/* 
  =========================================
  MEESALA SAI KIRAN - BIM ENGINEER PORTFOLIO
  DESIGN SYSTEM & STYLESHEET (VANILLA CSS)
  =========================================
*/

/* 1. Imports & Core Variables */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
  /* Color Palette (HSL Tailored Colors) */
  --bg-deep: hsl(222, 47%, 6%);       /* Deep Slate Midnight */
  --bg-surface: hsl(222, 44%, 11%);    /* Dark Surface Panel */
  --bg-card: hsl(222, 40%, 15%);       /* Glass Card Fill */
  --border-glow: hsla(186, 100%, 50%, 0.15); /* Tech Cyan Translucent */
  --border-muted: hsla(217, 30%, 30%, 0.4);   /* Soft Dark Border */

  /* Accents based on BIM/MEPF disciplines */
  --accent-mep: #10b981;              /* HVAC & Piping Green */
  --accent-elec: #00f0ff;             /* Electrical & Telecom Cyan */
  --accent-struct: #f97316;           /* Structural & Firefighting Orange */
  --accent-arch: #a855f7;             /* Architectural Purple */
  
  --text-primary: hsl(210, 40%, 98%);
  --text-secondary: hsl(215, 20%, 75%);
  --text-muted: hsl(215, 16%, 50%);

  /* Blur & Shadow systems */
  --glass-backdrop: blur(16px) saturate(180%);
  --shadow-neon-cyan: 0 0 15px rgba(0, 240, 255, 0.2);
  --shadow-neon-orange: 0 0 15px rgba(249, 115, 22, 0.2);
  --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.37);

  /* Layout and sizing */
  --container-max: 1200px;
  --transition-smooth: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
  --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 2. Global Reset & Blueprint Background */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* CAD Grid Background Layer */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-size: 40px 40px;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.015) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.015) 1px, transparent 1px);
  z-index: -2;
  pointer-events: none;
}

/* Glowing Radials for Depth */
body::after {
  content: "";
  position: fixed;
  top: -20%;
  left: -20%;
  width: 140vw;
  height: 140vh;
  background: 
    radial-gradient(circle at 20% 20%, rgba(0, 240, 255, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 80% 80%, rgba(249, 115, 22, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(16, 185, 129, 0.03) 0%, transparent 50%);
  z-index: -1;
  pointer-events: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition-fast);
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  transition: var(--transition-smooth);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-deep);
}
::-webkit-scrollbar-thumb {
  background: var(--bg-card);
  border-radius: 4px;
  border: 2px solid var(--bg-deep);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent-elec);
}

/* Typography Utility */
.gradient-text {
  background: linear-gradient(135deg, var(--accent-elec) 0%, var(--accent-mep) 50%, var(--accent-struct) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 3. Header & Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background-color: rgba(7, 11, 19, 0.7);
  backdrop-filter: var(--glass-backdrop);
  -webkit-backdrop-filter: var(--glass-backdrop);
  border-bottom: 1px solid var(--border-muted);
  transition: var(--transition-smooth);
}

.header--scrolled {
  background-color: rgba(7, 11, 19, 0.85);
  box-shadow: var(--shadow-glass);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 1.25rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  font-family: 'Outfit', sans-serif;
  color: var(--text-primary);
}

.logo span {
  color: var(--accent-elec);
  font-weight: 800;
}

.logo-icon {
  width: 24px;
  height: 24px;
  stroke: var(--accent-elec);
  stroke-width: 2;
  fill: none;
  animation: logo-spin 6s linear infinite;
}

@keyframes logo-spin {
  100% { transform: rotate(360deg); }
}

.nav-menu {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-secondary);
  position: relative;
  padding: 0.25rem 0;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(to right, var(--accent-elec), var(--accent-mep));
  transition: var(--transition-smooth);
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-cta {
  padding: 0.6rem 1.25rem;
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.1), rgba(16, 185, 129, 0.1));
  border: 1px solid var(--accent-elec);
  border-radius: 4px;
  color: var(--accent-elec);
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: var(--shadow-neon-cyan);
}

