/* =========================================================
   Hemanth S — Portfolio
   Dark developer/engineering theme
   ========================================================= */

:root{
  --bg:            #0a0e14;
  --bg-alt:        #0d1219;
  --surface:       #121822;
  --surface-hi:    #161e2c;
  --border:        #202a3a;
  --text:          #e6edf3;
  --text-dim:      #8b98ac;
  --text-faint:    #5c6982;
  --accent:        #3ddc97;
  --accent-2:      #5eb1ff;
  --accent-soft:   rgba(61, 220, 151, 0.12);
  --danger:        #ff6b6b;
  --font-sans:     'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:     'JetBrains Mono', 'Fira Code', Consolas, monospace;
  --container-w:   1120px;
  --radius:        10px;
  --radius-sm:     6px;
  --ease:          cubic-bezier(.16,.84,.44,1);
}

*, *::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-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

@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;
  }
}

.container{
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
}

a{ color: inherit; text-decoration: none; }
ul{ list-style: none; margin: 0; padding: 0; }
h1,h2,h3,p{ margin: 0; }

.skip-link{
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #06110c;
  padding: 10px 16px;
  z-index: 1000;
  font-weight: 600;
  border-radius: 0 0 6px 0;
}
.skip-link:focus{ left: 0; }

::selection{ background: var(--accent); color: #06110c; }

:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ===== Buttons ===== */
.btn{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.btn--primary{
  background: var(--accent);
  color: #06110c;
}
.btn--primary:hover{
  transform: translateY(-2px);
  box-shadow: 0 8px 24px -8px var(--accent-soft), 0 0 0 1px var(--accent);
}
.btn--ghost{
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover{
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

/* ===== Nav ===== */
.nav{
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 500;
  background: rgba(10, 14, 20, 0.72);
  backdrop-filter: blur(10px) saturate(140%);
  -webkit-backdrop-filter: blur(10px) saturate(140%);
  border-bottom: 1px solid transparent;
  transition: border-color .3s var(--ease), background .3s var(--ease);
}
.nav.is-scrolled{
  border-bottom-color: var(--border);
}
.nav__inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.nav__brand-mark{
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent);
  font-size: 1.1rem;
  letter-spacing: 0.5px;
}
.nav__links{
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav__link{
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-dim);
  position: relative;
  padding: 4px 2px;
  transition: color .2s var(--ease);
}
.nav__link:not(.nav__link--cta)::after{
  content: '';
  position: absolute;
  left: 0; bottom: -4px;
  width: 0; height: 2px;
  background: var(--accent);
  transition: width .25s var(--ease);
}
.nav__link:hover{ color: var(--text); }
.nav__link:hover:not(.nav__link--cta)::after{ width: 100%; }
.nav__link.is-active{ color: var(--accent); }
.nav__link--cta{
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 7px 14px;
  border-radius: var(--radius-sm);
}
.nav__link--cta:hover{
  background: var(--accent);
  color: #06110c;
}

.nav__toggle{
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px; height: 36px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 0;
}
.nav__toggle span{
  display: block;
  width: 16px;
  height: 2px;
  margin: 0 auto;
  background: var(--text);
  transition: transform .25s var(--ease), opacity .25s var(--ease);
}
.nav__toggle[aria-expanded="true"] span:nth-child(1){ transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2){ opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3){ transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero{
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 68px;
  overflow: hidden;
}
.hero__bg{
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(61,220,151,0.08), transparent 60%),
    var(--bg);
}
#grid-canvas{
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.5;
}
.hero__inner{
  position: relative;
  z-index: 1;
}
.hero__eyebrow{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 28px;
}
.dot{
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 var(--accent-soft);
  animation: pulse 2s infinite;
}
@keyframes pulse{
  0%{ box-shadow: 0 0 0 0 rgba(61,220,151,.5); }
  70%{ box-shadow: 0 0 0 8px rgba(61,220,151,0); }
  100%{ box-shadow: 0 0 0 0 rgba(61,220,151,0); }
}
.hero__name{
  font-size: clamp(2.6rem, 8vw, 5.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1;
  background: linear-gradient(180deg, #fff, #a9b6c9 140%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 18px;
}
.hero__role{
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.6vw, 1.5rem);
  color: var(--accent-2);
  min-height: 1.6em;
  margin-bottom: 20px;
}
.cursor{
  color: var(--accent);
  animation: blink 1s step-end infinite;
}
@keyframes blink{ 50%{ opacity: 0; } }
.hero__tagline{
  max-width: 560px;
  color: var(--text-dim);
  font-size: 1.1rem;
  margin-bottom: 40px;
}
.hero__actions{
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}
.hero__scroll{
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  width: 26px; height: 42px;
  border: 2px solid var(--border);
  border-radius: 14px;
  z-index: 1;
}
.hero__scroll span{
  position: absolute;
  top: 8px; left: 50%;
  width: 4px; height: 4px;
  background: var(--accent);
  border-radius: 50%;
  transform: translateX(-50%);
  animation: scrollDown 1.8s infinite;
}
@keyframes scrollDown{
  0%{ opacity: 1; top: 8px; }
  100%{ opacity: 0; top: 24px; }
}

/* ===== Sections ===== */
.section{ padding: 120px 0; }
.section--alt{ background: var(--bg-alt); }
.section__title{
  display: flex;
  align-items: baseline;
  gap: 12px;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 48px;
}
.section__num{
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 500;
}

