/* ==========================================================================
   Abhisan Ghimire — Portfolio
   Design tokens
   ========================================================================== */
:root{
  --bg:            #14171A;
  --bg-elevated:   #191D21;
  --surface:       #1E2327;
  --border:        #2B3136;
  --border-soft:   #24292E;

  --text:          #ECEAE4;
  --text-dim:      #A7ADB2;
  --text-faint:    #6E757B;

  --accent:        #C4623E;   /* muted orange / rust */
  --accent-dim:    #8F4A31;
  --accent-tint:   rgba(196,98,62,0.12);

  --sage:          #7C9385;   /* subtle green/gray */
  --sage-tint:     rgba(124,147,133,0.14);

  --font-display:  'Source Serif 4', Georgia, serif;
  --font-body:     'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:     'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  --max-w: 1120px;
  --radius: 3px;

  --dur: 0.5s;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

@media (prefers-reduced-motion: reduce){
  *, *::before, *::after{
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ==========================================================================
   Reset
   ========================================================================== */
*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; scroll-padding-top: 84px; }
body{
  margin:0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img,svg{ display:block; max-width:100%; }
a{ color: inherit; text-decoration: none; }
ul{ margin:0; padding:0; list-style:none; }
h1,h2,h3,h4{ margin:0; font-family: var(--font-display); font-weight: 600; line-height: 1.15; }
p{ margin:0; }
button{ font-family: inherit; }

.visually-hidden{
  position:absolute; width:1px; height:1px; padding:0; margin:-1px;
  overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
}

.skip-link{
  position:absolute; left:0; top:-48px;
  background: var(--accent); color:#14171A;
  padding: 10px 18px; font-family: var(--font-mono); font-size: .85rem;
  z-index: 200; transition: top .2s var(--ease);
}
.skip-link:focus{ top:0; }

:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ==========================================================================
   Type scale
   ========================================================================== */
.eyebrow{
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 14px;
}
h2{
  font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.35rem);
  color: var(--text);
  margin-bottom: 22px;
  max-width: 34ch;
}
h3{
  font-size: 1.15rem;
  color: var(--text);
}
.lede{
  font-size: 1.05rem;
  color: var(--text-dim);
  max-width: 62ch;
  margin-bottom: 34px;
}

/* ==========================================================================
   Layout helpers
   ========================================================================== */
.section{ padding: 96px 0; border-bottom: 1px solid var(--border-soft); }
.section-alt{ background: var(--bg-elevated); }
.section-inner{ max-width: var(--max-w); margin: 0 auto; padding: 0 32px; }

.reveal{ opacity:0; transform: translateY(18px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-visible{ opacity:1; transform:none; }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn{
  display:inline-flex; align-items:center; gap:6px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: .02em;
  padding: 11px 20px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background .25s var(--ease), color .25s var(--ease), border-color .25s var(--ease), transform .2s var(--ease);
  cursor:pointer;
}
.btn:hover{ transform: translateY(-1px); }
.btn-primary{ background: var(--accent); color:#15100D; border-color: var(--accent); }
.btn-primary:hover{ background:#d5734c; }
.btn-outline{ border-color: var(--border); color: var(--text); }
.btn-outline:hover{ border-color: var(--accent); color: var(--accent); }
.btn-ghost{ color: var(--text-dim); }
.btn-ghost:hover{ color: var(--accent); }
.btn-small{ padding: 7px 14px; font-size: 0.78rem; }

/* ==========================================================================
   Header / Nav
   ========================================================================== */
.site-header{
  position: fixed; top:0; left:0; right:0; z-index: 100;
  background: rgba(20,23,26,0.86);
  backdrop-filter: blur(10px) saturate(140%);
  border-bottom: 1px solid var(--border-soft);
  transition: border-color .3s var(--ease);
}
.header-inner{
  max-width: var(--max-w); margin:0 auto; padding: 0 32px;
  height: 68px;
  display:flex; align-items:center; justify-content:space-between;
}
.brand{ display:flex; align-items:center; gap:10px; }
.brand-mark{
  font-family: var(--font-mono); font-size: .78rem;
  border:1px solid var(--border); color: var(--accent);
  width: 30px; height:30px; display:flex; align-items:center; justify-content:center;
  border-radius: var(--radius);
}
.brand-name{ font-family: var(--font-display); font-weight:600; font-size: 1.02rem; }