.nav-cta:hover {
  background: linear-gradient(135deg, var(--accent-elec), var(--accent-mep));
  color: var(--bg-deep);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.4);
  transform: translateY(-2px);
}

.scroll-indicator-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(to right, var(--accent-elec), var(--accent-mep), var(--accent-struct));
  width: 0%;
  transition: width 0.1s ease-out;
}

/* 4. Hero Section & Technical Title */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 8rem 2rem 4rem;
  position: relative;
  z-index: 1;
}

.hero-container {
  max-width: var(--container-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 4rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(12, 19, 34, 0.6);
  border: 1px solid var(--border-muted);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--accent-elec);
  margin-bottom: 1.5rem;
  backdrop-filter: var(--glass-backdrop);
}

.hero-badge::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-mep);
  box-shadow: 0 0 8px var(--accent-mep);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.btn-primary {
  padding: 0.85rem 2rem;
  background: linear-gradient(135deg, var(--accent-elec), var(--accent-mep));
  color: var(--bg-deep);
  border-radius: 4px;
  font-weight: 700;
  font-size: 1rem;
  box-shadow: var(--shadow-neon-cyan);
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 0 25px rgba(0, 240, 255, 0.5);
}

.btn-secondary {
  padding: 0.85rem 2rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-muted);
  color: var(--text-primary);
  border-radius: 4px;
  font-weight: 600;
  font-size: 1rem;
  backdrop-filter: var(--glass-backdrop);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--text-primary);
  transform: translateY(-3px);
}

/* 3D Visual Mesh Mockup in Hero */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.technical-hud {
  width: 100%;
  max-width: 400px;
  height: 400px;
  position: relative;
  background: rgba(12, 19, 34, 0.4);
  border: 1px dashed rgba(0, 240, 255, 0.3);
  border-radius: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  backdrop-filter: var(--glass-backdrop);
  overflow: hidden;
  box-shadow: var(--shadow-glass);
}

.technical-hud::before {
  content: "";
  position: absolute;
  width: 150%;
  height: 150%;
  background-image: 
    radial-gradient(circle, transparent 35%, var(--bg-deep) 70%),
    linear-gradient(to right, rgba(0, 240, 255, 0.08) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 240, 255, 0.08) 1px, transparent 1px);
  background-size: 20px 20px;
  animation: grid-drift 20s linear infinite;
}

@keyframes grid-drift {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.hud-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(0, 240, 255, 0.1);
  display: flex;
  justify-content: center;
  align-items: center;
}

.hud-ring-1 {
  width: 280px;
  height: 280px;
  border: 2px dashed rgba(16, 185, 129, 0.2);
  animation: spin-clockwise 25s linear infinite;
}

.hud-ring-2 {
  width: 200px;
  height: 200px;
  border: 1px solid rgba(249, 115, 22, 0.3);
  border-top-color: transparent;
  border-bottom-color: transparent;
  animation: spin-counter 15s linear infinite;
}

.hud-ring-3 {
  width: 120px;
  height: 120px;
  border: 3px double rgba(0, 240, 255, 0.4);
  border-left-color: transparent;
  border-right-color: transparent;
  animation: spin-clockwise 8s linear infinite;
}

.hud-core {
  width: 60px;
  height: 60px;
  background: radial-gradient(circle, var(--accent-elec) 20%, transparent 70%);
  border-radius: 50%;
  box-shadow: var(--shadow-neon-cyan);
  z-index: 2;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hud-core svg {
  width: 24px;
  height: 24px;
  stroke: var(--bg-deep);
  stroke-width: 2.5;
  fill: none;
}

@keyframes spin-clockwise {
  100% { transform: rotate(360deg); }
}

@keyframes spin-counter {
  100% { transform: rotate(-360deg); }
}

/* 5. Section Layouts */
.section {
  padding: 7rem 2rem;
  max-width: var(--container-max);
  margin: 0 auto;
  position: relative;
}

.section-header {
  margin-bottom: 4rem;
  text-align: center;
}

.section-subtitle {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-elec);
  letter-spacing: 0.15em;
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 800;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(to right, var(--accent-elec), var(--accent-mep));
  border-radius: 2px;
}

