/* ==========================================================================
   MONOCHROME MINIMALIST PORTFOLIO - FATIH TEZCAN
   Color Palette: Pure Black (#000000), Dark Containers (#0A0A0A, #141414),
   Crisp White (#FFFFFF), Subtle Grey (#888888, #333333).
   ========================================================================== */

/* --- CSS Variables & Root Theme --- */
:root {
  --bg-pure-black: #000000;
  --bg-card: #0A0A0A;
  --bg-card-hover: #141414;
  --bg-glass: rgba(10, 10, 10, 0.85);
  
  --text-primary: #FFFFFF;
  --text-secondary: #888888;
  --text-muted: #555555;
  
  --border-white: #FFFFFF;
  --border-subtle: rgba(255, 255, 255, 0.15);
  --border-grey: #333333;
  
  --glow-white: 0 0 15px rgba(255, 255, 255, 0.7);
  --glow-white-intense: 0 0 25px rgba(255, 255, 255, 0.95), 0 0 50px rgba(255, 255, 255, 0.3);
  --glow-subtle: 0 0 10px rgba(255, 255, 255, 0.2);
  
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-medium: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Resets & Global Styles --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-pure-black);
  color: var(--text-primary);
  font-family: var(--font-main);
  overflow-x: hidden;
  font-size: 16px;
}

body {
  background-color: var(--bg-pure-black);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Selection & Scrollbar --- */
::selection {
  background: var(--text-primary);
  color: var(--bg-pure-black);
}

::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-pure-black);
}
::-webkit-scrollbar-thumb {
  background: #333333;
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: #888888;
}

/* --- Ambient Grid Background --- */
.ambient-grid {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  background-image: 
    radial-gradient(circle at 50% 30%, rgba(255, 255, 255, 0.03) 0%, transparent 60%),
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 100% 100%, 60px 60px, 60px 60px;
}

/* --- Fixed Interactive Cursor Glow --- */
.cursor-glow {
  display: none;
}

/* --- Navigation Header --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1.5rem 3rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 100;
  background: linear-gradient(to bottom, rgba(0, 0, 0, 0.9) 0%, rgba(0, 0, 0, 0) 100%);
  backdrop-filter: blur(8px);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-symbol {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: var(--glow-subtle);
  transition: var(--transition-fast);
}

.brand-logo:hover .brand-symbol {
  box-shadow: var(--glow-white);
  transform: scale(1.05);
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

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

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  transition: var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--text-primary);
  transition: width 0.3s ease;
}

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

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

.sound-toggle-btn {
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
}

.sound-toggle-btn:hover, .sound-toggle-btn.active {
  border-color: var(--border-white);
  color: var(--text-primary);
  box-shadow: var(--glow-subtle);
}

/* --- SVG Tree Root Container --- */
.tree-root-viewport {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 2;
}

#tree-root-svg {
  width: 100%;
  height: 100%;
  display: block;
}

.main-root-path {
  fill: none;
  stroke: var(--text-primary);
  stroke-width: 3.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.8)) drop-shadow(0 0 20px rgba(255, 255, 255, 0.4));
  transition: stroke-dashoffset 0.1s linear;
}

.secondary-branch-path {
  fill: none;
  stroke: var(--text-secondary);
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0.7;
  filter: drop-shadow(0 0 5px rgba(255, 255, 255, 0.4));
}

.root-knot-circle {
  fill: var(--bg-pure-black);
  stroke: var(--border-white);
  stroke-width: 2;
  filter: drop-shadow(0 0 10px rgba(255, 255, 255, 0.9));
}

.root-pulse-ring {
  display: none;
}

/* --- Main Layout Wrapper --- */
.main-content {
  position: relative;
  z-index: 10;
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --- Hero Section --- */
.hero-section {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding-top: 6rem;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.hero-badge .pulse-dot {
  width: 6px;
  height: 6px;
  background: var(--text-primary);
  border-radius: 50%;
  box-shadow: var(--glow-white);
  animation: blink 1.5s infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.3; transform: scale(0.8); }
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
  background: linear-gradient(180deg, #FFFFFF 30%, #888888 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.35rem);
  color: var(--text-secondary);
  max-width: 650px;
  margin: 0 auto 3rem;
  font-weight: 300;
}

.hero-subtitle strong {
  color: var(--text-primary);
  font-weight: 500;
}

.scroll-prompt {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  margin-top: 2rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.scroll-prompt:hover {
  color: var(--text-primary);
}

.scroll-prompt-icon {
  width: 24px;
  height: 40px;
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  position: relative;
  display: flex;
  justify-content: center;
  padding-top: 6px;
}

.scroll-prompt-icon::before {
  content: '';
  width: 3px;
  height: 8px;
  background: var(--text-primary);
  border-radius: 2px;
  box-shadow: var(--glow-white);
}

/* --- Section Formatting --- */
.section-wrapper {
  padding: 8rem 0;
  position: relative;
}

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

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.2em;
  display: block;
  margin-bottom: 0.5rem;
}

.section-title-large {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* --- Social Media Root Nodes Container --- */
.social-nodes-container {
  display: flex;
  flex-direction: column;
  gap: 12rem;
  position: relative;
  margin: 4rem 0;
}

.social-node-card-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 4rem;
  position: relative;
}

.social-node-card-row.row-reverse {
  direction: rtl;
}
.social-node-card-row.row-reverse > * {
  direction: ltr;
}

/* --- The Interactive Node Hub (Anchored on Root Knot) --- */
.node-anchor-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.social-root-node {
  width: 80px;
  height: 80px;
  background: var(--bg-card);
  border: 1.5px solid var(--border-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  text-decoration: none;
  cursor: pointer;
  position: relative;
  z-index: 15;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.9), 0 0 10px rgba(255, 255, 255, 0.2);
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.4s ease, border-color 0.4s ease;
}

