/* =====================================================
   DESIGN SYSTEM — Premium Portfolio v2
   ===================================================== */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800;900&family=Inter:wght@300;400;500;600&display=swap');

/* Prevent horizontal scroll on all viewports */
html, body { overflow-x: hidden; max-width: 100%; }

/* --- CSS Variables (Dark Mode Default) --- */
:root {
  /* Backgrounds */
  --bg:           #090d16;
  --bg-secondary: #0f172a;
  --card-bg:      rgba(30, 41, 59, 0.4);
  --card-border:  rgba(148, 163, 184, 0.1);
  --glass-bg:     rgba(9, 13, 22, 0.8);

  /* Text */
  --text-main:    #f8fafc;
  --text-muted:   #94a3b8;
  --text-subtle:  #64748b;

  /* Accents */
  --accent:       #2563eb;
  --accent-2:     #3b82f6;
  --accent-glow:  rgba(37, 99, 235, 0.15);
  --grad-1:       #3b82f6;
  --grad-2:       #2563eb;
  --grad-3:       #1d4ed8;

  /* Borders */
  --border:       rgba(148, 163, 184, 0.12);
  --border-hover: rgba(37, 99, 235, 0.45);

  /* Shadows */
  --shadow-card:  0 4px 20px rgba(0, 0, 0, 0.25);
  --shadow-glow:  0 4px 20px rgba(37, 99, 235, 0.08);

  /* Transitions */
  --ease:         cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Light Mode Overrides --- */
body:has(#dark-mode-toggle:not(:checked)) {
  --bg:           #f8fafc;
  --bg-secondary: #f1f5f9;
  --card-bg:      #ffffff;
  --card-border:  rgba(148, 163, 184, 0.15);
  --glass-bg:     rgba(248, 250, 252, 0.85);
  --text-main:    #0f172a;
  --text-muted:   #475569;
  --text-subtle:  #94a3b8;
  --accent:       #2563eb;
  --accent-glow:  rgba(37, 99, 235, 0.1);
  --border:       rgba(148, 163, 184, 0.12);
  --border-hover: rgba(37, 99, 235, 0.4);
  --shadow-card:  0 4px 12px rgba(15, 23, 42, 0.05);
  --shadow-glow:  0 4px 12px rgba(37, 99, 235, 0.05);
}

/* =====================================================
   RESET & BASE
   ===================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

/* Custom Scrollbar */
html::-webkit-scrollbar { width: 6px; }
html::-webkit-scrollbar-track { background: var(--bg); }
html::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 3px;
}
html::-webkit-scrollbar-thumb:hover { background: var(--accent-2); }

body {
  font-family: 'Inter', sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text-main);
  overflow-x: hidden;
}

/* Hidden toggle */
.toggle-checkbox { display: none; }

/* =====================================================
   ANIMATED MESH BACKGROUND (Disabled for professional look)
   ===================================================== */
.mesh-bg {
  display: none;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.15;
  animation: float-orb 20s ease-in-out infinite;
}

.orb-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, #7c3aed, transparent 70%);
  top: -200px; left: -200px;
  animation-duration: 25s;
  animation-delay: 0s;
}

.orb-2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, #6366f1, transparent 70%);
  top: 30%; right: -150px;
  animation-duration: 20s;
  animation-delay: -8s;
  opacity: 0.12;
}

.orb-3 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, #06b6d4, transparent 70%);
  bottom: 10%; left: 20%;
  animation-duration: 30s;
  animation-delay: -15s;
  opacity: 0.08;
}

@keyframes float-orb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33%       { transform: translate(40px, -60px) scale(1.08); }
  66%       { transform: translate(-30px, 40px) scale(0.95); }
}

/* Light mode: softer orbs */
.toggle-checkbox:not(:checked) ~ .mesh-bg .orb { opacity: 0.07; }

/* =====================================================
   SITE WRAPPER
   ===================================================== */
.site-wrapper {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  width: 100%;
  display: flex;
  flex-direction: column;
  transition: background-color 0.4s var(--ease), color 0.4s var(--ease);
}

/* =====================================================
   NAVIGATION
   ===================================================== */
nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 5%;
  width: 100%;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.logo {
  display: inline-flex;
  align-items: baseline;
}

.logo-link,
.logo-dot-link {
  font-family: 'Outfit', sans-serif;
  font-weight: 900;
  font-size: 1.6rem;
  letter-spacing: -2px;
  background: linear-gradient(135deg, var(--grad-1), var(--grad-2), var(--grad-3));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  display: inline-block;
}