.main-nav{ display:flex; align-items:center; gap: 30px; }
.main-nav ul{ display:flex; gap: 26px; }
.main-nav a[data-nav]{
  font-family: var(--font-mono); font-size: 0.82rem; color: var(--text-dim);
  position: relative; padding: 4px 0;
  transition: color .2s var(--ease);
}
.main-nav a[data-nav]::after{
  content:""; position:absolute; left:0; right:100%; bottom:-2px; height:1px;
  background: var(--accent); transition: right .25s var(--ease);
}
.main-nav a[data-nav]:hover,
.main-nav a[data-nav].active{ color: var(--text); }
.main-nav a[data-nav].active::after,
.main-nav a[data-nav]:hover::after{ right:0; }

.nav-toggle{
  display:none; flex-direction:column; justify-content:center; gap:5px;
  width: 38px; height: 38px; background:none; border:1px solid var(--border);
  border-radius: var(--radius); cursor:pointer;
}
.nav-toggle span{ display:block; height:1px; width:16px; margin:0 auto; background: var(--text); transition: transform .3s var(--ease), opacity .3s var(--ease); }
.nav-toggle[aria-expanded="true"] span:nth-child(1){ transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2){ opacity:0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3){ transform: translateY(-6px) rotate(-45deg); }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero{
  padding: 168px 0 96px;
  border-bottom: 1px solid var(--border-soft);
}
.hero-inner{
  max-width: var(--max-w); margin:0 auto; padding: 0 32px;
  display:grid; grid-template-columns: 1.15fr 0.85fr; gap: 48px; align-items:center;
}
.hero h1{
  font-size: clamp(2.6rem, 2rem + 3vw, 4.2rem);
  margin: 10px 0 14px;
}
.hero-roles{
  font-family: var(--font-mono); font-size: 0.95rem; color: var(--sage);
  margin-bottom: 22px; letter-spacing: .01em;
}
.hero-statement{
  font-size: 1.15rem; color: var(--text-dim); max-width: 46ch; margin-bottom: 34px;
}
.hero-actions{ display:flex; flex-wrap:wrap; gap: 12px; }

.hero-figure{ position:relative; }
.hero3d-wrap{
  width:100%; aspect-ratio: 1 / 1; max-height: 420px;
  overflow:hidden;
  position: relative;
  cursor: grab;
}
.hero3d-wrap.is-dragging{ cursor: grabbing; }
#hero3d{ width:100%; height:100%; display:block; touch-action: none; }

/* ==========================================================================
   Interest tags
   ========================================================================== */
.interest-grid{ display:flex; flex-wrap:wrap; gap:10px; margin-bottom: 48px; }
.interest-tag{
  font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-dim);
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 8px 14px; background: var(--surface);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.interest-tag:hover{ border-color: var(--accent); color: var(--text); }

.callout{
  border-left: 2px solid var(--accent);
  padding: 4px 0 4px 22px; margin-top: 44px;
}
.callout p{
  font-family: var(--font-display); font-style: italic; font-size: 1.2rem;
  color: var(--text); max-width: 52ch;
}

/* ==========================================================================
   Research diagrams (figures)
   ========================================================================== */
.research-diagram{ margin: 40px 0 8px; }
.fig-label{
  font-family: var(--font-mono); font-size: 0.75rem; color: var(--text-faint);
  margin-bottom: 16px;
}
.pipeline{
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); padding: 26px;
}
.pipeline-vertical{ display:flex; flex-direction:column; gap:0; max-width: 420px; }
.pipeline-vertical .pipeline-step{
  display:flex; align-items:center; gap:16px;
  padding: 13px 4px; border-bottom: 1px dashed var(--border);
  font-family: var(--font-mono); font-size: 0.88rem;
}
.pipeline-vertical .pipeline-step:last-child{ border-bottom:none; }

