/* ==========================================================================
   Debjyoti Saha — Backend Engineer Portfolio
   Modern Obsidian / Cyber-Emerald Engineering Theme
   ========================================================================== */

:root {
  /* Dark Theme Palette (Default) */
  --bg-primary: #080a0f;
  --bg-secondary: #0e1219;
  --bg-tertiary: #131922;
  --bg-card: rgba(14, 18, 25, 0.75);
  --bg-card-hover: rgba(22, 28, 38, 0.9);
  --bg-card-highlight: rgba(16, 185, 129, 0.04);
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --border-accent: rgba(16, 185, 129, 0.3);
  
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-heading: #ffffff;
  
  --accent-emerald: #10b981;
  --accent-emerald-bright: #34d399;
  --accent-cyan: #06b6d4;
  --accent-glow: rgba(16, 185, 129, 0.15);
  
  --status-green: #22c55e;
  --code-bg: #0b0e14;
  
  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.6);
  --shadow-accent: 0 0 30px rgba(16, 185, 129, 0.2);
  
  --transition-fast: 0.18s ease;
  --transition-normal: 0.28s ease;
}

:root[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: #ffffff;
  --bg-card-highlight: rgba(16, 185, 129, 0.05);
  
  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.16);
  --border-accent: rgba(5, 150, 105, 0.35);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-heading: #020617;
  
  --accent-emerald: #059669;
  --accent-emerald-bright: #047857;
  --accent-cyan: #0891b2;
  --accent-glow: rgba(5, 150, 105, 0.12);
  
  --status-green: #16a34a;
  --code-bg: #f8fafc;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
  --shadow-accent: 0 0 24px rgba(5, 150, 105, 0.15);
}

/* ==========================================================================
   CSS Reset & Base Rules
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-primary);
}

body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Background Atmosphere */
.ambient-glow {
  position: fixed;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(ellipse at center, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  opacity: 0.8;
}

.grid-pattern {
  position: fixed;
  inset: 0;
  background-size: 40px 40px;
  background-image: 
    linear-gradient(to right, var(--border-subtle) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border-subtle) 1px, transparent 1px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
}

/* Accessibility Skip Link */
.skip-link {
  position: absolute;
  top: -999px;
  left: 1rem;
  z-index: 9999;
  padding: 0.75rem 1.25rem;
  background: var(--accent-emerald);
  color: #000000;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-decoration: none;
}
.skip-link:focus {
  top: 1rem;
}

/* Base Typo & Links */
h1, h2, h3, h4 {
  color: var(--text-heading);
  font-weight: 700;
  line-height: 1.25;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--accent-emerald-bright);
}

/* Container */
.container {
  width: min(calc(100% - 2.5rem), 1160px);
  margin-inline: auto;
  position: relative;
  z-index: 1;
}

/* Section Shared */
.section {
  padding: clamp(3.5rem, 7vw, 6rem) 0;
  position: relative;
}

.section-header {
  margin-bottom: 2.75rem;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-emerald);
  margin-bottom: 0.5rem;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.section-title {
  font-size: clamp(1.8rem, 3.2vw, 2.5rem);
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 650px;
}

/* Gradient Text */
.text-gradient {
  background: linear-gradient(135deg, var(--accent-emerald-bright) 0%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   Buttons & Badges
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.925rem;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-sm {
  padding: 0.5rem 0.95rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.85rem 1.6rem;
  font-size: 0.98rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-emerald) 0%, #059669 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.35);
}
.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-emerald-bright) 0%, #10b981 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.45);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-strong);
}
.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-emerald);
  transform: translateY(-2px);
}

.btn-ghost {
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}
.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border-color: var(--border-strong);
  transform: translateY(-2px);
}

.btn-icon, .social-icon {
  flex-shrink: 0;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.badge-accent {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald-bright);
  border: 1px solid rgba(16, 185, 129, 0.35);
}

.badge-neutral {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

.badge-remote {
  background: rgba(6, 182, 212, 0.15);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.3);
}

/* Tech Pills */
.tech-pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.tech-pill {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.25rem 0.65rem;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}
.tech-pill:hover {
  border-color: var(--accent-emerald);
  color: var(--text-primary);
}

/* ==========================================================================
   Navigation Bar
   ========================================================================== */

