/* ============================================================
   Abhishek Vadlamudi — Portfolio
   Theme: "Schematic" — ink-dark base, amber/teal signal accents
   ============================================================ */

:root {
  /* Color system */
  --bg: #0a0e14;
  --bg-elevated: #0f141c;
  --surface: #141a24;
  --surface-2: #1a2130;
  --border: #232c3b;
  --border-soft: #1b222e;

  --text-primary: #edf0f5;
  --text-secondary: #a9b4c4;
  --text-muted: #7a8598;

  --accent-amber: #f2a541;
  --accent-amber-strong: #ffb955;
  --accent-teal: #4fd8c4;
  --accent-teal-strong: #6ee8d6;

  --amber-dim: rgba(242, 165, 65, 0.12);
  --teal-dim: rgba(79, 216, 196, 0.10);

  /* Type */
  --font-display: "Space Grotesk", "Inter", system-ui, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, monospace;

  /* Layout */
  --container: 1140px;
  --radius: 10px;
  --radius-sm: 6px;

  /* Motion */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast: 180ms;
  --dur-med: 420ms;
  --dur-slow: 900ms;
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --dur-fast: 0ms;
    --dur-med: 0ms;
    --dur-slow: 0ms;
  }
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
ul { margin: 0; padding: 0; }
a { color: inherit; text-decoration: none; }

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  margin: 0;
  letter-spacing: -0.01em;
}

.wrap {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 28px;
}

/* ---------- Focus & accessibility ---------- */
:focus-visible {
  outline: 2px solid var(--accent-teal);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent-amber);
  color: #0a0e14;
  padding: 12px 20px;
  z-index: 1000;
  font-weight: 600;
  border-radius: 0 0 8px 0;
}
.skip-link:focus {
  left: 0;
}

/* ---------- Background grid ---------- */
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(var(--border-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-soft) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.35;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 100%);
}

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 20, 0.78);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-soft);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.02rem;
}
.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent-amber) 0%, var(--accent-teal) 100%);
  color: #0a0e14;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
}
.brand-dot { color: var(--accent-amber); }

.main-nav ul {
  display: flex;
  gap: 32px;
  list-style: none;
}
.main-nav a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 6px 0;
  transition: color var(--dur-fast) var(--ease);
}
.main-nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  background: var(--accent-amber);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur-fast) var(--ease);
}
.main-nav a:hover,
.main-nav a:focus-visible { color: var(--text-primary); }
.main-nav a:hover::after,
.main-nav a:focus-visible::after { transform: scaleX(1); }
.main-nav a[aria-current="true"] { color: var(--accent-amber-strong); }
.main-nav a[aria-current="true"]::after { transform: scaleX(1); background: var(--accent-amber-strong); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-primary);
  transition: transform var(--dur-fast) var(--ease), opacity var(--dur-fast) 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); }

.mobile-nav {
  border-top: 1px solid var(--border-soft);
  background: var(--bg-elevated);
}
.mobile-nav ul {
  list-style: none;
  padding: 12px 28px 20px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.mobile-nav a {
  display: block;
  padding: 12px 4px;
  font-size: 1rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-soft);
}
.mobile-nav a:hover, .mobile-nav a:focus-visible { color: var(--accent-amber); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 72px;
}

.hero-net {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.55;
  pointer-events: none;
}
.net-path {
  stroke-dasharray: 6 10;
  animation: dashFlow 14s linear infinite;
}
.hero-net-nodes circle {
  animation: nodePulse 4.5s ease-in-out infinite;
}
.hero-net-nodes circle:nth-child(odd) { animation-delay: -1.5s; }
.hero-net-nodes circle:nth-child(3n) { animation-delay: -3s; }

@keyframes dashFlow {
  to { stroke-dashoffset: -160; }
}
@keyframes nodePulse {
  0%, 100% { opacity: 0.55; r: 4; }
  50% { opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
  .net-path { animation: none; }
  .hero-net-nodes circle { animation: none; }
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  align-items: center;
  gap: 48px;
}

