/* =============================================================
   DefTruth.github.io — stylesheet
   Dark GitHub-inspired theme. Customise the variables below.
   ============================================================= */

/* ---------- Theme variables — edit to retheme -------------- */
:root {
  --bg:        #0d1117;   /* page background                   */
  --bg-card:   #161b22;   /* card / nav background             */
  --border:    #30363d;   /* card borders                      */
  --accent:    #58a6ff;   /* links, active states, underlines  */
  --accent2:   #3fb950;   /* green tags                        */
  --text:      #c9d1d9;   /* body text                         */
  --muted:     #8b949e;   /* secondary text, meta              */
  --heading:   #f0f6fc;   /* headings                          */
  --radius:    8px;
  --ease:      0.22s ease;
}

/* ---------- Reset ------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html  { scroll-behavior: smooth; font-size: 115%; }
body  { background: var(--bg); color: var(--text);
        font: 1rem/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
img   { display: block; max-width: 100%; }
a     { color: var(--accent); text-decoration: none; transition: color var(--ease); }
a:hover { color: #79c0ff; }

/* ---------- Layout ----------------------------------------- */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
section    { padding: 80px 0; }
section:nth-child(even) { background: var(--bg-card); }

/* ---------- Nav -------------------------------------------- */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(13,17,23,.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between;
             padding: 16px 24px; max-width: 1100px; margin: 0 auto; }
.nav-logo  { font-weight: 700; font-size: 1.05rem; color: var(--heading); }
.nav-links { display: flex; gap: 22px; list-style: none; }
.nav-links a        { color: var(--muted); font-size: .9rem; }
.nav-links a:hover,
.nav-links a.active { color: var(--heading); }

/* ---------- Hero ------------------------------------------- */
#hero { padding: 104px 0 80px; text-align: center; }
.avatar { width: 128px; height: 128px; border-radius: 50%;
          margin: 0 auto 23px; border: 3px solid var(--border); object-fit: cover; }
#hero h1 { font-size: clamp(1.9rem, 5vw, 2.7rem); font-weight: 700;
           color: var(--heading); letter-spacing: -.4px; }
.tagline { margin: 10px auto 0; max-width: 667px; color: var(--muted); font-size: 1.05rem; }

/* Stats row */
.stats-row { display: flex; align-items: center; justify-content: center;
             gap: 0; margin: 36px auto 0; max-width: 506px;
             background: var(--bg-card); border: 1px solid var(--border);
             border-radius: var(--radius); overflow: hidden; }
.stat      { flex: 1; padding: 16px 8px; text-align: center; }
.stat-n    { display: block; font-size: 1.4rem; font-weight: 700; color: var(--accent); }
.stat-l    { display: block; font-size: .72rem; color: var(--muted); margin-top: 2px; }
.stat-sep  { width: 1px; height: 50px; background: var(--border); flex-shrink: 0; }
.stat-badge { display: block; margin: 0 auto 2px; height: 25px; }

/* Badge / button rows */
.badge-row { display: flex; flex-wrap: wrap; justify-content: center;
             gap: 8px; margin-top: 28px; }
.badge-row img { display: inline; }
.btn-row   { display: flex; flex-wrap: wrap; justify-content: center;
             gap: 14px; margin-top: 32px; }
.btn       { display: inline-flex; align-items: center; gap: 6px;
             padding: 10px 23px; border-radius: var(--radius);
             font-size: .88rem; font-weight: 600;
             transition: opacity var(--ease), transform var(--ease); }
.btn:hover { opacity: .82; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #0d1117; }
.btn-outline  { border: 1px solid var(--border); color: var(--text); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Section title ---------------------------------- */
.section-title { display: inline-block; font-size: 1.5rem; font-weight: 700;
                 color: var(--heading); margin-bottom: 40px; }
.section-title::after { content: ""; display: block; height: 3px; width: 40px;
                        background: var(--accent); margin-top: 7px; border-radius: 2px; }

/* ---------- About ------------------------------------------ */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
#about p { margin-bottom: 16px; }
.muted   { color: var(--muted); }

