:root {
    --navy: #0a192f;
    --light-navy: #112240;
    --lightest-navy: #233554;
    --slate: #8892b0;
    --light-slate: #a8b2d1;
    --lightest-slate: #ccd6f6;
    --white: #e6f1ff;
    --green: #64ffda;
    --green-dim: rgba(100,255,218,0.1);
    --font-sans: 'Noto Sans KR','Inter',system-ui,sans-serif;
    --font-mono: 'Fira Code','Consolas',monospace;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font-sans);background:var(--navy);color:var(--slate);line-height:1.7;font-size:16px}
::selection{background:var(--green-dim);color:var(--green)}
::-webkit-scrollbar{width:6px}
::-webkit-scrollbar-track{background:var(--navy)}
::-webkit-scrollbar-thumb{background:var(--lightest-navy);border-radius:3px}
img{display:block;max-width:100%}
a{color:var(--green);text-decoration:none;transition:color 0.2s}

.container{max-width:1000px;margin:0 auto;padding:0 20px}

/* ===== HEADER ===== */
header{position:fixed;top:0;left:0;right:0;z-index:100;transition:all 0.3s}
header.scrolled{background:rgba(10,25,47,0.92);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);box-shadow:0 10px 30px -10px rgba(2,12,27,0.7)}
nav{max-width:1200px;margin:0 auto;padding:0 40px;display:flex;justify-content:space-between;align-items:center;height:70px}
.nav-logo{font-family:var(--font-mono);font-size:18px;font-weight:700;color:var(--green);letter-spacing:2px}
.nav-list{display:flex;list-style:none;gap:6px}
.nav-list a{color:var(--light-slate);font-size:13px;padding:8px 14px;border-radius:4px;transition:all 0.2s}
.nav-list a:hover{color:var(--green)}
.nav-num{color:var(--green);font-family:var(--font-mono);font-size:12px;margin-right:4px}

/* Hamburger */
.nav-hamburger{display:none;background:none;border:none;cursor:pointer;width:30px;height:24px;position:relative;z-index:11}
.nav-hamburger span{display:block;width:100%;height:2px;background:var(--green);position:absolute;left:0;transition:all 0.3s}
.nav-hamburger span:nth-child(1){top:0}
.nav-hamburger span:nth-child(2){top:11px}
.nav-hamburger span:nth-child(3){top:22px}
.nav-hamburger.open span:nth-child(1){top:11px;transform:rotate(45deg)}
.nav-hamburger.open span:nth-child(2){opacity:0}
.nav-hamburger.open span:nth-child(3){top:11px;transform:rotate(-45deg)}
.nav-mobile{position:fixed;top:0;right:-100%;width:min(75vw,320px);height:100vh;background:var(--light-navy);z-index:10;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:24px;transition:right 0.3s;box-shadow:-10px 0 30px rgba(0,0,0,0.3)}
.nav-mobile.open{right:0}
.nav-mobile a{color:var(--lightest-slate);font-size:16px;font-family:var(--font-mono);padding:12px}

/* ===== HERO ===== */
.hero{min-height:100vh;display:flex;align-items:center}
.hero .container{padding-left:40px;padding-right:40px}
.hero-hello{font-family:var(--font-mono);font-size:16px;color:var(--green);margin-bottom:20px}
.hero-title{font-size:clamp(36px,6vw,64px);font-weight:700;color:var(--lightest-slate);line-height:1.15;margin-bottom:0}
.hero-name{font-size:clamp(36px,6vw,64px);font-weight:700;color:var(--slate);line-height:1.15;margin-bottom:24px}
.hero-desc{font-size:18px;color:var(--slate);max-width:520px;line-height:1.8;margin-bottom:32px}
.hero-social{display:flex;gap:20px}
.hero-social a{color:var(--light-slate);transition:color 0.2s,transform 0.2s}
.hero-social a:hover{color:var(--green);transform:translateY(-3px)}

/* Hero stagger animation */
.anim{opacity:0;transform:translateY(20px);transition:opacity 0.5s ease,transform 0.5s ease}
.anim.show{opacity:1;transform:translateY(0)}

/* ===== SECTIONS ===== */
.section{padding:80px 0;opacity:0;transform:translateY(20px);transition:opacity 0.6s ease,transform 0.6s ease}
.section.show{opacity:1;transform:translateY(0)}
.section-title{font-size:26px;font-weight:600;color:var(--lightest-slate);margin-bottom:40px;display:flex;align-items:center;gap:10px;white-space:nowrap}
.section-title::after{content:'';flex:1;height:1px;background:var(--lightest-navy);margin-left:16px}
.section-num{font-family:var(--font-mono);font-size:20px;color:var(--green);font-weight:400}

/* ===== ABOUT ===== */
.about-grid{display:flex;gap:48px;align-items:flex-start}
.about-text{flex:1}
.about-block{margin-bottom:24px}
.about-block h3{font-size:18px;color:var(--lightest-slate);font-weight:600;margin-bottom:8px}
.about-block p{font-size:15px;line-height:1.8}