/* 6. Profile / About Card */
.profile-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  align-items: center;
}

.about-card {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 2.5rem;
  backdrop-filter: var(--glass-backdrop);
  box-shadow: var(--shadow-glass);
}

.about-text {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.quick-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}

.stat-item {
  background: rgba(255, 255, 255, 0.02);
  border-left: 3px solid var(--accent-mep);
  padding: 1rem 1.25rem;
  border-radius: 0 6px 6px 0;
}

.stat-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  font-family: 'Outfit', sans-serif;
  line-height: 1.2;
}

.stat-num span {
  color: var(--accent-mep);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
}

/* Interactive Contact Fast List */
.quick-info-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.quick-info-item {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.quick-info-icon {
  width: 44px;
  height: 44px;
  background: rgba(0, 240, 255, 0.05);
  border: 1px solid rgba(0, 240, 255, 0.15);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-shrink: 0;
}

.quick-info-icon svg {
  width: 20px;
  height: 20px;
  stroke: var(--accent-elec);
  stroke-width: 2;
  fill: none;
}

.quick-info-text span {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.quick-info-text a,
.quick-info-text p {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
}

.quick-info-text a:hover {
  color: var(--accent-elec);
}

/* 7. Interactive Revit Viewport Simulator */
.viewport-wrapper {
  background: rgba(12, 19, 34, 0.65);
  border: 1px solid var(--border-muted);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-glass);
  margin-top: 2rem;
}

.viewport-toolbar {
  background: rgba(7, 11, 19, 0.8);
  border-bottom: 1px solid var(--border-muted);
  padding: 0.75rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.viewport-title {
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.viewport-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-elec);
  box-shadow: 0 0 6px var(--accent-elec);
}

.layer-controls {
  display: flex;
  gap: 0.5rem;
}

.layer-btn {
  padding: 0.4rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
}

.layer-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.layer-btn.active {
  color: var(--bg-deep);
  border-color: transparent;
  font-weight: 700;
}

.layer-btn[data-layer="arch"].active { background-color: var(--accent-arch); }
.layer-btn[data-layer="struct"].active { background-color: var(--accent-struct); }
.layer-btn[data-layer="mep"].active { background-color: var(--accent-mep); }
.layer-btn[data-layer="all"].active { background-color: var(--accent-elec); }

.viewport-canvas {
  height: 480px;
  position: relative;
  overflow: hidden;
  background-color: #05070a;
}

/* Grid overlay inside viewport */
.viewport-grid {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: 30px 30px;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.01) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.01) 1px, transparent 1px);
  z-index: 1;
}

.viewport-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity 0.5s ease;
  z-index: 2;
  filter: saturate(1.2) contrast(1.1);
}

.viewport-image.active {
  opacity: 1;
}

/* Simulated CAD heads-up displays overlays */
.viewport-overlay {
  position: absolute;
  bottom: 1.5rem;
  left: 1.5rem;
  background: rgba(7, 11, 19, 0.85);
  border: 1px solid var(--border-muted);
  border-radius: 6px;
  padding: 1rem;
  z-index: 5;
  backdrop-filter: var(--glass-backdrop);
  max-width: 320px;
}

.viewport-overlay h4 {
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.viewport-overlay p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.viewport-scale {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  background: rgba(7, 11, 19, 0.85);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  padding: 0.25rem 0.75rem;
  font-family: monospace;
  font-size: 0.75rem;
  color: var(--accent-elec);
  z-index: 5;
}

/* 8. Skills Section */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.skill-category {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 2rem;
  backdrop-filter: var(--glass-backdrop);
  transition: var(--transition-smooth);
}

.skill-category:hover {
  border-color: var(--accent-elec);
  transform: translateY(-5px);
  box-shadow: var(--shadow-neon-cyan);
}

.skill-cat-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 0.75rem;
}

.skill-cat-icon {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  background: rgba(0, 240, 255, 0.05);
  display: flex;
  justify-content: center;
  align-items: center;
}

