/* =================================================================
   김대호 교수 홈페이지 — Academic Style
   ================================================================= */

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 70px; }
body {
    font-family: 'Noto Sans KR', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: #1f2937;
    line-height: 1.7;
    background: #fff;
    word-break: keep-all;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
a { color: var(--c-primary); text-decoration: none; transition: color .15s; }
a:hover { color: var(--c-secondary); }
img { max-width: 100%; display: block; }

h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.3;
    color: #0f172a;
    letter-spacing: -.02em;
}

/* ── 상단 네비 ─────────────────── */
.pf-topbar {
    position: fixed; top: 0; left: 0; right: 0;
    height: 70px;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0,0,0,.06);
    z-index: 1000;
    transition: box-shadow .3s, background .3s;
}
.pf-topbar.scrolled { background: rgba(255,255,255,.99); box-shadow: 0 2px 16px rgba(0,0,0,.06); }
.pf-topbar-inner {
    max-width: 1200px; margin: 0 auto; padding: 0 24px;
    height: 100%; display: flex; align-items: center; justify-content: space-between;
}
.pf-brand { display: flex; align-items: center; gap: 12px; }
.pf-brand-mark {
    width: 38px; height: 38px; border-radius: 50%;
    display: inline-flex; align-items: center; justify-content: center;
    background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
    color: #fff; font-weight: 800; font-size: 17px;
    font-family: 'Noto Serif KR', serif;
    box-shadow: 0 2px 8px rgba(10,61,98,.25);
}
.pf-brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.pf-brand-text strong { font-size: 16px; color: var(--c-primary); font-weight: 700; }
.pf-brand-text small  { font-size: 11px; color: #64748b; font-weight: 400; font-family: 'Inter', sans-serif; }

.pf-nav { display: flex; align-items: center; gap: 4px; }
.pf-nav a {
    padding: 8px 14px; border-radius: 6px;
    color: #334155; font-size: 14px; font-weight: 500;
    transition: background .15s, color .15s;
    font-family: 'Inter', 'Noto Sans KR', sans-serif;
}
.pf-nav a:hover { background: rgba(10,61,98,.06); color: var(--c-primary); }
.pf-nav .pf-cta {
    margin-left: 10px;
    padding: 8px 16px;
    background: var(--c-primary);
    color: #fff !important;
    border-radius: 6px;
    font-weight: 600;
    font-family: 'Noto Sans KR', sans-serif;
}
.pf-nav .pf-cta:hover {
    background: var(--c-secondary);
    transform: translateY(-1px);
}

.pf-menu-toggle {
    display: none; width: 38px; height: 38px;
    background: transparent; border: none; cursor: pointer;
    flex-direction: column; gap: 5px;
    align-items: center; justify-content: center;
}
.pf-menu-toggle span {
    display: block; width: 22px; height: 2px;
    background: var(--c-primary); transition: transform .2s;
}
.pf-menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.pf-menu-toggle.open span:nth-child(2) { opacity: 0; }
.pf-menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 880px) {
    .pf-menu-toggle { display: flex; }
    .pf-nav {
        position: absolute; top: 70px; left: 0; right: 0;
        flex-direction: column; align-items: stretch;
        background: #fff; border-bottom: 1px solid rgba(0,0,0,.06);
        padding: 12px 16px 18px; gap: 4px;
        box-shadow: 0 6px 20px rgba(0,0,0,.08);
        max-height: 0; overflow: hidden; transition: max-height .25s ease;
    }
    .pf-nav.open { max-height: 480px; }
    .pf-nav a { padding: 12px 14px; font-size: 15px; }
    .pf-nav .pf-cta { margin: 8px 0 0; text-align: center; }
}

