@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700&family=Noto+Sans+KR:wght@400;500;600;700&display=swap');

:root {
  --bg-main: #efefec;
  --bg-soft: #f8f8f6;
  --bg-card: rgba(255, 255, 255, 0.84);
  --text-main: #181818;
  --text-muted: #565656;
  --line-soft: rgba(0, 0, 0, 0.14);
  --line-strong: rgba(0, 0, 0, 0.32);
  --btn-bg: #111111;
  --btn-hover: #000000;
  --result-bg: #f3f3f0;
  --shadow-soft: 0 12px 40px rgba(0, 0, 0, 0.07);
  --shadow-card: 0 10px 24px rgba(0, 0, 0, 0.06);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'JetBrains Mono', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', monospace;
  background:
    radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.65), transparent 40%),
    radial-gradient(circle at 82% 78%, rgba(0, 0, 0, 0.05), transparent 38%),
    repeating-linear-gradient(120deg, rgba(0, 0, 0, 0.022) 0, rgba(0, 0, 0, 0.022) 2px, transparent 2px, transparent 12px),
    var(--bg-main);
  background-size: auto, auto, 220px 220px, auto;
  color: var(--text-main);
  line-height: 1.66;
}

header {
  position: relative;
  text-align: center;
  padding: 4.2rem 1.2rem 3.4rem;
  border-bottom: 1px solid var(--line-soft);
  background:
    linear-gradient(165deg, rgba(255, 255, 255, 0.95), rgba(240, 240, 236, 0.9));
  box-shadow: var(--shadow-soft);
}

header::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(to right, transparent, rgba(0, 0, 0, 0.08), transparent);
  background-size: 100% 1px;
  background-repeat: no-repeat;
  background-position: 0 calc(100% - 1px);
}

header h1 {
  margin: 0 0 0.4rem;
  font-family: 'JetBrains Mono', 'Noto Sans KR', monospace;
  font-size: clamp(2.2rem, 5.4vw, 3.3rem);
  font-weight: 600;
  letter-spacing: 0.02em;
}

header p {
  margin: 0;
  color: var(--text-muted);
  font-size: 1.02rem;
}

.container {
  width: min(1100px, calc(100% - 2.4rem));
  margin: 2.4rem auto 3.2rem;
}

.section {
  margin-bottom: 2.2rem;
  padding: 1.35rem 1.2rem 1.4rem;
  border: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.58), rgba(248, 248, 245, 0.58));
  box-shadow: var(--shadow-card);
  border-radius: 14px;
  backdrop-filter: blur(2px);
}

.section > h2 {
  margin: 0 0 0.9rem;
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--line-strong);
  font-family: 'JetBrains Mono', 'Noto Sans KR', monospace;
  font-size: clamp(1.65rem, 2.2vw, 2.05rem);
  font-weight: 600;
  letter-spacing: 0.03em;
}

.section > p {
  margin: 0 0 1.2rem;
  color: var(--text-muted);
  font-size: 0.96rem;
}

.api-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

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

.api-card {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  padding: 1.15rem 1.1rem 1.15rem;
  background:
    linear-gradient(170deg, rgba(255, 255, 255, 0.95), rgba(246, 246, 243, 0.88));
}

.api-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(112deg, transparent 0%, transparent 34%, rgba(255, 255, 255, 0.45) 50%, transparent 66%, transparent 100%);
  opacity: 0;
  pointer-events: none;
  z-index: 0;
}

.api-card::after {
  content: '';
  position: absolute;
  left: 1rem;
  right: 1rem;
  top: 0.85rem;
  height: 1px;
  background: linear-gradient(to right, transparent, rgba(0, 0, 0, 0.16), transparent);
  z-index: 1;
}

.api-card > * {
  position: relative;
  z-index: 2;
}

.api-card:hover,
.api-card:focus-within {
  border-color: rgba(0, 0, 0, 0.38);
  background: linear-gradient(170deg, rgba(255, 255, 255, 0.98), rgba(249, 249, 246, 0.92));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 0 0 1px rgba(0, 0, 0, 0.05),
    0 12px 24px rgba(0, 0, 0, 0.08);
}

.api-card:hover::before,
.api-card:focus-within::before {
  opacity: 0;
}

.api-card h3 {
  margin: 0 0 0.48rem;
  padding-top: 0.55rem;
  font-size: 1.03rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.api-card p {
  margin: 0 0 0.95rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.input-group {
  display: flex;
  gap: 0.6rem;
  margin-bottom: 0.4rem;
}

.input-group input {
  flex: 1;
  min-width: 0;
  border: 1px solid var(--line-soft);
  border-radius: 9px;
  padding: 0.72rem 0.86rem;
  background: var(--bg-soft);
  color: var(--text-main);
  font-size: 0.92rem;
}

.input-group input::placeholder {
  color: #808080;
}

.input-group input:focus {
  outline: none;
  border-color: var(--line-strong);
  box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.08);
  background-color: #ffffff;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  padding: 0.68rem 1.16rem;
  background: linear-gradient(180deg, #1b1b1b, #0f0f0f);
  color: #f2f2f2;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  font-size: 0.87rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 7px 16px rgba(0, 0, 0, 0.22);
}

.btn:hover {
  background: linear-gradient(180deg, #121212, #040404);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18), 0 10px 20px rgba(0, 0, 0, 0.25);
}

.btn:active {
  background: linear-gradient(180deg, #0e0e0e, #030303);
}

.result-box {
  display: none;
  margin-top: 0.85rem;
  border-radius: 10px;
  border: 1px solid var(--line-soft);
  background: var(--result-bg);
  color: var(--text-main);
  padding: 0.92rem 0.96rem;
  min-height: 64px;
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.9rem;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: keep-all;
  overflow-wrap: anywhere;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.65);
}

.qr-container {
  text-align: center;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(247, 247, 244, 0.75));
}

.qr-container svg {
  max-width: min(100%, 320px);
  height: auto;
}

footer {
  text-align: center;
  padding: 2rem 1rem;
  margin-top: 3rem;
  border-top: 1px solid var(--line-soft);
  color: var(--text-muted);
  font-size: 0.9rem;
}

footer p {
  margin: 0.3rem 0;
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

footer a:hover {
  color: var(--text-main);
  text-decoration: underline;
}

@media (max-width: 760px) {
  header {
    padding: 3.4rem 1rem 2.8rem;
  }

  .container {
    width: min(1100px, calc(100% - 1.4rem));
    margin-top: 1.25rem;
  }

  .section {
    padding: 1rem 0.86rem 1.05rem;
    margin-bottom: 1.35rem;
  }

  .input-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}