*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #f8f9fc;
  --surface:   #ffffff;
  --surface-2: #f1f3f8;
  --border:    #e2e6f0;
  --border-md: #c8cedf;

  --navy:      #1a2744;
  --navy-2:    #243258;
  --blue:      #2563eb;
  --blue-dim:  rgba(37,99,235,0.08);
  --blue-bdr:  rgba(37,99,235,0.2);

  --text:      #111827;
  --text-2:    #4b5675;
  --text-3:    #8b96b5;

  --green:     #059669;
  --green-dim: rgba(5,150,105,0.08);
  --amber:     #d97706;
  --amber-dim: rgba(217,119,6,0.08);
  --purple:    #7c3aed;
  --purple-dim:rgba(124,58,237,0.08);
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
}

/* ── NAV ── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: 56px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 40px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-mark {
  width: 30px; height: 30px;
  background: var(--navy);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 500;
  color: #fff;
  letter-spacing: -0.02em;
}

.nav-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
}

.nav-links a {
  font-size: 12.5px;
  font-weight: 400;
  color: var(--text-2);
  text-decoration: none;
  padding: 6px 13px;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
}
.nav-links a:hover { color: var(--navy); background: var(--surface-2); }

/* ── HERO ── */
.hero-outer {
  background: var(--navy);
  padding-top: 56px;
}

.hero {
  max-width: 1080px;
  margin: 0 auto;
  padding: 72px 40px 64px;
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 64px;
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: rgba(255,255,255,0.45);
  letter-spacing: 0.06em;
  margin-bottom: 10px;
}

.hero-eyebrow-sep { color: rgba(255,255,255,0.2); }

h1.hero-name {
  font-size: clamp(38px, 5vw, 56px);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.05;
  color: #fff;
  margin-bottom: 10px;
}

.hero-role {
  font-size: 16px;
  font-weight: 300;
  color: rgba(255,255,255,0.55);
  margin-bottom: 22px;
  letter-spacing: -0.01em;
}

.hero-bio {
  font-size: 14px;
  color: rgba(255,255,255,0.65);
  line-height: 1.8;
  max-width: 460px;
  margin-bottom: 32px;
}

.hero-buttons { display: flex; gap: 10px; flex-wrap: wrap; }

.btn-white {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: #fff;
  color: var(--navy);
  font-size: 13px;
  font-weight: 600;
  padding: 9px 20px;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity 0.15s;
}
.btn-white:hover { opacity: 0.9; }

.btn-outline-white {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: transparent;
  color: rgba(255,255,255,0.7);
  font-size: 13px;
  font-weight: 400;
  padding: 9px 18px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.2);
  text-decoration: none;
  transition: color 0.15s, border-color 0.15s;
}
.btn-outline-white:hover { color: #fff; border-color: rgba(255,255,255,0.5); }

/* Hero info card */
.hero-info {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 14px;
  overflow: hidden;
}

.hero-info-header {
  padding: 13px 18px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  gap: 6px;
}

.wdot { width: 9px; height: 9px; border-radius: 50%; }
.wr { background: rgba(255,255,255,0.15); }
.wy { background: rgba(255,255,255,0.25); }
.wg { background: rgba(255,255,255,0.4); }

.hero-info-file {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: rgba(255,255,255,0.3);
  margin-left: 6px;
}

.info-list { padding: 6px 0; }

.info-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 9px 18px;
  border-bottom: 1px solid rgba(255,255,255,0.07);
  gap: 12px;
}
.info-row:last-child { border-bottom: none; }

.ikey {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: rgba(255,255,255,0.3);
  flex-shrink: 0;
}

.ival {
  font-size: 12px;
  color: rgba(255,255,255,0.75);
  text-align: right;
}

.ival .hi { color: #7dd3fc; font-weight: 500; }

/* ── MAIN WRAP ── */
.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 0px;
}

/* ── SECTION ── */
section {
  padding: 34px 0;
  border-top: 1px solid var(--border);
}

.sec-head {
  display: flex;
  align-items: center;
  gap: 5px;
  margin-bottom: 36px;
}

.sec-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--blue);
  background: var(--blue-dim);
  border: 1px solid var(--blue-bdr);
  border-radius: 5px;
  padding: 2px 8px;
}

