/* ============================================================
   ASSADUZZAMAN MUNNA — Portfolio Stylesheet
   Design: obsidian · controlled crimson · cinematic · technical
   ============================================================ */

/* ── TOKENS ── */
:root {
  /* Surfaces */
  --bg:            #050505;
  --surface:       #0A0A0B;
  --surface-2:     #111113;
  --surface-3:     #1A1A1D;

  /* Borders */
  --border:        rgba(255, 255, 255, 0.06);
  --border-hov:    rgba(255, 255, 255, 0.12);

  /* Accent — controlled crimson/red */
  --accent:        #C51624;
  --accent-dim:    #8F111B;
  --accent-hot:    #F02A3A;
  --accent-glow:   rgba(197, 22, 36, 0.18);
  --crimson-dark:  #3D080D;
  --crimson-subtle: rgba(197, 22, 36, 0.06);

  /* Text */
  --text:          #F2EEE9;
  --muted:         #969399;
  --faint:         #3A3A3E;
  --white:         #FFFFFF;

  /* Semantic */
  --green:         #4ADE80;
  --green-dim:     rgba(34, 197, 94, 0.08);
  --yellow:        #FBBF24;
  --yellow-dim:    rgba(251, 191, 36, 0.08);

  /* Typography */
  --sans:    'Inter', system-ui, -apple-system, sans-serif;
  --display: 'Space Grotesk', sans-serif;
  --mono:    'JetBrains Mono', monospace;

  /* Motion */
  --motion-micro:  80ms;
  --motion-fast:   200ms;
  --motion-medium: 350ms;
  --motion-slow:   600ms;
  --motion-hero:   1000ms;

  /* Easing */
  --ease:        cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --radius:    12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
}

/* ── RESET ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
  font-size: 16px;
}
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { cursor: pointer; font-family: var(--sans); border: none; background: none; }

/* ── GRAIN OVERLAY ── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.02'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
}

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--faint); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--muted); }

/* ── SELECTION ── */
::selection { background: rgba(197, 22, 36, 0.3); color: var(--white); }

/* ── SCROLL PROGRESS BAR ── */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-hot));
  width: 0%;
  z-index: 999;
  transition: none;
  pointer-events: none;
}

/* ============================================================
   LAYOUT
   ============================================================ */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 5vw, 3rem);
}
section { position: relative; z-index: 1; }

/* ── SECTION HEADER ── */
.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.6rem;
}
.section-eyebrow::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--accent);
  flex-shrink: 0;
}
.section-title {
  font-family: var(--display);
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.035em;
  color: var(--white);
  margin-bottom: 0.85rem;
}
.section-sub {
  font-size: 1rem;
  color: var(--muted);
  max-width: 540px;
  line-height: 1.75;
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.4; transform: scale(0.75); }
}
@keyframes pulseRing {
  0%, 100% { box-shadow: 0 0 0 3px rgba(197, 22, 36, 0.2); }
  50%      { box-shadow: 0 0 0 6px rgba(197, 22, 36, 0.06); }
}
@keyframes marquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}
@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%      { transform: translateX(-50%) translateY(7px); }
}
@keyframes floatCard {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}
@keyframes signalFlow {
  0%   { background-position: -200% center; }
  100% { background-position: 200% center; }
}
@keyframes nodeActivate {
  0%   { box-shadow: 0 0 0 0 rgba(197, 22, 36, 0); }
  50%  { box-shadow: 0 0 20px 4px rgba(197, 22, 36, 0.25); }
  100% { box-shadow: 0 0 0 0 rgba(197, 22, 36, 0); }
}
@keyframes heroGlowPulse {
  0%, 100% { opacity: 0.3; }
  50%      { opacity: 0.6; }
}

/* ── FADE ENTRANCE PRIMITIVES ── */
.fade-up {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity var(--motion-slow) var(--ease), transform var(--motion-slow) var(--ease);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}
.blur-in {
  opacity: 0;
  filter: blur(8px);
  transform: translateY(12px);
  transition: opacity var(--motion-hero) var(--ease),
              filter var(--motion-hero) var(--ease),
              transform var(--motion-hero) var(--ease);
}
.blur-in.visible {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
}

