/* =================================================
   portfolio.css — Mehrdad Alemzadeh
   Dark-theme single-page portfolio
   ================================================= */

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

/* ── Design tokens ── */
:root {
  --bg:            #05080f;
  --surface:       #0b1120;
  --surface-2:     #0f1929;
  --surface-3:     #162033;
  --border:        rgba(255,255,255,0.06);
  --border-2:      rgba(255,255,255,0.13);
  --cyan:          #00e5ff;
  --cyan-dim:      rgba(0,229,255,0.09);
  --cyan-glow:     rgba(0,229,255,0.22);
  --purple:        #8b5cf6;
  --purple-dim:    rgba(139,92,246,0.09);
  --purple-glow:   rgba(139,92,246,0.22);
  --green:         #10b981;
  --text:          #e2e8f0;
  --text-2:        #8fa3bf;
  --text-3:        #3d5068;
  --nav-h:         62px;
  --r:             12px;
  --r-sm:          7px;
  --ease:          cubic-bezier(0.4,0,0.2,1);
  --t:             0.22s;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1,h2,h3,h4 {
  font-family: 'Space Grotesk', 'Inter', sans-serif;
  line-height: 1.2;
}

a { color: var(--cyan); text-decoration: none; }

/* ══════════════════════════════════════
   NAVIGATION
══════════════════════════════════════ */
#topnav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 1000;
  height: var(--nav-h);
  border-bottom: 1px solid transparent;
  transition: background var(--t) var(--ease),
              border-color var(--t) var(--ease);
}

#topnav.scrolled {
  background: rgba(5,8,15,0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom-color: var(--border);
}

.nav-inner {
  max-width: 1300px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0 1.5rem;
}

/* Brand */
.nav-brand {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  flex-shrink: 0;
  letter-spacing: -0.01em;
  transition: color var(--t);
}
.nav-brand:hover { color: var(--cyan); }
.nav-bracket { color: var(--cyan); }

/* Links */
.nav-links {
  display: flex;
  gap: 0.15rem;
  flex: 1;
  justify-content: center;
}

.nav-link {
  font-size: 0.83rem;
  font-weight: 500;
  color: var(--text-2);
  padding: 0.38rem 0.7rem;
  border-radius: 6px;
  letter-spacing: 0.01em;
  transition: color var(--t), background var(--t);
}
.nav-link:hover,
.nav-link.active {
  color: var(--cyan);
  background: var(--cyan-dim);
}

/* Social + resume */
.nav-social {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  flex-shrink: 0;
}
.nav-social a {
  color: var(--text-2);
  font-size: 1rem;
  transition: color var(--t);
}
.nav-social a:hover { color: var(--cyan); }

.nav-resume {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.38rem 0.85rem;
  border: 1px solid var(--border-2);
  border-radius: 6px;
  color: var(--text) !important;
  transition: border-color var(--t), background var(--t), color var(--t) !important;
}
.nav-resume:hover {
  border-color: var(--cyan);
  background: var(--cyan-dim);
  color: var(--cyan) !important;
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  margin-left: auto;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-2);
  border-radius: 2px;
  transition: transform var(--t), opacity var(--t), background var(--t);
}
.nav-toggle:hover span { background: var(--cyan); }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Scroll-progress bar */
#scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--cyan), var(--purple));
  z-index: 1001;
  transition: width 0.1s linear;
}

/* ══════════════════════════════════════
   HERO
══════════════════════════════════════ */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: calc(var(--nav-h) + 3.5rem) 1.5rem 5rem;
}

/* Animated background */
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.3;
  animation: orbDrift 16s ease-in-out infinite;
}
.orb-1 {
  width: 560px; height: 560px;
  background: radial-gradient(circle, rgba(0,229,255,0.6) 0%, transparent 70%);
  top: -15%; left: -12%;
  animation-duration: 15s;
}
.orb-2 {
  width: 680px; height: 680px;
  background: radial-gradient(circle, rgba(139,92,246,0.55) 0%, transparent 70%);
  bottom: -20%; right: -12%;
  animation-duration: 20s;
  animation-delay: -7s;
}
.orb-3 {
  width: 380px; height: 380px;
  background: radial-gradient(circle, rgba(16,185,129,0.35) 0%, transparent 70%);
  top: 38%; left: 48%;
  animation-duration: 25s;
  animation-delay: -12s;
}

