/* ========== Reset & Base ========== */
*,
*::before,
*::after {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
html {
  background: var(--bg);
}

body {
  margin: 0;
  font-family: "Pretendard Variable", "Pretendard", -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo",
    "Noto Sans KR", "Segoe UI", Inter, system-ui, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: transparent;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  inset: -20% -20% -20% -20%;
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(
      1000px 700px at 8% -10%,
      color-mix(in oklab, var(--primary) 16%, transparent),
      transparent 58%
    ),
    radial-gradient(900px 600px at 105% 0%, color-mix(in oklab, var(--primary) 12%, transparent), transparent 54%),
    radial-gradient(
      800px 560px at -10% 60%,
      color-mix(in oklab, var(--primary) 10%, transparent),
      transparent 60%
    ),
    linear-gradient(var(--bg), var(--bg));
  filter: saturate(110%);
}

:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --muted-surface: #f6f8fb;
  --text: #0b0d11;
  --muted: #5b6876;
  --primary: #3182f6;
  --primary-ink: #0a48b3;
  --border: rgba(12, 18, 28, 0.08);
  --shadow: 0 8px 30px rgba(12, 18, 28, 0.08);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 10px;
  --container: 1120px;
  --content-width: 800px; /* For blog posts */
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0d11;
    --surface: #0e1117;
    --muted-surface: #0b0f15;
    --text: #eef2f6;
    --muted: #9aa6b2;
    --border: rgba(255, 255, 255, 0.08);
    --shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
    --primary: #5aa0ff;
    --primary-ink: #cfe0ff;
  }
  body {
    background: transparent;
  }
  body::before {
    background: radial-gradient(
        1000px 700px at 8% -10%,
        color-mix(in oklab, var(--primary) 20%, transparent),
        transparent 60%
      ),
      radial-gradient(
        900px 600px at 105% 0%,
        color-mix(in oklab, var(--primary) 16%, transparent),
        transparent 56%
      ),
      radial-gradient(
        800px 560px at -10% 60%,
        color-mix(in oklab, var(--primary) 12%, transparent),
        transparent 62%
      ),
      linear-gradient(var(--bg), var(--bg));
  }
}
a {
  color: inherit;
  text-decoration: none;
}
.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 20px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--primary-ink);
  background: color-mix(in oklab, var(--primary) 12%, transparent);
  border: 1px solid color-mix(in oklab, var(--primary) 26%, transparent);
}

/* ========== Nav ========== */
.skip {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip:focus {
  left: 12px;
  top: 12px;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--surface);
  border-radius: 8px;
  box-shadow: var(--shadow);
  z-index: 1001;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: saturate(180%) blur(12px);
  background: color-mix(in oklab, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--border);
}
.nav__inner {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

/* Hamburger toggle */
.nav__toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  padding: 0;
}
.nav__toggle:focus-visible {
  outline: 2px solid color-mix(in oklab, var(--primary) 60%, transparent);
  outline-offset: 2px;
}
.nav__toggle .bar {
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.2s ease;
}
.nav__toggle .bar + .bar {
  margin-top: 5px;
}
.nav[data-open="true"] .nav__toggle .bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav[data-open="true"] .nav__toggle .bar:nth-child(2) {
  opacity: 0;
}
.nav[data-open="true"] .nav__toggle .bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Toggle icons */
.nav__toggle svg {
  width: 22px;
  height: 22px;
  display: block;
}
.nav__toggle .icon--close {
  display: none;
}
.nav[data-open="true"] .nav__toggle .icon--menu {
  display: none;
}
.nav[data-open="true"] .nav__toggle .icon--close {
  display: block;
}

