/* ============================================================
   CHANDEEPA VIDUSARA KUMARASIRI — PORTFOLIO DESIGN SYSTEM
   Role: Automation Engineer | IoT & Embedded Systems Specialist
   Theme: Precision Engineering Cyber-Industrial (Ultra-Vibrant, Crisp & 100% Responsive)
   Optimized for: Mobile, Foldable, Tablet, Laptop, Desktop & 4K Displays
   ============================================================ */

:root {
  --color-primary: #00A3C4;         /* Electric Cyan */
  --color-primary-dark: #077993;    /* Deep Technical Cyan */
  --color-primary-soft: #E0F2FE;    /* Luminous Ice Blue Tint */
  --color-primary-glow: rgba(0, 163, 196, 0.25);
  
  --color-navy: #0B1924;            /* Dark Cyber Slate Navy */
  --color-navy-card: #102434;       /* Elevated Navy Card */
  --color-gold: #F59E0B;            /* Warm Amber Gold / Award Accent */
  --color-emerald: #10B981;         /* Precision Emerald / Active Status */
  
  --color-ink: #0F172A;             /* Ultra High-Contrast Dark Slate */
  --color-slate: #334155;           /* Clear Secondary Body Text */
  --color-slate-light: #64748B;     /* Muted Meta Text */
  
  --color-bg: #F8FAFC;              /* Clean Technical Light Canvas */
  --color-surface: #FFFFFF;         /* Crisp White Cards */
  --color-surface-trans: rgba(255, 255, 255, 0.94);
  --color-border: #E2E8F0;          /* Clean Blueprint Border */
  --color-border-strong: #CBD5E1;   /* Technical Frame Border */
  --color-border-glow: rgba(0, 163, 196, 0.4);
  
  --color-success: #10B981;
  --color-danger: #EF4444;

  --font-display: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", Consolas, monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(11, 25, 36, 0.05), 0 1px 2px rgba(11, 25, 36, 0.03);
  --shadow-md: 0 10px 25px -5px rgba(11, 25, 36, 0.08), 0 8px 10px -6px rgba(11, 25, 36, 0.04);
  --shadow-lg: 0 20px 40px -10px rgba(11, 25, 36, 0.12), 0 10px 15px -5px rgba(11, 25, 36, 0.05);
  --shadow-glow: 0 0 25px rgba(0, 163, 196, 0.2);

  --content-width: 1220px;
  --header-height: 68px;
  --bottom-bar-height: 64px;
}

/* ---------------- GLOBAL RESET & FLUID BASE ---------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  background-image: radial-gradient(rgba(0, 163, 196, 0.06) 1px, transparent 1px), radial-gradient(rgba(11, 25, 36, 0.03) 1px, var(--color-bg) 1px);
  background-size: 24px 24px, 12px 12px;
  background-position: 0 0, 12px 12px;
  color: var(--color-ink);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* Subtle Animated Background Silhouette Rails (Desktop Only) */
.bg-rail {
  position: fixed;
  top: 0;
  bottom: 0;
  width: calc((100vw - var(--content-width)) / 2);
  min-width: 0;
  max-width: 320px;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
  opacity: 0.12;
  display: none;
}

@media (min-width: 1380px) {
  .bg-rail {
    display: block;
  }
}

.bg-rail.left {
  left: 0;
  background: url('../assets/img/bg-silhouette.png') no-repeat left center;
  background-size: contain;
  animation: railPulse 12s infinite alternate ease-in-out;
}

.bg-rail.right {
  right: 0;
  background: url('../assets/img/bg-circuit.svg') no-repeat right center;
  background-size: contain;
  animation: railPulse 14s infinite alternate-reverse ease-in-out;
}

@keyframes railPulse {
  0% { opacity: 0.08; transform: translateY(0); }
  50% { opacity: 0.16; }
  100% { opacity: 0.08; transform: translateY(15px); }
}

/* ---------------- IMAGE & MEDIA OPTIMIZATIONS ---------------- */
img, picture, video, iframe {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Smooth skeleton shimmer while images load */
.img-placeholder, .project-thumb, .vision-portrait-frame, .cover-photo-wrap, .profile-photo-frame {
  background-color: #0E1E2C;
  background-image: linear-gradient(90deg, #0E1E2C 0%, #162C3F 50%, #0E1E2C 100%);
  background-size: 200% 100%;
  animation: skeletonPulse 2s infinite ease-in-out;
}