@keyframes orbDrift {
  0%,100% { transform: translate(0,0) scale(1); }
  33%      { transform: translate(35px,-35px) scale(1.05); }
  66%      { transform: translate(-25px,25px) scale(0.97); }
}

.dot-grid {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,0.055) 1px, transparent 1px);
  background-size: 30px 30px;
  mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 0%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 0%, transparent 100%);
}

/* Hero content */
.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 980px;
  width: 100%;
  margin: 0 auto;
}

/* Avatar */
.avatar-wrap {
  position: relative;
  display: inline-block;
  margin-bottom: 2rem;
  animation: heroPop 0.7s var(--ease) 0.1s both;
}
.avatar-ring {
  position: absolute;
  inset: -5px;
  border-radius: 50%;
  background: conic-gradient(from 0deg, var(--cyan), var(--purple), #ec4899, var(--cyan));
  animation: ringRotate 5s linear infinite;
  z-index: 0;
}
.avatar-ring::after {
  content: '';
  position: absolute;
  inset: 3px;
  background: var(--bg);
  border-radius: 50%;
}
.avatar-img {
  width: 118px; height: 118px;
  border-radius: 50%;
  object-fit: cover;
  position: relative;
  z-index: 1;
  border: 2px solid var(--border-2);
}
.avatar-dot {
  position: absolute;
  bottom: 4px; right: 4px;
  width: 16px; height: 16px;
  background: var(--green);
  border-radius: 50%;
  border: 3px solid var(--bg);
  z-index: 2;
  animation: dotPulse 2.2s ease-in-out infinite;
}

@keyframes ringRotate {
  to { transform: rotate(360deg); }
}
@keyframes dotPulse {
  0%,100% { box-shadow: 0 0 0 0 rgba(16,185,129,0); }
  50%      { box-shadow: 0 0 0 6px rgba(16,185,129,0.18); }
}
@keyframes heroPop {
  from { opacity:0; transform: scale(0.85) translateY(16px); }
  to   { opacity:1; transform: scale(1)    translateY(0); }
}

/* Hero text */
.hero-name {
  font-size: clamp(2rem, 5.5vw, 3.6rem);
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.035em;
  margin-bottom: 0.7rem;
  animation: heroFade 0.7s var(--ease) 0.3s both;
}
.hero-name .grad {
  background: linear-gradient(135deg, var(--cyan) 0%, var(--purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-role {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(0.82rem, 2vw, 1.1rem);
  color: var(--text-2);
  margin-bottom: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: heroFade 0.7s var(--ease) 0.5s both;
}
.role-prefix { color: var(--cyan); opacity: 0.75; margin-right: 0.4em; }
.role-text   { color: var(--text); font-weight: 500; }
.cursor-blink {
  color: var(--cyan);
  animation: blink 1.1s step-end infinite;
  margin-left: 1px;
}

@keyframes blink  { 0%,100% { opacity:1; } 50% { opacity:0; } }
@keyframes heroFade {
  from { opacity:0; transform: translateY(18px); }
  to   { opacity:1; transform: translateY(0); }
}

/* Summary cards */
.summary-grid {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 0.9rem;
  text-align: left;
  margin-bottom: 3rem;
  animation: heroFade 0.7s var(--ease) 0.7s both;
}

.summary-card {
  background: rgba(11,17,32,0.82);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 1.15rem 1.2rem;
  backdrop-filter: blur(10px);
  transition: border-color var(--t), transform var(--t), background var(--t);
}
.summary-card:hover {
  border-color: rgba(0,229,255,0.28);
  background: rgba(0,229,255,0.04);
  transform: translateY(-3px);
}
.s-icon { font-size: 1.4rem; margin-bottom: 0.55rem; }
.summary-card p {
  font-size: 0.8rem;
  color: var(--text-2);
  line-height: 1.6;
}

