/* XSRG — Xaverians Space Research Group | Academic light theme */
:root {
  --navy:#142B4D; --blue:#2463A6; --blue-light:#6EA7E8;
  --bg:#F5F7FA; --white:#FFFFFF;
  --text:#202B3C; --muted:#64748B;
  --border:rgba(20,43,77,0.10); --border-strong:rgba(20,43,77,0.16);
  --fh:"Space Grotesk","Inter",system-ui,sans-serif;
  --fb:"Inter",system-ui,sans-serif;
  --fm:"JetBrains Mono","Consolas",monospace;
  --ease:cubic-bezier(.22,1,.36,1);
  --container:1240px; --gutter:clamp(20px,5vw,64px);
  --section:clamp(72px,9vw,128px);
  --radius:14px;
  --shadow:0 8px 28px rgba(20,43,77,0.08);
  --shadow-sm:0 2px 10px rgba(20,43,77,0.06);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--fb);color:var(--text);background:var(--bg);line-height:1.65;-webkit-font-smoothing:antialiased;overflow-x:hidden}
body::before{content:"";position:fixed;inset:0;z-index:-1;background:url("../assets/xaverians1.png") center/cover no-repeat;opacity:0.18;filter:grayscale(0.15);pointer-events:none}
body::after{content:"";position:fixed;inset:0;z-index:9998;background:url("../assets/xpacespace-logo.png") center/320px no-repeat;opacity:0.04;pointer-events:none}
img,svg{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit;cursor:pointer;border:none;background:none}

h1,h2,h3,h4{font-family:var(--fh);font-weight:700;letter-spacing:-.02em;line-height:1.05;margin:0 0 .5em;color:var(--navy)}
h1{font-size:clamp(2.4rem,6vw,4.6rem)}
h2{font-size:clamp(1.9rem,4vw,3.2rem)}
h3{font-size:clamp(1.2rem,2.2vw,1.7rem)}
p{margin:0 0 1em}

.eyebrow{font-family:var(--fm);font-size:.7rem;letter-spacing:.2em;text-transform:uppercase;color:var(--blue);display:inline-flex;align-items:center;gap:12px;margin-bottom:1.2rem}
.eyebrow::before{content:"";width:28px;height:1px;background:var(--blue)}

.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 var(--gutter)}

/* header */
.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.92);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--border);box-shadow:var(--shadow-sm)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:80px;gap:20px}
.brand{display:flex;align-items:center;gap:12px;font-family:var(--fh);font-weight:700;letter-spacing:.02em;font-size:1rem;color:var(--navy)}
.brand-logo{height:46px;width:auto;max-width:none;flex-shrink:0}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-text .name{font-size:.95rem}
.brand-text .sub{font-size:.7rem;color:var(--muted);font-weight:500;letter-spacing:.04em}
.nav{display:flex;align-items:center;gap:24px}
.nav a{color:var(--text);font-size:.82rem;letter-spacing:.08em;text-transform:uppercase;font-weight:500;opacity:.85;transition:opacity .2s,color .2s}
.nav a:hover{opacity:1;color:var(--blue)}
.nav a.is-active{opacity:1;color:var(--blue)}
.nav-cta{padding:10px 20px;border-radius:999px;background:var(--blue);color:#fff!important;opacity:1!important;font-weight:600;transition:background .2s,transform .2s}
.nav-cta:hover{background:var(--navy);transform:translateY(-1px)}
.parent-brand{display:flex;align-items:center;gap:8px;margin-left:12px;padding-left:16px;border-left:1px solid var(--border)}
.parent-brand .label{font-size:.62rem;color:#4b5563;letter-spacing:.1em;text-transform:uppercase;font-family:var(--fm)}
.parent-brand img{height:22px;width:auto;max-width:none;opacity:.85}
.menu-toggle{display:none;width:36px;height:36px;align-items:center;justify-content:center;flex-direction:column;gap:5px;color:var(--navy)}
.menu-toggle span{width:22px;height:2px;background:currentColor;border-radius:2px}
.mobile-nav{display:none;position:fixed;inset:80px 0 0 0;background:rgba(255,255,255,.98);backdrop-filter:blur(14px);padding:24px var(--gutter);flex-direction:column;gap:4px;z-index:99;overflow-y:auto}
.mobile-nav.is-open{display:flex}
.mobile-nav a{color:var(--text);font-size:1.05rem;letter-spacing:.06em;text-transform:uppercase;padding:14px 0;border-bottom:1px solid var(--border);font-weight:500}
.mobile-nav a:hover{color:var(--blue)}
.mobile-nav .mobile-parent{margin-top:16px;padding-top:16px;border-top:1px solid var(--border);display:flex;align-items:center;gap:10px}
.mobile-nav .mobile-parent .label{font-size:.62rem;color:#4b5563;text-transform:uppercase;letter-spacing:.1em;font-family:var(--fm)}
.mobile-nav .mobile-parent img{height:20px;max-width:none}
@media(max-width:900px){.nav{display:none}.menu-toggle{display:flex}.parent-brand{display:none}}

