/* ponytail: Wanted Sans CDN 미검증으로 폴백 사용, 실제 폰트 라이선스 확보 후 교체 */

:root {
  --color-primary: #334155;
  --color-primary-dark: #1E293B;
  --color-bg: #FFFFFF;
  --color-bg-alt: #F1F5F9;
  --color-accent: #0EA5E9;
  --color-accent-text: #0C6E9E; /* accent darkened for text-level contrast */
  --color-text: #1E293B;
  --color-text-muted: #475569;
  --color-border: #CBD5E1;

  --font-heading: 'Wanted Sans', 'Pretendard', 'Noto Sans KR', sans-serif;
  --font-body: 'Pretendard', 'Noto Sans KR', sans-serif;

  /* type scale: perfect fourth (1.333) */
  --step-0: 1rem;
  --step-1: 1.333rem;
  --step-2: 1.777rem;
  --step-3: 2.369rem;
  --step-4: 3.157rem;

  --section-py: 96px;
  --radius: 4px;
}

@media (max-width: 640px) {
  :root {
    --section-py: 64px;
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-display: swap;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: var(--step-0);
  overflow-x: hidden;
}

h1, h2, h3 {
  font-family: var(--font-heading);
  font-display: swap;
  color: var(--color-primary-dark);
  line-height: 1.3;
  margin: 0 0 0.6em;
}

h2 {
  font-size: var(--step-2);
}

p {
  margin: 0 0 1.1em;
  color: var(--color-text);
}

a {
  color: var(--color-accent-text);
}

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

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* --- header --- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: 68px;
  display: flex;
  align-items: center;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-primary-dark);
}

.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-weight: 700;
  text-decoration: none;
  border-radius: var(--radius);
  padding: 10px 18px;
  border: 2px solid var(--color-primary);
  transition: background-color 0.15s ease, color 0.15s ease;
}

@media (prefers-reduced-motion: reduce) {
  .btn {
    transition: none;
  }
}

.btn-header {
  background: var(--color-primary);
  color: #FFFFFF;
  font-size: 0.95rem;
  padding: 9px 16px;
}

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

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

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

.btn-large {
  font-size: 1.05rem;
  padding: 14px 28px;
}

/* --- hero: 천장 시점 배경 --- */

.hero {
  position: relative;
  background: var(--color-primary-dark);
  overflow: hidden;
  padding: 88px 0 96px;
}

.hero-ceiling {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(14, 165, 233, 0.35) 0, rgba(14, 165, 233, 0.35) 30px, transparent 32px),
    radial-gradient(circle at 78% 22%, rgba(14, 165, 233, 0.35) 0, rgba(14, 165, 233, 0.35) 30px, transparent 32px),
    radial-gradient(circle at 50% 70%, rgba(14, 165, 233, 0.25) 0, rgba(14, 165, 233, 0.25) 30px, transparent 32px),
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.08) 0, rgba(255, 255, 255, 0.08) 2px, transparent 2px, transparent 120px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.08) 0, rgba(255, 255, 255, 0.08) 2px, transparent 2px, transparent 120px);
  opacity: 0.9;
}

.hero-inner {
  position: relative;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
  text-align: center;
  animation: hero-rise 0.6s ease-out both;
}

@keyframes hero-rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-inner {
    animation: none;
  }
}

.hero h1 {
  color: #FFFFFF;
  font-size: var(--step-4);
  margin-bottom: 0.5em;
}

.hero-lead {
  color: #E2E8F0;
  font-size: var(--step-1);
  margin-bottom: 1.6em;
}

/* --- sections --- */

.section {
  padding: var(--section-py) 0;
}

.section-core {
  background: var(--color-bg-alt);
}

.section-eyebrow {
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  color: var(--color-accent-text);
  text-transform: uppercase;
  margin-bottom: 0.4em;
}

.section-core h2 {
  margin-top: 1.4em;
}

.section-core h2:first-of-type {
  margin-top: 0;
}

/* --- diagram --- */

.diagram-figure {
  margin: 32px 0 0;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px;
}

.diagram-figure svg {
  width: 100%;
  height: auto;
  display: block;
}

/* --- table --- */

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 560px;
}

caption {
  text-align: left;
  padding: 12px 16px;
  font-weight: 700;
  color: var(--color-primary-dark);
  background: var(--color-bg-alt);
}

th, td {
  padding: 12px 16px;
  text-align: left;
  border-top: 1px solid var(--color-border);
  font-size: 0.95rem;
}

thead th {
  background: var(--color-primary);
  color: #FFFFFF;
  border-top: none;
}

tbody th {
  color: var(--color-primary-dark);
  white-space: nowrap;
}

/* --- photos --- */

.photo-grid {
  display: flex;
  flex-direction: column;
  gap: 24px;
  align-items: center;
}

@media (min-width: 640px) {
  .photo-grid {
    flex-direction: row;
    justify-content: center;
    align-items: flex-start;
  }
}

.photo-card {
  margin: 0;
  max-width: 340px;
  width: 100%;
  text-align: center;
}

.photo-card picture {
  display: block;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--color-bg-alt);
}

.photo-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-card figcaption {
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* --- faq --- */

.faq-list {
  margin: 24px 0 0;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: 20px 0;
}

.faq-item dt {
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 0.5em;
}

.faq-item dd {
  margin: 0;
  color: var(--color-text-muted);
}

/* --- cta --- */

.section-cta {
  background: var(--color-primary-dark);
  color: #FFFFFF;
  text-align: center;
}

.section-cta h2 {
  color: #FFFFFF;
}

.section-cta p {
  color: #CBD5E1;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* --- footer --- */

.site-footer {
  background: var(--color-bg-alt);
  padding: 48px 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-bottom: 20px;
}

.footer-links a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--color-accent-text);
  text-decoration: underline;
}

.footer-info {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* --- breakpoints --- */

@media (min-width: 1024px) {
  .container {
    padding: 0 32px;
  }
}

@media (min-width: 1280px) {
  .hero h1 {
    font-size: 3.6rem;
  }
}