/* ============================================================
   NISHANTH SAKA — PORTFOLIO
   Design concept: cyanotype engineering blueprint / systems
   status sheet. Grounded in the subject's own vernacular —
   production AI architecture, pipelines, revision history,
   circuit reference designators (B.E. Electronics & Comms).
   ============================================================ */

:root{
  /* --- color tokens --- */
  --navy-950:#0c2138;
  --navy-900:#123356;
  --navy-800:#194370;
  --navy-700:#22568c;
  --line:rgba(224,240,255,0.14);
  --line-strong:rgba(224,240,255,0.28);
  --ink-100:#eef6ff;
  --ink-300:#bcd6ec;
  --ink-500:#84a8c6;
  --ink-600:#6690b3;
  --signal-live:#5fe1b0;
  --signal-flag:#f2a93b;
  --signal-flag-dim:rgba(242,169,59,0.16);
  --signal-live-dim:rgba(95,225,176,0.16);

  /* --- type tokens --- */
  --font-display:'Space Grotesk', sans-serif;
  --font-body:'IBM Plex Sans', sans-serif;
  --font-mono:'IBM Plex Mono', monospace;

  --radius-sm:2px;
  --radius-md:4px;
}

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

html{ scroll-behavior:smooth; }

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{
    animation-duration:0.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:0.01ms !important;
    scroll-behavior:auto !important;
  }
}

body{
  margin:0;
  background:var(--navy-950);
  color:var(--ink-300);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}

/* faint blueprint grid, fixed to viewport */
body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  z-index:0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size:40px 40px;
  opacity:0.35;
}

a{ color:inherit; text-decoration:none; }
img{ max-width:100%; display:block; }

::selection{ background:var(--signal-flag); color:var(--navy-950); }

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

h1,h2,h3{
  font-family:var(--font-display);
  color:var(--ink-100);
  margin:0;
  letter-spacing:-0.01em;
}

.eyebrow{
  font-family:var(--font-mono);
  font-size:0.72rem;
  letter-spacing:0.14em;
  text-transform:uppercase;
  color:var(--signal-flag);
  margin:0 0 0.9rem;
  display:flex;
  align-items:center;
  gap:0.6em;
}
.eyebrow::before{
  content:"";
  width:18px;
  height:1px;
  background:var(--signal-flag);
  display:inline-block;
}

.wrap{
  position:relative;
  z-index:1;
  max-width:1080px;
  margin:0 auto;
  padding:0 clamp(1.25rem, 4vw, 3rem);
}

/* ---------------- top bar ---------------- */
.topbar{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(12,33,56,0.86);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar-inner{
  max-width:1080px;
  margin:0 auto;
  padding:0.9rem clamp(1.25rem, 4vw, 3rem);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
}
.brand{
  font-family:var(--font-mono);
  font-size:0.82rem;
  color:var(--ink-100);
  white-space:nowrap;
}
.brand span{ color:var(--signal-live); }
.topnav{
  display:flex;
  gap:1.4rem;
  font-family:var(--font-mono);
  font-size:0.78rem;
  color:var(--ink-500);
}
.topnav a{ transition:color 0.15s ease; }
.topnav a:hover{ color:var(--signal-flag); }
@media (max-width:560px){
  .topnav{ display:none; }
}

/* ---------------- hero ---------------- */
.hero{
  position:relative;
  padding:clamp(3rem,8vw,6rem) 0 clamp(2.5rem,6vw,4rem);
  border-bottom:1px solid var(--line);
  overflow:hidden;
}
.hero::after{
  content:"";
  position:absolute;
  right:-10%;
  top:-20%;
  width:520px;
  height:520px;
  border:1px solid var(--line);
  border-radius:50%;
  pointer-events:none;
}
.hero-grid{
  display:grid;
  grid-template-columns:1.4fr 1fr;
  gap:3rem;
  align-items:end;
}
@media (max-width:800px){
  .hero-grid{ grid-template-columns:1fr; }
}

.hero h1{
  font-size:clamp(2.6rem, 6.2vw, 4.6rem);
  line-height:1.02;
  font-weight:600;
}
.hero-role{
  font-family:var(--font-mono);
  color:var(--ink-100);
  font-size:clamp(1rem,2vw,1.2rem);
  margin-top:1.1rem;
  min-height:1.6em;
}
.hero-role .cursor{
  display:inline-block;
  width:0.55em;
  background:var(--signal-flag);
  margin-left:2px;
  animation:blink 1s steps(1) infinite;
}
@keyframes blink{ 50%{ opacity:0; } }

