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

:root {
    --bg: #ffffff;
    --bg-subtle: #f6f9ff;
    --bg-card: #ffffff;
    --border: #e4ecff;
    --border-hover: #b8cdff;
    --primary: #4a7cf7;
    --primary-light: #eef3ff;
    --primary-muted: #7fa4f9;
    --primary-dark: #2d5edc;
    --text: #1c2340;
    --text-secondary: #5a6a8a;
    --text-muted: #8fa0c0;
    --tag-bg: #eef3ff;
    --tag-text: #4a7cf7;
    --shadow-sm: 0 1px 4px rgba(74,124,247,0.06), 0 2px 8px rgba(30,50,100,0.04);
    --shadow-md: 0 4px 16px rgba(74,124,247,0.10), 0 2px 8px rgba(30,50,100,0.06);
    --shadow-lg: 0 8px 32px rgba(74,124,247,0.14), 0 4px 12px rgba(30,50,100,0.06);
    --radius: 14px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --font-sans: 'Plus Jakarta Sans', 'Noto Sans KR', sans-serif;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }
body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

/* ── NAV ── */
header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    background: rgba(255,255,255,0.88);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    transition: box-shadow var(--transition);
}
header.scrolled { box-shadow: var(--shadow-sm); }
nav {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 24px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.nav-logo {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 1.18rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.03em;
    cursor: pointer;
    user-select: none;
}
.nav-logo span { color: var(--text); font-weight: 300; }
.nav-tabs {
    display: flex;
    gap: 4px;
}
.nav-tab {
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: none;
    border: none;
    padding: 6px 14px;
    border-radius: 100px;
    cursor: pointer;
    transition: background var(--transition), color var(--transition);
    letter-spacing: -0.01em;
}
.nav-tab:hover { background: var(--primary-light); color: var(--primary); }
.nav-tab.active {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 8px rgba(74,124,247,0.30);
}

/* ── LAYOUT ── */
main {
    max-width: 900px;
    margin: 0 auto;
    padding: 88px 24px 80px;
}

/* ── PAGE TRANSITION ── */
.page {
    display: none;
    animation: fadeUp 0.45s cubic-bezier(0.4,0,0.2,1) both;
}
.page.active { display: block; }
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ── HOME ── */
.home-hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 80px;

    padding: 56px 0 48px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 48px;
    animation: fadeUp 0.5s 0.05s both;
}
.hero-left{
    flex:1;
}
.hero-right{
    flex-shrink:0;
}
.hero-profile{
    width:200px;
    height:200px;
    border-radius:50%;
    object-fit:cover;
    object-position:center 10%;
    transform:scale(0.8);
}
.home-greeting {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--primary);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.home-greeting::before {
    content: '';
    display: inline-block;
    width: 24px; height: 2px;
    background: var(--primary);
    border-radius: 2px;
}
.home-title {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    color: var(--text);
    letter-spacing: -0.04em;
    line-height: 1.18;
    margin-bottom: 18px;
}
.home-title .highlight {
    color: var(--primary);
}
.home-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    max-width: 520px;
    line-height: 1.8;
    margin-bottom: 28px;
    font-weight: 400;
}
.btn-github {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--text);
    color: #fff;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    padding: 10px 20px;
    border-radius: 100px;
    text-decoration: none;
    transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
    letter-spacing: -0.01em;
}
.btn-github:hover {
    background: var(--primary);
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(74,124,247,0.32);
}
.btn-github svg { width: 16px; height: 16px; }

.home-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 56px;
    animation: fadeUp 0.5s 0.12s both;
}
.stat-card {
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 20px;
    text-align: center;
    transition: border-color var(--transition), box-shadow var(--transition);
}
.stat-card:hover { border-color: var(--border-hover); box-shadow: var(--shadow-sm); }
.stat-num {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: 6px;
}
.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
    letter-spacing: 0.02em;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}
.section-title {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.03em;
}
.section-more {
    font-size: 0.82rem;
    color: var(--primary);
    font-weight: 500;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px 10px;
    border-radius: 100px;
    transition: background var(--transition);
    letter-spacing: -0.01em;
}
.section-more:hover { background: var(--primary-light); }

/* ── POST CARD ── */
.post-card {
    display: flex;
    flex-direction: column;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
    text-decoration: none;
    color: inherit;
}
.post-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.post-card-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.tag {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--tag-text);
    background: var(--tag-bg);
    padding: 3px 10px;
    border-radius: 100px;
    letter-spacing: 0.02em;
    transition: background var(--transition), color var(--transition);
}
.tag.clickable { cursor: pointer; }
.tag.clickable:hover { background: var(--primary); color: #fff; }
.post-card-title {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
    line-height: 1.45;
    margin-bottom: 8px;
    letter-spacing: -0.025em;
}
.post-card-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.7;
    flex: 1;
    margin-bottom: 16px;
    font-weight: 400;
}
.post-card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 400;
}
.post-card-date { letter-spacing: 0.01em; }
.post-card-read {
    display: flex;
    align-items: center;
    gap: 4px;
    color: var(--primary-muted);
    font-weight: 500;
}

.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}
.posts-list { display: flex; flex-direction: column; gap: 12px; }

.post-container{
  max-width:760px;
  margin:120px auto 80px;
  padding:0 20px;
}

.post-title{
  font-family:'Plus Jakarta Sans',sans-serif;
  font-size:2.2rem;
  font-weight:800;
  margin-bottom:10px;
}