.pipeline-horizontal{ display:flex; flex-wrap:wrap; gap: 10px; align-items:stretch; }
.pipeline-horizontal .pipeline-step{
  flex: 1 1 130px;
  display:flex; flex-direction:column; align-items:flex-start; gap:8px;
  padding: 14px 16px; border: 1px solid var(--border); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 0.82rem; background: var(--bg-elevated);
  position: relative;
}
.pipeline-horizontal .pipeline-step:not(:last-child)::after{
  content:"→"; position:absolute; right:-19px; top:50%; transform: translateY(-50%);
  color: var(--text-faint); font-family: var(--font-mono);
}
@media (max-width: 860px){
  .pipeline-horizontal .pipeline-step:not(:last-child)::after{ content:"↓"; right:auto; left:16px; top:auto; bottom:-18px; transform:none; }
  .pipeline-horizontal{ flex-direction:column; }
}

.step-index{
  font-size: 0.7rem; color: var(--accent);
  border: 1px solid var(--accent-dim); border-radius: 50%;
  width: 20px; height: 20px; display:flex; align-items:center; justify-content:center;
  flex-shrink:0;
}
.pipeline-step.accent{ color: var(--sage); }
.pipeline-step.accent .step-index{ color: var(--sage); border-color: var(--sage); }

/* ==========================================================================
   Status tags
   ========================================================================== */
.status-tag{
  display:inline-block; font-family: var(--font-mono); font-size: 0.72rem;
  text-transform: uppercase; letter-spacing: .06em;
  padding: 5px 10px; border-radius: var(--radius); margin-bottom: 14px;
}
.status-progress{ color: var(--accent); background: var(--accent-tint); border:1px solid var(--accent-dim); }
.status-pub{ color: var(--sage); background: var(--sage-tint); border:1px solid var(--sage); }
.status-project{ color: var(--text-dim); background: var(--surface); border:1px solid var(--border); }
.status-experience{ color: var(--text-faint); background: transparent; border:1px solid var(--border); }

/* ==========================================================================
   Research detail grid / resource links
   ========================================================================== */
.research-detail-grid{
  display:grid; grid-template-columns: 1.4fr 1fr; gap: 40px; margin: 28px 0 8px;
}
.research-detail-grid h3{ margin-bottom: 10px; font-size: 1.02rem; }
.research-detail-grid p{ color: var(--text-dim); margin-bottom: 10px; }
.plain-list{ display:flex; flex-direction:column; gap:6px; }
.plain-list li{
  font-size: 0.92rem; color: var(--text-dim);
  padding-left: 16px; position:relative;
}
.plain-list li::before{ content:"—"; position:absolute; left:0; color: var(--text-faint); }
.stat-list li::before{ content:none; }
.stat-list li{ padding-left:0; display:flex; align-items:baseline; gap:8px; }
.stat{ font-family: var(--font-display); font-size: 1.3rem; color: var(--accent); font-weight:600; }
.stat-label{ font-family: var(--font-mono); font-size: 0.75rem; color: var(--text-faint); text-transform:uppercase; }

.resource-links{ display:flex; flex-wrap:wrap; gap: 12px; margin-top: 26px; }
.resource-link{
  font-family: var(--font-mono); font-size: 0.78rem;
  border: 1px dashed var(--border); border-radius: var(--radius);
  padding: 8px 14px; color: var(--text-faint);
}
.resource-link.disabled{ cursor:not-allowed; }
a.resource-link{
  border-style: solid; color: var(--accent); border-color: var(--accent-dim);
  transition: background .2s var(--ease), color .2s var(--ease);
}
a.resource-link:hover{ background: var(--accent-tint); }