/* Scroll caret */
.scroll-caret {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  opacity: 0.45;
  transition: opacity var(--t);
  animation: caretBounce 2s ease-in-out infinite;
  text-decoration: none;
}
.scroll-caret:hover { opacity: 0.85; }
.scroll-caret::before,
.scroll-caret::after {
  content: '';
  display: block;
  width: 9px; height: 9px;
  border-right: 2px solid var(--cyan);
  border-bottom: 2px solid var(--cyan);
  transform: rotate(45deg);
}
@keyframes caretBounce {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(9px); }
}

/* ══════════════════════════════════════
   SECTION SHELLS
══════════════════════════════════════ */
.section { padding: 6.5rem 1.5rem; }
.section-alt { background: var(--surface); }
.section-inner { max-width: 1300px; margin: 0 auto; }

.section-header { margin-bottom: 3rem; }
.section-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--cyan);
  letter-spacing: 0.12em;
  opacity: 0.75;
  display: block;
  margin-bottom: 0.45rem;
}
.section-title {
  font-size: clamp(1.7rem, 4vw, 2.45rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
  display: inline-block;
  position: relative;
}
.section-title::after {
  content: '';
  position: absolute;
  left: 0; bottom: -5px;
  width: 38%;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  border-radius: 2px;
}

/* ══════════════════════════════════════
   TAGS (shared)
══════════════════════════════════════ */
.tag-row { display: flex; flex-wrap: wrap; gap: 0.4rem; }

.tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.69rem;
  font-weight: 500;
  padding: 0.22rem 0.58rem;
  border-radius: 4px;
  border: 1px solid transparent;
  letter-spacing: 0.03em;
  transition: transform var(--t);
  cursor: default;
}
.tag:hover { transform: translateY(-1px); }

.t-ai        { color:#a78bfa; background:rgba(139,92,246,0.1);  border-color:rgba(139,92,246,0.25); }
.t-backend   { color:#34d399; background:rgba(52,211,153,0.1);  border-color:rgba(52,211,153,0.25); }
.t-frontend  { color:#60a5fa; background:rgba(96,165,250,0.1);  border-color:rgba(96,165,250,0.25); }
.t-mobile    { color:#f472b6; background:rgba(244,114,182,0.1); border-color:rgba(244,114,182,0.25); }
.t-db        { color:#fbbf24; background:rgba(251,191,36,0.1);  border-color:rgba(251,191,36,0.25); }
.t-cloud     { color:#38bdf8; background:rgba(56,189,248,0.1);  border-color:rgba(56,189,248,0.25); }
.t-sec       { color:#f87171; background:rgba(248,113,113,0.1); border-color:rgba(248,113,113,0.25); }
.t-chain     { color:#fb923c; background:rgba(251,146,60,0.1);  border-color:rgba(251,146,60,0.25); }

/* ══════════════════════════════════════
   TECH GRID
══════════════════════════════════════ */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px,1fr));
  gap: 1rem;
}

.tech-cat {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 1.4rem;
  transition: border-color var(--t), transform var(--t);
}
.tech-cat:hover { border-color: var(--border-2); transform: translateY(-2px); }

.tech-cat-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

/* ══════════════════════════════════════
   EXPERIENCE
══════════════════════════════════════ */
.exp-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  padding-left: 0.25rem;
}

.exp-card {
  background: transparent;
  border: none;
  border-left: 2px solid rgba(0,229,255,0.18);
  border-radius: 0;
  padding: 0 0 2.75rem 1.75rem;
  position: relative;
  transition: border-left-color var(--t);
}
.exp-card:last-child { padding-bottom: 0; }

/* Timeline dot */
.exp-card::before {
  content: '';
  position: absolute;
  left: -5px; top: 7px;
  width: 8px; height: 8px;
  background: var(--bg);
  border: 2px solid var(--cyan);
  border-radius: 50%;
  transition: border-color var(--t), background var(--t);
  z-index: 1;
}
.exp-card:hover { border-left-color: rgba(139,92,246,0.5); transform: none; }
.exp-card:hover::before { border-color: var(--purple); background: var(--purple-dim); }

.exp-meta { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.4rem 0.85rem; margin-bottom: 0.9rem; }

.exp-co {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--cyan);
}
.exp-role {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
}
.exp-proj {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.73rem;
  color: var(--text-3);
  letter-spacing: 0.03em;
}

.exp-tags { display: flex; flex-wrap: wrap; gap: 0.33rem; margin-bottom: 0.9rem; }