.hero-sub{
  margin-top:0.75rem;
  color:var(--ink-500);
  font-size:0.98rem;
}

.hero-cta{
  display:flex;
  flex-wrap:wrap;
  gap:0.75rem;
  margin-top:2rem;
}
.btn{
  font-family:var(--font-mono);
  font-size:0.8rem;
  padding:0.72em 1.15em;
  border:1px solid var(--line-strong);
  border-radius:var(--radius-sm);
  color:var(--ink-100);
  transition:border-color 0.15s ease, background 0.15s ease, color 0.15s ease;
  letter-spacing:0.02em;
}
.btn:hover{
  border-color:var(--signal-flag);
  color:var(--signal-flag);
}
.btn-primary{
  background:var(--signal-flag);
  border-color:var(--signal-flag);
  color:var(--navy-950);
  font-weight:600;
}
.btn-primary:hover{
  background:transparent;
  color:var(--signal-flag);
}

/* title block, engineering-drawing style */
.title-block{
  border:1px solid var(--line-strong);
  border-radius:var(--radius-md);
  background:var(--navy-900);
  overflow:hidden;
}
.tb-row{
  display:flex;
  justify-content:space-between;
  gap:1rem;
  padding:0.65rem 0.9rem;
  font-family:var(--font-mono);
  font-size:0.76rem;
  border-bottom:1px solid var(--line);
}
.tb-row:last-child{ border-bottom:none; }
.tb-row span:first-child{
  color:var(--ink-600);
  letter-spacing:0.08em;
}
.tb-row span:last-child{
  color:var(--ink-100);
  text-align:right;
}
.status-live{ color:var(--signal-live) !important; }
.status-live::before{
  content:"●";
  margin-right:0.4em;
  animation:pulse 1.8s ease-in-out infinite;
}
@keyframes pulse{ 0%,100%{opacity:1;} 50%{opacity:0.35;} }

/* ---------------- generic section ---------------- */
.section{
  padding:clamp(3rem,7vw,5rem) 0;
  border-bottom:1px solid var(--line);
}
.section-head{
  display:flex;
  justify-content:space-between;
  align-items:flex-end;
  gap:1rem;
  margin-bottom:2.2rem;
  flex-wrap:wrap;
}
.section-head h2{
  font-size:clamp(1.5rem,3vw,2.1rem);
}
.sheet-index{
  font-family:var(--font-mono);
  font-size:0.75rem;
  color:var(--ink-600);
}

.lede{
  max-width:70ch;
  font-size:1.02rem;
  color:var(--ink-300);
}
.lede + .lede{ margin-top:1rem; }

/* ---------------- modules grid ---------------- */
.modules{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:1px;
  background:var(--line);
  border:1px solid var(--line);
  border-radius:var(--radius-md);
  overflow:hidden;
}
@media (max-width:820px){ .modules{ grid-template-columns:repeat(2,1fr); } }
@media (max-width:540px){ .modules{ grid-template-columns:1fr; } }

.module{
  background:var(--navy-900);
  padding:1.5rem;
  position:relative;
}
.module .ref{
  font-family:var(--font-mono);
  font-size:0.72rem;
  color:var(--signal-flag);
  letter-spacing:0.06em;
}
.module h3{
  font-size:1.02rem;
  margin-top:0.5rem;
  margin-bottom:0.55rem;
  font-weight:600;
}
.module p{
  font-size:0.87rem;
  color:var(--ink-500);
  margin:0;
  line-height:1.55;
}

/* ---------------- systems (pipeline cards) ---------------- */
.sys-card{
  border:1px solid var(--line-strong);
  border-radius:var(--radius-md);
  background:var(--navy-900);
  padding:clamp(1.4rem,3vw,2.2rem);
  margin-bottom:1.4rem;
}
.sys-head{
  display:flex;
  align-items:center;
  gap:0.8rem;
  flex-wrap:wrap;
  margin-bottom:0.8rem;
}
.dot{
  width:8px;height:8px;border-radius:50%;
  flex:none;
}
.dot-live{ background:var(--signal-live); box-shadow:0 0 0 3px var(--signal-live-dim); }
.dot-flag{ background:var(--signal-flag); box-shadow:0 0 0 3px var(--signal-flag-dim); }

.sys-head h3{ font-size:1.25rem; }
.sys-tag{
  margin-left:auto;
  font-family:var(--font-mono);
  font-size:0.68rem;
  letter-spacing:0.1em;
  padding:0.3em 0.6em;
  border:1px solid var(--line-strong);
  border-radius:var(--radius-sm);
  color:var(--ink-500);
}
.sys-meta{
  font-family:var(--font-mono);
  font-size:0.72rem;
  color:var(--ink-600);
  margin:-0.4rem 0 1rem;
}
.sys-desc{
  font-size:0.94rem;
  color:var(--ink-300);
  max-width:66ch;
  margin:0 0 1.3rem;
}

.pipeline{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:0.5rem 0.35rem;
  padding-top:1rem;
  border-top:1px dashed var(--line-strong);
}
.pnode{
  font-family:var(--font-mono);
  font-size:0.74rem;
  color:var(--ink-100);
  background:var(--navy-800);
  border:1px solid var(--line-strong);
  border-radius:var(--radius-sm);
  padding:0.45em 0.75em;
  opacity:0;
  transform:translateY(6px);
  transition:opacity 0.5s ease, transform 0.5s ease;
}
.sys-card.in-view .pnode{ opacity:1; transform:translateY(0); }
.parrow{
  color:var(--signal-flag);
  font-family:var(--font-mono);
  font-size:0.8rem;
  opacity:0.8;
}