.about-img-wrap{position:relative;flex-shrink:0;width:280px;height:280px}
.about-img-border{position:absolute;top:16px;left:16px;width:100%;height:100%;border:2px solid var(--green);border-radius:6px;transition:all 0.3s}
.about-img-wrap:hover .about-img-border{top:10px;left:10px}
.about-img{position:relative;width:100%;height:100%;border-radius:6px;overflow:hidden;background:var(--light-navy)}
.about-img-placeholder{width:100%;height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;background:linear-gradient(135deg,var(--light-navy),var(--lightest-navy))}
.stat-big{font-size:56px;font-weight:800;color:var(--green);font-family:var(--font-mono);line-height:1}
.stat-sub{font-size:12px;color:var(--slate);text-transform:uppercase;letter-spacing:3px}
.about-mini-stats{display:flex;gap:24px;margin-top:16px;font-size:14px;color:var(--light-slate)}
.about-mini-stats strong{color:var(--green);font-family:var(--font-mono)}

/* ===== SKILLS ===== */
.skill-tabs{display:flex;gap:0;border-bottom:2px solid var(--lightest-navy);margin-bottom:0;overflow-x:auto}
.tab{background:none;border:none;color:var(--slate);font-family:var(--font-mono);font-size:13px;padding:14px 24px;cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-2px;transition:all 0.2s;white-space:nowrap}
.tab:hover{color:var(--green);background:var(--green-dim)}
.tab.active{color:var(--green);border-bottom-color:var(--green)}
.tab-panel{display:none}
.tab-panel.active{display:block}
.skill-item{padding:20px 24px;border-left:2px solid var(--lightest-navy);transition:all 0.2s}
.skill-item:hover{border-left-color:var(--green);background:var(--green-dim)}
.skill-item h4{font-size:16px;color:var(--lightest-slate);font-weight:600;margin-bottom:6px}
.skill-item p{font-size:14px;line-height:1.7}

/* ===== FEATURED PROJECTS ===== */
.featured{display:grid;grid-template-columns:3fr 2fr;gap:0;align-items:center;margin-bottom:80px;position:relative;opacity:0;transform:translateY(20px);transition:opacity 0.6s,transform 0.6s}
.featured.show{opacity:1;transform:translateY(0)}
.featured-reverse{grid-template-columns:2fr 3fr;direction:rtl}
.featured-reverse>*{direction:ltr}
.featured-reverse .featured-info{text-align:right}
.featured-reverse .featured-tags{justify-content:flex-end}
.featured-reverse .featured-links{justify-content:flex-end}

.featured-img{aspect-ratio:16/10;border-radius:6px;overflow:hidden;display:flex;align-items:center;justify-content:center;position:relative;cursor:pointer;transition:all 0.3s}
.featured-img::after{content:'';position:absolute;inset:0;background:var(--green-dim);transition:background 0.3s}
.featured-img:hover::after{background:transparent}
.featured-img img{width:72px;height:72px;border-radius:16px;object-fit:cover;position:relative;z-index:1;filter:grayscale(20%);transition:filter 0.3s}
.featured-img:hover img{filter:none}

.featured-info{position:relative;z-index:2}
.featured-label{font-family:var(--font-mono);font-size:13px;color:var(--green);margin-bottom:4px}
.featured-name{font-size:26px;font-weight:700;color:var(--lightest-slate);margin-bottom:16px;cursor:pointer;transition:color 0.2s}
.featured-name:hover{color:var(--green)}
.featured-desc{background:var(--light-navy);padding:20px 24px;border-radius:6px;margin-bottom:16px;box-shadow:0 10px 30px -15px rgba(2,12,27,0.7)}
.featured-desc p{font-size:14px;line-height:1.7;color:var(--light-slate)}
.featured-tags{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:12px}
.featured-tags span{font-family:var(--font-mono);font-size:12px;color:var(--light-slate)}
.featured-links{display:flex;gap:16px}

.link-icon{background:none;border:none;color:var(--light-slate);cursor:pointer;padding:4px;transition:color 0.2s,transform 0.2s}
.link-icon:hover{color:var(--green);transform:translateY(-2px)}

/* ===== SUB PROJECTS ===== */
.sub-title{font-size:22px;font-weight:600;color:var(--lightest-slate);text-align:center;margin-bottom:32px}
.sub-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.sub-card{background:var(--light-navy);border-radius:6px;padding:28px 28px 24px;display:flex;flex-direction:column;transition:all 0.3s;opacity:0;transform:translateY(20px);cursor:pointer}
.sub-card.show{opacity:1;transform:translateY(0)}
.sub-card:hover{transform:translateY(-8px)}