/* ============================================================
   NAVIGATION
   ============================================================ */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
  height: 64px;
  background: rgba(5, 5, 5, 0.75);
  backdrop-filter: blur(24px) saturate(1.4);
  -webkit-backdrop-filter: blur(24px) saturate(1.4);
  border-bottom: 1px solid transparent;
  transition: background var(--motion-medium), border-color var(--motion-medium);
}
nav.scrolled {
  background: rgba(5, 5, 5, 0.95);
  border-color: var(--border);
}
.nav-logo {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--white);
  flex-shrink: 0;
}
.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}
.nav-links a {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--muted);
  transition: color var(--motion-fast);
  letter-spacing: 0.01em;
  position: relative;
}
.nav-links a:hover { color: var(--white); }
.nav-links a.active { color: var(--white); }
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0; right: 0;
  height: 1px;
  background: var(--accent);
  border-radius: 1px;
}

.nav-cta {
  font-size: 0.8rem !important;
  font-weight: 600 !important;
  color: var(--white) !important;
  background: var(--accent);
  padding: 0.45rem 1.1rem;
  border-radius: 6px;
  transition: background var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast) !important;
}
.nav-cta:hover {
  background: var(--accent-dim) !important;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(197, 22, 36, 0.35);
}
.nav-cta.active::after { display: none; }

.nav-hamburger {
  display: none;
  cursor: pointer;
  padding: 4px;
  flex-direction: column;
  gap: 5px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--muted);
  border-radius: 2px;
  transition: transform var(--motion-medium), opacity var(--motion-medium), background var(--motion-fast);
}
.nav-hamburger:hover span { background: var(--white); }
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================
   HERO — Cinematic, text-only
   ============================================================ */
#hero {
  min-height: auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 96px clamp(1.5rem, 5vw, 4rem) 1.5rem;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(ellipse 85% 70% at 50% 35%, rgba(45, 12, 18, 0.5) 0%, rgba(22, 6, 10, 0.65) 50%, var(--bg) 88%),
    linear-gradient(180deg, rgba(32, 8, 14, 0.35) 0%, var(--bg) 100%);
}

/* ── Hero Cinematic Background Media ── */
.hero-bg-media {
  position: absolute;
  inset: 0;
  overflow: hidden;
  z-index: 0;
  pointer-events: none;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-bg-gif {
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: min(540px, 85vw);
  height: min(440px, 65vh);
  object-fit: contain;
  opacity: 0.44;
  filter: blur(1px) brightness(0.95) contrast(1.2);
  mask-image: radial-gradient(ellipse 58% 52% at 50% 50%, black 25%, rgba(0, 0, 0, 0.5) 55%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 58% 52% at 50% 50%, black 25%, rgba(0, 0, 0, 0.5) 55%, transparent 75%);
  pointer-events: none;
}

.hero-bg-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 75% 65% at 50% 40%, rgba(20, 5, 8, 0.1) 0%, rgba(5, 5, 5, 0.55) 85%, var(--bg) 100%),
    linear-gradient(to bottom, rgba(5, 5, 5, 0.25) 0%, transparent 20%, transparent 80%, var(--bg) 100%);
  pointer-events: none;
}

/* ── Deep Black Cinematic Vignette ── */
.hero-vignette {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 60% at 50% 45%, transparent 20%, rgba(5, 5, 5, 0.45) 58%, rgba(5, 5, 5, 0.94) 86%, #050505 100%),
    linear-gradient(to bottom, rgba(5, 5, 5, 0.85) 0%, transparent 15%, transparent 80%, #050505 100%),
    linear-gradient(to right, rgba(5, 5, 5, 0.88) 0%, transparent 15%, transparent 85%, rgba(5, 5, 5, 0.88) 100%);
  z-index: 1;
}

/* Ambient system topology background */
#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 50% 30%, rgba(95, 20, 32, 0.12) 0%, transparent 60%),
    radial-gradient(circle at 20% 60%, rgba(70, 15, 24, 0.07) 0%, transparent 50%),
    radial-gradient(circle at 80% 50%, rgba(70, 15, 24, 0.07) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
}

/* Subtle grid overlay */
#hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.015) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 60% 50% at 50% 50%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 60% 50% at 50% 50%, black 20%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* ── Hero Top Row (Identity Pill + Status Pill) ── */
.hero-top-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  flex-wrap: wrap;
  margin-bottom: 2.25rem;
}