.logo-dot-link {
  cursor: default;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 7px 14px;
  border-radius: 8px;
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
  letter-spacing: 0.02em;
}

.nav-links a:hover {
  color: var(--text-main);
  background: var(--card-bg);
}

.nav-links a.active-nav {
  color: var(--accent);
  background: rgba(37, 99, 235, 0.1);
}

/* Theme Toggle */
.mode-btn {
  cursor: pointer;
  margin-left: 8px;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  font-size: 1.1rem;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
  user-select: none;
}
.mode-btn:hover { border-color: var(--border-hover); transform: scale(1.05); }

body:has(#dark-mode-toggle:checked) .icon-sun  { display: none; }
body:has(#dark-mode-toggle:checked) .icon-moon { display: flex; }
body:has(#dark-mode-toggle:not(:checked)) .icon-moon { display: none; }
body:has(#dark-mode-toggle:not(:checked)) .icon-sun  { display: flex; }

/* Hamburger */
.hamburger {
  display: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: all 0.3s var(--ease);
}
.hamburger.active .bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.active .bar:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.active .bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =====================================================
   SCROLL REVEAL
   ===================================================== */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}
.reveal.active {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* =====================================================
   HERO SECTION
   ===================================================== */
.hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 60px;
  padding: clamp(60px, 10vw, 120px) 5% clamp(50px, 8vw, 100px);
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}

.hero-text { flex: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(37, 99, 235, 0.1);
  border: 1px solid rgba(37, 99, 235, 0.25);
  border-radius: 50px;
  padding: 6px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 20px;
}
.hero-badge .dot {
  width: 7px; height: 7px;
  background: #22c55e;
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.6; transform: scale(0.8); }
}

h1 {
  font-family: 'Outfit', sans-serif;
  font-size: clamp(2.8rem, 5.5vw, 4rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -2px;
  margin-bottom: 20px;
  color: var(--text-main);
}

.highlight {
  background: linear-gradient(135deg, var(--grad-1) 0%, var(--grad-2) 50%, var(--grad-3) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-muted);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  margin-bottom: 30px;
  max-width: 500px;
  line-height: 1.7;
}

.hero-btns {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* =====================================================
   BUTTONS
   ===================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  padding: 13px 26px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.25s var(--ease);
  border: none;
  cursor: pointer;
  font-family: inherit;
  letter-spacing: 0.01em;
}

.btn.primary {
  background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
  color: #fff;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}
.btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.4);
}

.btn.secondary {
  background: var(--card-bg);
  color: var(--text-main);
  border: 1px solid var(--border);
  backdrop-filter: blur(10px);
}
.btn.secondary:hover {
  transform: translateY(-2px);
  border-color: var(--border-hover);
  background: rgba(37, 99, 235, 0.08);
}

.btn.full-width { width: 100%; justify-content: center; }

/* =====================================================
   HERO PROFILE IMAGE
   ===================================================== */
.hero-img-container {
  position: relative;
  width: 280px;
  height: 280px;
  flex-shrink: 0;
}

.img-ring {
  position: absolute;
  inset: -8px;
  border-radius: 24px;
  border: 2px solid var(--accent);
  background: transparent;
  z-index: 0;
  opacity: 0.4;
}

.profile-pic {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  border-radius: 20px;
  border: 2px solid var(--border);
  z-index: 2;
  transition: opacity 0.4s var(--ease);
  opacity: 0;
}

/* Dark mode (default) image states */
.img-night-normal { opacity: 1; z-index: 3; cursor: default; }
.hero-img-container:hover .img-night-hover { opacity: 1; z-index: 4; cursor: default; }
.hero-img-container:hover .img-night-normal { opacity: 0; }

/* Light mode image states */
body:has(#dark-mode-toggle:not(:checked)) .img-night-normal,
body:has(#dark-mode-toggle:not(:checked)) .img-night-hover { opacity: 0 !important; }
body:has(#dark-mode-toggle:not(:checked)) .img-day-normal { opacity: 1; z-index: 3; cursor: default; }
body:has(#dark-mode-toggle:not(:checked)) .hero-img-container:hover .img-day-hover { opacity: 1; z-index: 4; cursor: default; }
body:has(#dark-mode-toggle:not(:checked)) .hero-img-container:hover .img-day-normal { opacity: 0; }

.glow-effect {
  position: absolute;
  inset: 0;
  background: var(--accent);
  border-radius: 20px;
  opacity: 0.12;
  z-index: 1;
  filter: blur(30px);
  transform: translate(10px, 10px);
  transition: opacity 0.4s;
}
.hero-img-container:hover .glow-effect { opacity: 0.2; }