.post-meta{
  color:#888;
  font-size:0.9rem;
  margin-bottom:40px;
}

.post-content h2{
  margin-top:40px;
  margin-bottom:10px;
  font-size:1.4rem;
}

.post-content p{
  line-height:1.8;
  margin-bottom:16px;
}

.post-content ul{
  padding-left:20px;
  margin-bottom:20px;
}

.post-content li{
  margin-bottom:6px;
}

.post-image {
margin:40px 0;
text-align:center;
}

.post-image img {
max-width:100%;
border-radius:10px;
}

.image-caption{
font-size:14px;
color:#666;
margin-top:8px;
}

/* ── SKELETON ── */
.skeleton {
    background: linear-gradient(90deg, #f0f4ff 25%, #e4ecff 50%, #f0f4ff 75%);
    background-size: 200% 100%;
    animation: shimmer 1.6s infinite;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 24px;
}
@keyframes shimmer {
    0%   { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}
.skel-line {
    height: 12px;
    background: rgba(74,124,247,0.12);
    border-radius: 6px;
    margin-bottom: 10px;
}
.skel-line.short { width: 40%; }
.skel-line.med   { width: 70%; }
.skel-line.long  { width: 95%; margin-bottom: 6px; }
.skel-tag {
    height: 20px; width: 56px;
    background: rgba(74,124,247,0.10);
    border-radius: 100px;
    display: inline-block;
    margin-right: 6px;
    margin-bottom: 12px;
}

/* ── REVEAL ── */
.reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.5s cubic-bezier(0.4,0,0.2,1), transform 0.5s cubic-bezier(0.4,0,0.2,1);
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ── ABOUT ── */
.about-hero {
    padding: 48px 0 40px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 48px;
}
.about-name {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 800;
    color: var(--text);
    letter-spacing: -0.04em;
    margin-bottom: 8px;
}
.about-role {
    font-size: 1rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 20px;
    letter-spacing: -0.01em;
}
.about-bio {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.85;
    max-width: 580px;
    font-weight: 400;
}
.about-section { margin-bottom: 44px; }
.about-section-title {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 16px;
}
.skills-wrap { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-chip {
    font-size: 0.825rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    padding: 6px 14px;
    border-radius: 100px;
    transition: border-color var(--transition), color var(--transition), background var(--transition);
    letter-spacing: -0.01em;
}
.skill-chip:hover { border-color: var(--primary-muted); color: var(--primary); background: var(--primary-light); }
.timeline { display: flex; flex-direction: column; gap: 0; }
.timeline-item {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 20px;
    padding: 20px 0;
    border-bottom: 1px solid var(--border);
}
.timeline-item:last-child { border-bottom: none; }
.timeline-date {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
    padding-top: 2px;
    letter-spacing: -0.01em;
}
.timeline-content-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 4px;
    letter-spacing: -0.02em;
}
.timeline-content-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    font-weight: 400;
}
.contact-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}
.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 18px;
    text-decoration: none;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 500;
    transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
    letter-spacing: -0.01em;
}
.contact-item:hover {
    border-color: var(--primary-muted);
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
    color: var(--primary);
}
.contact-icon {
    width: 36px; height: 36px;
    background: var(--primary-light);
    border-radius: 10px;
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.contact-icon svg { width: 16px; height: 16px; color: var(--primary); }

/* ── ALL POSTS ── */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 28px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}
.filter-btn {
    font-family: var(--font-sans);
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    padding: 6px 14px;
    border-radius: 100px;
    cursor: pointer;
    transition: all var(--transition);
    letter-spacing: -0.01em;
}
.filter-btn:hover { border-color: var(--primary-muted); color: var(--primary); background: var(--primary-light); }
.filter-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); box-shadow: 0 2px 8px rgba(74,124,247,0.25); }
.load-more-area {
    text-align: center;
    padding: 32px 0 16px;
}
.end-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.05em;
}

/* ── TAGS PAGE ── */
.tags-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 14px;
}
.tag-card {
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 20px;
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}
.tag-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.tag-card-name {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
    letter-spacing: -0.02em;
}
.tag-card-count {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 400;
}
.tag-card-bar {
    height: 3px;
    background: var(--primary-light);
    border-radius: 2px;
    margin-top: 14px;
    overflow: hidden;
}
.tag-card-bar-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 2px;
    transition: width 0.6s cubic-bezier(0.4,0,0.2,1);
}

/* ── SCROLL SENTINEL ── */
#scroll-sentinel { height: 1px; }

/* ── PAGE TITLE ── */
.page-title {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-size: clamp(1.5rem, 3.5vw, 2rem);
    font-weight: 800;
    color: var(--text);
    letter-spacing: -0.04em;
    margin-bottom: 8px;
    padding-top: 40px;
}
.page-subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 36px;
    font-weight: 400;
    line-height: 1.6;
}

/* ── FOOTER ── */
footer {
    border-top: 1px solid var(--border);
    padding: 32px 24px;
    text-align: center;
}
.footer-inner { max-width: 900px; margin: 0 auto; }
.footer-text {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: -0.01em;
}

@media (max-width: 600px) {
    nav { padding: 0 16px; }
    main { padding: 80px 16px 60px; }
    .nav-tab { padding: 5px 10px; font-size: 0.8rem; }
    .home-stats { grid-template-columns: repeat(3, 1fr); gap: 10px; }
    .stat-num { font-size: 1.4rem; }
    .posts-grid { grid-template-columns: 1fr; }
    .timeline-item { grid-template-columns: 90px 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .tags-grid { grid-template-columns: repeat(2, 1fr); }
}