.exp-bullets { list-style: none; display: flex; flex-direction: column; gap: 0.38rem; }
.exp-bullets li {
  font-size: 0.855rem;
  color: var(--text-2);
  padding-left: 1.2rem;
  position: relative;
  line-height: 1.65;
}
.exp-bullets li::before {
  content: '▸';
  position: absolute;
  left: 0; top: 0.22em;
  color: var(--cyan);
  font-size: 0.68rem;
}

/* ══════════════════════════════════════
   EDUCATION
══════════════════════════════════════ */
.edu-grid {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}
.edu-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 1.6rem;
  transition: border-color var(--t), transform var(--t);
  width: 100%;
}
.edu-card:hover { border-color: var(--border-2); transform: translateY(-3px); }
.edu-card.acad-card {
  max-width: 620px;
  align-self: center;
}

.edu-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-wrap: wrap;
}

/* Certifications accordion */
.cert-toggle {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--cyan);
  background: var(--cyan-dim);
  border: 1px solid rgba(0,229,255,0.2);
  border-radius: 20px;
  padding: 0.25rem 0.75rem;
  cursor: pointer;
  transition: background var(--t), border-color var(--t);
  white-space: nowrap;
}
.cert-toggle:hover { background: rgba(0,229,255,0.15); border-color: rgba(0,229,255,0.4); }
.cert-chevron {
  font-size: 0.65rem;
  transition: transform 0.3s var(--ease);
}
.cert-toggle[aria-expanded="true"] .cert-chevron { transform: rotate(180deg); }

.cert-more {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.38s var(--ease);
  margin-top: 0;
}
.cert-more.open { grid-template-rows: 1fr; }
.cert-more > ul { overflow: hidden; min-height: 0; }

.cert-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0.9rem 0;
}
.edu-list { list-style: none; display: flex; flex-direction: column; gap: 0.48rem; }
.edu-list li {
  font-size: 0.855rem;
  color: var(--text-2);
  padding-left: 1.15rem;
  position: relative;
  line-height: 1.58;
}
.edu-list li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--purple);
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1.4;
}

/* ══════════════════════════════════════
   PROJECTS
══════════════════════════════════════ */
.proj-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px,1fr));
  gap: 1.1rem;
}

.proj-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  transition: border-color var(--t), transform var(--t), box-shadow var(--t);
}
.proj-card:hover {
  border-color: rgba(0,229,255,0.28);
  transform: translateY(-4px);
  box-shadow: 0 14px 44px rgba(0,229,255,0.07);
}

.proj-cat {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--cyan);
  opacity: 0.78;
}
.proj-title {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.45rem;
}
.proj-list {
  list-style: none;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.38rem;
}
.proj-list li {
  font-size: 0.835rem;
  color: var(--text-2);
  padding-left: 1.1rem;
  position: relative;
  line-height: 1.58;
}
.proj-list li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--cyan);
  font-size: 1.1rem;
  line-height: 1.3;
}
.proj-link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.76rem;
  color: var(--cyan);
  transition: opacity var(--t);
}
.proj-link:hover { opacity: 0.7; }
.proj-actions { display: flex; flex-wrap: wrap; gap: 0.7rem; align-items: center; }
.inline-link { color: var(--cyan); }

/* ══════════════════════════════════════
   CONTACT
══════════════════════════════════════ */
.contact-grid {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}
.contact-info-row {
  display: flex;
  gap: 1.1rem;
  justify-content: center;
  align-items: stretch;
  flex-wrap: wrap;
}
.contact-info {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 1.5rem 2rem;
  text-align: center;
  flex: 1 1 0;
  max-width: 260px;
  min-width: 0;
  word-break: break-word;
  transition: border-color var(--t), transform var(--t);
}
.contact-info:hover { border-color: var(--border-2); transform: translateY(-3px); }
.c-icon  { font-size: 1.75rem; margin-bottom: 0.55rem; }
.contact-info h3 { font-size: 0.9rem; font-weight: 600; color: var(--text); margin-bottom: 0.3rem; }
.contact-info p  { font-size: 0.82rem; color: var(--text-2); }