.skill-cat-icon svg {
  width: 20px;
  height: 20px;
  stroke: var(--accent-elec);
  stroke-width: 2;
  fill: none;
}

.skill-cat-header h3 {
  font-size: 1.25rem;
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.skill-item {
  position: relative;
}

.skill-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.skill-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.skill-level {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-mep);
}

.skill-progress-bg {
  height: 6px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 3px;
  overflow: hidden;
}

.skill-progress-bar {
  height: 100%;
  border-radius: 3px;
  width: 0%; /* Populated by JS on scroll trigger */
  transition: width 1.5s cubic-bezier(0.1, 0.8, 0.2, 1);
}

/* Progress bar colors */
.skill-category:nth-child(1) .skill-progress-bar { background: var(--accent-elec); }
.skill-category:nth-child(2) .skill-progress-bar { background: var(--accent-mep); }
.skill-category:nth-child(3) .skill-progress-bar { background: var(--accent-struct); }

/* Custom extra-skills tags box */
.extra-skills {
  margin-top: 3rem;
  background: rgba(12, 19, 34, 0.2);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.extra-skills-title {
  font-size: 1rem;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.1em;
}

.tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.tag-skill {
  padding: 0.4rem 1rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.tag-skill:hover {
  background: rgba(0, 240, 255, 0.05);
  border-color: var(--accent-elec);
  color: var(--accent-elec);
}

/* 9. Experience Timeline */
.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  left: 31px;
  width: 2px;
  height: 100%;
  background: linear-gradient(to bottom, var(--accent-elec), var(--accent-mep), transparent);
}

.timeline-item {
  position: relative;
  padding-left: 5rem;
  margin-bottom: 4rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-node {
  position: absolute;
  top: 0;
  left: 16px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--bg-deep);
  border: 2px solid var(--accent-elec);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2;
  box-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
}

.timeline-node svg {
  width: 14px;
  height: 14px;
  stroke: var(--accent-elec);
  stroke-width: 2.5;
  fill: none;
}

.timeline-item:nth-child(2) .timeline-node { border-color: var(--accent-mep); }
.timeline-item:nth-child(2) .timeline-node svg { stroke: var(--accent-mep); }
.timeline-item:nth-child(3) .timeline-node { border-color: var(--accent-struct); }
.timeline-item:nth-child(3) .timeline-node svg { stroke: var(--accent-struct); }

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.timeline-role {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
}

.timeline-company {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent-elec);
}

.timeline-item:nth-child(2) .timeline-company { color: var(--accent-mep); }
.timeline-item:nth-child(3) .timeline-company { color: var(--accent-struct); }

.timeline-date {
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.35rem 0.85rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  color: var(--text-secondary);
}

.timeline-body {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 2rem;
  backdrop-filter: var(--glass-backdrop);
}

.timeline-projects-title {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1rem;
  letter-spacing: 0.05em;
}

.timeline-project-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  list-style: none;
}

.timeline-project-item {
  position: relative;
  padding-left: 1.5rem;
}

.timeline-project-item::before {
  content: "↳";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent-elec);
  font-weight: 700;
}

.timeline-item:nth-child(2) .timeline-project-item::before { color: var(--accent-mep); }
.timeline-item:nth-child(3) .timeline-project-item::before { color: var(--accent-struct); }

.timeline-project-item strong {
  color: var(--text-primary);
}

.timeline-project-item p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

/* 10. Filterable Project Catalog */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.6rem 1.25rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
}

.filter-btn:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
}

.filter-btn.active {
  background: linear-gradient(135deg, var(--accent-elec), var(--accent-mep));
  color: var(--bg-deep);
  border-color: transparent;
  font-weight: 700;
  box-shadow: var(--shadow-neon-cyan);
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 2.5rem;
}

.project-card {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 10px;
  overflow: hidden;
  backdrop-filter: var(--glass-backdrop);
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent-mep);
  box-shadow: 0 10px 30px rgba(16, 185, 129, 0.15);
}

.project-img-wrapper {
  position: relative;
  height: 200px;
  overflow: hidden;
  background-color: #000;
}