.hero-intro-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.3rem 0.85rem 0.3rem 0.35rem;
  border-radius: 100px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.hero-intro-pill:hover {
  border-color: rgba(197, 22, 36, 0.3);
  transform: translateY(-1px);
}
.hero-intro-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  overflow: hidden;
  border: 1.5px solid var(--accent);
  flex-shrink: 0;
  background: var(--surface-2);
}
.hero-intro-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 15%;
}
.hero-intro-text {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
}
.hero-intro-name {
  color: var(--white);
  font-weight: 600;
}
.hero-intro-sep {
  color: var(--faint);
}
.hero-intro-role {
  color: var(--muted);
}

.hero-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.2);
  padding: 0.28rem 0.72rem;
  border-radius: 100px;
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--accent);
  font-weight: 500;
  letter-spacing: 0.03em;
  box-shadow: 0 4px 16px rgba(197, 22, 36, 0.08);
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.hero-status-pill:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}
.hero-badge-dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2.5s infinite;
}

.hero-headline {
  font-family: var(--display);
  font-size: clamp(3.2rem, 7vw, 5.5rem);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.04em;
  color: var(--white);
  margin-bottom: 1.75rem;
}
.hero-headline .accent {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hot) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-roles {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}
.hero-role {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 100px;
  transition: color var(--motion-fast), border-color var(--motion-fast);
}
.hero-role:hover {
  color: var(--text);
  border-color: var(--border-hov);
}

.hero-description {
  font-size: 1.05rem;
  color: var(--muted);
  line-height: 1.8;
  max-width: 580px;
  margin: 0 auto 2.5rem;
}
.hero-description em {
  font-style: normal;
  color: var(--text);
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

/* ── BUTTONS ── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent);
  color: var(--white);
  padding: 0.8rem 1.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  transition: background var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast);
}
.btn-primary:hover {
  background: var(--accent-dim);
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(197, 22, 36, 0.35);
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: transparent;
  color: var(--text);
  padding: 0.8rem 1.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  border: 1px solid var(--border-hov);
  transition: border-color var(--motion-fast), background var(--motion-fast), transform var(--motion-fast);
}
.btn-secondary:hover {
  border-color: var(--faint);
  background: rgba(255, 255, 255, 0.03);
  transform: translateY(-2px);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  max-width: 520px;
  width: 100%;
  margin: 0 auto;
  gap: 1.5rem;
  padding: 1.5rem 0 0.5rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
}
.hero-stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.hero-stat-value {
  font-family: var(--display);
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.04em;
  line-height: 1;
}
.hero-stat-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--muted);
  font-weight: 400;
  letter-spacing: 0.04em;
  margin-top: 0.25rem;
}

/* ── SCROLL HINT ── */
.scroll-hint {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: var(--faint);
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  animation: scrollBounce 2.4s ease-in-out infinite;
  z-index: 1;
}
.scroll-hint-line {
  width: 1px;
  height: 36px;
  background: linear-gradient(to bottom, var(--faint), transparent);
}

/* ============================================================
   MARQUEE TICKER
   ============================================================ */
.marquee-section {
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  overflow: hidden;
  position: relative;
  z-index: 1;
}
.marquee-section::before,
.marquee-section::after {
  content: '';
  position: absolute;
  top: 0; bottom: 0;
  width: 120px;
  z-index: 2;
  pointer-events: none;
}
.marquee-section::before {
  left: 0;
  background: linear-gradient(to right, var(--bg), transparent);
}
.marquee-section::after {
  right: 0;
  background: linear-gradient(to left, var(--bg), transparent);
}
.marquee-track {
  display: flex;
  gap: 3rem;
  align-items: center;
  animation: marquee 28s linear infinite;
  white-space: nowrap;
  width: max-content;
}
.marquee-section:hover .marquee-track { animation-play-state: paused; }
.marquee-item {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--faint);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  flex-shrink: 0;
  transition: color var(--motion-fast);
}
.marquee-item:hover { color: var(--muted); }
.marquee-sep {
  width: 3px;
  height: 3px;
  background: var(--faint);
  border-radius: 50%;
  flex-shrink: 0;
}

/* ============================================================
   ENGINEERING PHILOSOPHY
   ============================================================ */
#philosophy {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  position: relative;
  overflow: hidden;
}
#philosophy::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(ellipse 50% 40% at 50% 50%, rgba(197, 22, 36, 0.03), transparent);
  pointer-events: none;
}