@keyframes skeletonPulse {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  user-select: none;
  -webkit-user-select: none;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

ul {
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ---------------- TYPOGRAPHY HIERARCHY ---------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--color-navy);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  word-break: break-word;
}

h1 { font-size: clamp(1.4rem, 2.5vw + 0.8rem, 2.3rem); }
h2 { font-size: clamp(1.25rem, 2vw + 0.6rem, 1.95rem); }
h3 { font-size: clamp(1.1rem, 1.5vw + 0.5rem, 1.45rem); }
h4 { font-size: clamp(1rem, 1vw + 0.4rem, 1.2rem); }
h5 { font-size: 0.95rem; }

p {
  color: var(--color-slate);
  margin-bottom: 0.75rem;
  font-size: clamp(0.9rem, 0.5vw + 0.75rem, 1rem);
  line-height: 1.65;
}

p:last-child {
  margin-bottom: 0;
}

/* ---------------- LAYOUT & SHELL CONTAINERS ---------------- */
.shell {
  flex: 1;
  width: 100%;
  position: relative;
  z-index: 1;
  padding-bottom: 40px;
}

.container {
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 clamp(16px, 3vw, 28px);
}

.section {
  padding: clamp(28px, 4vw, 48px) 0;
  position: relative;
}

.section-alt {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: clamp(18px, 3vw, 28px);
  flex-wrap: wrap;
  gap: 16px;
}

.section-head > div {
  max-width: 680px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: clamp(0.72rem, 0.4vw + 0.6rem, 0.8rem);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  background: var(--color-primary);
  display: inline-block;
  border-radius: var(--radius-full);
}

/* ---------------- UNIVERSAL HEADER & NAVIGATION ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-surface-trans);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 1px 6px rgba(11, 25, 36, 0.05);
  transition: all 0.3s ease;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: 12px;
  position: relative;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(0.98rem, 1.2vw + 0.6rem, 1.15rem);
  color: var(--color-navy);
  white-space: nowrap;
  flex-shrink: 0;
}

.brand-badge {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  box-shadow: 0 4px 12px var(--color-primary-glow);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: nowrap;
}

.nav-link {
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-slate);
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-link:hover {
  color: var(--color-primary-dark);
  background: var(--color-primary-soft);
}

.nav-link.active {
  color: var(--color-primary-dark);
  background: var(--color-primary-soft);
  font-weight: 600;
  border: 1px solid rgba(0, 163, 196, 0.25);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.mobile-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-navy);
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.mobile-toggle:hover {
  background: var(--color-primary-soft);
  color: var(--color-primary-dark);
  border-color: var(--color-primary);
}

.mobile-toggle svg {
  transition: transform 0.3s ease;
}

.mobile-toggle.active svg {
  transform: rotate(90deg);
}

/* Navigation backdrop overlay for mobile */
.nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(11, 25, 36, 0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 990;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.nav-backdrop.open {
  opacity: 1;
  visibility: visible;
}

/* ---------------- PROFILE BANNER — FULLY FLUID & COMPACT ---------------- */
.profile-banner {
  margin-top: clamp(14px, 2vw, 24px);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.cover-photo-wrap {
  width: 100%;
  height: clamp(130px, 18vw, 195px);
  position: relative;
  background: var(--color-navy);
  overflow: hidden;
}

body:not([data-page="home"]) .cover-photo-wrap {
  height: clamp(90px, 12vw, 135px);
}

.cover-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  filter: brightness(0.96);
}

.profile-card-content {
  padding: 0 clamp(16px, 3vw, 30px) clamp(16px, 2.5vw, 24px) clamp(16px, 3vw, 30px);
  background: var(--color-surface);
  position: relative;
}

.profile-main-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-top: clamp(-45px, -6vw, -65px);
  flex-wrap: wrap;
}

.profile-identity-group {
  display: flex;
  align-items: flex-end;
  gap: clamp(12px, 2vw, 22px);
  flex: 1;
  min-width: min(100%, 280px);
}

.profile-photo-frame {
  width: clamp(84px, 14vw, 135px);
  height: clamp(84px, 14vw, 135px);
  border-radius: 50%;
  border: clamp(3px, 0.5vw, 4px) solid var(--color-surface);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  background: var(--color-surface);
  overflow: hidden;
  position: relative;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1 / 1;
}