/* =====================================================
   SECTION COMMONS
   ===================================================== */
.section-pad {
  padding: clamp(60px, 8vw, 100px) 5%;
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}

.section-header {
  margin-bottom: 60px;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent-2);
  margin-bottom: 12px;
}

.section-title {
  font-family: 'Outfit', sans-serif;
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--text-main) 60%, var(--text-muted));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* =====================================================
   ABOUT SECTION
   ===================================================== */
.about-content {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 60px;
  align-items: start;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 18px;
  font-size: 1.05rem;
  line-height: 1.8;
}
.about-text p strong { color: var(--text-main); font-weight: 600; }

.tech-stack h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tags span {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 7px 16px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
  transition: all 0.2s var(--ease);
  backdrop-filter: blur(10px);
}
.tags span:hover {
  border-color: var(--border-hover);
  color: var(--accent-2);
  background: rgba(37, 99, 235, 0.08);
  transform: translateY(-1px);
}

/* =====================================================
   STATS ROW
   ===================================================== */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 50px;
  padding-top: 50px;
  border-top: 1px solid var(--border);
}

.stat-item {
  text-align: center;
}
.stat-number {
  font-family: 'Outfit', sans-serif;
  font-size: 2.2rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 6px;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* =====================================================
   PROJECT CARDS
   ===================================================== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(320px, 100%), 1fr));
  gap: 24px;
}

a.project-card {
  text-decoration: none;
  color: inherit;
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
  backdrop-filter: blur(10px);
}
a.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.card-img {
  position: relative;
  height: 200px;
  overflow: hidden;
}
.card-img img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}
a.project-card:hover .card-img img { transform: scale(1.05); }

.card-img-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, transparent 40%, rgba(9, 13, 22, 0.8));
  transition: opacity 0.3s;
}

.card-content { padding: 24px; }

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 10px;
  gap: 10px;
}
.card-header h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.3;
}
.arrow-icon {
  font-size: 1.1rem;
  opacity: 0;
  transform: translate(-6px, 6px);
  transition: all 0.3s var(--ease);
  color: var(--accent-2);
  flex-shrink: 0;
}
a.project-card:hover .arrow-icon {
  opacity: 1;
  transform: translate(0, 0);
}

.card-content p {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 18px;
  line-height: 1.7;
}

.stack-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.stack-badge {
  padding: 4px 10px;
  border-radius: 50px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.25);
  color: var(--accent-2);
}

/* =====================================================
   CERTIFICATIONS
   ===================================================== */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: 20px;
}

.cert-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  display: flex;
  align-items: center;
  gap: 20px;
  transition: all 0.3s var(--ease);
  backdrop-filter: blur(10px);
  cursor: default;
}
.cert-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

.cert-icon {
  font-size: 2rem;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(37, 99, 235, 0.1);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: 14px;
  flex-shrink: 0;
  transition: background 0.3s;
}
.cert-card:hover .cert-icon { background: rgba(37, 99, 235, 0.18); }

.cert-info h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text-main);
}
.issuer {
  color: var(--accent-2);
  font-size: 0.82rem;
  font-weight: 600;
}
.date {
  display: block;
  font-size: 0.75rem;
  color: var(--text-subtle);
  margin-top: 4px;
}

/* =====================================================
   BLOG CARDS
   ===================================================== */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr));
  gap: 24px;
}

.blog-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 32px;
  border-radius: 16px;
  display: flex;
  flex-direction: column;
  transition: all 0.3s var(--ease);
  backdrop-filter: blur(10px);
}
.blog-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.blog-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--text-subtle);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}
.blog-tag {
  color: var(--accent-2);
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.25);
  padding: 3px 10px;
  border-radius: 50px;
}

.blog-title {
  font-family: 'Outfit', sans-serif;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
  color: var(--text-main);
}

.blog-excerpt {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 24px;
  flex-grow: 1;
  line-height: 1.7;
}

.read-more {
  text-decoration: none;
  color: var(--accent-2);
  font-weight: 600;
  font-size: 0.85rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.2s var(--ease), opacity 0.2s;
}
.read-more:hover { gap: 10px; opacity: 0.8; }

/* =====================================================
   VIEW ALL BUTTON
   ===================================================== */
.view-all-container {
  display: flex;
  justify-content: center;
  margin-top: 50px;
}

/* =====================================================
   CONTACT SECTION
   ===================================================== */
.contact-container {
  max-width: 620px;
  margin: 0 auto;
  text-align: center;
}
.contact-container > p {
  color: var(--text-muted);
  margin-bottom: 40px;
  font-size: 1.05rem;
  line-height: 1.8;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 14px;
  margin-bottom: 50px;
}