.philosophy-content {
  max-width: 780px;
  margin: 0 auto;
  text-align: center;
}

.philosophy-quote {
  font-family: var(--display);
  font-size: clamp(1.5rem, 3.5vw, 2.5rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.03em;
  color: var(--white);
  margin-bottom: 1.75rem;
  opacity: 0.95;
}
.philosophy-quote .word {
  display: inline-block;
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--motion-slow) var(--ease), transform var(--motion-slow) var(--ease);
}
.philosophy-quote .word.visible {
  opacity: 1;
  transform: translateY(0);
}

.philosophy-principles {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.philosophy-principle {
  text-align: center;
  padding: 1.5rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.philosophy-principle:hover {
  border-color: rgba(197, 22, 36, 0.2);
  transform: translateY(-3px);
}
.philosophy-principle-number {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--accent);
  letter-spacing: 0.12em;
  margin-bottom: 0.5rem;
}
.philosophy-principle-text {
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 1.65;
  font-weight: 400;
}
.philosophy-principle-text strong {
  color: var(--text);
  font-weight: 500;
}

/* ============================================================
   ABOUT
   ============================================================ */
#about { padding: clamp(2.75rem, 4.5vw, 3.75rem) 0; }

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  align-items: start;
}

/* photo side */
.about-visual { position: relative; }
.about-photo-stack {
  position: relative;
  width: 100%;
  max-width: 340px;
}
.about-photo-main {
  width: 100%;
  aspect-ratio: 3 / 4;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 28px 72px rgba(0, 0, 0, 0.5);
}
.about-photo-main img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  filter: brightness(1.04) contrast(1.06) saturate(0.9);
  transition: transform var(--motion-slow) var(--ease);
}
.about-photo-main:hover img { transform: scale(1.04); }

.about-card-float {
  position: absolute;
  bottom: -1.5rem;
  right: -1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.25rem;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
  min-width: 170px;
  animation: floatCard 4s ease-in-out infinite;
}
.about-card-flag { font-size: 2rem; line-height: 1; margin-bottom: 0.4rem; }
.about-card-label { font-size: 0.78rem; font-weight: 600; color: var(--white); line-height: 1.35; }
.about-card-sub { font-family: var(--mono); font-size: 0.68rem; color: var(--muted); margin-top: 0.2rem; }

/* text side */
.about-text p {
  color: var(--muted);
  line-height: 1.82;
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
}
.about-text p strong { color: var(--text); font-weight: 500; }

.about-highlights {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 2.25rem;
}
.about-highlight-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1rem;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.about-highlight-item:hover {
  border-color: rgba(197, 22, 36, 0.18);
  transform: translateY(-2px);
}
.about-highlight-icon { font-size: 1.3rem; margin-bottom: 0.55rem; }
.about-highlight-title {
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 0.25rem;
  letter-spacing: -0.01em;
}
.about-highlight-desc {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
  line-height: 1.55;
}

/* ============================================================
   SKILLS / CAPABILITIES
   ============================================================ */
#skills {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  background: var(--surface);
}
.skills-header { margin-bottom: 1.75rem; }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.15rem;
}

.skill-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast);
}
.skill-card:hover {
  border-color: rgba(197, 22, 36, 0.22);
  transform: translateY(-3px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
}
.skill-card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}
.skill-card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.icon-red     { background: rgba(197, 22, 36, 0.1); }
.icon-crimson { background: rgba(61, 8, 13, 0.35); }
.icon-warm    { background: rgba(242, 238, 233, 0.06); }
.icon-muted   { background: rgba(150, 147, 153, 0.1); }
.icon-dark    { background: rgba(255, 255, 255, 0.04); }
.icon-accent  { background: rgba(197, 22, 36, 0.08); }
.skill-card-title {
  font-size: 0.87rem;
  font-weight: 600;
  color: var(--white);
  letter-spacing: -0.01em;
}
.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.skill-tag {
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  transition: color var(--motion-fast), border-color var(--motion-fast), background var(--motion-fast);
}
.skill-card:hover .skill-tag {
  color: var(--text);
  border-color: var(--faint);
  background: rgba(255, 255, 255, 0.05);
}

