/* =========================
   Theme tokens (logo-friendly)
========================= */
:root {
  /* Dark (default) */
  --bg: #0b1220;
  --surface: #0f1a2b;
  --surface-2: #111f33;
  --text: #e8eef9;
  --muted: #a7b3c7;
  --line: rgba(255, 255, 255, 0.10);

  --accent: #2aa6a8;
  --accent-2: #8fe3c9;

  --shadow: 0 16px 40px rgba(0, 0, 0, 0.35);

  --radius: 18px;
  --radius-sm: 12px;
  --container: 1120px;
}

html[data-theme="light"] {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --text: #0b1220;
  --muted: #475569;
  --line: rgba(2, 6, 23, 0.10);

  --accent: #1e8f92;
  --accent-2: #18a57d;

  --shadow: 0 16px 40px rgba(2, 6, 23, 0.10);
}

/* =========================
   Base
========================= */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background:
    radial-gradient(900px 500px at 20% 0%, rgba(42,166,168,0.20), transparent 55%),
    radial-gradient(900px 500px at 90% 10%, rgba(143,227,201,0.12), transparent 55%),
    var(--bg);
}

html[data-theme="light"] body {
  color: var(--text);
  background:
    radial-gradient(900px 500px at 20% 0%, rgba(30,143,146,0.12), transparent 55%),
    radial-gradient(900px 500px at 90% 10%, rgba(24,165,125,0.10), transparent 55%),
    var(--bg);
}

/* Accessibility */
.skip-link {
  position: absolute;
  left: -999px;
  top: 12px;
  padding: 10px 12px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--text);
  z-index: 999;
}
.skip-link:focus { left: 12px; }

/* Layout */
.container {
  width: min(var(--container), calc(100% - 40px));
  margin: 0 auto;
}

/* =========================
   Header
========================= */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(11, 18, 32, 0.72);
  border-bottom: 1px solid var(--line);
}

html[data-theme="light"] .header {
  background: rgba(246, 248, 251, 0.92);
  border-bottom: 1px solid rgba(2, 6, 23, 0.10);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
}

.brand__logo {
  width: 34px;
  height: 34px;
  object-fit: contain;
  filter: drop-shadow(0 6px 18px rgba(0,0,0,0.35));
}

/* Wordmark (logo.svg includes text) */
.brand__logo--wordmark {
  width: auto;
  height: 42px;
  max-width: 220px;
}

.logo--light { display: none; }
.logo--dark  { display: block; }

html[data-theme="light"] .logo--dark  { display: none; }
html[data-theme="light"] .logo--light { display: block; }

.nav { display: inline-flex; gap: 14px; }

.nav__link {
  color: var(--muted);
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid transparent;
}
.nav__link:hover {
  color: var(--text);
  border-color: var(--line);
  background: rgba(255,255,255,0.04);
}

html[data-theme="light"] .nav__link {
  color: var(--text);
}
html[data-theme="light"] .nav__link:hover {
  border-color: rgba(2, 6, 23, 0.10);
  background: rgba(2, 6, 23, 0.04);
}

/* (If you ever use a plain nav button in addition to theme toggle) */
.nav__btn {
  color: var(--muted);
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  font: inherit;
}
.nav__btn:hover {
  color: var(--text);
  border-color: var(--line);
  background: rgba(255,255,255,0.04);
}
html[data-theme="light"] .nav__btn:hover {
  background: rgba(2, 6, 23, 0.04);
}

/* =========================
   Theme toggle (Material Symbols)
========================= */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  display: inline-grid;
  place-items: center;
  padding: 0;
}

.theme-toggle:hover {
  border-color: var(--line);
  background: rgba(255,255,255,0.04);
}
html[data-theme="light"] .theme-toggle {
  border-color: rgba(2, 6, 23, 0.08);
}
html[data-theme="light"] .theme-toggle:hover {
  background: rgba(2, 6, 23, 0.06);
}

.theme-toggle:focus-visible {
  outline: 2px solid rgba(42,166,168,0.55);
  outline-offset: 2px;
}

.theme-toggle__icon {
  position: relative;
  width: 22px;
  height: 22px;
  display: block;
}

.theme-icon {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 22px;
  line-height: 1;
  color: var(--muted);
  user-select: none;

  transform-origin: 50% 50%;
  will-change: transform, opacity, color;
  transition:
    transform 260ms cubic-bezier(0.2, 0.8, 0.2, 1),
    opacity 180ms ease,
    color 180ms ease;
}