.hero-text { max-width: 640px; }

.hero-portrait { justify-self: end; }

.portrait-frame {
  position: relative;
  width: 100%;
  max-width: 320px;
  aspect-ratio: 3 / 4;
}
.portrait-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
  filter: saturate(0.96);
}
.frame-corner {
  position: absolute;
  width: 26px;
  height: 26px;
  border-style: solid;
  border-width: 0;
  opacity: 0.85;
  pointer-events: none;
}
.frame-corner.tl { top: -8px; left: -8px; border-top-width: 2px; border-left-width: 2px; border-color: var(--accent-amber); }
.frame-corner.tr { top: -8px; right: -8px; border-top-width: 2px; border-right-width: 2px; border-color: var(--accent-teal); }
.frame-corner.bl { bottom: -8px; left: -8px; border-bottom-width: 2px; border-left-width: 2px; border-color: var(--accent-teal); }
.frame-corner.br { bottom: -8px; right: -8px; border-bottom-width: 2px; border-right-width: 2px; border-color: var(--accent-amber); }

@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-portrait { justify-self: center; }
  .portrait-frame { max-width: 240px; }
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--accent-teal);
  margin-bottom: 18px;
}

.hero h1 {
  font-size: clamp(2.2rem, 4.6vw, 3.6rem);
  margin-bottom: 20px;
  color: var(--text-primary);
}

.hero-role {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 1.6vw, 1.15rem);
  color: var(--accent-amber-strong);
  margin: 0 0 22px;
}
.hero-role .arrow { color: var(--text-muted); }

.hero-lede {
  font-size: 1.08rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 0 34px;
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

.scroll-cue {
  position: absolute;
  bottom: 34px;
  left: 50%;
  transform: translateX(-50%);
  width: 22px;
  height: 36px;
  border: 2px solid var(--border);
  border-radius: 12px;
}
.scroll-cue span {
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  border-radius: 2px;
  background: var(--accent-amber);
  animation: scrollDown 1.8s ease-in-out infinite;
}
@keyframes scrollDown {
  0% { opacity: 1; top: 6px; }
  100% { opacity: 0; top: 18px; }
}
@media (prefers-reduced-motion: reduce) {
  .scroll-cue span { animation: none; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 26px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: transform var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.btn-primary {
  background: var(--accent-amber);
  color: #0a0e14;
}
.btn-primary:hover { background: var(--accent-amber-strong); transform: translateY(-1px); }
.btn-ghost {
  border-color: var(--border);
  color: var(--text-primary);
  background: transparent;
}
.btn-ghost:hover { border-color: var(--accent-teal); color: var(--accent-teal-strong); transform: translateY(-1px); }

/* ---------- Sections (shared) ---------- */
.section { padding: 120px 0; }
.section-alt { background: var(--bg-elevated); }

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  color: var(--accent-teal);
  margin: 0 0 14px;
  text-transform: uppercase;
}

.section h2 {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  margin-bottom: 18px;
}

.section-lede {
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 0 48px;
  font-size: 1.02rem;
}

/* ---------- Reveal on scroll ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity var(--dur-slow) var(--ease), transform var(--dur-slow) var(--ease);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; transition: none; }
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 56px;
  align-items: start;
}
.about-copy p {
  color: var(--text-secondary);
  margin: 0 0 18px;
  font-size: 1.02rem;
}
.about-copy p:last-child { margin-bottom: 0; }

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.stat-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-amber-strong), var(--accent-teal));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* ---------- Skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.skill-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
}
.skill-card h3 {
  font-size: 1.05rem;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.skill-icon { color: var(--accent-amber); font-size: 0.7rem; }

.skill-bars { list-style: none; display: flex; flex-direction: column; gap: 16px; }
.skill-bars li {
  display: grid;
  grid-template-columns: 1fr 120px;
  align-items: center;
  gap: 14px;
}
.skill-name {
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.bar {
  position: relative;
  height: 6px;
  background: var(--surface-2);
  border-radius: 4px;
  overflow: hidden;
}
.bar-fill {
  position: absolute;
  inset: 0;
  width: 0%;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--accent-teal), var(--accent-amber));
  transition: width 1.1s var(--ease);
}
li[data-level="5"] .bar-fill { --lvl: 100%; }
li[data-level="4"] .bar-fill { --lvl: 80%; }
li[data-level="3"] .bar-fill { --lvl: 60%; }
li[data-level="2"] .bar-fill { --lvl: 40%; }
li[data-level="1"] .bar-fill { --lvl: 20%; }
.skill-card.in-view .bar-fill { width: var(--lvl); }