/* ============================================================
   EXPERIENCE TIMELINE
   ============================================================ */
#experience { padding: clamp(2.75rem, 4.5vw, 3.75rem) 0; }

.exp-timeline {
  position: relative;
  margin-top: 1.75rem;
  padding-left: 0;
}
.exp-timeline::before {
  content: '';
  position: absolute;
  left: 20px;
  top: 6px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(to bottom, var(--accent), var(--faint) 60%, transparent);
}

.exp-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 1.5rem;
  margin-bottom: 2.25rem;
  position: relative;
}

.exp-dot {
  width: 40px;
  display: flex;
  justify-content: center;
  padding-top: 0.3rem;
  flex-shrink: 0;
}
.exp-dot-inner {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 3px rgba(197, 22, 36, 0.2);
  position: relative;
  z-index: 1;
  transition: box-shadow var(--motion-medium);
}
.exp-dot-inner.current { animation: pulseRing 2.2s infinite; }
.exp-item:hover .exp-dot-inner { box-shadow: 0 0 0 5px rgba(197, 22, 36, 0.15); }

.exp-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.exp-card:hover {
  border-color: rgba(197, 22, 36, 0.15);
  transform: translateX(4px);
}
.exp-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.4rem;
  gap: 1rem;
  flex-wrap: wrap;
}
.exp-role {
  font-size: 1rem;
  font-weight: 600;
  color: var(--white);
  letter-spacing: -0.01em;
}
.exp-period {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--muted);
  font-weight: 400;
  white-space: nowrap;
  background: rgba(255, 255, 255, 0.03);
  padding: 0.22rem 0.7rem;
  border-radius: 100px;
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.exp-company {
  font-size: 0.84rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 1rem;
}
.exp-bullets { padding-left: 0; }
.exp-bullets li {
  font-size: 0.87rem;
  color: var(--muted);
  line-height: 1.7;
  margin-bottom: 0.5rem;
  padding-left: 1.1rem;
  position: relative;
}
.exp-bullets li:last-child { margin-bottom: 0; }
.exp-bullets li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 600;
}

.exp-current-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.2);
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.18rem 0.55rem;
  border-radius: 100px;
  margin-left: 0.6rem;
  vertical-align: middle;
}
.exp-current-tag::before {
  content: '';
  width: 5px;
  height: 5px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

/* ============================================================
   PROJECTS — Case Study Style
   ============================================================ */
#projects {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  background: var(--surface);
}

/* ── Category Tab Selector ── */
.project-categories {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.25rem;
  margin-bottom: 1.5rem;
}

.category-btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.5rem 1.25rem;
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
  border-radius: 100px;
  cursor: pointer;
  letter-spacing: 0.03em;
  transition: all var(--motion-fast) var(--ease);
}

.category-btn:hover {
  color: var(--white);
  border-color: var(--border-hov);
  background: rgba(255, 255, 255, 0.02);
}

.category-btn.active {
  background: var(--crimson-subtle);
  border-color: var(--accent);
  color: var(--white);
  box-shadow: 0 0 20px rgba(197, 22, 36, 0.1);
}

.projects-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.4rem;
  margin-top: 1.75rem;
}

.project-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  transition: border-color var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast);
}

.project-card.card-hidden {
  display: none !important;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-hot));
  opacity: 0;
  transition: opacity var(--motion-medium);
}
.project-card:hover {
  border-color: rgba(197, 22, 36, 0.18);
  transform: translateY(-4px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}
.project-card:hover::before { opacity: 1; }

/* Featured project card — full width */
.project-card.featured {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  padding: 2.25rem;
}
.project-card.featured .project-meta-col {
  display: flex;
  flex-direction: column;
}

.project-number {
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  color: var(--faint);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.project-title {
  font-family: var(--display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--white);
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.project-desc {
  font-size: 0.87rem;
  color: var(--muted);
  line-height: 1.72;
  margin-bottom: 1.25rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
  margin-top: auto;
}
.project-tag {
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.15);
  padding: 0.2rem 0.58rem;
  border-radius: 100px;
  letter-spacing: 0.03em;
}

.project-links {
  display: flex;
  gap: 1rem;
}
.project-link {
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color var(--motion-fast);
}
.project-link:hover { color: var(--accent); }