/* ═══════════════════════════════════════════════════════
   HERO — 학자 프로필
   ═══════════════════════════════════════════════════════ */
.pf-hero {
    position: relative;
    margin-top: 70px;
    padding: 80px 0 100px;
    background: linear-gradient(180deg, #f8fafc 0%, #fff 100%);
    overflow: hidden;
}
.pf-hero-bg {
    position: absolute; inset: 0;
    background:
        radial-gradient(circle at 80% 20%, rgba(30,136,168,.08) 0%, transparent 50%),
        radial-gradient(circle at 20% 80%, rgba(10,61,98,.06)  0%, transparent 50%);
    pointer-events: none;
}
.pf-hero-inner {
    position: relative; z-index: 1;
    max-width: 1100px; margin: 0 auto; padding: 0 24px;
    display: grid; grid-template-columns: 280px 1fr; gap: 60px;
    align-items: center;
}
.pf-hero-photo {
    width: 280px; height: 350px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow:
        0 1px 3px rgba(0,0,0,.06),
        0 14px 40px rgba(10,61,98,.18);
    position: relative;
    background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
}
.pf-hero-photo::after {
    content: '';
    position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(10,61,98,.12), transparent 60%);
    pointer-events: none;
}
.pf-hero-photo img {
    width: 100%; height: 100%;
    object-fit: cover;
    object-position: center top;
}
.pf-hero-text { min-width: 0; }
.pf-hero-eyebrow {
    display: inline-block;
    color: var(--c-secondary);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: .15em;
    text-transform: uppercase;
    margin-bottom: 14px;
    font-family: 'Inter', sans-serif;
}
.pf-hero-text h1 {
    font-size: clamp(34px, 5vw, 54px);
    font-weight: 800;
    color: var(--c-primary);
    margin-bottom: 6px;
    letter-spacing: -.03em;
    font-family: 'Noto Sans KR', sans-serif;
}
.pf-hero-text h1 .pf-hero-title {
    font-size: .55em;
    font-weight: 500;
    color: #64748b;
    margin-left: 10px;
    vertical-align: middle;
}
.pf-hero-en {
    font-size: 18px;
    color: #64748b;
    font-style: italic;
    font-family: 'Noto Serif KR', serif;
    margin-bottom: 18px;
}
.pf-hero-tagline {
    font-size: 17px;
    font-weight: 500;
    color: var(--c-primary);
    margin-bottom: 14px;
    padding-left: 16px;
    border-left: 3px solid var(--c-accent);
}
.pf-hero-intro {
    font-size: 15.5px;
    color: #475569;
    line-height: 1.85;
    margin-bottom: 28px;
    max-width: 600px;
}
.pf-hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }

@media (max-width: 760px) {
    .pf-hero { padding: 50px 0 60px; }
    .pf-hero-inner { grid-template-columns: 1fr; gap: 28px; text-align: center; }
    .pf-hero-photo { margin: 0 auto; max-width: 220px; height: 280px; }
    .pf-hero-tagline { display: inline-block; padding: 10px 16px; border-left: none; background: rgba(200,155,60,.1); border-radius: 6px; }
    .pf-hero-actions { justify-content: center; }
}

/* ═══════════════════════════════════════════════════════
   공통 섹션
   ═══════════════════════════════════════════════════════ */
.pf-section { padding: 80px 0; }
.pf-section.pf-about      { background: #fff; }
.pf-section.pf-research   { background: #f8fafc; }
.pf-section.pf-pubs       { background: #fff; }
.pf-section.pf-teaching   { background: #f8fafc; }
.pf-section.pf-activities { background: #fff; }
.pf-section.pf-contact    { background: #f8fafc; }

.pf-container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

.pf-section-head { text-align: center; margin-bottom: 50px; }
.pf-eyebrow {
    display: inline-block;
    color: var(--c-accent);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: .25em;
    margin-bottom: 12px;
    font-family: 'Inter', sans-serif;
    position: relative;
    padding-bottom: 12px;
}
.pf-eyebrow::after {
    content: '';
    position: absolute;
    bottom: 0; left: 50%;
    transform: translateX(-50%);
    width: 32px; height: 2px;
    background: var(--c-accent);
}
.pf-section-head h2 {
    font-size: clamp(26px, 4vw, 38px);
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--c-primary);
    font-family: 'Noto Sans KR', sans-serif;
}
.pf-lead {
    color: #64748b;
    font-size: 15px;
    max-width: 640px;
    margin: 0 auto;
}

/* 버튼 */
.pf-btn {
    display: inline-block;
    padding: 12px 28px;
    background: var(--c-primary);
    color: #fff !important;
    border-radius: 6px;
    font-weight: 600;
    font-size: 14.5px;
    transition: background .15s, transform .15s, box-shadow .15s;
    box-shadow: 0 2px 8px rgba(10,61,98,.2);
}
.pf-btn:hover {
    background: var(--c-secondary);
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(10,61,98,.3);
    color: #fff !important;
}
.pf-btn-outline {
    background: transparent;
    color: var(--c-primary) !important;
    border: 2px solid var(--c-primary);
    box-shadow: none;
    padding: 10px 26px;
}
.pf-btn-outline:hover {
    background: var(--c-primary);
    color: #fff !important;
}