.profile-photo-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
}

.status-indicator {
  position: absolute;
  bottom: 6px;
  right: 6px;
  width: clamp(12px, 2vw, 16px);
  height: clamp(12px, 2vw, 16px);
  background: var(--color-emerald);
  border: 2.5px solid var(--color-surface);
  border-radius: 50%;
  box-shadow: 0 0 8px rgba(16, 185, 129, 0.7);
}

.profile-text-block {
  padding-bottom: 4px;
  flex: 1;
}

.profile-text-block h1 {
  font-size: clamp(1.2rem, 2vw + 0.6rem, 1.7rem);
  color: var(--color-ink);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 2px;
}

.verified-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: clamp(0.68rem, 0.4vw + 0.55rem, 0.74rem);
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--color-primary-dark);
  background: var(--color-primary-soft);
  padding: 3px 8px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(0, 163, 196, 0.3);
  white-space: nowrap;
}

.profile-subtitle {
  font-size: clamp(0.85rem, 0.6vw + 0.6rem, 0.98rem);
  color: var(--color-navy);
  font-weight: 600;
  margin-bottom: 2px;
}

.profile-role-company {
  font-size: clamp(0.8rem, 0.5vw + 0.6rem, 0.9rem);
  color: var(--color-slate);
  margin-bottom: 2px;
}

.profile-location {
  font-size: clamp(0.78rem, 0.4vw + 0.6rem, 0.86rem);
  color: var(--color-slate-light);
  display: flex;
  align-items: center;
  gap: 5px;
}

.profile-cta-group {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 6px;
  flex-shrink: 0;
  flex-wrap: wrap;
}

/* ---------------- BUTTON SYSTEM ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 9px 18px;
  min-height: 40px;
  border-radius: 10px;
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-sm);
  white-space: nowrap;
  touch-action: manipulation;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #FFFFFF;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px var(--color-primary-glow);
}

.btn-secondary {
  background: var(--color-navy);
  color: #FFFFFF;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
  background: #142838;
  transform: translateY(-2px);
}

.btn-ghost {
  background: var(--color-surface);
  color: var(--color-ink);
  border: 1px solid var(--color-border-strong);
}

.btn-ghost:hover {
  background: var(--color-bg);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}

.btn-linkedin {
  background: #0A66C2;
  color: #FFFFFF;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-linkedin:hover {
  background: #084E96;
  transform: translateY(-2px);
}

.btn-sm {
  padding: 6px 14px;
  min-height: 34px;
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
}

.btn-block {
  width: 100%;
}

/* ---------------- HERO & METRICS GRID ---------------- */
.hero-layout {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: clamp(16px, 2.5vw, 24px);
  margin-top: clamp(16px, 2.5vw, 24px);
  align-items: stretch;
}

.hero-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 30px);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.hero-card h2 {
  margin: 8px 0 12px 0;
  font-size: clamp(1.3rem, 1.8vw + 0.6rem, 1.75rem);
}

.hero-lede {
  font-size: clamp(0.92rem, 0.4vw + 0.75rem, 1rem);
  line-height: 1.7;
  color: var(--color-slate);
  margin-bottom: 20px;
}

.stats-card {
  background: linear-gradient(135deg, #0284C7 0%, #0F6E8C 60%, #084C5E 100%);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 28px);
  color: #FFFFFF;
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  box-shadow: 0 10px 30px rgba(2, 132, 199, 0.25);
  position: relative;
  overflow: hidden;
}

.stats-card::after {
  content: "";
  position: absolute;
  top: -40%;
  right: -40%;
  width: 90%;
  height: 90%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.2) 0%, transparent 70%);
  pointer-events: none;
}

.stat-item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding: 10px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.stat-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.stat-label {
  font-size: clamp(0.82rem, 0.3vw + 0.7rem, 0.9rem);
  color: #E0F2FE;
  font-weight: 500;
}

.stat-num {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 1.2vw + 0.8rem, 1.6rem);
  font-weight: 700;
  color: #FFFFFF;
  text-shadow: 0 2px 8px rgba(0,0,0,0.2);
  white-space: nowrap;
}

/* ---------------- PHILOSOPHY & VISION ---------------- */
.vision-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: clamp(20px, 3vw, 32px);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3.5vw, 36px);
  box-shadow: var(--shadow-sm);
  align-items: center;
}