/* hero */
.hero{position:relative;min-height:86vh;display:flex;align-items:center;color:var(--text);overflow:hidden;background:var(--white)}
.hero-media{position:absolute;inset:0;z-index:0}
.hero-media img{width:100%;height:100%;object-fit:cover;opacity:.28}
.hero-overlay{position:absolute;inset:0;z-index:1;background:linear-gradient(180deg,rgba(245,247,250,.6) 0%,rgba(255,255,255,.95) 100%)}
.hero-content{position:relative;z-index:2;width:100%;max-width:var(--container);margin:0 auto;padding:var(--gutter);padding-top:clamp(40px,8vw,100px)}
.hero h1{max-width:14ch;margin-bottom:1.4rem;color:var(--navy)}
.hero-sub{max-width:56ch;color:var(--muted);margin-bottom:2.4rem;font-size:1.15rem}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.hero-badge{display:inline-flex;align-items:center;gap:8px;padding:6px 14px;border-radius:999px;background:rgba(36,99,166,.08);color:var(--blue);font-size:.78rem;font-weight:600;margin-bottom:1.6rem}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:10px;padding:14px 26px;font-family:var(--fh);font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;font-weight:600;border:1px solid transparent;border-radius:999px;transition:all .25s var(--ease)}
.btn-primary{background:var(--blue);color:#fff;border-color:var(--blue)}
.btn-primary:hover{background:var(--navy);border-color:var(--navy);transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--navy);border-color:var(--border-strong)}
.btn-ghost:hover{border-color:var(--blue);color:var(--blue)}
.btn-sm{padding:9px 18px;font-size:.72rem}

/* page hero */
.page-hero{padding:clamp(96px,13vw,150px) 0 clamp(48px,7vw,80px);background:var(--white);color:var(--text);border-bottom:1px solid var(--border)}
.page-hero .eyebrow{color:var(--blue)}
.page-hero h1{max-width:20ch;color:var(--navy)}
.page-hero .lead{color:var(--muted);font-size:1.12rem;max-width:66ch;margin-top:1.2rem}

/* sections */
.section{padding:var(--section) 0}
.section--alt{background:var(--white)}
.section--muted{background:var(--bg)}
.section--dark{background:var(--navy);color:#fff}
.section--dark h1,.section--dark h2,.section--dark h3,.section--dark h4{color:#fff}
.section-head{display:grid;grid-template-columns:1fr 1fr;gap:32px;align-items:end;margin-bottom:clamp(36px,5vw,64px)}
.section-head .lead{color:var(--muted);font-size:1.05rem;max-width:56ch}
.section--dark .section-head .lead{color:rgba(255,255,255,.7)}
@media(max-width:760px){.section-head{grid-template-columns:1fr;gap:12px}}