.sec-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--navy);
  letter-spacing: -0.02em;
}

.sec-line { flex: 1; height: 1px; background: var(--border); }

/* ── ENTRY ── */
.entry {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.entry:last-child { border-bottom: none; }

.entry-logo {
  width: 44px;
  height: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  font-weight: 500;
  color: var(--text-3);
  flex-shrink: 0;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.entry-logo img {
  width: 26px;
  height: 26px;
  object-fit: contain;
}

.e-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 3px;
}

.e-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: -0.015em;
}

.e-period {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--text-3);
  white-space: nowrap;
  padding-top: 2px;
  flex-shrink: 0;
}

.e-org {
  font-size: 12px;
  font-weight: 500;
  color: var(--blue);
  margin-bottom: 8px;
}

.e-desc {
  font-size: 13px;
  color: var(--text-2);
  line-height: 1.75;
  margin-bottom: 6px;
}

.tags { display: flex; flex-wrap: wrap; gap: 6px; }

.tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  padding: 3px 9px;
  border-radius: 5px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-2);
}

.tag-blue   { background: var(--blue-dim);   border-color: var(--blue-bdr);            color: var(--blue);   }
.tag-green  { background: var(--green-dim);  border-color: rgba(5,150,105,0.2);        color: var(--green);  }
.tag-amber  { background: var(--amber-dim);  border-color: rgba(217,119,6,0.2);        color: var(--amber);  }
.tag-purple { background: var(--purple-dim); border-color: rgba(124,58,237,0.2);       color: var(--purple); }

.detail-btn {
    margin-top: 0px;
    margin-bottom: 10px;

    border: none;
    background: none;

    color: #2563eb;
    font-weight: 600;

    cursor: pointer;
}

.cert-detail-btn {
    margin-top: 15px;
    margin-bottom: 0px;

    border: 1px solid #e5e7eb;
    background-color: #ffffff;

    color: #000000;
    font-weight: 600;

    padding: 10px 16px;
    border-radius: 10px;

    cursor: pointer;

    transition: all 0.2s ease-in-out;
    margin-left: auto;
    margin-right: auto;
    
    display: block;
    width: fit-content;

    margin: 15px auto 0 auto;
}

.cert-detail-btn:hover {
    background-color: #f3f4f6;
    transform: translateY(-1px);
}

.detail-content {
    max-height: 0;
    overflow: hidden;

    transition:
        max-height 0.4s ease,
        margin-top 0.4s ease;

    margin-top: 0;
}

.detail-content ul {
    margin-left: 20px;
}

.detail-content.active {
    max-height: 500px;
    margin-top: 0px;
}

.detail-content ul {
    padding-left: 20px;
}

.detail-content li {
    margin-bottom: 10px;
    line-height: 1.7;
}

/* ── CERTIFICATIONS ── */

.cert-grid {
    display: flex;
    gap: 24px;

    overflow-x: auto;
    overflow-y: hidden;

    padding: 10px 4px 20px;

    scroll-behavior: smooth;
    scroll-snap-type: x mandatory;
}

/* - 좌우 스크롤 - */
.cert-grid::-webkit-scrollbar {
    height: 8px;
}

.cert-grid::-webkit-scrollbar-track {
    background: #e2e8f0;
    border-radius: 999px;
}

.cert-grid::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 999px;
}

.cert-card {
    flex: 0 0 320px;

    width: 200px;
    height: 260px;

    perspective: 1200px;
    cursor: pointer;

    scroll-snap-align: start;
}

.cert-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform .8s;
    transform-style: preserve-3d;
}

.cert-card:hover .cert-card-inner {
    transform: rotateY(180deg);
}

/* 클릭 방식 사용할 경우 */
.cert-card.flipped .cert-card-inner {
    transform: rotateY(180deg);
}

/* Front & Back */

.cert-front,
.cert-back {
    position: absolute;
    width: 100%;
    height: 100%;

    border-radius: 20px;