.vision-portrait-frame {
  width: 100%;
  height: clamp(240px, 30vw, 330px);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-md), 0 0 20px var(--color-primary-glow);
  position: relative;
  aspect-ratio: 4 / 3;
}

.vision-portrait-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
}

/* ---------------- RESPONSIVE CARD GRID & PROJECT CARDS ---------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 330px), 1fr));
  gap: clamp(16px, 2.5vw, 24px);
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease, border-color 0.3s ease;
  position: relative;
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border-color: var(--color-primary);
}

.project-thumb {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--color-navy);
  position: relative;
  overflow: hidden;
}

.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.project-card:hover .project-thumb img {
  transform: scale(1.05);
}

.project-badge-tag {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(11, 25, 36, 0.9);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--color-primary-soft);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(0, 163, 196, 0.4);
}

.project-body {
  padding: clamp(16px, 2.5vw, 22px);
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.project-body h3 {
  font-size: clamp(1.1rem, 1vw + 0.5rem, 1.25rem);
  margin-bottom: 8px;
  color: var(--color-navy);
}

.project-body p {
  font-size: 0.9rem;
  color: var(--color-slate);
  margin-bottom: 14px;
  line-height: 1.6;
}

.tech-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}

.tech-chip {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  background: var(--color-primary-soft);
  color: var(--color-primary-dark);
  padding: 3px 8px;
  border-radius: 6px;
  font-weight: 500;
}

/* ---------------- CATEGORY & FILTER TABS (SWIPEABLE ON MOBILE) ---------------- */
.filter-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(18px, 3vw, 24px);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding: 4px 2px 10px 2px;
  scroll-snap-type: x mandatory;
}

.filter-tabs::-webkit-scrollbar {
  display: none;
}

.filter-tab-btn {
  padding: 8px 16px;
  min-height: 40px;
  border-radius: var(--radius-full);
  font-size: 0.86rem;
  font-weight: 600;
  background: var(--color-surface);
  color: var(--color-slate);
  border: 1px solid var(--color-border-strong);
  white-space: nowrap;
  flex-shrink: 0;
  scroll-snap-align: start;
  transition: all 0.2s ease;
  touch-action: manipulation;
}

.filter-tab-btn:hover {
  background: var(--color-bg);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}

.filter-tab-btn.active {
  background: var(--color-navy);
  color: #FFFFFF;
  border-color: var(--color-navy);
  box-shadow: 0 4px 12px rgba(11, 25, 36, 0.15);
}

/* ---------------- QUALIFICATIONS TIMELINE ---------------- */
.timeline-list {
  display: flex;
  flex-direction: column;
  gap: clamp(16px, 2.5vw, 22px);
}

.tl-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 26px);
  box-shadow: var(--shadow-sm);
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: clamp(16px, 2.5vw, 24px);
  position: relative;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.tl-item:hover {
  border-color: var(--color-primary);
}

.tl-meta {
  border-right: 1px solid var(--color-border);
  padding-right: 18px;
}

.tl-period {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 6px;
}

.tl-org {
  font-size: 0.88rem;
  color: var(--color-slate);
  font-weight: 500;
}

.tl-content h4 {
  font-size: clamp(1.05rem, 1vw + 0.5rem, 1.22rem);
  color: var(--color-navy);
  margin-bottom: 8px;
}

.tl-desc {
  font-size: 0.92rem;
  color: var(--color-slate);
  line-height: 1.65;
  margin-bottom: 14px;
}

.credential-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px dashed var(--color-border);
  flex-wrap: wrap;
}

.credential-id-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: #F1F5F9;
  padding: 4px 8px;
  border-radius: 6px;
  color: var(--color-navy);
  border: 1px solid var(--color-border-strong);
}

/* ---------------- SKILLS & PROOF-OF-WORK ---------------- */
.skills-domain-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 26px);
  box-shadow: var(--shadow-sm);
  margin-bottom: clamp(16px, 2.5vw, 22px);
}

.skills-domain-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 12px;
}

.skills-domain-head h3 {
  font-size: clamp(1.1rem, 1vw + 0.5rem, 1.3rem);
  color: var(--color-navy);
}

.proof-of-work-box {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: clamp(12px, 2vw, 16px);
  margin-top: 16px;
  border-left: 4px solid var(--color-primary);
}