.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color var(--transition-normal);
}

:root[data-theme="light"] .navbar {
  background: rgba(248, 250, 252, 0.85);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(calc(100% - 2.5rem), 1160px);
  margin-inline: auto;
  height: 68px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-heading);
}
.nav-brand .brand-bracket { color: var(--accent-emerald); }
.nav-brand .brand-slash { color: var(--accent-cyan); }
.brand-badge {
  font-size: 0.72rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  margin-left: 0.35rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding-block: 0.35rem;
}
.nav-link:hover, .nav-link.active {
  color: var(--accent-emerald-bright);
}
.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-emerald);
  border-radius: var(--radius-full);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.theme-toggle-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  transition: all var(--transition-fast);
}
.theme-toggle-btn:hover {
  border-color: var(--border-strong);
  transform: scale(1.05);
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}
.hamburger-bar {
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero-section {
  padding-top: clamp(3rem, 6vw, 5.5rem);
  padding-bottom: clamp(3rem, 6vw, 5rem);
}

.hero-container {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  align-items: center;
  gap: clamp(2rem, 5vw, 4rem);
}

.status-badge-wrapper {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0.85rem;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.25);
  border-radius: var(--radius-full);
  margin-bottom: 1.5rem;
}

.status-indicator {
  width: 8px;
  height: 8px;
  background-color: var(--status-green);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--status-green);
  animation: pulse-glow 2s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.55; transform: scale(1.2); }
}

.status-text {
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--status-green);
}

.hero-title {
  font-size: clamp(2.2rem, 4.4vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  line-height: 1.15;
}

.hero-description {
  font-size: 1.12rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 2rem;
  max-width: 600px;
}
.hero-description strong {
  color: var(--text-heading);
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 2.75rem;
}

/* Quick Specs Bar */
.quick-specs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.25rem;
  padding: 1rem 1.4rem;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.spec-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.spec-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
}

.spec-value {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
}

.spec-divider {
  width: 1px;
  height: 28px;
  background: var(--border-subtle);
}

/* Developer Profile Card */
.hero-card-wrapper {
  position: relative;
}

.developer-profile-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), var(--shadow-accent);
  overflow: hidden;
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}
.developer-profile-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
}

.profile-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-subtle);
}

.profile-window-dots {
  display: flex;
  gap: 6px;
}
.profile-window-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border-strong);
}
.profile-window-dots span:nth-child(1) { background: #ef4444; }
.profile-window-dots span:nth-child(2) { background: #f59e0b; }
.profile-window-dots span:nth-child(3) { background: #10b981; }

.profile-file-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.profile-image-container {
  display: flex;
  justify-content: center;
  padding: 1.75rem 1.5rem 1rem;
  position: relative;
}

.profile-avatar {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: 50%;
  border: 3px solid var(--border-accent);
  box-shadow: 0 0 25px var(--accent-glow);
}

.profile-meta {
  text-align: center;
  padding-inline: 1.5rem;
  margin-bottom: 1.25rem;
}

.profile-name {
  font-size: 1.4rem;
  margin-bottom: 0.25rem;
}

.profile-title {
  color: var(--accent-emerald-bright);
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 0.4rem;
}

.profile-org {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
}

.profile-terminal-stats {
  padding: 1rem 1.4rem;
  background: var(--code-bg);
  border-top: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.stat-line {
  display: flex;
  justify-content: space-between;
}
.stat-key { color: var(--text-muted); }
.stat-val { color: var(--text-primary); font-weight: 500; }
.stat-val.highlight { color: var(--accent-emerald-bright); font-weight: 600; }

/* ==========================================================================
   Experience Section
   ========================================================================== */

.experience-card-container {
  max-width: 900px;
}

.experience-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent-emerald);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}
.experience-card:hover {
  border-color: var(--border-accent);
  border-left-color: var(--accent-emerald-bright);
  transform: translateY(-2px);
}

.experience-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.experience-org-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.org-icon-badge {
  width: 46px;
  height: 46px;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-md);
  color: var(--accent-emerald-bright);
  display: flex;
  align-items: center;
  justify-content: center;
}

.experience-org {
  font-size: 1.3rem;
  margin-bottom: 0.2rem;
}

.experience-role-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.experience-role {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.experience-timeline {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-emerald-bright);
  background: var(--bg-tertiary);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-subtle);
}

