:root {
  color-scheme: light;
  --bg: #f3f7fb;
  --surface: rgba(255, 255, 255, 0.84);
  --surface-strong: #ffffff;
  --text: #162033;
  --muted: #5d6a82;
  --line: rgba(22, 32, 51, 0.1);
  --shadow: 0 18px 40px rgba(24, 40, 72, 0.12);
  --good: #0d8b57;
  --fair: #de8b00;
  --bad: #cf4040;
  --accent: #3f6fff;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Noto Sans KR", system-ui, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top, rgba(63, 111, 255, 0.15), transparent 32%),
    linear-gradient(180deg, #f8fbff 0%, var(--bg) 100%);
}

button,
input,
select {
  font: inherit;
}

.app-shell {
  width: min(100%, 72rem);
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
}

.hero {
  padding: 1.25rem 0 1rem;
}

.eyebrow {
  margin: 0 0 0.5rem;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1.1;
}

.hero-copy {
  margin: 0.85rem 0 0;
  max-width: 38rem;
  color: var(--muted);
  line-height: 1.6;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-top: 1rem;
}

.hero-meta span {
  color: var(--muted);
  font-size: 0.95rem;
}

#refresh-button {
  border: 0;
  border-radius: 999px;
  padding: 0.7rem 1rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #4b7bff, #2f58d8);
  box-shadow: 0 10px 25px rgba(63, 111, 255, 0.28);
  cursor: pointer;
}

#refresh-button:disabled {
  opacity: 0.6;
  cursor: wait;
}

.card {
  backdrop-filter: blur(20px);
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.75);
  border-radius: 1.5rem;
  box-shadow: var(--shadow);
}

.section-heading h2 {
  margin: 0;
  font-size: 1.2rem;
}

.section-heading p {
  margin: 0.35rem 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.calculator {
  padding: 1rem;
}

.calculator-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin-top: 1rem;
}

.field {
  display: grid;
  gap: 0.45rem;
  color: var(--muted);
  font-size: 0.94rem;
}

.field select,
.field input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 1rem;
  padding: 0.9rem 1rem;
  background: var(--surface-strong);
  color: var(--text);
}

.calculator-result {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.result-label {
  color: var(--muted);
  font-size: 0.95rem;
}

#converted-amount {
  font-size: clamp(1.15rem, 4vw, 1.6rem);
}

.summary-heading {
  margin-top: 1.5rem;
}

.status-banner {
  margin-top: 1rem;
  padding: 0.9rem 1rem;
  border-radius: 1rem;
  background: rgba(63, 111, 255, 0.1);
  color: #2849a0;
  font-size: 0.95rem;
}

.status-banner.error {
  background: rgba(207, 64, 64, 0.12);
  color: #982f2f;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.currency-card {
  padding: 1rem;
}

.card-top {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  align-items: flex-start;
}

.card-label {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.card-title {
  margin: 0.25rem 0 0;
  font-size: 1.2rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 4.5rem;
  border-radius: 999px;
  padding: 0.45rem 0.8rem;
  font-weight: 800;
  font-size: 0.88rem;
}

.currency-card[data-tone="good"] .badge {
  color: var(--good);
  background: rgba(13, 139, 87, 0.12);
}

.currency-card[data-tone="fair"] .badge {
  color: var(--fair);
  background: rgba(222, 139, 0, 0.12);
}

.currency-card[data-tone="bad"] .badge {
  color: var(--bad);
  background: rgba(207, 64, 64, 0.12);
}

.primary-rate {
  display: grid;
  gap: 0.25rem;
  margin-top: 1rem;
}

.rate-value {
  font-size: clamp(1.4rem, 5vw, 2rem);
  line-height: 1.1;
}

.rate-caption {
  color: var(--muted);
  font-size: 0.86rem;
}

.strategy {
  margin: 1rem 0 0;
  font-weight: 800;
}

.summary {
  margin: 0.55rem 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin: 1rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.metrics div {
  display: grid;
  gap: 0.25rem;
}

.metrics dt {
  color: var(--muted);
  font-size: 0.84rem;
}

.metrics dd {
  margin: 0;
  font-weight: 700;
}

.logic {
  margin-top: 1rem;
  padding: 1rem;
}

.logic-grid {
  display: grid;
  gap: 0.9rem;
  margin-top: 1rem;
}

.logic-item {
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.75);
}

.logic-item strong,
.logic-item span {
  display: block;
}

.logic-item span {
  margin-top: 0.25rem;
  font-weight: 800;
}

.logic-item p {
  margin: 0.55rem 0 0;
  color: var(--muted);
  line-height: 1.55;
}

@media (max-width: 860px) {
  .cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .app-shell {
    padding-inline: 0.9rem;
  }

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

  .calculator-result,
  .hero-meta {
    align-items: flex-start;
    flex-direction: column;
  }

  .currency-card,
  .calculator,
  .logic {
    border-radius: 1.25rem;
  }
}