.proof-of-work-box h5 {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary-dark);
  margin-bottom: 6px;
}

/* ---------------- RESEARCH & PUBLICATIONS ---------------- */
.research-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 28px);
  box-shadow: var(--shadow-sm);
  margin-bottom: clamp(16px, 2.5vw, 22px);
  position: relative;
  transition: all 0.3s ease;
}

.research-card:hover {
  border-color: var(--color-gold);
  box-shadow: 0 10px 30px rgba(245, 158, 11, 0.08);
}

.award-ribbon {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #FEF3C7;
  color: #92400E;
  font-weight: 700;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  border: 1px solid #FDE68A;
}

.research-abstract {
  background: #F8FAFC;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: clamp(12px, 2vw, 16px);
  margin: 14px 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--color-slate);
}

/* ---------------- CERTIFICATE MODAL VIEWER ---------------- */
.cert-protect-shield {
  position: relative;
  user-select: none;
  -webkit-user-select: none;
}

.cert-watermark-overlay {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(11, 25, 36, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 6px;
  pointer-events: none;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(11, 25, 36, 0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(12px, 3vw, 24px);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.modal-backdrop.open {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  max-width: min(100%, 740px);
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  box-shadow: var(--shadow-lg);
  transform: scale(0.96);
  transition: transform 0.3s ease;
}

.modal-backdrop.open .modal-content {
  transform: scale(1);
}

.modal-head {
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-body {
  padding: clamp(14px, 2.5vw, 20px);
}

/* ---------------- CONTACT FORM ---------------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.35fr;
  gap: clamp(20px, 3vw, 32px);
}

.contact-info-card {
  background: var(--color-navy);
  color: #FFFFFF;
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 32px);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.contact-info-card h3 {
  color: #FFFFFF;
  margin-bottom: 12px;
}

.contact-info-card p {
  color: #94A3B8;
  margin-bottom: 18px;
}

.contact-channels {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.contact-channel-item {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #E2E8F0;
  font-size: 0.92rem;
}

.contact-channel-item svg {
  color: var(--color-primary);
  flex-shrink: 0;
}

.contact-form-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 32px);
  box-shadow: var(--shadow-sm);
}

.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--color-navy);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 12px 14px;
  border-radius: 9px;
  border: 1px solid var(--color-border-strong);
  font-family: inherit;
  font-size: 1rem; /* 16px to avoid Safari iOS auto zoom */
  color: var(--color-ink);
  background: var(--color-bg);
  transition: all 0.2s ease;
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  background: #FFFFFF;
  box-shadow: 0 0 0 4px var(--color-primary-soft);
}

/* ---------------- FOOTER ---------------- */
.site-footer {
  background: var(--color-navy);
  color: #94A3B8;
  padding: clamp(32px, 4vw, 48px) 0 clamp(20px, 3vw, 26px) 0;
  margin-top: auto;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: clamp(20px, 3vw, 32px);
  padding-bottom: clamp(24px, 3vw, 32px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand h4 {
  color: #FFFFFF;
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.footer-brand p {
  color: #94A3B8;
  max-width: 440px;
  font-size: 0.88rem;
}

.footer-links-col h5 {
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-nav a {
  color: #94A3B8;
  font-size: 0.88rem;
  padding: 3px 0;
}

.footer-nav a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  padding-top: 22px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------------- TOAST SYSTEM ---------------- */
.toast-container {
  position: fixed;
  bottom: clamp(16px, 3vw, 24px);
  right: clamp(16px, 3vw, 24px);
  z-index: 3000;
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: min(100% - 32px, 380px);
}

.toast {
  background: var(--color-navy);
  color: #FFFFFF;
  padding: 12px 18px;
  border-radius: 9px;
  font-size: 0.88rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  border-left: 4px solid var(--color-primary);
  animation: slideInToast 0.3s ease;
}

.toast.success { border-left-color: var(--color-success); }
.toast.danger { border-left-color: var(--color-danger); }

@keyframes slideInToast {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ---------------- MOBILE FLOATING QUICK-NAV BAR ---------------- */
.mobile-quick-nav {
  display: none;
}

@media (max-width: 768px) {
  body {
    padding-bottom: calc(var(--bottom-bar-height) + env(safe-area-inset-bottom, 12px));
  }