/* Responsive menu container */
.nav__menu {
  display: flex;
  align-items: center;
  gap: 8px 10px;
}
/* Desktop layout */
@media (min-width: 881px) {
  .nav__menu {
    display: flex;
  }
}
/* Mobile layout */
@media (max-width: 880px) {
  .nav__toggle {
    display: inline-flex;
  }
  .nav__menu {
    position: fixed;
    left: 0;
    right: 0;
    top: 64px; /* below navbar */
    background: color-mix(in oklab, var(--surface) 96%, transparent);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    display: grid;
    gap: 4px;
    padding: 12px 16px 18px;
    transform: translateY(-6px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
  }
  .nav[data-open="true"] .nav__menu {
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }
  .nav__menu nav {
    display: grid;
  }
  .nav__menu nav a.link {
    padding: 12px 10px;
    border-radius: 10px;
    font-size: 1.02rem;
  }
  .nav__menu .nav__actions {
    display: grid;
    grid-template-columns: 1fr;
    margin-top: 4px;
  }
  .nav__menu .btn {
    width: 100%;
  }
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  font-size: 1.05rem;
}
/* NEW: logo styles */
.logo-wrap {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  box-shadow: 0 0 0 6px color-mix(in oklab, var(--primary) 25%, transparent);
}
.logo-wrap .logo {
  width: 22px;
  height: 22px;
  object-fit: contain;
  filter: drop-shadow(0 0 1px rgba(0, 0, 0, 0.25));
}

.nav a.link {
  font-weight: 600;
  color: var(--muted);
  padding: 10px 12px;
  border-radius: 10px;
}
.nav a.link:hover, .nav a.link.active {
  color: var(--text);
  background: color-mix(in oklab, var(--border) 30%, transparent);
}
.nav__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  border-radius: 12px;
  font-weight: 700;
  letter-spacing: -0.01em;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.03);
}
.btn--primary {
  background: var(--primary);
  color: white;
  border-color: color-mix(in oklab, var(--primary) 70%, black 0%);
}
.btn--primary:hover {
  filter: brightness(1.02);
  transform: translateY(-1px);
  box-shadow: 0 10px 26px color-mix(in oklab, var(--primary) 35%, transparent);
}
.btn:hover {
  transform: translateY(-1px);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

/* ========== Hero (About Page) ========== */
.hero {
  padding: 88px 0 36px;
}
.hero__content {
  text-align: center;
}
.hero h1 {
  margin: 20px 0 10px;
  font-size: clamp(32px, 6vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.hero .lead {
  max-width: 720px;
  margin: 0 auto;
  color: var(--muted);
  font-size: clamp(16px, 2.4vw, 19px);
}
.hero__cta {
  margin-top: 28px;
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.badge-row {
  margin-top: 22px;
  display: flex;
  gap: 0.6rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ========== Sections (About Page) ========== */
section {
  padding: 36px 0;
}
.section__head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 26px;
}
.section__head h2 {
  font-size: clamp(24px, 3.5vw, 36px);
  margin: 0;
  letter-spacing: -0.02em;
}
.section__head p {
  margin: 8px 0 0;
  color: var(--muted);
  max-width: 680px;
}

.card {
  background: color-mix(in oklab, var(--surface) 92%, transparent);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}
.grid {
  display: grid;
  gap: 16px;
}
.grid.cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.grid.cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
@media (max-width: 880px) {
  .grid.cols-3 {
    grid-template-columns: 1fr;
  }
  .grid.cols-2 {
    grid-template-columns: 1fr;
  }
}

/* About */
.about-card {
  padding: 26px;
  font-size: 1.05rem;
}
.about-card p {
  margin: 0;
}
.about-card p + p {
  margin-top: 10px;
}

/* Activities */
.activity {
  padding: 24px;
  display: grid;
  gap: 8px;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.2s ease;
}
.activity:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.08);
  border-color: color-mix(in oklab, var(--primary) 25%, var(--border));
}
.activity .emoji {
  font-size: 26px;
}
.activity h3 {
  margin: 4px 0 6px;
  letter-spacing: -0.01em;
}
.activity p {
  margin: 0;
  color: var(--muted);
}

/* Stats */
.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}
@media (max-width: 720px) {
  .stats {
    grid-template-columns: 1fr;
  }
}
.stat {
  padding: 22px 22px 20px;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, color-mix(in oklab, var(--primary) 13%, transparent), transparent 30%),
    var(--surface);
  border: 1px solid var(--border);
}
.stat .label {
  color: var(--muted);
  font-weight: 600;
}
.stat .num {
  font-weight: 900;
  font-size: clamp(24px, 5vw, 42px);
  letter-spacing: -0.02em;
  margin-top: 4px;
}
.stat .sub {
  color: var(--muted);
  font-size: 0.95rem;
}