.project-metric {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--green-dim);
  border: 1px solid rgba(34, 197, 94, 0.22);
  color: var(--green);
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  padding: 0.22rem 0.65rem;
  border-radius: 100px;
  margin-bottom: 0.75rem;
  letter-spacing: 0.03em;
}

/* ============================================================
   SYSTEMS / UNIFIED PRODUCTION & GITHUB ARCHITECTURE
   ============================================================ */
#systems {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
}

.systems-unified-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: clamp(1.75rem, 3.5vw, 2.5rem);
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}
.systems-unified-card::before {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 350px; height: 350px;
  background: radial-gradient(circle at top right, rgba(197, 22, 36, 0.05), transparent 70%);
  pointer-events: none;
}

.pipeline-track {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pipeline-track-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.pipeline-track-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.01em;
}
.pipeline-track-badge span {
  font-size: 1.15rem;
  line-height: 1;
}

.pipeline-track-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.legend-pill {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.22rem 0.6rem;
  border-radius: 100px;
}
.legend-pill code {
  color: var(--accent-hot);
}

/* ── Node Flow (Scrollable Linear Stream) ── */
.track-flow {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  overflow-x: auto;
  padding: 0.75rem 0.25rem;
  scrollbar-width: thin;
}
.flow-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  min-width: 105px;
  flex-shrink: 0;
  transition: all var(--motion-fast);
}
.flow-node:hover, .flow-node.active {
  border-color: rgba(197, 22, 36, 0.4);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
}
.flow-node.highlight {
  border-color: rgba(197, 22, 36, 0.35);
  background: var(--crimson-subtle);
}
.flow-node.highlight-prod {
  border-color: rgba(34, 197, 94, 0.35);
  background: var(--green-dim);
}

.flow-icon {
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}
.flow-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--white);
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.flow-sub {
  font-size: 0.62rem;
  color: var(--muted);
  margin-top: 0.2rem;
  white-space: nowrap;
}

.flow-arrow {
  color: var(--faint);
  font-family: var(--mono);
  font-size: 0.8rem;
  flex-shrink: 0;
  padding: 0 0.1rem;
}

/* ── Inline Branch Bar ── */
.track-branch-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.85rem;
  font-family: var(--mono);
  font-size: 0.72rem;
}
.branch-tag {
  padding: 0.18rem 0.5rem;
  border-radius: 4px;
  font-weight: 500;
}
.main-tag {
  color: var(--accent-hot);
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.2);
}
.feat-tag {
  color: #60A5FA;
  background: rgba(96, 165, 250, 0.08);
  border: 1px solid rgba(96, 165, 250, 0.15);
}
.fix-tag {
  color: #FBBF24;
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.15);
}
.branch-sep {
  color: var(--faint);
}

/* ── Divider ── */
.pipeline-track-divider {
  height: 1px;
  background: var(--border);
  margin: 2rem 0;
}

/* ============================================================
   ENGINEERING METRICS
   ============================================================ */
#metrics {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  background: var(--surface);
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-top: 1.75rem;
}

.metric-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  text-align: center;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.metric-card:hover {
  border-color: rgba(197, 22, 36, 0.18);
  transform: translateY(-3px);
}
.metric-value {
  font-family: var(--display);
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 0.5rem;
}
.metric-value .metric-accent {
  color: var(--accent);
}
.metric-label {
  font-family: var(--mono);
  font-size: 0.66rem;
  color: var(--muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  line-height: 1.4;
}
.metric-context {
  font-size: 0.76rem;
  color: var(--faint);
  margin-top: 0.5rem;
  line-height: 1.45;
}

/* ============================================================
   PUBLICATIONS
   ============================================================ */
#publications { padding: clamp(2.75rem, 4.5vw, 3.75rem) 0; }

.pub-list { margin-top: 1.75rem; display: flex; flex-direction: column; gap: 1.25rem; }

.pub-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 1.75rem;
  align-items: start;
  transition: border-color var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast);
}
.pub-card:hover {
  border-color: rgba(197, 22, 36, 0.2);
  transform: translateX(5px);
  box-shadow: -4px 0 0 var(--accent), 4px 0 0 transparent;
}

.pub-year-badge { text-align: center; }
.pub-year {
  font-family: var(--display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.pub-venue-short {
  font-family: var(--mono);
  font-size: 0.58rem;
  color: var(--faint);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 0.25rem;
}