  .mobile-quick-nav {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 950;
    height: var(--bottom-bar-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid var(--color-border);
    box-shadow: 0 -4px 16px rgba(11, 25, 36, 0.08);
    align-items: center;
    justify-content: space-around;
    padding: 0 8px;
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }

  .quick-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--color-slate);
    padding: 4px 8px;
    border-radius: 8px;
    flex: 1;
    text-align: center;
    transition: all 0.2s ease;
  }

  .quick-nav-item svg {
    width: 20px;
    height: 20px;
  }

  .quick-nav-item.active {
    color: var(--color-primary-dark);
  }

  .quick-nav-item.active svg {
    color: var(--color-primary);
  }
}

/* ---------------- ADMIN DASHBOARD STYLES ---------------- */
.admin-shell {
  padding-bottom: 60px;
}

.admin-tabs {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding-bottom: 12px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
  scroll-snap-type: x mandatory;
}

.admin-tabs::-webkit-scrollbar {
  display: none;
}

.admin-tab-btn {
  padding: 9px 18px;
  min-height: 42px;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  background: var(--color-surface);
  color: var(--color-slate);
  border: 1px solid var(--color-border-strong);
  white-space: nowrap;
  flex-shrink: 0;
  scroll-snap-align: start;
}

.admin-tab-btn.active {
  background: var(--color-navy);
  color: #FFFFFF;
  border-color: var(--color-navy);
}

.admin-panel {
  display: none;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 32px);
  box-shadow: var(--shadow-sm);
}

.admin-panel.show {
  display: block;
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   RESPONSIVE BREAKPOINTS: DESKTOP -> LAPTOP -> TABLET -> MOBILE
   ============================================================ */

/* 1. Large Laptops & Tablets Landscape (<= 1100px) */
@media (max-width: 1100px) {
  .nav-link {
    padding: 6px 9px;
    font-size: 0.84rem;
  }
  .nav-wrap {
    gap: 8px;
  }
}

/* 2. Tablets & Small Laptops (<= 992px) */
@media (max-width: 992px) {
  .hero-layout, .vision-grid {
    grid-template-columns: 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .tl-item {
    grid-template-columns: 1fr;
  }
  .tl-meta {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    padding-right: 0;
    padding-bottom: 12px;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
  .nav-link {
    font-size: 0.82rem;
    padding: 6px 8px;
  }
}

/* 3. Mobile Devices & Portrait Tablets (<= 860px) */
@media (max-width: 860px) {
  :root {
    --header-height: 60px;
  }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 20px 24px;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    box-shadow: var(--shadow-lg);
    z-index: 999;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: all 0.25s ease;
  }

  .nav-links.open {
    display: flex;
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    font-size: 1rem;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: var(--color-bg);
  }

  .nav-link.active {
    background: var(--color-primary-soft);
    border-color: var(--color-primary);
  }

  .mobile-toggle {
    display: flex;
  }

  .profile-main-row {
    margin-top: -45px;
    flex-direction: column;
    align-items: flex-start;
  }

  .profile-identity-group {
    width: 100%;
  }

  .profile-cta-group {
    width: 100%;
    margin-top: 10px;
  }

  .profile-cta-group .btn {
    flex: 1;
    min-width: 140px;
  }
}

/* 4. Small Mobile Phones (<= 480px) */
@media (max-width: 480px) {
  .container {
    padding: 0 14px;
  }

  .brand-logo span {
    font-size: 0.95rem;
  }

  .brand-badge {
    width: 32px;
    height: 32px;
    font-size: 0.85rem;
  }

  .nav-actions .btn {
    display: none;
  }

  .profile-photo-frame {
    width: 80px;
    height: 80px;
  }

  .profile-main-row {
    margin-top: -38px;
  }

  .profile-identity-group {
    gap: 12px;
  }

  .profile-text-block h1 {
    font-size: 1.25rem;
  }

  .verified-badge {
    font-size: 0.68rem;
  }

  .footer-top {
    grid-template-columns: 1fr;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .hero-card, .stats-card, .vision-grid, .contact-info-card, .contact-form-card {
    padding: 18px 16px;
  }

  .tl-item, .skills-domain-card, .research-card {
    padding: 18px 14px;
  }

  .profile-cta-group {
    flex-direction: column;
  }

  .profile-cta-group .btn {
    width: 100%;
  }

  .stat-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}