/* ---------- Tags ------------------------------------------- */
.tag { display: inline-block; background: rgba(88,166,255,.1);
       border: 1px solid rgba(88,166,255,.25); color: var(--accent);
       border-radius: 20px; font-size: .76rem; padding: 2px 9px; }

/* ---------- Filter bar ------------------------------------- */
#filter-bar  { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; }
.filter-btn  { background: var(--bg-card); border: 1px solid var(--border);
               color: var(--muted); border-radius: 20px; padding: 5px 16px;
               font-size: .83rem; cursor: pointer;
               transition: background var(--ease), border-color var(--ease), color var(--ease); }
.filter-btn:hover,
.filter-btn.active { background: rgba(88,166,255,.1); border-color: var(--accent);
                     color: var(--accent); }

/* ---------- Project cards ---------------------------------- */
.projects-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(308px,1fr));
                 gap: 18px; }
.project-card  { background: var(--bg-card); border: 1px solid var(--border);
                 border-radius: var(--radius); padding: 20px 22px;
                 display: flex; flex-direction: column; gap: 10px;
                 transition: border-color var(--ease), transform var(--ease); }
.project-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.project-card[hidden] { display: none; }

.project-top { display: flex; align-items: flex-start;
               justify-content: space-between; gap: 8px; }
.project-top h3 { font-size: .92rem; font-weight: 600; line-height: 1.35; }
.project-top h3 a { color: var(--accent); }
.stars-badge { height: 20px; flex-shrink: 0; }
.stars-na    { font-size: .72rem; color: var(--muted); flex-shrink: 0; }

.project-card > p { color: var(--muted); font-size: .86rem; flex: 1; }

.project-bottom { display: flex; align-items: center; flex-wrap: wrap; gap: 6px; }
.proj-date { margin-left: auto; font-size: .76rem; color: var(--muted); white-space: nowrap; }

/* ---------- Publications ----------------------------------- */
#pub-list  { display: flex; flex-direction: column; gap: 16px; }
.pub-card  { display: flex; gap: 20px; align-items: flex-start;
             background: var(--bg-card); border: 1px solid var(--border);
             border-radius: var(--radius); padding: 20px 25px;
             transition: border-color var(--ease); }
.pub-card:hover { border-color: var(--accent); }
.pub-type  { flex-shrink: 0; align-self: flex-start;
             background: rgba(63,185,80,.1); border: 1px solid rgba(63,185,80,.28);
             color: var(--accent2); border-radius: var(--radius);
             padding: 3px 11px; font-size: .78rem; font-weight: 700; }
.pub-title { font-size: .92rem; font-weight: 600; color: var(--heading);
             line-height: 1.45; margin-bottom: 5px; }
.pub-venue { color: var(--muted); font-size: .86rem; margin-bottom: 3px; }
.pub-meta  { color: var(--muted); font-size: .8rem; }

/* ---------- Contact ---------------------------------------- */
.contact-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; }
.contact-link  { display: flex; align-items: center; gap: 8px;
                 background: var(--bg-card); border: 1px solid var(--border);
                 border-radius: var(--radius); padding: 13px 23px;
                 color: var(--text); font-size: .88rem;
                 transition: border-color var(--ease), color var(--ease), transform var(--ease); }
.contact-link:hover { border-color: var(--accent); color: var(--accent);
                      transform: translateY(-2px); }
.contact-link svg { width: 19px; height: 19px; fill: currentColor; flex-shrink: 0; }

/* ---------- Footer ----------------------------------------- */
footer { background: var(--bg); border-top: 1px solid var(--border);
         padding: 28px; text-align: center; color: var(--muted); font-size: .83rem; }

/* ---------- Fade-in ---------------------------------------- */
.fade-in         { opacity: 0; transform: translateY(14px);
                   transition: opacity .45s ease, transform .45s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ---------- Responsive ------------------------------------- */
@media (max-width: 740px) {
  .two-col        { grid-template-columns: 1fr; }
  .projects-grid  { grid-template-columns: 1fr; }
  .stats-row      { max-width: 100%; }
  .nav-links      { gap: 14px; }
  /* hide Works + Papers links on smallest screens, keep About + Contact */
  .nav-links li:nth-child(2),
  .nav-links li:nth-child(3) { display: none; }
  .pub-card       { flex-direction: column; }
}