.experience-summary {
  font-size: 1.02rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.experience-bullets {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.experience-bullets li {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.bullet-icon {
  color: var(--accent-emerald);
  font-family: var(--font-mono);
  font-weight: bold;
}

/* ==========================================================================
   Projects Section (Stacked Case Studies)
   ========================================================================== */

.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.project-case-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: clamp(1.75rem, 4vw, 2.5rem);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  position: relative;
}

.project-case-card:hover {
  border-color: var(--border-accent);
  box-shadow: var(--shadow-lg), var(--shadow-accent);
}

.project-case-card.highlight-card {
  border-color: rgba(16, 185, 129, 0.35);
  background: linear-gradient(180deg, var(--bg-card-highlight) 0%, var(--bg-card) 100%);
}

.project-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

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

.project-external-links {
  display: flex;
  gap: 0.75rem;
}

.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  transition: all var(--transition-fast);
}
.link-btn:hover {
  border-color: var(--accent-emerald);
  color: var(--accent-emerald-bright);
  transform: translateY(-1px);
}

.link-btn.live-btn {
  background: rgba(16, 185, 129, 0.12);
  border-color: rgba(16, 185, 129, 0.35);
  color: var(--accent-emerald-bright);
}

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent-emerald-bright);
  box-shadow: 0 0 8px var(--accent-emerald);
}

.project-title {
  font-size: clamp(1.4rem, 2.4vw, 1.85rem);
  margin-bottom: 0.65rem;
}

.project-lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.75rem;
}

/* Architecture Pipeline Diagram */
.architecture-diagram {
  background: var(--code-bg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.75rem;
}

.arch-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  color: var(--accent-emerald);
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pipeline-flow {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
}

.pipeline-node {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.95rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  min-width: 150px;
  flex-shrink: 0;
}

.pipeline-node.highlight {
  border-color: var(--border-accent);
  background: rgba(16, 185, 129, 0.08);
}

.node-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-emerald-bright);
}

.node-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.pipeline-arrow {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 1.1rem;
  flex-shrink: 0;
}

/* Project Highlights Grid */
.project-highlights-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

.highlight-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 1.1rem;
}

.highlight-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.highlight-box p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

/* ==========================================================================
   Interactive API Sandbox / Playground
   ========================================================================== */

.sandbox-window {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.sandbox-window-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.4rem;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-subtle);
}

.window-controls {
  display: flex;
  gap: 6px;
}
.window-controls span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border-strong);
}
.window-controls span:nth-child(1) { background: #ef4444; }
.window-controls span:nth-child(2) { background: #f59e0b; }
.window-controls span:nth-child(3) { background: #10b981; }

.window-title {
  font-family: var(--font-mono);
  font-size: 0.825rem;
  color: var(--text-secondary);
}

.window-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  background: var(--code-bg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
}

.sandbox-body {
  padding: 1.5rem;
}

.endpoint-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-bottom: 1.25rem;
}

.endpoint-tab {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.9rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.endpoint-tab:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.endpoint-tab.active {
  border-color: var(--accent-emerald);
  background: rgba(16, 185, 129, 0.1);
  color: var(--text-primary);
}

.http-method {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
}
.http-method.get { background: rgba(16, 185, 129, 0.2); color: var(--accent-emerald-bright); }
.http-method.post { background: rgba(6, 182, 212, 0.2); color: var(--accent-cyan); }

/* Request Bar */
.request-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--code-bg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.85rem;
  margin-bottom: 1.25rem;
}

.active-method {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-emerald-bright);
}

.active-url {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  outline: none;
}

/* Payload Box */
.payload-container {
  background: var(--code-bg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  margin-bottom: 1.25rem;
}

.payload-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.payload-hint { color: var(--accent-cyan); }

.payload-textarea {
  width: 100%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  resize: vertical;
  outline: none;
}
.payload-textarea:focus { border-color: var(--accent-emerald); }

/* Response Box */
.response-container {
  background: var(--code-bg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.response-meta-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.65rem 1rem;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.status-indicator-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.meta-label { color: var(--text-muted); }
.status-code { color: var(--accent-emerald-bright); font-weight: 700; }
.latency-val { color: var(--accent-cyan); font-weight: 600; }
.content-type-val { color: var(--text-secondary); }
.meta-separator { color: var(--border-strong); }