.social-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  border-radius: 13px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: all 0.25s var(--ease);
  text-decoration: none;
}
.social-btn svg { width: 20px; height: 20px; }
.social-btn:hover {
  border-color: var(--border-hover);
  color: var(--accent-2);
  transform: translateY(-3px);
  background: rgba(37, 99, 235, 0.08);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.email-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
  text-align: left;
}

input, textarea {
  width: 100%;
  padding: 14px 18px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text-main);
  border-radius: 12px;
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s;
  backdrop-filter: blur(10px);
  outline: none;
}
input::placeholder, textarea::placeholder { color: var(--text-subtle); }
input:focus, textarea:focus {
  border-color: var(--border-hover);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  background: rgba(37, 99, 235, 0.03);
}

/* reCAPTCHA centering */
.g-recaptcha { display: flex; justify-content: center; }

/* =====================================================
   FOOTER
   ===================================================== */
footer {
  padding: 50px 5%;
  text-align: center;
  color: var(--text-subtle);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  margin-top: auto;
}

/* =====================================================
   BACK TO TOP
   ===================================================== */
#back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
  color: white;
  border-radius: 13px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-decoration: none;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.3s var(--ease);
}
#back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
#back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.4);
}

/* =====================================================
   PAGE HERO (Sub-pages)
   ===================================================== */
.page-hero {
  padding: clamp(50px, 8vw, 80px) 5% clamp(40px, 6vw, 60px);
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}
.page-hero h1 { font-size: clamp(1.8rem, 5vw, 3rem); margin-bottom: 14px; }
.page-hero .subtitle { max-width: 500px; }

/* =====================================================
   DIVIDER
   ===================================================== */
.section-divider {
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border), transparent);
  margin: 0 5%;
}

/* =====================================================
   RESPONSIVE — TABLET (≤ 900px)
   ===================================================== */
@media (max-width: 900px) {
  .hero { gap: 40px; }
  .hero-img-container { width: 220px; height: 220px; }
  .about-content { grid-template-columns: 1fr; gap: 40px; }
  .stats-row { grid-template-columns: repeat(3, 1fr); }
}

/* =====================================================
   RESPONSIVE — MOBILE (≤ 768px)
   ===================================================== */
@media (max-width: 768px) {
  /* Hamburger visible */
  .hamburger { display: flex; }

  /* Nav desktop links hidden by default on mobile */
  .nav-links {
    /* Nav is full viewport width (no container offset), so left: 0 = screen edge */
    position: fixed;
    top: 0;
    left: -100vw;      /* hide completely off-screen */
    width: 100vw;
    height: 100vh;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px 20px;
    gap: 8px;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-right: 1px solid var(--border);
    transition: left 0.35s var(--ease);
    z-index: 999;
    box-shadow: 4px 0 40px rgba(0, 0, 0, 0.3);
  }
  /* Slide in from left */
  .nav-links.active { left: 0; }

  .nav-links a {
    font-size: 1.2rem;
    font-weight: 600;
    display: block;
    padding: 14px 30px;
    width: 100%;
    border-radius: 12px;
  }

  /* Close button (mode-btn) repositioned */
  .mode-btn {
    margin-top: 20px;
    margin-left: 0;
  }

  /* Hero */
  .hero {
    flex-direction: column-reverse;
    text-align: center;
    gap: 30px;
  }
  .hero-btns { justify-content: center; flex-wrap: wrap; }
  .subtitle { margin: 0 auto 24px; }
  .hero-badge { margin: 0 auto 16px; }
  .hero-img-container { width: 180px; height: 180px; }

  /* Stats */
  .stats-row { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .stat-number { font-size: 1.6rem; }
  .stat-label { font-size: 0.7rem; }

  /* Certs */
  .cert-card { flex-direction: column; text-align: center; }

  /* Project grid single column on very narrow */
  .project-grid,
  .blog-grid {
    grid-template-columns: 1fr;
  }

  /* Back to top smaller */
  #back-to-top { bottom: 16px; right: 16px; width: 42px; height: 42px; }

  /* Section divider */
  .section-divider { margin: 0 4%; }
}

/* =====================================================
   RESPONSIVE — SMALL MOBILE (≤ 480px)
   ===================================================== */
@media (max-width: 480px) {
  h1 { letter-spacing: -1px; }
  .stats-row { grid-template-columns: repeat(3, 1fr); }
  .cert-grid { grid-template-columns: 1fr; }
  .btn { padding: 11px 18px; font-size: 0.9rem; }
  .hero-img-container { width: 150px; height: 150px; }
  .social-links { gap: 10px; }
  .social-btn { width: 44px; height: 44px; }
}

