/* ============================================================
   KAMALESH S — PORTFOLIO STYLESHEET
   Edit variables in :root to retheme the entire site instantly
   ============================================================ */

/* ── Google Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@300;400;500;600&display=swap');

/* ── Design Tokens ── */
:root {
  --bg:          #0A0F1E;   /* deep navy background */
  --bg-card:     #111827;   /* card surface */
  --bg-card2:    #1a2235;   /* elevated card */
  --accent:      #6366F1;   /* electric indigo */
  --accent-soft: #818CF8;   /* lighter indigo */
  --accent-glow: rgba(99,102,241,0.18);
  --text:        #E2E8F0;   /* primary text */
  --text-muted:  #94A3B8;   /* secondary text */
  --border:      rgba(99,102,241,0.2);
  --radius:      12px;
  --radius-sm:   8px;
  --nav-h:       68px;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body:    'Inter', sans-serif;
  --transition:   0.25s ease;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

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

/* ── Typography ── */
h1,h2,h3,h4,h5 { font-family: var(--font-display); font-weight: 700; line-height: 1.2; }
h1 { font-size: clamp(2.4rem, 6vw, 4rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); }
h3 { font-size: 1.25rem; }

/* ── Layout helpers ── */
.container { width: 90%; max-width: 1140px; margin-inline: auto; }
.section    { padding: 90px 0; }
.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 10px;
}
.section-title { color: var(--text); margin-bottom: 48px; }
.section-title span { color: var(--accent); }

/* ── Navbar ── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: rgba(10,15,30,0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  display: flex;
  align-items: center;
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 90%;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}
.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 4px;
  align-items: center;
}
.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 6px 14px;
  border-radius: 6px;
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--accent-glow);
}
.nav-links a.active { color: var(--accent-soft); }

/* ── Hamburger (mobile) ── */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-soft);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(99,102,241,0.35);
}
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent-soft);
  transform: translateY(-2px);
}
.btn-sm { padding: 8px 16px; font-size: 0.8rem; }

/* ── Cards ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 12px 32px rgba(99,102,241,0.12);
}

/* ── Tags / Badges ── */
.tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 4px 10px;
  border-radius: 4px;
  background: var(--accent-glow);
  color: var(--accent-soft);
  border: 1px solid var(--border);
}

/* ── Page hero (inner pages) ── */
.page-hero {
  padding: calc(var(--nav-h) + 60px) 0 60px;
  text-align: center;
}
.page-hero p {
  color: var(--text-muted);
  margin-top: 12px;
  font-size: 1.05rem;
}

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 36px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}
footer a { color: var(--accent-soft); }

/* ============================================================
   HOME PAGE — index.html
   ============================================================ */

/* ── Hero ── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: var(--nav-h);
}

/* Animated dot-grid background (signature element) */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(99,102,241,0.25) 1px, transparent 1px);
  background-size: 36px 36px;
  animation: gridPan 20s linear infinite;
  opacity: 0.5;
}
@keyframes gridPan {
  0%   { background-position: 0 0; }
  100% { background-position: 36px 36px; }
}
/* Gradient overlay so grid fades at edges */
.hero-grid::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 50%, transparent 30%, var(--bg) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 18px;
}
.hero-eyebrow::before {
  content: '';
  display: block;
  width: 28px;
  height: 1.5px;
  background: var(--accent);
}
.hero h1 { color: var(--text); letter-spacing: -0.03em; }
.hero h1 em {
  font-style: normal;
  color: var(--accent);
  position: relative;
}
.hero-tagline {
  font-size: clamp(1rem, 2.5vw, 1.3rem);
  color: var(--text-muted);
  margin: 16px 0 36px;
  max-width: 560px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }

/* Profile photo (static, no floating) */
.hero-photo {
  position: absolute;
  right: 6%;
  top: 50%;
  transform: translateY(-50%);
  width: 280px;
  height: 380px;
  border-radius: 16px;
  overflow: hidden;
  border: 2px solid var(--accent);
  box-shadow: 0 20px 60px rgba(99, 102, 241, 0.25);
  z-index: 10;
}