.sub-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}
.sub-folder{color:var(--green)}
.sub-name{font-size:18px;font-weight:600;color:var(--lightest-slate);margin-bottom:10px;transition:color 0.2s}
.sub-card:hover .sub-name{color:var(--green)}
.sub-desc{font-size:14px;color:var(--slate);line-height:1.6;margin-bottom:auto;padding-bottom:20px}
.sub-tags{display:flex;flex-wrap:wrap;gap:10px}
.sub-tags span{font-family:var(--font-mono);font-size:12px;color:var(--slate)}

/* ===== MODAL ===== */
.modal-overlay{position:fixed;inset:0;background:rgba(10,25,47,0.85);z-index:200;display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transition:opacity 0.3s,visibility 0.3s;padding:24px}
.modal-overlay.active{opacity:1;visibility:visible}
.modal-content{background:var(--light-navy);border:1px solid var(--lightest-navy);border-radius:8px;max-width:680px;width:100%;max-height:85vh;overflow-y:auto;padding:40px 36px;position:relative;transform:translateY(20px) scale(0.98);transition:transform 0.3s}
.modal-overlay.active .modal-content{transform:translateY(0) scale(1)}
.modal-content::-webkit-scrollbar{width:4px}
.modal-content::-webkit-scrollbar-thumb{background:var(--lightest-navy);border-radius:2px}
.modal-close{position:absolute;top:16px;right:20px;background:none;border:none;color:var(--slate);font-size:28px;cursor:pointer;line-height:1;transition:color 0.2s}
.modal-close:hover{color:var(--green)}
.modal-head{margin-bottom:20px}
.modal-head h2{font-size:24px;font-weight:700;color:var(--lightest-slate)}
.modal-sub{font-size:14px;color:var(--slate);margin:4px 0 12px}
.modal-meta{display:flex;gap:20px;font-family:var(--font-mono);font-size:12px;color:var(--green)}
.modal-desc{font-size:15px;line-height:1.8;margin-bottom:28px}
.modal-label{font-family:var(--font-mono);font-size:13px;color:var(--green);margin-bottom:14px}
.modal-hl{margin-bottom:28px}
.mh{display:flex;gap:14px;padding:10px 14px;border-radius:4px;align-items:flex-start}
.mh:nth-child(odd){background:rgba(100,255,218,0.03)}
.mh-n{font-family:var(--font-mono);font-size:12px;color:var(--green);flex-shrink:0;padding-top:3px}
.mh p{font-size:14px;color:var(--light-slate);line-height:1.6}
.modal-tags{display:flex;flex-wrap:wrap;gap:8px}
.modal-tags span{font-family:var(--font-mono);font-size:12px;color:var(--green);padding:4px 12px;border-radius:4px;background:var(--green-dim);border:1px solid rgba(100,255,218,0.15)}

/* ===== CONTACT ===== */
.contact-wrap{text-align:center;max-width:600px;padding:80px 0}
.section-num-big{font-family:var(--font-mono);font-size:16px;color:var(--green);margin-bottom:12px}
.contact-title{font-size:clamp(36px,5vw,52px);font-weight:700;color:var(--lightest-slate);margin-bottom:20px}
.contact-desc{font-size:17px;line-height:1.8;margin-bottom:40px}
.btn-outline{display:inline-block;font-family:var(--font-mono);font-size:14px;color:var(--green);border:1px solid var(--green);border-radius:4px;padding:16px 48px;transition:all 0.3s;cursor:pointer}
.btn-outline:hover{background:var(--green-dim)}

/* ===== FOOTER ===== */
footer{padding:24px;text-align:center}
.footer-links{display:flex;justify-content:center;gap:24px;margin-bottom:16px}
.footer-links a{color:var(--slate);transition:color 0.2s,transform 0.2s;display:block}
.footer-links a:hover{color:var(--green);transform:translateY(-3px)}
.footer-credit{font-family:var(--font-mono);font-size:12px;color:var(--slate);line-height:1.8}

/* ===== RESPONSIVE ===== */
@media(max-width:768px){
    nav{padding:0 20px}
    .nav-list{display:none}
    .nav-hamburger{display:block}
    .hero .container{padding-left:20px;padding-right:20px}
    .section{padding:60px 0}
    .about-grid{flex-direction:column}
    .about-img-wrap{width:200px;height:200px;margin:0 auto}
    .featured,.featured-reverse{grid-template-columns:1fr;direction:ltr}
    .featured-reverse .featured-info{text-align:left}
    .featured-reverse .featured-tags{justify-content:flex-start}
    .featured-reverse .featured-links{justify-content:flex-start}
    .featured-img{aspect-ratio:16/9}
    .featured-desc{margin-left:0;margin-right:0}
    .sub-grid{grid-template-columns:1fr}
    .modal-content{padding:28px 20px}
    .tab{padding:12px 16px;font-size:12px}
    .stat-big{font-size:40px}
}

@media(max-width:480px){
    .hero-title,.hero-name{font-size:32px}
    .about-img-wrap{width:160px;height:160px}
}

@media(prefers-reduced-motion:reduce){
    *,*::before,*::after{animation-duration:0.01ms!important;transition-duration:0.01ms!important}
}