/* Members */
.tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.tab {
  padding: 0.55rem 0.85rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-weight: 700;
  color: var(--muted);
}
.tab[aria-selected="true"] {
  color: white;
  background: var(--primary);
  border-color: color-mix(in oklab, var(--primary) 75%, transparent);
}
.member-card {
  padding: 18px 18px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  box-shadow: var(--shadow);
}
.member-card h3 {
  margin: 0 0 10px;
  letter-spacing: -0.01em;
}
.names {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.name {
  padding: 0.4rem 0.6rem;
  border-radius: 10px;
  font-weight: 700;
  background: color-mix(in oklab, var(--primary) 12%, transparent);
  border: 1px solid color-mix(in oklab, var(--primary) 28%, transparent);
}

/* Footer */
footer {
  padding: 48px 0 72px;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

/* Reveal animation */
[data-animate] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
[data-animate].in {
  opacity: 1;
  transform: translateY(0);
}

/* Reduce motion */
@media (prefers-reduced-motion: reduce) {
  .btn,
  .activity {
    transition: none;
  }
  [data-animate] {
    transition: none;
    transform: none;
    opacity: 1;
  }
}

/* ===== Blog Specific Styles ===== */

.page-header { padding: 40px 0 20px; text-align: center; }
.page-header h1 { font-size: clamp(36px, 6vw, 56px); line-height: 1.2; letter-spacing: -0.025em; margin: 0 0 12px; }
.page-header p { max-width: 600px; margin-inline: auto; color: var(--muted); font-size: 1.1rem; }
.post-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 32px; padding-bottom: 80px; }
.post-card {
  display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden; transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.post-card:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05); }
@media (prefers-color-scheme: dark) { .post-card:hover { box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15); } }
.post-card__content { padding: 24px; display: flex; flex-direction: column; flex-grow: 1; }
.post-card__title { font-size: 1.3rem; font-weight: 700; line-height: 1.4; letter-spacing: -0.01em; margin: 0 0 12px; }
.post-card__title a:hover { text-decoration: underline; }
.post-card__excerpt { color: var(--muted); margin: 0 0 20px; flex-grow: 1; }
.post-card__meta { font-size: 0.9rem; font-weight: 500; color: var(--muted); }
.post-card__meta a { color: var(--text); text-decoration: underline; }

/* Article Page Specific */
.article-header { padding: 40px 0 10px; text-align: center; }
.article-header h1 {
  max-width: var(--content-width); margin-inline: auto; font-size: clamp(32px, 5vw, 52px);
  line-height: 1.2; letter-spacing: -0.025em; margin-top: 0; margin-bottom: 20px;
}
.article-meta { color: var(--muted); font-weight: 500; }
.article-meta a { color: var(--text); text-decoration: underline; }
.article-content { max-width: var(--content-width); margin-inline: auto; font-size: 1.1rem; line-height: 1.8; }
.article-content > * + * { margin-top: 1.5em; }
.article-content h2, .article-content h3 {
  line-height: 1.3; letter-spacing: -0.02em; margin-top: 1.3em; margin-bottom: 0.5em; font-weight: 800;
}
.article-content h2 { font-size: 2rem; padding-bottom: 0.3em; border-bottom: 1px solid var(--border); }
.article-content h3 { font-size: 1.5rem; }
.article-content a {
  color: var(--primary); text-decoration: underline; text-decoration-thickness: 2px; text-underline-offset: 3px;
}
.article-content img { max-width: 100%; height: auto; border-radius: var(--radius-md); border: 1px solid var(--border); }
.article-content blockquote {
  margin: 2em 0; padding: 1em 1.5em; border-left: 4px solid var(--primary);
  background-color: color-mix(in oklab, var(--primary) 8%, transparent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; font-size: 1.05rem; font-style: italic;
}
.article-content ul, .article-content ol { padding-left: 2em; }
.article-content hr { border: 0; border-top: 1px solid var(--border); margin: 3em 0; }
.article-content pre {
  background: var(--muted-surface); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 1.2em 1.5em; overflow-x: auto; font-size: 0.95em; line-height: 1.6;
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
}
.article-content code { font-family: inherit; }
.article-content p > code, .article-content li > code {
  background: color-mix(in oklab, var(--primary) 10%, transparent);
  padding: 0.2em 0.4em; border-radius: 6px; font-size: 0.9em; font-weight: 600;
}