/* ═══════════════════════════════════════════════════════
   ABOUT — 학력 / 경력 타임라인
   ═══════════════════════════════════════════════════════ */
.pf-about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}
.pf-timeline-block h3 {
    font-size: 18px;
    color: var(--c-primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--c-accent);
    display: inline-block;
}
.pf-timeline {
    list-style: none;
    border-left: 2px solid #e2e8f0;
    padding-left: 24px;
    position: relative;
}
.pf-timeline li {
    position: relative;
    padding-bottom: 22px;
}
.pf-timeline li::before {
    content: '';
    position: absolute;
    left: -32px; top: 6px;
    width: 12px; height: 12px;
    background: var(--c-primary);
    border: 3px solid #fff;
    border-radius: 50%;
    box-shadow: 0 0 0 1px var(--c-primary);
}
.pf-tl-year {
    display: inline-block;
    background: rgba(10,61,98,.08);
    color: var(--c-primary);
    padding: 2px 9px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    margin-bottom: 4px;
}
.pf-tl-body strong {
    display: block;
    color: #0f172a;
    font-size: 15px;
    margin-bottom: 2px;
}
.pf-tl-body p {
    color: #64748b;
    font-size: 14px;
    margin: 0;
}

@media (max-width: 760px) {
    .pf-about-grid { grid-template-columns: 1fr; gap: 36px; }
}

/* ═══════════════════════════════════════════════════════
   RESEARCH — 카드 그리드
   ═══════════════════════════════════════════════════════ */
.pf-research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 18px;
}
.pf-research-card {
    background: #fff;
    border: 1px solid rgba(0,0,0,.06);
    border-radius: 10px;
    padding: 26px 22px;
    transition: transform .2s, box-shadow .2s, border-color .2s;
    position: relative;
}
.pf-research-card::before {
    content: '';
    position: absolute;
    top: 0; left: 24px; right: 24px;
    height: 3px;
    background: var(--c-accent);
    transform: scaleX(0); transform-origin: left;
    transition: transform .3s;
}
.pf-research-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 28px rgba(10,61,98,.1);
    border-color: rgba(10,61,98,.15);
}
.pf-research-card:hover::before { transform: scaleX(1); }
.pf-research-icon { font-size: 32px; margin-bottom: 14px; line-height: 1; }
.pf-research-card h3 { font-size: 16px; color: var(--c-primary); margin-bottom: 8px; }
.pf-research-card p { color: #64748b; font-size: 13.5px; line-height: 1.7; }

/* ═══════════════════════════════════════════════════════
   PUBLICATIONS — 학술 리스트
   ═══════════════════════════════════════════════════════ */
.pf-pub-list {
    list-style: none;
    counter-reset: pub-counter;
    border-top: 2px solid var(--c-primary);
}
.pf-pub-item {
    counter-increment: pub-counter;
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 20px;
    padding: 22px 8px;
    border-bottom: 1px solid #eef2f7;
    transition: background .15s;
}
.pf-pub-item:hover { background: #f8fafc; }
.pf-pub-meta {
    display: flex; flex-direction: column; align-items: flex-start; gap: 6px;
}
.pf-pub-year {
    font-family: 'Inter', sans-serif;
    font-size: 17px;
    font-weight: 700;
    color: var(--c-primary);
    letter-spacing: -.01em;
}
.pf-pub-type {
    font-size: 11px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 4px;
    letter-spacing: .03em;
}
.pf-pub-type-paper { background: rgba(10,61,98,.1);    color: var(--c-primary); }
.pf-pub-type-book  { background: rgba(200,155,60,.18); color: #92651a; }
.pf-pub-type-conf  { background: rgba(30,136,168,.12); color: var(--c-secondary); }

.pf-pub-body h4 {
    font-size: 16px;
    color: #0f172a;
    margin-bottom: 6px;
    font-family: 'Noto Serif KR', serif;
    font-weight: 600;
    line-height: 1.5;
}
.pf-pub-body h4::before {
    content: counter(pub-counter) ".";
    color: #cbd5e1;
    margin-right: 8px;
    font-family: 'Inter', sans-serif;
    font-weight: 700;
}
.pf-pub-authors {
    color: #475569;
    font-size: 14px;
    margin-bottom: 4px;
}
.pf-pub-venue {
    color: #94a3b8;
    font-size: 13px;
}
.pf-pub-venue em { font-style: normal; color: #64748b; }

@media (max-width: 600px) {
    .pf-pub-item { grid-template-columns: 1fr; gap: 8px; padding: 18px 6px; }
    .pf-pub-meta { flex-direction: row; gap: 10px; align-items: center; }
}