    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;

    overflow: hidden;
}

/* =========================
   FRONT
========================= */

.cert-front {
    background: white;

    border: 1px solid #e2e8f0;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    padding: 28px;

    text-align: center;

    box-shadow:
        0 10px 30px rgba(0,0,0,.05);

    transition: .3s;
}

.cert-front:hover {
    transform: translateY(-5px);
    box-shadow:
        0 18px 40px rgba(0,0,0,.08);
}

.cert-logo {
    width: 90px;
    height: 90px;

    object-fit: contain;

    margin-bottom: 0px;
}

.cert-name {
    font-size: 1.15rem;
    font-weight: 700;
    

    color: #0f172a;

    margin-bottom: 10px;
}

.cert-org {
    color: #64748b;
    font-size: .95rem;
}

/* =========================
   BACK
========================= */

.cert-back {
    background: linear-gradient(
        135deg,
        #0f172a,
        #1e293b
    );

    color: white;

    transform: rotateY(180deg);

    padding: 28px;

    display: flex;
    flex-direction: column;
    justify-content: center;
}

.cert-back h3 {
    font-size: 1.1rem;
    margin-bottom: 18px;
}

.cert-info {
    list-style: none;
    padding: 0;
    margin: 0 0 24px;
}

.cert-info li {
    margin-bottom: 10px;
    font-size: .92rem;
    line-height: 1.5;
}

.cert-info strong {
    color: #cbd5e1;
}

.cert-verify {
    display: inline-flex;
    align-items: center;
    justify-content: center;

    text-decoration: none;

    background: white;
    color: #0f172a;

    font-weight: 600;

    padding: 12px 18px;
    border-radius: 12px;

    transition: .25s;
}

.cert-verify:hover {
    transform: translateY(-2px);
}

/* =========================
   MOBILE
========================= */

@media (max-width: 768px) {

    .cert-grid {
        grid-template-columns: 1fr;
    }

    .cert-card {
        height: 300px;
    }

}

/* ── PUBLICATIONS ── */
.pub {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 16px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.pub:last-child { border-bottom: none; }

.pub-n {
  font-family: 'JetBrains Mono', monospace;
  font-size: 22px;
  font-weight: 500;
  color: var(--border-md);
  text-align: right;
  padding-top: 2px;
  line-height: 1;
}

.pub-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.45;
  margin-bottom: 5px;
  letter-spacing: -0.01em;
}

.pub-authors {
  font-size: 12px;
  color: var(--text-3);
  margin-bottom: 4px;
}
.pub-authors strong { color: var(--text-2); font-weight: 500; }

.pub-venue {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--green);
  margin-bottom: 10px;
}
.pub-venue::before {
  content:'';
  width:5px; height:5px;
  border-radius:50%;
  background: var(--green);
  flex-shrink:0;
}

.pub-links { display: flex; gap: 8px; }
.pub-link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--text-3);
  text-decoration: none;
  padding: 3px 10px;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  transition: color 0.15s, border-color 0.15s;
}
.pub-link:hover { color: var(--blue); border-color: var(--blue-bdr); }

/* ── CREDENTIALS ── */
.cred-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 12px;
}

.cred-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.cred-card:hover {
  border-color: var(--border-md);
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.cred-issuer {
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  color: var(--text-3);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 6px;
}

.cred-name {
  font-size: 13px;
  font-weight: 500;
  color: var(--navy);
  line-height: 1.4;
  margin-bottom: 8px;
}

.cred-year {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--blue);
}

/* ── FOOTER ── */
footer {
  background: var(--navy);
  border-top: 1px solid var(--border);
  margin-top: 20px;
}

.footer-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 28px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-name { font-weight: 600; font-size: 14px; color: #fff; }

.footer-links { display: flex; gap: 20px; }
.footer-links a {
  font-size: 12px;
  color: rgba(255,255,255,0.4);
  text-decoration: none;
  transition: color 0.15s;
}
.footer-links a:hover { color: rgba(255,255,255,0.75); }

.footer-copy {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: rgba(255,255,255,0.25);
}

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; gap: 40px; padding: 52px 24px 48px; }
  .hero-info { display: none; }
  .nav-links { display: none; }
  .nav-inner, .wrap { padding: 0 0px; }
  .footer-inner { flex-direction: column; gap: 12px; text-align: center; }
  .entry { grid-template-columns: 1fr; }
  .entry-logo { display: none; }
}