.hero-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ── About section ── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.about-bio { color: var(--text-muted); line-height: 1.85; }
.about-bio p + p { margin-top: 14px; }
.about-highlights {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.highlight-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
}
.highlight-item .hi-icon {
  font-size: 1.6rem;
  margin-bottom: 8px;
}
.highlight-item h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 4px;
}
.highlight-item p { font-size: 0.8rem; color: var(--text-muted); }

/* ── Skills overview (home) ── */
.skills-overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}
.skill-pill {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: border-color var(--transition), background var(--transition);
}
.skill-pill:hover { border-color: var(--accent); background: var(--accent-glow); }
.skill-pill .sp-icon { font-size: 1.3rem; }

/* ============================================================
   STUDIES PAGE
   ============================================================ */
.timeline { position: relative; padding-left: 36px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 8px; top: 0; bottom: 0;
  width: 1.5px;
  background: var(--border);
}
.timeline-item {
  position: relative;
  margin-bottom: 36px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -30px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-glow);
}
.timeline-date {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 8px;
}
.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  transition: border-color var(--transition);
}
.timeline-card:hover { border-color: var(--accent); }
.timeline-card h3 { margin-bottom: 4px; }
.timeline-card .inst { color: var(--accent-soft); font-size: 0.9rem; font-weight: 500; margin-bottom: 10px; }
.timeline-card p { color: var(--text-muted); font-size: 0.9rem; }

/* ============================================================
   PROJECTS PAGE
   ============================================================ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 12px 32px rgba(99,102,241,0.12);
}
.project-card .pc-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}
.project-card .pc-icon { font-size: 2rem; }
.project-card h3 { margin-bottom: 4px; }
.project-card .pc-desc { color: var(--text-muted); font-size: 0.9rem; line-height: 1.65; flex: 1; }
.project-card .pc-stack { display: flex; flex-wrap: wrap; gap: 6px; }
.project-card .pc-actions { display: flex; gap: 10px; margin-top: 4px; }

/* ============================================================
   CERTIFICATES PAGE
   ============================================================ */
.certs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.certs-grid--direct {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}
.cert-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.cert-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 10px 28px rgba(99,102,241,0.12);
}
.cert-card .cert-icon { font-size: 2rem; }
.cert-card h3 { font-size: 1rem; }
.cert-card .cert-issuer { color: var(--accent-soft); font-size: 0.85rem; font-weight: 500; }
.cert-card .cert-year { color: var(--text-muted); font-size: 0.8rem; }
.cert-card .cert-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--accent-soft);
  margin-top: auto;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  transition: color var(--transition);
}
.cert-card .cert-link:hover { color: var(--text); }
.cert-card--preview {
  overflow: hidden;
  align-items: center;
  text-align: center;
}
.cert-preview-wrap {
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  background: var(--bg-card2);
  aspect-ratio: 4 / 3;
  margin-bottom: 8px;
}
.cert-preview-wrap--pdf {
  background: #fff;
}
.cert-preview {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}
.cert-preview--pdf {
  border: 0;
  object-fit: fill;
}
.cert-preview-fallback {
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 16px;
}

@media (max-width: 640px) {
  .certs-grid--direct {
    grid-template-columns: 1fr;
  }
}

/* ============================================================
   SKILLS PAGE
   ============================================================ */
.skills-category { margin-bottom: 56px; }
.skills-category h3 {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.skills-category h3::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.skills-bars { display: flex; flex-direction: column; gap: 18px; }
.skill-bar-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
  font-size: 0.9rem;
  font-weight: 500;
}
.skill-bar-track {
  height: 6px;
  background: var(--bg-card2);
  border-radius: 99px;
  overflow: hidden;
}
.skill-bar-fill {
  height: 100%;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--accent), var(--accent-soft));
  width: 0;
  transition: width 1s cubic-bezier(0.4,0,0.2,1);
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 12px;
}
.tool-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 18px 10px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
  text-align: center;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}
.tool-badge:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
  transform: translateY(-3px);
}
.tool-badge .tb-icon { font-size: 1.6rem; }