/* cards */
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
@media(max-width:960px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}}
@media(max-width:620px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}
.card{background:var(--white);border:1px solid var(--border);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow-sm);transition:border-color .25s,transform .25s var(--ease),box-shadow .25s}
.card:hover{border-color:var(--blue-light);transform:translateY(-4px);box-shadow:var(--shadow)}
.card-img{aspect-ratio:16/10;border-radius:10px 10px 0 0;margin:-28px -28px 20px;overflow:hidden;position:relative;background:url("../assets/xaverians1.png") center/cover no-repeat}
.card-img img{width:100%;height:100%;object-fit:cover;transition:transform .5s var(--ease)}
.card:hover .card-img img{transform:scale(1.04)}
.card-img .placeholder{display:none}
.split-media .placeholder{display:none}
.card-tag{font-family:var(--fm);font-size:.68rem;letter-spacing:.16em;text-transform:uppercase;color:var(--blue);margin-bottom:10px}
.card h3{font-size:1.25rem;margin-bottom:.4rem}
.card p{color:var(--muted);font-size:.93rem}
.card-link{display:inline-flex;align-items:center;gap:6px;font-family:var(--fh);font-size:.76rem;letter-spacing:.1em;text-transform:uppercase;color:var(--blue);margin-top:12px;font-weight:600;transition:gap .2s}
.card-link:hover{gap:10px}
.section--dark .card{background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.12);color:#fff;box-shadow:none}
.section--dark .card p{color:rgba(255,255,255,.7)}
.section--dark .card h3{color:#fff}

/* empty state */
.empty-state{border:1px dashed var(--border-strong);border-radius:var(--radius);padding:56px 24px;text-align:center;color:var(--muted);background:var(--white)}
.empty-state h3{color:var(--navy);margin-bottom:6px}
.empty-state p{max-width:52ch;margin:0 auto}

/* split */
.split{display:grid;grid-template-columns:1fr 1fr;gap:clamp(32px,5vw,64px);align-items:center}
.split-media{aspect-ratio:4/3;border-radius:var(--radius);background:url("../assets/xaverians1.png") center/cover no-repeat;position:relative;overflow:hidden}
.split-media .placeholder{position:absolute;inset:0;display:grid;place-items:center;color:var(--muted);font-family:var(--fm);font-size:.72rem;letter-spacing:.16em;text-transform:uppercase}
.split-media img{width:100%;height:100%;object-fit:cover}
.card-img::after,.split-media::after{content:"Generated by xpaceAI";position:absolute;bottom:8px;right:10px;font-family:var(--fm);font-size:.6rem;letter-spacing:.08em;color:rgba(255,255,255,.85);background:rgba(20,43,77,.45);padding:2px 8px;border-radius:999px;pointer-events:none;z-index:2}
@media(max-width:860px){.split{grid-template-columns:1fr}}

/* timeline */
.timeline{position:relative;padding-left:28px}
.timeline::before{content:"";position:absolute;left:8px;top:4px;bottom:4px;width:1px;background:var(--border-strong)}
.timeline-item{position:relative;padding-bottom:24px}
.timeline-item::before{content:"";position:absolute;left:-24px;top:6px;width:10px;height:10px;border-radius:50%;background:var(--blue);border:2px solid var(--white);box-shadow:0 0 0 3px rgba(36,99,166,.15)}
.timeline-item h4{font-size:1rem;margin-bottom:4px;color:var(--navy)}
.timeline-item p{color:var(--muted);font-size:.9rem;margin:0}

/* filters */
.filters{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:28px}
.filter{padding:8px 16px;border:1px solid var(--border-strong);border-radius:999px;color:var(--muted);font-family:var(--fm);font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;background:var(--white);transition:all .2s;cursor:pointer}
.filter:hover{border-color:var(--blue);color:var(--blue)}
.filter.is-active{background:var(--blue);color:#fff;border-color:var(--blue)}