/* ==========================================================================
   Publications
   ========================================================================== */
.pub-entry{
  border-top: 1px solid var(--border-soft); padding: 30px 0;
}
.pub-entry:first-of-type{ border-top:none; padding-top:0; }
.pub-entry h3{ margin-bottom: 8px; font-size: 1.3rem; max-width: 40ch; }
.pub-meta{ font-family: var(--font-mono); font-size: 0.85rem; color: var(--text-dim); margin-bottom: 14px; }
.pub-venue{ color: var(--sage); }
.pub-entry p{ color: var(--text-dim); max-width: 68ch; margin-bottom: 16px; }
.pub-entry a{ color: var(--accent); border-bottom: 1px solid var(--accent-dim); }

.tag-list{ display:flex; flex-wrap:wrap; gap:8px; }
.tag-list li{
  font-family: var(--font-mono); font-size: 0.74rem; color: var(--text-faint);
  border:1px solid var(--border); border-radius: var(--radius); padding: 5px 10px;
}

/* ==========================================================================
   Project cards
   ========================================================================== */
.project-grid{
  display:grid; grid-template-columns: repeat(3, 1fr); gap: 22px;
}
.project-card{
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); padding: 26px;
  display:flex; flex-direction:column; gap: 6px;
  transition: border-color .25s var(--ease), transform .25s var(--ease);
}
.project-card:hover{ border-color: var(--accent-dim); transform: translateY(-3px); }
.project-card h3{ margin-bottom: 6px; font-size: 1.05rem; }
.project-field, .project-q{ font-size: 0.87rem; color: var(--text-dim); line-height:1.55; }
.project-field strong, .project-q strong{ color: var(--text-faint); font-weight:500; font-family: var(--font-mono); font-size: 0.76rem; text-transform:uppercase; letter-spacing:.03em; display:block; margin-top:8px; }
.project-card .resource-link{ margin-top: 14px; align-self:flex-start; }

/* ==========================================================================
   Experience timeline
   ========================================================================== */
.experience-list{ display:flex; flex-direction:column; gap:0; }
.experience-item{
  padding: 26px 0; border-top: 1px solid var(--border-soft);
  display:grid; grid-template-columns: 260px 1fr; gap: 24px;
}
.experience-item:first-child{ border-top:none; padding-top:0; }
.exp-head h3{ font-size: 1.08rem; margin-bottom: 6px; }
.exp-meta{ font-family: var(--font-mono); font-size: 0.8rem; color: var(--sage); }
.experience-item .plain-list{ gap:9px; }
.experience-item .plain-list li{ font-size: 0.92rem; }

.misc-links{
  margin-top: 34px; padding-top: 22px; border-top: 1px dashed var(--border);
  display:flex; flex-wrap:wrap; align-items:center; gap: 14px;
}
.misc-links-label{ font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-faint); }
.misc-links .resource-link{ border-style: solid; color: var(--accent); border-color: var(--accent-dim); }

.edu-honors{
  font-family: var(--font-mono); font-size: 0.82rem; color: var(--text-dim);
  margin-top: 14px; max-width: 640px;
}
.cert-row{ display:flex; flex-wrap:wrap; gap:10px; margin-top: 26px; }

@media (max-width: 720px){
  .experience-item{ grid-template-columns: 1fr; gap: 8px; }
}

/* ==========================================================================
   Toolkit
   ========================================================================== */
.toolkit-grid{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.toolkit-card{
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; background: var(--bg);
}
.toolkit-desc{ color: var(--text-dim); font-size: 0.88rem; margin: 8px 0 16px; }
.chip-list{ display:flex; flex-wrap:wrap; gap:8px; }
.chip-list li{
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--text-dim);
  border: 1px solid var(--border-soft); border-radius: var(--radius);
  padding: 5px 9px; background: var(--surface);
}

/* ==========================================================================
   Career grid
   ========================================================================== */
.career-grid{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--border-soft); border: 1px solid var(--border-soft); }
.career-item{ background: var(--bg-elevated); padding: 26px; }
.career-item h3{ font-size: 1rem; margin-bottom: 8px; color: var(--accent); }
.career-item p{ font-size: 0.88rem; color: var(--text-dim); }