.theme-toggle:hover .theme-icon,
.theme-toggle.show-next .theme-icon {
  color: var(--text);
}

html[data-theme="light"] .theme-icon {
  color: rgba(2, 6, 23, 0.70);
}
html[data-theme="light"] .theme-toggle:hover .theme-icon,
html[data-theme="light"] .theme-toggle.show-next .theme-icon {
  color: rgba(2, 6, 23, 0.92);
}

/* default visibility based on theme */
html[data-theme="light"] .theme-icon--sun  { opacity: 1; transform: rotate(0deg)  scale(1); }
html[data-theme="light"] .theme-icon--moon { opacity: 0; transform: rotate(90deg) scale(0.85); }

html:not([data-theme]) .theme-icon--moon,
html[data-theme="dark"] .theme-icon--moon { opacity: 1; transform: rotate(0deg)  scale(1); }

html:not([data-theme]) .theme-icon--sun,
html[data-theme="dark"] .theme-icon--sun  { opacity: 0; transform: rotate(90deg) scale(0.85); }

/* hover / preview next theme */
html[data-theme="light"] .theme-toggle:hover .theme-icon--sun,
html[data-theme="light"] .theme-toggle.show-next .theme-icon--sun {
  opacity: 0;
  transform: rotate(-90deg) scale(0.85);
}
html[data-theme="light"] .theme-toggle:hover .theme-icon--moon,
html[data-theme="light"] .theme-toggle.show-next .theme-icon--moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

html:not([data-theme]) .theme-toggle:hover .theme-icon--moon,
html[data-theme="dark"] .theme-toggle:hover .theme-icon--moon,
html:not([data-theme]) .theme-toggle.show-next .theme-icon--moon,
html[data-theme="dark"] .theme-toggle.show-next .theme-icon--moon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.85);
}

html:not([data-theme]) .theme-toggle:hover .theme-icon--sun,
html[data-theme="dark"] .theme-toggle:hover .theme-icon--sun,
html:not([data-theme]) .theme-toggle.show-next .theme-icon--sun,
html[data-theme="dark"] .theme-toggle.show-next .theme-icon--sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* Theme fade (during toggling) */
html.theme-fade, html.theme-fade * {
  transition:
    background-color 280ms ease,
    color 280ms ease,
    border-color 280ms ease,
    box-shadow 280ms ease,
    fill 280ms ease,
    stroke 280ms ease;
}
html.theme-fade .theme-icon {
  transition:
    transform 260ms cubic-bezier(0.2, 0.8, 0.2, 1),
    opacity 180ms ease,
    color 180ms ease;
}

/* =========================
   Hero
========================= */
.hero { padding: 54px 0 34px; }

.hero__inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 28px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.24em;
}

.hero__title {
  margin: 0 0 12px;
  font-size: clamp(30px, 3.8vw, 48px);
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.accent { color: var(--accent-2); }

.hero__subtitle {
  margin: 0 0 18px;
  color: var(--muted);
  max-width: 58ch;
}

.hero__cta { display: flex; gap: 12px; flex-wrap: wrap; }

.hero__media { display: flex; justify-content: flex-end; }

.hero__card {
  width: 100%;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.03));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 18px;
  min-height: 210px;
}

.hero__cardTitle { margin: 0 0 8px; font-weight: 650; }
.hero__cardText  { margin: 0; color: var(--muted); }

/* =========================
   Buttons
========================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  text-decoration: none;
  color: var(--text);
  background: rgba(255,255,255,0.04);
}
.btn:hover { background: rgba(255,255,255,0.07); }

.btn--primary {
  border-color: rgba(42,166,168,0.45);
  background: linear-gradient(180deg, rgba(42,166,168,0.35), rgba(42,166,168,0.18));
}
.btn--primary:hover {
  background: linear-gradient(180deg, rgba(42,166,168,0.45), rgba(42,166,168,0.22));
}
.btn--ghost { background: transparent; }
.btn--small { padding: 10px 12px; border-radius: 11px; font-size: 14px; }

/* =========================
   Sections / typography
========================= */
.section { padding: 56px 0; }

.section--alt {
  background: var(--surface-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section__head h2 {
  margin: 0 0 6px;
  letter-spacing: 0.02em;
}

.section__desc {
  margin: 0 0 22px;
  color: var(--muted);
  max-width: 72ch;
}

.muted { color: var(--muted); }
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.95em; }

/* =========================
   Content blocks
========================= */
.prose,
.card,
.stat,
.contact__card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.prose { padding: 20px; }
.prose p { margin: 0 0 14px; }
.prose p:last-child { margin-bottom: 0; }