/* ============================================================
   RESUME PAGE
   ============================================================ */
.resume-layout {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 32px;
  align-items: start;
}
.resume-preview {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  font-size: 0.9rem;
}
.resume-preview h2 {
  font-size: 1.6rem;
  margin-bottom: 4px;
}
.resume-preview .rp-tagline {
  color: var(--accent-soft);
  font-size: 0.9rem;
  margin-bottom: 16px;
}
.resume-preview .rp-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}
.resume-section { margin-bottom: 24px; }
.resume-section h4 {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 12px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}
.resume-entry { margin-bottom: 14px; }
.resume-entry .re-title { font-weight: 600; font-size: 0.9rem; }
.resume-entry .re-sub { color: var(--text-muted); font-size: 0.82rem; margin-bottom: 4px; }
.resume-entry ul { padding-left: 16px; }
.resume-entry ul li {
  list-style: disc;
  color: var(--text-muted);
  font-size: 0.82rem;
  margin-bottom: 3px;
}

.resume-sidebar { display: flex; flex-direction: column; gap: 16px; }
.resume-action-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}
.resume-action-card h3 { margin-bottom: 8px; font-size: 1rem; }
.resume-action-card p { color: var(--text-muted); font-size: 0.85rem; margin-bottom: 18px; }
.resume-action-card .btn { width: 100%; justify-content: center; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; gap: 36px; }
  .resume-layout { grid-template-columns: 1fr; }
  .hero {
    min-height: auto;
    padding: calc(var(--nav-h) + 32px) 0 56px;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .hero-content { max-width: 100%; }
  .hero-eyebrow { justify-content: center; margin-inline: auto; }
  .hero-tagline { margin-inline: auto; }
  .hero-cta { justify-content: center; }
  .hero-photo {
    position: relative;
    top: auto;
    right: auto;
    transform: none;
    width: min(260px, 72vw);
    height: 320px;
    margin-top: 28px;
  }
  .page-hero {
    padding-top: calc(var(--nav-h) + 70px);
    padding-bottom: 42px;
  }
  .timeline { padding-left: 24px; }
  .timeline-item::before { left: -22px; }
  .resume-preview .rp-contact { flex-direction: column; gap: 8px; }
}

@media (max-width: 700px) {
  .container { width: min(92%, 1140px); }
  .nav-links {
    display: none;
    flex-direction: column;
    gap: 2px;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 16px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 14px; border-radius: var(--radius-sm); }
  .hamburger { display: flex; }
  .hero {
    padding-top: calc(var(--nav-h) + 28px);
  }
  .hero h1 { font-size: clamp(2.1rem, 8vw, 3rem); }
  .page-hero h1 { font-size: clamp(1.9rem, 7vw, 2.6rem); }
  .page-hero p { font-size: 0.95rem; }
  .hero-tagline {
    font-size: 1rem;
    max-width: 100%;
  }
  .hero-cta {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }
  .hero-cta .btn {
    width: 100%;
    justify-content: center;
  }
  .about-highlights { grid-template-columns: 1fr 1fr; }
  .section { padding: 56px 0; }
  .card, .project-card, .cert-card, .timeline-card, .resume-preview, .resume-action-card {
    padding: 20px;
  }
  .projects-grid, .certs-grid, .tools-grid { grid-template-columns: 1fr; }
  .timeline { padding-left: 18px; }
  .timeline-item::before { left: -18px; }
  .timeline-card, .project-card, .cert-card, .resume-action-card {
    border-radius: 10px;
  }
}

@media (max-width: 480px) {
  .navbar .container { width: 92%; }
  .nav-logo { font-size: 1.1rem; }
  .hero-photo {
    width: min(220px, 78vw);
    height: 280px;
  }
  .hero h1 br { display: none; }
  .about-highlights { grid-template-columns: 1fr; }
  .section-title { margin-bottom: 28px; }
  .page-hero { padding-top: calc(var(--nav-h) + 50px); }
  .resume-preview { padding: 24px; }
  .resume-preview .rp-contact { gap: 10px; }
  footer { padding: 28px 0; }
  footer a { display: inline-block; margin: 4px 8px; }
}

/* ── Fade-in animation ── */
.fade-up {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}