/* ---------- Timeline ---------- */
.timeline {
  list-style: none;
  position: relative;
  margin-top: 12px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(var(--accent-amber), var(--accent-teal));
  opacity: 0.4;
}
.timeline-item {
  position: relative;
  padding-left: 40px;
  margin-bottom: 52px;
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent-amber);
}
.timeline-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 4px;
}
.timeline-head h3 { font-size: 1.2rem; }
.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent-teal);
}
.timeline-org {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin: 0 0 16px;
}
.timeline-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.timeline-list li {
  position: relative;
  padding-left: 20px;
  color: var(--text-secondary);
  font-size: 0.96rem;
}
.timeline-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 1px;
  background: var(--accent-teal);
  transform: rotate(45deg);
}

/* ---------- Projects ---------- */
.project-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 26px;
  transition: border-color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
.project-card:hover {
  border-color: var(--accent-amber);
  transform: translateY(-3px);
}
.project-tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 20px;
  background: var(--teal-dim);
  color: var(--accent-teal-strong);
  border: 1px solid rgba(79, 216, 196, 0.25);
}
.project-card h3 { font-size: 1.12rem; margin-bottom: 12px; }
.project-card p { color: var(--text-secondary); font-size: 0.95rem; margin: 0 0 12px; }
.project-impact {
  font-size: 0.88rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-soft);
  padding-top: 12px;
  margin: 12px 0 0 !important;
}
.project-impact strong { color: var(--accent-amber-strong); }

/* ---------- Education ---------- */
.edu-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 56px;
}
.edu-col-h {
  font-size: 1.05rem;
  margin-bottom: 24px;
  color: var(--accent-teal);
}
.edu-item {
  border-left: 2px solid var(--border);
  padding: 2px 0 2px 20px;
  margin-bottom: 28px;
}
.edu-item:last-child { margin-bottom: 0; }
.edu-item-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}
.edu-degree { font-weight: 600; font-size: 1rem; }
.edu-date { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-muted); white-space: nowrap; }
.edu-school { color: var(--text-muted); font-size: 0.9rem; margin: 0 0 10px; }
.edu-notes { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.edu-notes li { color: var(--text-secondary); font-size: 0.9rem; padding-left: 14px; position: relative; }
.edu-notes li::before {
  content: "";
  position: absolute; left: 0; top: 8px;
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--accent-amber);
}

.cert-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-soft);
}
.cert-name { font-weight: 600; font-size: 0.95rem; }
.cert-issuer { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-muted); white-space: nowrap; }
.cert-note {
  margin-top: 20px;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  background: var(--amber-dim);
  border: 1px solid rgba(242, 165, 65, 0.2);
}
.cert-note p { margin: 0; font-size: 0.86rem; color: var(--text-secondary); }

/* ---------- Contact ---------- */
.section-contact { text-align: left; }
.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.contact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
a.contact-card:hover, a.contact-card:focus-visible {
  border-color: var(--accent-teal);
  transform: translateY(-2px);
}
.contact-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.contact-value { font-size: 0.95rem; font-weight: 600; word-break: break-word; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border-soft);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer-inner a { color: var(--text-muted); transition: color var(--dur-fast) var(--ease); }
.footer-inner a:hover { color: var(--accent-amber); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .main-nav { display: none; }
  .nav-toggle { display: flex; }

  .about-grid, .edu-grid { grid-template-columns: 1fr; gap: 36px; }
  .skills-grid { grid-template-columns: 1fr; }
  .project-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
  .section { padding: 84px 0; }
}

@media (max-width: 560px) {
  .wrap { padding: 0 20px; }
  .hero { min-height: auto; padding: 140px 0 100px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .skill-bars li { grid-template-columns: 1fr 90px; }
}