:root {
  --bg: #0b0f19;
  --panel: #131c2e;
  --panel-alt: #182338;
  --text: #f3f4f6;
  --muted: #9ca3af;
  --accent: #38bdf8;
  --ok: #34d399;
  --warn: #fbbf24;
  --bad: #f87171;
  --border: #1f2937;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Pretendard", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

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

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.topbar {
  border-bottom: 1px solid var(--border);
  background: rgba(11, 15, 25, 0.9);
  position: sticky;
  top: 0;
  z-index: 20;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  color: var(--text);
}

.brand small {
  color: var(--muted);
  font-weight: 500;
}

.brand-icon {
  width: 30px;
  height: 30px;
  border-radius: 7px;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  color: #0b0f19;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.9rem;
}

.lang-btn {
  background: var(--panel-alt);
  color: var(--accent);
  border: 1px solid var(--border);
  padding: 0.3rem 0.7rem;
  border-radius: 6px;
  font-weight: 700;
  cursor: pointer;
}

.main-content {
  padding: 2.5rem 1.25rem 4rem;
}

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  background: rgba(56, 189, 248, 0.12);
  padding: 0.2rem 0.65rem;
  border-radius: 999px;
  margin-bottom: 0.75rem;
}

.intro h1 {
  font-size: clamp(1.6rem, 3.2vw, 2.35rem);
  margin-bottom: 0.65rem;
}

.intro p {
  color: var(--muted);
  max-width: 780px;
  margin-bottom: 2rem;
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
}

.panel h2 {
  font-size: 1.18rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
}

.field {
  margin-bottom: 1.15rem;
}

.field label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.field select,
.field input[type="range"] {
  width: 100%;
}

.field select {
  background: var(--panel-alt);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  font-size: 0.92rem;
}

.range-val {
  text-align: right;
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 700;
}

.kpi-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.kpi-box {
  background: var(--panel-alt);
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: 10px;
  padding: 1rem;
}

.kpi-label {
  display: block;
  font-size: 0.78rem;
  color: var(--muted);
  margin-bottom: 0.3rem;
}

.kpi-value {
  font-size: 1.65rem;
  color: var(--accent);
}

.breakdown {
  background: var(--bg);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  margin-bottom: 1.4rem;
}

.breakdown-item {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  padding: 0.35rem 0;
  border-bottom: 1px solid var(--border);
}

.breakdown-item:last-child {
  border-bottom: none;
}

.results-panel h3 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.hw-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.hw-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  background: var(--panel-alt);
  border: 1px solid var(--border);
  font-size: 0.88rem;
}

.status-pill {
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
}

.status-ok {
  background: rgba(52, 211, 153, 0.15);
  color: var(--ok);
}

.status-warn {
  background: rgba(251, 191, 36, 0.15);
  color: var(--warn);
}

.status-bad {
  background: rgba(248, 113, 113, 0.15);
  color: var(--bad);
}

.guide-section {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
}

.guide-section h2 {
  font-size: 1.35rem;
  margin-bottom: 1rem;
}

.guide-section h3 {
  font-size: 1.1rem;
  margin: 1.4rem 0 0.5rem;
  color: var(--accent);
}

.guide-section p {
  color: var(--muted);
  margin-bottom: 0.9rem;
}

.footer {
  border-top: 1px solid var(--border);
  padding: 1.75rem 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-links {
  display: flex;
  gap: 1.2rem;
}

@media (max-width: 768px) {
  .calc-grid {
    grid-template-columns: 1fr;
  }
}