/* footer */
.site-footer{background:#0B1A2E;color:#fff;padding:72px 0 28px;margin-top:0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
@media(max-width:860px){.footer-grid{grid-template-columns:1fr 1fr}}
@media(max-width:520px){.footer-grid{grid-template-columns:1fr}}
.footer-col .footer-heading{font-size:.7rem;letter-spacing:.16em;text-transform:uppercase;color:rgba(255,255,255,.55);margin-bottom:16px;font-family:var(--fm)}
.footer-col a{display:block;color:rgba(255,255,255,.85);font-size:.9rem;margin-bottom:8px;transition:color .2s}
.footer-col a:hover{color:var(--blue-light)}
.footer-brand p{color:rgba(255,255,255,.7);font-size:.9rem;max-width:38ch}
.footer-brand .brand{color:#fff}
.footer-brand .brand span.accent{color:var(--blue-light)}
.footer-brand .brand img{height:40px;width:auto;max-width:none}
.footer-parent{margin-top:18px;padding-top:18px;border-top:1px solid rgba(255,255,255,.12)}
.footer-parent .label{font-size:.62rem;color:rgba(255,255,255,.7);text-transform:uppercase;letter-spacing:.12em;font-family:var(--fm);display:block;margin-bottom:8px}
.footer-parent img{height:26px;width:auto;max-width:none;opacity:.9}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;padding-top:20px;border-top:1px solid rgba(255,255,255,.12);font-size:.78rem;color:rgba(255,255,255,.55)}
.footer-domain{font-family:var(--fm);color:var(--blue-light)}

/* reveal */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.is-visible{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* utility */
.text-muted{color:var(--muted)} .mono{font-family:var(--fm)} .center{text-align:center}
.mt-1{margin-top:1rem} .mt-2{margin-top:2rem} .mt-3{margin-top:3rem}
.mt-4{margin-top:4rem}
.mb-1{margin-bottom:1rem}
.badge{display:inline-block;padding:4px 12px;border-radius:999px;background:rgba(36,99,166,.1);color:var(--blue);font-family:var(--fm);font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;font-weight:600}
.badge--status{background:rgba(36,99,166,.12)}
.empty{color:var(--muted);font-style:italic}

/* forms */
.form{display:grid;gap:18px;max-width:720px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:620px){.form-row{grid-template-columns:1fr}}
.field{display:flex;flex-direction:column;gap:6px}
.field label{font-size:.82rem;font-weight:600;color:var(--navy);letter-spacing:.02em}
.field label .req{color:#c0392b;margin-left:2px}
.field input,.field select,.field textarea{padding:12px 14px;border:1px solid var(--border-strong);border-radius:10px;background:var(--white);color:var(--text);font-family:var(--fb);font-size:.95rem;transition:border-color .2s,box-shadow .2s}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(36,99,166,.12)}
.field textarea{min-height:120px;resize:vertical}
.field .hint{font-size:.75rem;color:var(--muted)}
.field .error{font-size:.78rem;color:#c0392b;display:none}
.field.is-invalid .error{display:block}
.field.is-invalid input,.field.is-invalid select,.field.is-invalid textarea{border-color:#c0392b}
.form-actions{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.form-status{padding:14px 18px;border-radius:10px;font-size:.9rem;display:none}
.form-status.is-success{display:block;background:rgba(39,174,96,.1);color:#1e7e4a;border:1px solid rgba(39,174,96,.25)}
.form-status.is-error{display:block;background:rgba(192,57,43,.08);color:#c0392b;border:1px solid rgba(192,57,43,.2)}
.form-status.is-info{display:block;background:rgba(36,99,166,.08);color:var(--blue);border:1px solid rgba(36,99,166,.2)}

/* search */
.search-input{width:100%;padding:13px 16px;background:var(--white);border:1px solid var(--border-strong);border-radius:10px;color:var(--text);font-family:var(--fb);font-size:.95rem;margin-bottom:24px}
.search-input:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(36,99,166,.12)}

/* detail page */
.detail{max-width:820px}
.detail .meta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:1.2rem}
.detail .meta span{font-family:var(--fm);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--blue);background:rgba(36,99,166,.08);padding:4px 10px;border-radius:999px}
.detail h1{margin-bottom:.6rem}
.detail .authors{color:var(--muted);font-size:1.05rem;margin-bottom:1.6rem}
.detail .abstract{font-size:1.05rem;line-height:1.75;color:var(--text)}
.detail .actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:2rem}