/* ═══════════════════════════════════════════════════════
   TEACHING
   ═══════════════════════════════════════════════════════ */
.pf-teaching-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 36px;
}
.pf-teaching-block h3 {
    font-size: 17px;
    color: var(--c-primary);
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--c-accent);
    display: inline-block;
}
.pf-course-list { list-style: none; }
.pf-course-list li {
    display: grid;
    grid-template-columns: 70px 80px 1fr;
    gap: 14px;
    padding: 13px 4px;
    border-bottom: 1px solid #eef2f7;
    align-items: center;
}
.pf-course-list.pf-course-past li { opacity: .82; }
.pf-course-sem {
    font-family: 'Inter', sans-serif;
    color: var(--c-secondary);
    font-size: 12.5px;
    font-weight: 700;
    background: rgba(30,136,168,.08);
    padding: 3px 8px;
    border-radius: 4px;
    text-align: center;
}
.pf-course-code {
    font-family: 'Inter', sans-serif;
    color: #94a3b8;
    font-size: 12.5px;
    font-weight: 600;
    letter-spacing: .03em;
}
.pf-course-name { color: #0f172a; font-weight: 500; font-size: 14.5px; }
.pf-course-note {
    grid-column: 3;
    color: #94a3b8;
    font-size: 12.5px;
    margin-top: 2px;
}

@media (max-width: 760px) {
    .pf-teaching-grid { grid-template-columns: 1fr; gap: 28px; }
    .pf-course-list li { grid-template-columns: 70px 1fr; }
    .pf-course-code { display: none; }
}

/* ═══════════════════════════════════════════════════════
   ACTIVITIES
   ═══════════════════════════════════════════════════════ */
.pf-activity-list {
    list-style: none;
    max-width: 800px;
    margin: 0 auto;
}
.pf-activity-list li {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 18px;
    padding: 18px 0;
    border-bottom: 1px solid #eef2f7;
}
.pf-activity-list li:last-child { border-bottom: none; }
.pf-act-year {
    font-family: 'Inter', sans-serif;
    font-size: 16px;
    font-weight: 700;
    color: var(--c-accent);
}
.pf-act-body strong {
    display: block;
    color: #0f172a;
    font-size: 15.5px;
    margin-bottom: 4px;
}
.pf-act-body p {
    color: #64748b;
    font-size: 13.5px;
}

/* ═══════════════════════════════════════════════════════
   CONTACT
   ═══════════════════════════════════════════════════════ */
.pf-contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
}
.pf-contact-card {
    background: #fff;
    border: 1px solid rgba(0,0,0,.06);
    border-radius: 10px;
    padding: 26px 20px;
    text-align: center;
    transition: transform .2s, box-shadow .2s;
}
.pf-contact-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 22px rgba(10,61,98,.08);
}
.pf-contact-icon { font-size: 28px; margin-bottom: 10px; line-height: 1; }
.pf-contact-card h3 { font-size: 14px; color: var(--c-primary); margin-bottom: 6px; }
.pf-contact-card p { color: #475569; font-size: 14px; }
.pf-contact-card a { color: var(--c-primary); }

.pf-links {
    display: flex; flex-wrap: wrap; gap: 10px;
    justify-content: center;
    margin-top: 36px;
    padding-top: 32px;
    border-top: 1px solid #e2e8f0;
}
.pf-link-btn {
    padding: 9px 18px;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    color: var(--c-primary) !important;
    font-size: 13.5px;
    font-weight: 500;
    transition: all .15s;
}
.pf-link-btn:hover {
    background: var(--c-primary);
    color: #fff !important;
    border-color: var(--c-primary);
}

/* ═══════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════ */
.pf-footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 56px 0 0;
}
.pf-footer-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 36px;
}
.pf-footer-col h4 {
    color: #fff;
    font-size: 15px;
    margin-bottom: 14px;
    padding-bottom: 12px;
    border-bottom: 2px solid rgba(255,255,255,.08);
}
.pf-footer-col p {
    font-size: 13px;
    line-height: 1.85;
    color: #94a3b8;
}
.pf-footer-col p a { color: #cbd5e1; }
.pf-footer-col p a:hover { color: #fff; }
.pf-footer-col ul { list-style: none; }
.pf-footer-col li { margin-bottom: 8px; }
.pf-footer-col li a { color: #94a3b8; font-size: 13px; }
.pf-footer-col li a:hover { color: #fff; }
.pf-footer-bottom {
    margin-top: 44px;
    padding: 18px 24px;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,.08);
    color: #64748b;
    font-size: 12px;
}

@media (max-width: 760px) {
    .pf-footer-inner { grid-template-columns: 1fr; gap: 24px; }
}

/* 페이드 인 */
.pf-fade-in { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.pf-fade-in.visible { opacity: 1; transform: none; }