:root {
  --indigo:  #4f46e5;
  --indigo2: #4338ca;
  --bg:      #f1f5f9;
  --card:    #ffffff;
  --ink:     #0f172a;
  --muted:   #64748b;
  --line:    #e2e8f0;
  --red:     #ef4444;
  --green:   #16a34a;
  --shadow:  0 4px 18px rgba(79,70,229,.10);
  --radius:  14px;
  --radius2: 10px;
}

* { box-sizing: border-box }

body {
  margin-top: 70px;
  font-family: 'Pretendard', ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(900px 450px at 15% -10%, rgba(79,70,229,.10), transparent 60%),
    radial-gradient(700px 350px at 90% 5%, rgba(99,102,241,.07), transparent 55%),
    var(--bg);
}

.wrap { max-width: 100%; padding: 0 0 60px }

/* ── 헤더 ── */
.top { padding: 16px 0 20px }
.brand { display: flex; align-items: center; gap: 16px }
.logo {
  width: 48px; height: 48px; border-radius: 13px;
  background: linear-gradient(135deg, #4f46e5 0%, #6366f1 100%);
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(79,70,229,.35);
}
.brand h1 { margin: 0; font-size: 22px; font-weight: 800; letter-spacing: -.03em }
.brand .sub { margin: 4px 0 0; font-size: 13px; color: var(--muted) }

/* ── 탭 ── */
.tab-nav { display: flex; gap: 8px; margin: 0 0 20px; flex-wrap: wrap }
.tab-btn {
  padding: 9px 18px; border-radius: 999px;
  border: 1.5px solid var(--line); background: var(--card);
  font-size: 13px; font-weight: 700; cursor: pointer; color: var(--muted);
  transition: all .18s;
}
.tab-btn:hover { border-color: var(--indigo); color: var(--indigo) }
.tab-btn.active { background: var(--indigo); border-color: var(--indigo); color: #fff }

/* ── 레이아웃 ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: start;
}

/* ── 카드 ── */
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px;
  box-shadow: var(--shadow);
}
.card-title { font-size: 15px; font-weight: 800; margin: 0 0 18px; color: var(--ink) }

/* ── 폼 ── */
.form-group { margin: 0 0 14px }
.form-group label {
  display: block; font-size: 12px; font-weight: 600;
  color: var(--muted); margin: 0 0 5px;
}
.form-group input, .form-group select {
  width: 100%; padding: 10px 12px;
  border: 1.5px solid var(--line); border-radius: 9px;
  font-size: 15px; font-weight: 600; outline: none;
  transition: border-color .12s; background: var(--card);
  color: var(--ink);
}
.form-group input:focus, .form-group select:focus { border-color: var(--indigo) }

/* VAT 세율 선택 */
.vat-rate-row { display: flex; align-items: center; gap: 12px; margin-top: 6px }
.vat-rate-row > label { font-size: 12px; font-weight: 600; color: var(--muted); white-space: nowrap }
.rate-chips { display: flex; gap: 8px }
.rate-chip {
  padding: 6px 14px; border-radius: 999px;
  border: 1.5px solid var(--line); background: var(--card);
  font-size: 12px; font-weight: 700; cursor: pointer; color: var(--muted);
  transition: all .15s;
}
.rate-chip:hover  { border-color: var(--indigo); color: var(--indigo) }
.rate-chip.active { background: var(--indigo); border-color: var(--indigo); color: #fff }

/* ── 결과 ── */
.result-placeholder {
  color: var(--muted); font-size: 14px; text-align: center;
  padding: 30px 0;
}

.big-result { text-align: center; padding: 16px 0 20px }
.big-label  { font-size: 12px; color: var(--muted); font-weight: 600 }
.big-value  { font-size: 30px; font-weight: 900; color: var(--indigo); margin: 4px 0 }
.big-sub    { font-size: 13px; color: var(--muted) }

.result-rows { display: flex; flex-direction: column; gap: 0 }
.result-row {
  display: flex; justify-content: space-between;
  padding: 7px 0; border-bottom: 1px solid var(--line);
  font-size: 13px;
}
.result-row:last-child { border-bottom: none }
.result-row span:first-child { color: var(--muted) }
.result-row.deduct  span:last-child { color: #e55 }
.result-row.total   { font-weight: 700; background: #f8faff; border-radius: 6px; padding: 8px 6px }
.result-row.highlight { font-weight: 800; color: var(--indigo) }
.result-row.highlight span { color: var(--indigo) !important }
.result-row.success { font-weight: 800; color: var(--green) }
.result-row.success span { color: var(--green) !important }

/* ── 과세표준 테이블 ── */
.bracket-card { margin-top: 16px }
.bracket-table {
  width: 100%; border-collapse: collapse; font-size: 13px;
}
.bracket-table th {
  text-align: left; padding: 8px 10px; background: #f1f5f9;
  border-bottom: 2px solid var(--line); font-size: 12px; color: var(--muted);
}
.bracket-table td {
  padding: 7px 10px; border-bottom: 1px solid var(--line);
}
.bracket-table tr:last-child td { border-bottom: none }
.bracket-table td:nth-child(2) { font-weight: 700; color: var(--indigo); text-align: center }
.bracket-table td:nth-child(3) { text-align: right; color: var(--muted) }

/* ── 정보 리스트 ── */
.info-list {
  margin: 0; padding-left: 18px;
  font-size: 13px; color: var(--muted); line-height: 1.85;
}
.info-list strong { color: var(--ink) }

/* ── 주석 ── */
.note {
  font-size: 12px; color: var(--muted); line-height: 1.6;
  padding: 10px 12px; background: #fefce8;
  border: 1px solid #fde68a; border-radius: 8px; margin-top: 6px;
}

/* ── 사용 안내 ── */
.guide-section {
  margin-top: 28px;
  background: rgba(246,248,255,.6);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.guide-section h2 { font-size: 15px; font-weight: 800; margin: 0 0 10px; color: var(--ink) }
.guide-section h2:not(:first-child) { margin-top: 18px }
.guide-steps, .guide-features, .guide-usecase {
  margin: 0; padding-left: 18px;
  color: var(--muted); font-size: 13px; line-height: 1.8;
}
.guide-steps li, .guide-features li, .guide-usecase li { margin-bottom: 4px }
.guide-steps strong, .guide-features strong { color: var(--ink) }
.guide-privacy {
  margin-top: 16px;
  background: #eff6ff; border: 1px solid rgba(37,99,235,.22);
  border-radius: 12px; padding: 12px 14px;
  font-size: 12px; color: #1e40af; line-height: 1.55;
}

/* ── 반응형 ── */
@media (max-width: 640px) {
  .two-col { grid-template-columns: 1fr }
}