/* ===== About ===== */
.about__grid{
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 56px;
  align-items: start;
}
.about__text{
  color: var(--text-dim);
  font-size: 1.08rem;
}
.about__tags{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-content: flex-start;
}
.about__tags li{
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent);
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 7px 12px;
  border-radius: var(--radius-sm);
}

/* ===== Skills ===== */
.skills__grid{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}
.skill-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform .25s var(--ease), border-color .25s var(--ease);
}
.skill-card:hover{
  transform: translateY(-4px);
  border-color: var(--accent);
}
.skill-card h3{
  font-size: 1rem;
  color: var(--accent-2);
  margin-bottom: 14px;
  font-family: var(--font-mono);
}
.skill-card ul{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.skill-card li{
  font-size: 0.85rem;
  color: var(--text-dim);
  background: var(--surface-hi);
  padding: 5px 10px;
  border-radius: 5px;
}

/* ===== Projects ===== */
.filter-bar{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 36px;
}
.filter-btn{
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-dim);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 9px 18px;
  border-radius: 999px;
  cursor: pointer;
  transition: all .2s var(--ease);
}
.filter-btn:hover{ color: var(--text); border-color: var(--accent-2); }
.filter-btn.is-active{
  background: var(--accent);
  color: #06110c;
  border-color: var(--accent);
}

.projects__grid{
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.project-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: transform .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
}
.project-card:hover{
  transform: translateY(-6px);
  border-color: var(--accent);
  box-shadow: 0 20px 40px -20px rgba(0,0,0,0.5);
}
.project-card--hero{
  border-color: var(--accent-2);
  background: linear-gradient(180deg, var(--surface-hi), var(--surface));
}
.project-card__head{
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.project-card__category{
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.status-badge{
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: #ffcf6b;
  border: 1px solid rgba(255,207,107,0.4);
  background: rgba(255,207,107,0.08);
  padding: 3px 9px;
  border-radius: 999px;
}
.project-card__title{
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.project-card__desc{
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 18px;
  flex: 1;
}
.project-card__stack{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}
.project-card__stack li{
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-faint);
  background: var(--surface-hi);
  padding: 4px 9px;
  border-radius: 4px;
}
.project-card__actions{
  display: flex;
  gap: 16px;
}
.link-btn{
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--accent);
  transition: gap .2s var(--ease);
}
.link-btn:hover{ text-decoration: underline; }
.link-btn--muted{ color: var(--text-dim); cursor: default; }
.link-btn--muted:hover{ text-decoration: none; }

.project-card.is-hidden{
  display: none;
}

/* ===== Experience / Timeline ===== */
.timeline{
  border-left: 2px solid var(--border);
  padding-left: 32px;
  max-width: 720px;
}
.timeline__item{
  position: relative;
  padding-bottom: 8px;
}
.timeline__item + .timeline__item{
  margin-top: 32px;
}
.timeline__content .link-btn{
  display: inline-block;
  margin-top: 12px;
}
.timeline__marker{
  position: absolute;
  left: -38px;
  top: 4px;
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 2px solid var(--accent);
}
.timeline__content h3{
  font-size: 1.15rem;
  margin-bottom: 4px;
}
.timeline__org{
  font-family: var(--font-mono);
  color: var(--accent-2);
  font-size: 0.9rem;
  margin-bottom: 10px;
}
.timeline__desc{
  color: var(--text-dim);
}
.timeline__desc em{
  color: var(--text-faint);
  font-style: normal;
  border-bottom: 1px dashed var(--text-faint);
}

/* ===== GitHub ===== */
.github-panel{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
  max-width: 640px;
  margin: 0 auto;
}
.github-panel p{
  color: var(--text-dim);
  margin-bottom: 24px;
}

/* ===== Contact ===== */
.contact{ text-align: center; }
.contact .section__title{ justify-content: center; }
.contact__lead{
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  margin-bottom: 28px;
}
.contact__links{
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}
.contact-link{
  font-family: var(--font-mono);
  color: var(--text-dim);
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.contact-link:hover{
  color: var(--accent);
  border-color: var(--accent);
}

/* ===== Footer ===== */
.footer{
  border-top: 1px solid var(--border);
  padding: 28px 0;
}
.footer__inner{
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-faint);
}
.footer__top:hover{ color: var(--accent); }

/* ===== Reveal-on-scroll ===== */
.reveal{
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.is-visible{
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 900px){
  .about__grid{ grid-template-columns: 1fr; gap: 32px; }
  .projects__grid{ grid-template-columns: 1fr; }
}

@media (max-width: 760px){
  .nav__toggle{ display: flex; }
  .nav__links{
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: var(--bg-alt);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px 28px;
    gap: 18px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity .25s var(--ease), transform .25s var(--ease), visibility .25s;
  }
  .nav__links.is-open{
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }
  .section{ padding: 88px 0; }
  .hero__actions{ flex-direction: column; align-items: stretch; }
  .hero__actions .btn{ justify-content: center; }
}

@media (max-width: 480px){
  .container{ padding: 0 18px; }
  .skills__grid{ grid-template-columns: 1fr; }
  .filter-bar{ gap: 8px; }
  .filter-btn{ padding: 8px 14px; font-size: 0.8rem; }
}