.contact-cta {
  background: linear-gradient(135deg, rgba(0,229,255,0.07) 0%, rgba(139,92,246,0.07) 100%);
  border: 1px solid rgba(0,229,255,0.18);
  border-radius: var(--r);
  padding: 2.2rem;
  text-align: center;
}
.contact-cta h3 { font-size: 1.2rem; color: var(--text); margin-bottom: 0.45rem; }
.contact-cta p  { font-size: 0.875rem; color: var(--text-2); margin-bottom: 1.5rem; }

.cta-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  justify-content: center;
  align-items: center;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.38rem;
  padding: 0.55rem 1.2rem;
  border-radius: var(--r-sm);
  font-size: 0.855rem;
  font-weight: 600;
  transition: all var(--t) var(--ease);
  cursor: pointer;
  border: none;
  text-decoration: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--cyan), var(--purple));
  color: #03060e;
}
.btn-primary:hover { opacity: 0.84; transform: translateY(-2px); color: #03060e; }

.btn-ghost {
  border: 1px solid var(--border-2);
  color: var(--text);
  background: transparent;
}
.btn-ghost:hover {
  border-color: var(--cyan);
  background: var(--cyan-dim);
  color: var(--cyan);
  transform: translateY(-2px);
}

.appstore-btn img { height: 36px; border-radius: 6px; display: block; }

/* ══════════════════════════════════════
   FOOTER
══════════════════════════════════════ */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
}
.site-footer p {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-3);
  letter-spacing: 0.05em;
}

/* ══════════════════════════════════════
   REVEAL ANIMATIONS
══════════════════════════════════════ */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger siblings */
.tech-grid  .reveal:nth-child(n+2) { transition-delay: calc((var(--i,0) - 1) * 0.06s); }
.tech-grid  .reveal:nth-child(2)  { transition-delay: 0.06s; }
.tech-grid  .reveal:nth-child(3)  { transition-delay: 0.12s; }
.tech-grid  .reveal:nth-child(4)  { transition-delay: 0.18s; }
.tech-grid  .reveal:nth-child(5)  { transition-delay: 0.24s; }
.tech-grid  .reveal:nth-child(6)  { transition-delay: 0.30s; }
.tech-grid  .reveal:nth-child(7)  { transition-delay: 0.36s; }
.tech-grid  .reveal:nth-child(8)  { transition-delay: 0.42s; }
.tech-grid  .reveal:nth-child(9)  { transition-delay: 0.48s; }

.proj-grid  .reveal:nth-child(2)  { transition-delay: 0.06s; }
.proj-grid  .reveal:nth-child(3)  { transition-delay: 0.12s; }
.proj-grid  .reveal:nth-child(4)  { transition-delay: 0.18s; }
.proj-grid  .reveal:nth-child(5)  { transition-delay: 0.24s; }
.proj-grid  .reveal:nth-child(6)  { transition-delay: 0.30s; }

.edu-grid   .reveal:nth-child(2)  { transition-delay: 0.08s; }
.edu-grid   .reveal:nth-child(3)  { transition-delay: 0.16s; }

/* ══════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════ */
@media (max-width: 1024px) {
  .summary-grid { grid-template-columns: repeat(2,1fr); }
}

@media (max-width: 768px) {
  :root { --nav-h: 54px; }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    background: rgba(5,8,15,0.97);
    backdrop-filter: blur(18px);
    flex-direction: column;
    padding: 0.75rem 1.25rem 1.25rem;
    gap: 0.15rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-link { padding: 0.7rem 0.9rem; font-size: 0.92rem; }
  .nav-toggle { display: flex; }
  .nav-social { display: none; }

  .summary-grid { grid-template-columns: 1fr; gap: 0.7rem; }
  .section { padding: 4.5rem 1rem; }

  .tech-grid,
  .proj-grid { grid-template-columns: 1fr; }

  .edu-card.acad-card { max-width: 100%; }

  .contact-info { max-width: 100%; }

  .cta-buttons { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
}

@media (max-width: 480px) {
  #hero { padding-top: calc(var(--nav-h) + 1.75rem); }
  .avatar-img { width: 96px; height: 96px; }
  .hero-role  { font-size: 0.78rem; }
  .section-title { font-size: 1.45rem; }
  .exp-card { padding: 0 0 2rem 1.25rem; }
}