.pub-status {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.18rem 0.6rem;
  border-radius: 100px;
  margin-bottom: 0.65rem;
}
.pub-status.published {
  color: var(--green);
  background: var(--green-dim);
  border: 1px solid rgba(34, 197, 94, 0.22);
}
.pub-status.review {
  color: var(--yellow);
  background: var(--yellow-dim);
  border: 1px solid rgba(251, 191, 36, 0.22);
}
.pub-status-dot { width: 6px; height: 6px; border-radius: 50%; background: currentColor; }

.pub-title {
  font-size: 0.97rem;
  font-weight: 600;
  color: var(--white);
  line-height: 1.42;
  margin-bottom: 0.45rem;
  letter-spacing: -0.01em;
}
.pub-authors {
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 0.45rem;
  line-height: 1.55;
}
.pub-authors strong { color: var(--text); font-weight: 500; }
.pub-venue {
  font-size: 0.76rem;
  color: var(--faint);
  font-style: italic;
  margin-bottom: 0.85rem;
  line-height: 1.5;
}
.pub-highlights { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.pub-highlight {
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.15);
  padding: 0.18rem 0.55rem;
  border-radius: 100px;
  letter-spacing: 0.02em;
}

/* ============================================================
   EDUCATION
   ============================================================ */
#education {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  background: var(--surface);
}
.edu-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 2.25rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 2rem;
  align-items: center;
  margin-top: 1.75rem;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.edu-card:hover {
  border-color: rgba(197, 22, 36, 0.2);
  transform: translateY(-2px);
}
.edu-icon {
  width: 58px;
  height: 58px;
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.15);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  flex-shrink: 0;
}
.edu-degree {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 0.3rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.edu-institution {
  font-family: var(--display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.025em;
  margin-bottom: 0.3rem;
}
.edu-field { font-size: 0.84rem; color: var(--muted); }
.edu-stats { text-align: right; }
.edu-gpa {
  font-family: var(--display);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.04em;
  line-height: 1;
}
.edu-gpa-label {
  font-family: var(--mono);
  font-size: 0.66rem;
  color: var(--muted);
  font-weight: 400;
  margin-top: 0.2rem;
  letter-spacing: 0.04em;
}
.edu-duration {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--faint);
  margin-top: 0.5rem;
}

/* ============================================================
   CERTIFICATIONS / ACHIEVEMENTS
   ============================================================ */
#certifications { padding: clamp(2.75rem, 4.5vw, 3.75rem) 0; }

.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.2rem;
  margin-top: 1.75rem;
}
.cert-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}
.cert-card:hover {
  border-color: rgba(197, 22, 36, 0.2);
  transform: translateY(-3px);
}
.cert-icon {
  width: 46px;
  height: 46px;
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.12);
  border-radius: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}
.cert-issuer {
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}
.cert-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--white);
  line-height: 1.38;
  margin-bottom: 0.3rem;
  letter-spacing: -0.01em;
}
.cert-date { font-family: var(--mono); font-size: 0.7rem; color: var(--muted); }

/* ============================================================
   CONTACT
   ============================================================ */
#contact {
  padding: clamp(2.75rem, 4.5vw, 3.75rem) 0;
  background: var(--surface);
}

.contact-closing {
  text-align: center;
  margin-bottom: 2rem;
}
.contact-closing-line {
  font-family: var(--display);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.03em;
  margin-top: 1rem;
  line-height: 1.2;
}
.contact-closing-line .accent {
  color: var(--accent);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}
.contact-intro {
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: 0.5rem;
}
.contact-intro strong { color: var(--white); font-weight: 500; }
.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin-top: 1.75rem;
}
.contact-info-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.9rem 1.2rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--motion-fast), transform var(--motion-fast);
  text-decoration: none;
}
.contact-info-item:hover {
  border-color: rgba(197, 22, 36, 0.15);
  transform: translateX(4px);
}
.contact-info-icon {
  width: 38px;
  height: 38px;
  background: var(--crimson-subtle);
  border: 1px solid rgba(197, 22, 36, 0.1);
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  flex-shrink: 0;
}
.contact-info-label {
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.contact-info-value {
  font-size: 0.88rem;
  color: var(--white);
  font-weight: 500;
  margin-top: 0.1rem;
}