.social-root-node svg {
  width: 32px;
  height: 32px;
  transition: transform 0.3s ease;
}

.social-root-node::before {
  content: '';
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  border: 1px dashed rgba(255, 255, 255, 0.3);
  transition: border-color 0.3s ease;
}

/* Active/Focused Node State (Triggered on Scroll Focus or Hover) */
.social-root-node.active-focus, .social-root-node:hover {
  transform: scale(1.3);
  border-color: #FFFFFF;
  box-shadow: var(--glow-white-intense);
  background: var(--bg-card-hover);
}

.social-root-node.active-focus svg, .social-root-node:hover svg {
  transform: scale(1.15);
  filter: drop-shadow(0 0 5px #FFFFFF);
}

.social-root-node.active-focus::before {
  border-color: rgba(255, 255, 255, 0.8);
  border-style: solid;
}

/* Floating Platform Tag --- */
.node-platform-tag {
  position: absolute;
  top: -30px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  background: var(--bg-pure-black);
  border: 1px solid var(--border-white);
  border-radius: 4px;
  color: var(--text-primary);
  white-space: nowrap;
  box-shadow: var(--glow-subtle);
}

/* --- Social Detail Card (Attached to Node) --- */
.social-detail-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 2rem;
  position: relative;
  z-index: 10;
  transition: transform 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

.social-node-card-row.focused .social-detail-card {
  border-color: var(--border-white);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.8), 0 0 20px rgba(255, 255, 255, 0.15);
  transform: translateY(-5px);
}

.social-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-grey);
  padding-bottom: 0.75rem;
}

.social-card-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.social-handle {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.social-card-body {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.social-card-metrics {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-value {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.metric-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.social-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  background: transparent;
  border: 1px solid var(--border-white);
  color: var(--text-primary);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  border-radius: 6px;
  transition: var(--transition-fast);
}

.social-action-btn:hover {
  background: var(--text-primary);
  color: var(--bg-pure-black);
  box-shadow: var(--glow-white);
}

/* --- Computer Engineering Featured Showcase Section --- */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.showcase-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 2.5rem 2rem;
  position: relative;
  overflow: hidden;
  transition: var(--transition-medium);
}

.showcase-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, #FFFFFF, transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.showcase-card:hover {
  border-color: var(--border-white);
  transform: translateY(-8px);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.9), var(--glow-subtle);
  background: var(--bg-card-hover);
}

.showcase-card:hover::before {
  opacity: 1;
}

.showcase-icon {
  width: 48px;
  height: 48px;
  border: 1px solid var(--border-grey);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.03);
}

.showcase-title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.showcase-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

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

.tech-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-grey);
  border-radius: 4px;
  color: var(--text-secondary);
}

/* --- ABOUT ME SECTION (Placed Gracefully at Bottom) --- */
.about-section {
  padding: 10rem 0 6rem;
  position: relative;
}

.about-card-container {
  background: var(--bg-card);
  border: 1px solid var(--border-white);
  border-radius: 16px;
  padding: 4rem;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.95), 0 0 30px rgba(255, 255, 255, 0.08);
  position: relative;
  overflow: hidden;
}

.about-card-container::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 0;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.04) 0%, transparent 70%);
  pointer-events: none;
}

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

.about-bio-heading {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -0.01em;
}

.about-bio-text {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.about-bio-text strong {
  color: var(--text-primary);
  font-weight: 600;
}

.about-stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-grey);
  margin-top: 2.5rem;
}

.about-stat-number {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  margin-bottom: 0.3rem;
  text-shadow: var(--glow-subtle);
}

.about-stat-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* Sidebar Info Box in About Card */
.about-sidebar-box {
  background: #000000;
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 2rem;
}

.sidebar-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sidebar-title::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--text-primary);
  border-radius: 50%;
  box-shadow: var(--glow-white);
}

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

.skill-item-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

.skill-name {
  color: var(--text-secondary);
}

.skill-bar-wrapper {
  width: 100px;
  height: 4px;
  background: var(--border-grey);
  border-radius: 2px;
  overflow: hidden;
}

.skill-bar-fill {
  height: 100%;
  background: var(--text-primary);
  box-shadow: var(--glow-white);
  border-radius: 2px;
}

/* --- Contact & Footer --- */
.footer-contact-box {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-grey);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.contact-email-link {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-primary);
  text-decoration: none;
  border-bottom: 1px solid var(--border-white);
  padding-bottom: 2px;
  transition: var(--transition-fast);
}

.contact-email-link:hover {
  box-shadow: var(--glow-white);
  color: #FFFFFF;
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Responsive Media Queries --- */
@media (max-width: 1024px) {
  .site-header {
    padding: 1.2rem 1.5rem;
  }
  
  .social-node-card-row {
    grid-template-columns: 80px 1fr;
    gap: 2rem;
  }
  
  .social-node-card-row.row-reverse {
    direction: ltr;
    grid-template-columns: 80px 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  
  .about-card-container {
    padding: 2.5rem;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* Can be toggled or kept simple for minimalist focus */
  }

  .hero-section {
    padding-top: 5rem;
  }
  
  .social-nodes-container {
    gap: 7rem;
  }
  
  .social-node-card-row {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
    gap: 1.5rem;
  }
  
  .social-card-header {
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .social-card-metrics {
    justify-content: center;
  }

  .about-stats-row {
    grid-template-columns: 1fr;
    gap: 1rem;
    text-align: center;
  }

  .footer-contact-box {
    flex-direction: column;
    text-align: center;
  }
}