.copy-response-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
}
.copy-response-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.response-output {
  padding: 1.25rem;
  max-height: 380px;
  overflow-y: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.55;
  color: var(--text-primary);
}

/* ==========================================================================
   Skills Section
   ========================================================================== */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.skill-category-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: all var(--transition-normal);
}
.skill-category-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.skill-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  color: var(--accent-emerald-bright);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.skill-category-card h3 {
  font-size: 1.15rem;
  margin-bottom: 1rem;
}

.skill-badge-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.skill-badge-list li {
  font-size: 0.92rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
}
.skill-badge-list li::before {
  content: "—";
  color: var(--accent-emerald);
  margin-right: 0.65rem;
  font-weight: bold;
}

/* ==========================================================================
   Education & Certifications Section
   ========================================================================== */

.education-grid {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 1.75rem;
}

.edu-card, .cert-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-md);
}

.edu-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.85rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.edu-institution {
  font-size: 1.25rem;
  margin-top: 0.5rem;
  margin-bottom: 0.25rem;
}

.edu-degree {
  color: var(--accent-emerald-bright);
  font-weight: 600;
  font-size: 0.98rem;
}

.edu-timeline {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.edu-location {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 1.25rem;
}

.coursework-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 1rem;
}

.coursework-title {
  display: block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
  letter-spacing: 0.04em;
}

.coursework-box p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}

.cert-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1.75rem;
}

.cert-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.cert-badge-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.25);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.cert-name {
  font-size: 1.05rem;
  margin-bottom: 0.25rem;
}

.cert-detail {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.cert-year {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-emerald);
}

/* ==========================================================================
   Contact Section
   ========================================================================== */

.contact-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: clamp(2rem, 5vw, 3.5rem);
  box-shadow: var(--shadow-lg), var(--shadow-accent);
}

.contact-header {
  max-width: 650px;
  margin-bottom: 2.5rem;
}

.contact-title {
  font-size: clamp(1.8rem, 3.2vw, 2.5rem);
  margin-top: 0.5rem;
  margin-bottom: 0.75rem;
}

.contact-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.6;
}

.contact-actions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
}

.contact-action-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  transition: all var(--transition-fast);
}
.contact-action-box:hover {
  border-color: var(--border-accent);
  transform: translateY(-2px);
}

.contact-action-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.contact-email-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.contact-email-link, .file-name-text {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.contact-email-link:hover {
  color: var(--accent-emerald-bright);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2rem 0;
  margin-top: 3rem;
  background: var(--bg-secondary);
}

.footer-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.footer-copy {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.system-status {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--status-green);
  box-shadow: 0 0 6px var(--status-green);
}

.back-to-top {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}
.back-to-top:hover {
  color: var(--accent-emerald-bright);
}

/* ==========================================================================
   Toast Notification
   ========================================================================== */

.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 10000;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--accent-emerald);
  box-shadow: var(--shadow-lg), 0 0 20px rgba(16, 185, 129, 0.3);
  padding: 0.85rem 1.4rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  transform: translateY(100px);
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */

@media (max-width: 992px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: left;
  }
  
  .hero-card-wrapper {
    max-width: 480px;
    margin: 0 auto;
    width: 100%;
  }
  
  .education-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 68px;
    left: 0;
    width: 100%;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-strong);
    flex-direction: column;
    align-items: flex-start;
    padding: 1.5rem 2rem;
    gap: 1.5rem;
    transform: translateY(-150%);
    transition: transform var(--transition-normal);
  }
  
  .nav-menu.is-open {
    transform: translateY(0);
  }
  
  .nav-links {
    flex-direction: column;
    gap: 1rem;
    width: 100%;
  }
  
  .nav-actions {
    width: 100%;
    justify-content: space-between;
    padding-top: 1rem;
    border-top: 1px solid var(--border-subtle);
  }
  
  .nav-toggle {
    display: flex;
  }

  .quick-specs {
    flex-direction: column;
    align-items: flex-start;
  }
  .spec-divider {
    display: none;
  }
  
  .pipeline-flow {
    flex-direction: column;
    align-items: stretch;
  }
  .pipeline-arrow {
    transform: rotate(90deg);
    text-align: center;
  }
}