.tech-logos {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  padding: 10px 0 6px;
  align-items: center;
}
.tech-logos img {
  width: 100%;
  max-height: 72px;
  object-fit: contain;
  padding: 12px;
  border-radius: var(--radius-sm);
  border: 1px dashed rgba(255,255,255,0.16);
  background: rgba(255,255,255,0.02);
}

.embed {
  margin: 10px 0 14px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: rgba(0,0,0,0.25);
}
.embed iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  display: block;
}

.figure {
  margin: 10px 0 14px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.02);
}
.figure img { width: 100%; height: auto; display: block; }
.figure figcaption {
  padding: 10px 12px;
  font-size: 14px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* Stats */
.stats {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}
.stat { padding: 14px; }
.stat__num { font-weight: 750; letter-spacing: -0.02em; font-size: 20px; }
.stat__label { color: var(--muted); font-size: 14px; }

/* Team cards */
.team {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

/* 첫 번째 인물 카드만 2칸을 차지 */
.team > .card:first-child {
  grid-column: 1 / -1; /* = span 2 */
}

/* 모바일에서는 전부 1열로 */
@media (max-width: 920px) {
  .team {
    grid-template-columns: 1fr;
  }
  .team > .card:first-child {
    grid-column: auto;
  }
}

.team > .card:first-child .card__text {
  max-width: 90ch;
}

.card { padding: 16px; }

.card__top {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  object-fit: cover;
  border: 1px solid rgba(255,255,255,0.12);
}

.card__title { margin: 0; font-size: 18px; }
.card__role  { margin: 2px 0 0; color: var(--muted); font-size: 14px; }
.card__text  { margin: 0 0 12px; color: var(--muted); }
.card__actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* Wide media placeholder */
.wideMedia { margin-top: 16px; }
.wideMedia__placeholder {
  border-radius: var(--radius);
  border: 1px dashed rgba(255,255,255,0.18);
  background: rgba(255,255,255,0.02);
  padding: 18px;
}
.wideMedia__title { margin: 0 0 6px; font-weight: 650; }
.wideMedia__text  { margin: 0; color: var(--muted); }

/* Contact */
.contact {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 12px;
}

.contact__card { padding: 18px; }
.contact__card--alt { background: var(--surface-2); }

.contact__list {
  margin: 12px 0 14px;
  padding: 0;
  list-style: none;
}
.contact__list li { padding: 8px 0; border-bottom: 1px solid rgba(255,255,255,0.06); }
.contact__list li:last-child { border-bottom: 0; }

.contact__label { display: inline-block; width: 74px; color: var(--muted); }
.contact a { color: var(--text); }
.contact__actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* Footer */
.footer {
  padding: 22px 0;
  border-top: 1px solid var(--line);
  background: rgba(11, 18, 32, 0.55);
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
}
.footer__links { display: inline-flex; gap: 14px; }
.footer__links a { color: var(--muted); text-decoration: none; }
.footer__links a:hover { color: var(--text); }

/* Floating Action Button */
.fab {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 48px;
  height: 48px;
  border-radius: 16px;
  border: 1px solid rgba(255,255,255,0.16);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  box-shadow: var(--shadow);
  cursor: pointer;
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transform: translateY(6px);
  transition: opacity 160ms ease, transform 160ms ease, background 160ms ease;
}
.fab:hover { background: rgba(255,255,255,0.10); }
.fab.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 920px) {
  .hero__inner { grid-template-columns: 1fr; }
  .team { grid-template-columns: 1fr; }
  .contact { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fab { transition: none; }
  .theme-icon { transition: none; }
}

.details {
  display: flex;
  flex-direction: column;
}


.details > summary {
  list-style: none;
  cursor: pointer;
  color: var(--muted);
  user-select: none;
  order: 1;
}

/* default marker (triangle) removal */
.details > summary::-webkit-details-marker { display: none; }
.details > summary::marker { content: ""; }

/* hover effect */
.details > summary:hover { color: var(--text); }

/* wrapper body */
.details__content {
  order: 2;
}

/* toggle: "See more" as default */
.details__label--open { display: none; }

/* when opened: "See less" + summary at the bottom */
.details[open] > summary {
  order: 3;
  margin-top: 10px;
}

.details[open] .details__label--closed { display: none; }
.details[open] .details__label--open { display: inline; }

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}

@media (max-width: 920px) {
    .feature-grid {
        grid-template-columns: 1fr;
    }
}