/* profile card */
.profile{display:grid;grid-template-columns:110px 1fr;gap:20px;align-items:start}
.profile-img{width:110px;height:110px;border-radius:50%;background:linear-gradient(135deg,#e8eef7,#dce6f5);overflow:hidden;display:grid;place-items:center;color:var(--muted);font-family:var(--fm);font-size:.7rem}
.profile-img img{width:100%;height:100%;object-fit:cover}
.profile h3{margin-bottom:.2rem}
.profile .role{color:var(--blue);font-size:.85rem;font-weight:600;margin-bottom:.6rem}
.profile .interests{font-size:.85rem;color:var(--muted)}

/* 404 */
.notfound{min-height:70vh;display:grid;place-items:center;text-align:center;padding:60px 20px}
.notfound h1{font-size:clamp(4rem,12vw,8rem);color:var(--blue)}
.notfound p{color:#4b5563;max-width:44ch;margin:0 auto 2rem}

/* back top */
.back-top{position:fixed;right:20px;bottom:20px;width:42px;height:42px;border-radius:50%;border:1px solid var(--border-strong);background:var(--white);color:var(--navy);display:grid;place-items:center;opacity:0;pointer-events:none;transition:opacity .2s,transform .2s;box-shadow:var(--shadow-sm);z-index:50}
.back-top.is-visible{opacity:1;pointer-events:auto}
.back-top:hover{color:var(--blue);border-color:var(--blue)}

/* loader (orbit) */
.loader{position:fixed;inset:0;z-index:9999;background:var(--bg);display:grid;place-items:center;transition:opacity .8s var(--ease),visibility .8s;overflow:hidden}
.loader.is-done{opacity:0;visibility:hidden;pointer-events:none}
.loader-inner{display:flex;flex-direction:column;align-items:center;gap:24px}
.loader-orbit{position:relative;width:300px;height:300px;display:grid;place-items:center}
.loader-logo{height:80px;width:auto;max-width:none;opacity:0;animation:logoIn .9s var(--ease) .2s forwards}
.loader-dot{position:absolute;inset:0;border-radius:50%;border:2px solid transparent;border-top-color:var(--blue);border-right-color:var(--blue-light);animation:orbitSpin 1.6s linear infinite}
.loader-dot::before{content:"";position:absolute;top:-5px;left:50%;transform:translateX(-50%);width:10px;height:10px;border-radius:50%;background:var(--blue);box-shadow:0 0 12px var(--blue)}
.loader-text{display:flex;flex-direction:column;align-items:center;gap:4px;opacity:0;animation:textIn .8s var(--ease) .5s forwards}
.loader-title{font-family:var(--fh);font-size:1.1rem;font-weight:700;color:var(--navy);letter-spacing:.02em}
.loader-tag{font-family:var(--fb);font-size:.85rem;color:var(--muted);font-style:italic}
.loader-bar{width:220px;height:3px;background:var(--border-strong);border-radius:999px;overflow:hidden;opacity:0;animation:textIn .8s var(--ease) .7s forwards}
.loader-bar-fill{height:100%;width:0;background:linear-gradient(90deg,var(--blue),var(--blue-light));border-radius:999px;animation:barFill 1.6s var(--ease) .3s forwards}
@keyframes logoIn{0%{opacity:0;filter:blur(6px)}100%{opacity:1;filter:blur(0)}}
@keyframes orbitSpin{0%{transform:rotate(0deg)}100%{transform:rotate(360deg)}}
@keyframes textIn{0%{opacity:0;transform:translateY(10px)}100%{opacity:1;transform:translateY(0)}}
@keyframes barFill{0%{width:0}100%{width:100%}}

/* responsive tweaks */
@media(max-width:620px){.profile{grid-template-columns:80px 1fr}.profile-img{width:80px;height:80px}}