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

.project-card:hover .project-img {
  transform: scale(1.08);
}

.project-badges {
  position: absolute;
  top: 1rem;
  left: 1rem;
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.badge {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.35rem 0.75rem;
  border-radius: 4px;
  color: var(--bg-deep);
}

.badge-lod350 { background-color: var(--accent-elec); color: var(--bg-deep); }
.badge-lod400 { background-color: var(--accent-mep); color: var(--bg-deep); }
.badge-other { background-color: var(--text-secondary); color: var(--bg-deep); }

.project-meta-badge {
  position: absolute;
  bottom: 1rem;
  right: 1rem;
  background: rgba(7, 11, 19, 0.85);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  padding: 0.25rem 0.6rem;
  font-size: 0.75rem;
  font-family: monospace;
  color: var(--accent-elec);
}

.project-info {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-title {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.project-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  color: var(--text-muted);
}

/* 11. Contact Form & Footer */
.contact-container {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 4rem;
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.contact-card {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 2.5rem;
  backdrop-filter: var(--glass-backdrop);
}

.contact-form-panel {
  background: rgba(12, 19, 34, 0.4);
  border: 1px solid var(--border-muted);
  border-radius: 8px;
  padding: 2.5rem;
  backdrop-filter: var(--glass-backdrop);
  position: relative;
  overflow: hidden;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  letter-spacing: 0.05em;
}

.form-input {
  width: 100%;
  padding: 0.85rem 1rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-muted);
  border-radius: 4px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

.form-input:focus {
  outline: none;
  background: rgba(255, 255, 255, 0.04);
  border-color: var(--accent-elec);
  box-shadow: 0 0 10px rgba(0, 240, 255, 0.15);
}

textarea.form-input {
  min-height: 150px;
  resize: vertical;
}

.form-submit-btn {
  width: 100%;
  padding: 1rem;
  background: linear-gradient(135deg, var(--accent-elec), var(--accent-mep));
  color: var(--bg-deep);
  border-radius: 4px;
  font-weight: 700;
  font-size: 1rem;
  box-shadow: var(--shadow-neon-cyan);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.75rem;
}

.form-submit-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 25px rgba(0, 240, 255, 0.4);
}

/* Success notification overlay on form */
.form-success-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem;
  z-index: 10;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s ease;
}

.form-success-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.success-icon-box {
  width: 72px;
  height: 72px;
  background: rgba(16, 185, 129, 0.1);
  border: 2px solid var(--accent-mep);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 1.5rem;
}

.success-icon-box svg {
  width: 36px;
  height: 36px;
  stroke: var(--accent-mep);
  stroke-width: 2.5;
  fill: none;
}

/* 12. Footer */
.footer {
  background-color: #05070a;
  border-top: 1px solid var(--border-muted);
  padding: 4rem 2rem 2rem;
  position: relative;
  z-index: 1;
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 3rem;
}

.footer-nav {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.footer-nav-link {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-nav-link:hover {
  color: var(--accent-elec);
}

.footer-divider {
  max-width: var(--container-max);
  margin: 0 auto;
  border: 0;
  height: 1px;
  background: rgba(255, 255, 255, 0.05);
  margin-bottom: 2rem;
}

.footer-bottom {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-copy {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-copy span {
  color: var(--accent-struct);
}

/* 13. Scroll Animation Triggers */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* 14. Responsive Breakpoints */
@media (max-width: 992px) {
  .hero-container {
    grid-template-columns: 1fr;
    gap: 3rem;
    text-align: center;
  }
  .hero-badge {
    justify-content: center;
  }
  .hero-subtitle {
    margin: 0 auto 2rem;
  }
  .hero-actions {
    justify-content: center;
  }
  .profile-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .contact-container {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none; /* Can add a simplified hamburger menu or hide it for a sleek profile layout */
  }
  .timeline::before {
    left: 20px;
  }
  .timeline-node {
    left: 5px;
  }
  .timeline-item {
    padding-left: 3rem;
  }
  .viewport-canvas {
    height: 350px;
  }
  .viewport-overlay {
    bottom: 1rem;
    left: 1rem;
    right: 1rem;
    max-width: none;
  }
}