: none;
}

.mt-3 {
    margin-top: 1rem;
}

@media (max-width: 980px) {
  .hero-grid,
  .calculator-wrap,
  .grid-3,
  .grid-4,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    padding: 14px 0;
  }

  .nav {
    gap: 10px 12px;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 40px;
  }

  .hero-copy,
  .hero-side,
  .card {
    padding: 22px;
  }
}