/* ==========================================================================
   Trajectory
   ========================================================================== */
.trajectory-list{ display:flex; flex-direction:column; max-width: 520px; }
.trajectory-list li{
  display:flex; align-items:center; gap:20px;
  padding: 15px 0; border-bottom: 1px dashed var(--border);
}
.trajectory-list li:last-child{ border-bottom:none; }
.traj-index{ font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-faint); width: 26px; }
.traj-label{ font-size: 1rem; color: var(--text-dim); }
.traj-label.accent{ color: var(--accent); font-weight:500; }

/* ==========================================================================
   Education
   ========================================================================== */
.edu-entry{
  display:flex; justify-content:space-between; align-items:center;
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px; background: var(--surface); max-width: 640px; gap: 20px; flex-wrap:wrap;
}
.edu-main h3{ font-size: 1.3rem; margin-bottom: 6px; }
.edu-meta{ font-family: var(--font-mono); font-size: 0.85rem; color: var(--text-dim); }
.edu-stat{ text-align:right; display:flex; flex-direction:column; gap:2px; }
.edu-stat .stat{ font-size: 1.5rem; }
.edu-stat .stat-label{ }

/* ==========================================================================
   About
   ========================================================================== */
.about-inner{ max-width: 900px; }
.about-text p{ color: var(--text-dim); max-width: 68ch; margin-bottom: 18px; font-size: 1rem; }
.about-text p:last-child{ margin-bottom:0; }

/* ==========================================================================
   Contact
   ========================================================================== */
.contact-grid{ display:grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--border-soft); border: 1px solid var(--border-soft); margin-top: 12px; }
.contact-item{
  background: var(--bg); padding: 22px 24px; display:flex; flex-direction:column; gap:6px;
  transition: background .2s var(--ease);
}
.contact-item:hover{ background: var(--surface); }
.contact-label{ font-family: var(--font-mono); font-size: 0.72rem; text-transform:uppercase; letter-spacing:.06em; color: var(--text-faint); }
.contact-value{ font-size: 0.98rem; color: var(--text); }
.contact-note{ margin-top: 20px; font-size: 0.82rem; color: var(--text-faint); font-family: var(--font-mono); }
.contact-note code{ color: var(--accent); }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer{ padding: 40px 0; }
.footer-inner{
  max-width: var(--max-w); margin:0 auto; padding: 0 32px;
  display:flex; justify-content:space-between; flex-wrap:wrap; gap:8px;
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-faint);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 980px){
  .hero-inner{ grid-template-columns: 1fr; }
  .hero-figure{ order:-1; max-width: 280px; margin: 0 auto 20px; }
  .research-detail-grid{ grid-template-columns: 1fr; }
  .project-grid{ grid-template-columns: repeat(2, 1fr); }
  .toolkit-grid{ grid-template-columns: repeat(2, 1fr); }
  .career-grid{ grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px){
  .main-nav{
    position:fixed; top:68px; left:0; right:0; bottom:0;
    background: var(--bg); border-top: 1px solid var(--border-soft);
    flex-direction:column; align-items:flex-start; justify-content:flex-start;
    padding: 32px; gap: 28px;
    transform: translateX(100%); transition: transform .35s var(--ease);
  }
  .main-nav.open{ transform: translateX(0); }
  .main-nav ul{ flex-direction:column; gap: 22px; }
  .main-nav a[data-nav]{ font-size: 1.1rem; }
  .nav-toggle{ display:flex; }

  .section{ padding: 68px 0; }
  .project-grid{ grid-template-columns: 1fr; }
  .toolkit-grid{ grid-template-columns: 1fr; }
  .career-grid{ grid-template-columns: 1fr; }
  .contact-grid{ grid-template-columns: 1fr; }
  .edu-entry{ flex-direction:column; align-items:flex-start; }
  .edu-stat{ text-align:left; }
}