.sys-video{
  position:relative;
  width:100%;
  aspect-ratio:16/9;
  margin:1.3rem 0;
  border:1px solid var(--line-strong);
  border-radius:var(--radius-sm);
  overflow:hidden;
  background:var(--navy-800);
}
.sys-video iframe{
  position:absolute;
  inset:0;
  width:100%;
  height:100%;
  border:0;
}

/* ---------------- revision table (experience) ---------------- */
.rev-table{
  width:100%;
  border-collapse:collapse;
  font-size:0.9rem;
}
.rev-table thead th{
  text-align:left;
  font-family:var(--font-mono);
  font-size:0.7rem;
  letter-spacing:0.1em;
  color:var(--ink-600);
  border-bottom:1px solid var(--line-strong);
  padding:0 0.8rem 0.7rem 0;
}
.rev-table td{
  padding:1rem 0.8rem 1rem 0;
  border-bottom:1px solid var(--line);
  vertical-align:top;
}
.rev-num{
  font-family:var(--font-mono);
  color:var(--signal-flag);
  white-space:nowrap;
}
.rev-date{
  font-family:var(--font-mono);
  color:var(--ink-500);
  white-space:nowrap;
  font-size:0.82rem;
}
.rev-role{
  color:var(--ink-100);
  font-weight:600;
}
.rev-role small{
  display:block;
  color:var(--ink-500);
  font-weight:400;
  font-family:var(--font-mono);
  font-size:0.76rem;
  margin-top:0.2rem;
}
.rev-notes{ color:var(--ink-300); }

@media (max-width:700px){
  .rev-table thead{ display:none; }
  .rev-table, .rev-table tbody, .rev-table tr, .rev-table td{ display:block; width:100%; }
  .rev-table tr{
    border-bottom:1px solid var(--line-strong);
    padding:1.1rem 0;
  }
  .rev-table td{ border-bottom:none; padding:0.2rem 0; }
  .rev-notes{ margin-top:0.4rem; }
}

/* ---------------- notes / education ---------------- */
.notes-grid{
  display:grid;
  grid-template-columns:1fr 1.4fr;
  gap:2.5rem;
}
@media (max-width:700px){ .notes-grid{ grid-template-columns:1fr; } }
.notes-grid h3{
  font-size:0.95rem;
  font-family:var(--font-mono);
  color:var(--ink-100);
  margin-bottom:0.9rem;
  letter-spacing:0.04em;
}
.notes-list{
  list-style:none;
  margin:0; padding:0;
  font-size:0.9rem;
  color:var(--ink-300);
}
.notes-list li{
  padding:0.55rem 0;
  border-bottom:1px solid var(--line);
  display:flex;
  gap:0.6rem;
}
.notes-list li::before{
  content:"—";
  color:var(--signal-flag);
  flex:none;
}
.edu-item{
  font-size:0.92rem;
  color:var(--ink-300);
}
.edu-item strong{ color:var(--ink-100); display:block; margin-bottom:0.2rem; }

/* ---------------- footer / contact title block ---------------- */
footer{
  padding:clamp(2.5rem,6vw,4rem) 0 3rem;
}
.footer-head{
  display:flex;
  justify-content:space-between;
  align-items:flex-end;
  gap:1.5rem;
  flex-wrap:wrap;
  margin-bottom:2rem;
}
.footer-head h2{ font-size:clamp(1.6rem,4vw,2.3rem); max-width:20ch; }
.contact-links{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  border:1px solid var(--line-strong);
  border-radius:var(--radius-md);
  overflow:hidden;
}
@media (max-width:700px){ .contact-links{ grid-template-columns:repeat(2,1fr); } }
.contact-links a{
  padding:1.1rem 1rem;
  border-right:1px solid var(--line);
  border-bottom:1px solid var(--line);
  font-family:var(--font-mono);
  font-size:0.78rem;
  color:var(--ink-300);
  transition:background 0.15s ease, color 0.15s ease;
}
.contact-links a:hover{ background:var(--navy-800); color:var(--signal-flag); }
.contact-links a span{
  display:block;
  color:var(--ink-600);
  font-size:0.68rem;
  letter-spacing:0.08em;
  margin-bottom:0.35rem;
}
.foot-bottom{
  margin-top:2.2rem;
  display:flex;
  justify-content:space-between;
  flex-wrap:wrap;
  gap:0.6rem;
  font-family:var(--font-mono);
  font-size:0.7rem;
  color:var(--ink-600);
}

/* reveal-on-scroll utility */
.reveal{
  opacity:0;
  transform:translateY(14px);
  transition:opacity 0.6s ease, transform 0.6s ease;
}
.reveal.in-view{ opacity:1; transform:translateY(0); }