/* =====================================================
   PORTFOLIO AI CHATBOT
   ===================================================== */
#portfolio-chatbot-widget {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  font-family: 'Inter', sans-serif;
}

#chatbot-toggle-btn {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
  color: #fff;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
#chatbot-toggle-btn:hover {
  transform: scale(1.08) translateY(-2px);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.45);
}
#chatbot-toggle-btn svg {
  width: 24px;
  height: 24px;
}

.pulse-notification-dot {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 12px;
  height: 12px;
  background: #22c55e;
  border: 2px solid var(--bg);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

#chatbot-window {
  position: fixed;
  bottom: 96px;
  right: 24px;
  width: 360px;
  height: min(500px, 80vh);
  display: flex;
  flex-direction: column;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  overflow: hidden;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
  transform: translateY(10px);
  opacity: 0;
  pointer-events: none;
}
#chatbot-window.active {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}
#chatbot-window.hidden {
  display: none !important;
}

#chatbot-header {
  padding: 14px 18px;
  background: rgba(30, 41, 59, 0.3);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.header-avatar-info {
  display: flex;
  align-items: center;
  gap: 10px;
}
.avatar-container {
  position: relative;
  width: 36px;
  height: 36px;
}
.chat-avatar {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  border: 1.5px solid var(--accent);
}
.status-indicator {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1.5px solid var(--bg);
}
.status-indicator.online {
  background: #22c55e;
}
.header-text-info h4 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.2;
}
.status-text {
  font-size: 0.72rem;
  color: var(--text-muted);
}
#chatbot-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s;
  border-radius: 6px;
}
#chatbot-close-btn:hover {
  color: var(--text-main);
  background: var(--card-bg);
}

#chatbot-messages {
  flex-grow: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: rgba(0, 0, 0, 0.05);
}

/* Custom Scrollbar for Chat */
#chatbot-messages::-webkit-scrollbar { width: 4px; }
#chatbot-messages::-webkit-scrollbar-track { background: transparent; }
#chatbot-messages::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

.chat-message {
  display: flex;
  width: 100%;
}
.chat-message.user-msg {
  justify-content: flex-end;
}
.chat-message.bot-msg {
  justify-content: flex-start;
}
.msg-bubble {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 14px;
  font-size: 0.88rem;
  line-height: 1.5;
  word-break: break-word;
}
.user-msg .msg-bubble {
  background: var(--accent);
  color: #fff;
  border-bottom-right-radius: 2px;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.2);
}
.bot-msg .msg-bubble {
  background: var(--card-bg);
  color: var(--text-main);
  border: 1px solid var(--border);
  border-bottom-left-radius: 2px;
}
.bot-msg.error-msg .msg-bubble {
  border-color: rgba(239, 68, 68, 0.3);
  background: rgba(239, 68, 68, 0.05);
  color: #ef4444;
}

/* Form & Input */
#chatbot-input-form {
  padding: 12px 16px;
  background: var(--glass-bg);
  border-top: 1px solid var(--border);
  display: flex;
  gap: 8px;
  align-items: center;
}
#chatbot-input-field {
  flex-grow: 1;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 10px 14px;
  border-radius: 10px;
  font-size: 0.88rem;
  outline: none;
  transition: border-color 0.2s;
}
#chatbot-input-field:focus {
  border-color: var(--border-hover);
}
#chatbot-send-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
  flex-shrink: 0;
}
#chatbot-send-btn:hover {
  background: var(--accent-2);
  transform: scale(1.05);
}
#chatbot-send-btn svg {
  width: 16px;
  height: 16px;
}

/* Typing Indicator Animation */
.typing-bubble {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 12px 16px !important;
}
.dot-bounce {
  width: 6px;
  height: 6px;
  background: var(--text-muted);
  border-radius: 50%;
  display: inline-block;
  animation: bounce 1.4s infinite ease-in-out both;
}
.dot-bounce:nth-child(1) { animation-delay: -0.32s; }
.dot-bounce:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1.0); }
}

/* Markdown spacing inside bubbles */
.msg-bubble ul {
  padding-left: 20px;
  margin: 6px 0;
}
.msg-bubble li {
  margin-bottom: 4px;
}

/* Mobile Responsive */
@media (max-width: 480px) {
  #portfolio-chatbot-widget {
    bottom: 16px;
    right: 16px;
  }
  #chatbot-window {
    width: calc(100vw - 32px);
    right: 16px;
    bottom: 80px;
    height: 60vh;
  }
}