/* ── FORM ── */
.contact-form-wrap {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}
.contact-form-heading {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 1.5rem;
  letter-spacing: -0.01em;
}
.contact-form-group { margin-bottom: 1.25rem; }
.contact-form-label {
  display: block;
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.06em;
  margin-bottom: 0.45rem;
  text-transform: uppercase;
}
.contact-form-input,
.contact-form-textarea {
  width: 100%;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  color: var(--text);
  font-family: var(--sans);
  transition: border-color var(--motion-fast), box-shadow var(--motion-fast);
  outline: none;
}
.contact-form-input:focus,
.contact-form-textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(197, 22, 36, 0.1);
}
.contact-form-textarea {
  min-height: 120px;
  resize: vertical;
}
.contact-form-input::placeholder,
.contact-form-textarea::placeholder { color: var(--faint); }
.contact-form-btn {
  width: 100%;
  background: var(--accent);
  color: var(--white);
  border: none;
  padding: 0.88rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  transition: background var(--motion-fast), transform var(--motion-fast), box-shadow var(--motion-fast);
}
.contact-form-btn:hover {
  background: var(--accent-dim);
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(197, 22, 36, 0.3);
}
.contact-form-success {
  display: none;
  margin-top: 1rem;
  padding: 0.75rem;
  background: var(--green-dim);
  border: 1px solid rgba(34, 197, 94, 0.22);
  border-radius: var(--radius-sm);
  color: var(--green);
  font-size: 0.82rem;
  font-weight: 500;
  text-align: center;
}

/* ============================================================
   FOOTER
   ============================================================ */
footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 1;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.footer-copy { font-size: 0.76rem; color: var(--faint); }
.footer-links { display: flex; gap: 1.75rem; }
.footer-links a {
  font-size: 0.76rem;
  color: var(--faint);
  transition: color var(--motion-fast);
}
.footer-links a:hover { color: var(--accent); }
.footer-back-top {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--faint);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  transition: color var(--motion-fast);
}
.footer-back-top:hover { color: var(--accent); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
  .philosophy-principles { grid-template-columns: 1fr; gap: 1rem; }
  .about-highlights { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  /* Nav */
  .nav-links {
    display: none;
    position: fixed;
    top: 64px;
    left: 0; right: 0;
    background: rgba(5, 5, 5, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 1.75rem clamp(1.5rem, 5vw, 3rem);
    gap: 1.25rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-hamburger { display: flex; }

  /* Hero */
  #hero {
    padding-top: 80px;
    min-height: auto;
    padding-bottom: 3rem;
  }
  .hero-intro-pill {
    flex-wrap: wrap;
    justify-content: center;
    border-radius: var(--radius);
    padding: 0.45rem 0.8rem;
    gap: 0.5rem;
  }
  .hero-headline {
    font-size: clamp(2.2rem, 8vw, 3.5rem);
  }

  /* About */
  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  .about-photo-stack { max-width: 280px; margin: 0 auto; }
  .about-card-float { right: -0.5rem; bottom: -1rem; }
  .about-highlights { grid-template-columns: repeat(2, 1fr); margin-top: 1.75rem; }

  /* Projects */
  .projects-grid { grid-template-columns: 1fr; }
  .project-card.featured { grid-column: auto; display: flex; flex-direction: column; }

  /* Systems */
  .track-branch-bar { font-size: 0.68rem; gap: 0.3rem; }

  /* Education */
  .edu-card { grid-template-columns: 1fr; text-align: center; gap: 1.25rem; }
  .edu-stats { text-align: center; }

  /* Publication */
  .pub-card { grid-template-columns: 1fr; gap: 0.75rem; }

  /* Contact */
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }

  /* Footer */
  .footer-inner { flex-direction: column; text-align: center; gap: 1.25rem; }
}

@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
  .about-highlights { grid-template-columns: 1fr; }
  .hero-stats { gap: 1.5rem; flex-wrap: wrap; }
  .cert-grid { grid-template-columns: 1fr; }
  .metrics-grid { grid-template-columns: 1fr 1fr; }
}

/* ── REDUCED MOTION ── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .fade-up, .blur-in { opacity: 1 !important; transform: none !important; filter: none !important; }
  .philosophy-quote .word { opacity: 1 !important; transform: none !important; }
}