/* ============================================
       CSS RESET & BASE STYLES
       ============================================ */
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    :root {
      --background: 210 20% 98%;
      --foreground: 215 25% 15%;
      --card: 0 0% 100%;
      --card-foreground: 215 25% 15%;
      --primary: 215 85% 30%;
      --primary-foreground: 0 0% 100%;
      --secondary: 205 100% 50%;
      --secondary-foreground: 0 0% 100%;
      --muted: 210 20% 95%;
      --muted-foreground: 215 15% 45%;
      --accent: 205 90% 92%;
      --accent-foreground: 215 85% 30%;
      --border: 214 20% 88%;
      --radius: 0.75rem;
    }
    
    .dark {
      --background: 215 30% 8%;
      --foreground: 210 20% 95%;
      --card: 215 25% 12%;
      --card-foreground: 210 20% 95%;
      --primary: 205 100% 50%;
      --primary-foreground: 0 0% 100%;
      --secondary: 215 25% 18%;
      --secondary-foreground: 210 20% 95%;
      --muted: 215 25% 18%;
      --muted-foreground: 215 10% 60%;
      --accent: 205 100% 50%;
      --accent-foreground: 0 0% 100%;
      --border: 215 25% 18%;
    }
    


     body {
      font-family: Times New Roman, sans-serif;
      background-color: hsl(var(--background));
      color: hsl(var(--foreground));
      line-height: 1.6;
      transition: background-color 0.3s ease, color 0.3s ease;
    }

    
    a {
      color: hsl(var(--primary));
      text-decoration: none;
    }
    
    a:hover {
      text-decoration: underline;
    }
    
    img {
      max-width: 100%;
      height: auto;
    }
    

     /* ============================================
       NAVIGATION STYLES
       ============================================ */
    
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      z-index: 50;
      background: hsl(var(--card) / 0.8);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid hsl(var(--border));
    }
    
    .nav-container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 64px;
    }
    
    .nav-brand {
      font-size: 1.25rem;
      font-weight: 700;
      color: hsl(var(--primary));
    }
    
    .nav-links {
      display: none;
      gap: 0.5rem;
    }
    
    @media (min-width: 768px) {
      .nav-links {
        display: flex;
      }
    }
    
    .nav-link {
      padding: 0.5rem 1rem;
      border-radius: var(--radius);
      color: hsl(var(--foreground));
      transition: all 0.2s;
    }
    
    .nav-link:hover, .nav-link.active {
      background: hsl(var(--primary));
      color: hsl(var(--primary-foreground));
      text-decoration: none;
    }
    
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    
    .theme-toggle, .mobile-menu-btn {
      width: 40px;
      height: 40px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: none;
      background: transparent;
      border-radius: var(--radius);
      cursor: pointer;
      color: hsl(var(--foreground));
    }
    
    .theme-toggle:hover, .mobile-menu-btn:hover {
      background: hsl(var(--accent));
    }
    
    .mobile-menu-btn {
      display: flex;
    }
    
    @media (min-width: 768px) {
      .mobile-menu-btn {
        display: none;
      }
    }
    
    /* ===============================
   Mobile Nav Animation
   =============================== */

.mobile-nav {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transform: translateY(-8px);

  transition:
    max-height 0.4s ease,
    opacity 0.3s ease,
    transform 0.3s ease;

  padding-bottom: 0;
}

.mobile-nav.open {
  max-height: 500px; /* enough for menu items */
  opacity: 1;
  transform: translateY(0);
  padding-bottom: 1rem;
}

.mobile-menu-btn i {
  transition: transform 0.3s ease;
}

.mobile-nav.open ~ .nav-actions .mobile-menu-btn i {
  transform: rotate(90deg);
}

    
    .mobile-nav-link {
      display: block;
      padding: 0.75rem 1rem;
      border-radius: var(--radius);
      color: hsl(var(--foreground));
    }
    



     /* ============================================
       HERO SECTION
       ============================================ */
    
   .hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background-image: linear-gradient(rgba(238, 238, 238, 0.7), rgba(238, 238, 238, 0.7)), 
                    url('https://i.ibb.co.com/qL145KHF/retouch-2026012316031424.jpg');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  padding: 2rem;
}


    
    .dark .hero {
      background: linear-gradient(180deg, hsl(215 30% 8% / 0.95), hsl(215 25% 12% / 0.9));
    }
    
    .hero-avatar {
      width: 180px;
      height: 180px;
      border-radius: 50%;
      border: 4px solid white;
      background: hsl(var(--primary));
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2.5rem;
      font-weight: 700;
      margin: 5rem auto 1.5rem;
      box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    }
    
    .hero h1 {
      font-size: clamp(2rem, 5vw, 4rem);
      color: white;
      margin-bottom: 0.5rem;
    }
    
    .hero p {
      color: black;
      font-size: 1.25rem;
      margin-bottom: 0.5rem;
    }


.dark .hero p {
 color: white;
text-shadow: 2px 2px 4px #000000;
}
    
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      justify-content: center;
      margin-top: 2rem;
    }
    
    .btn {
      padding: 0.75rem 2rem;
      border-radius: var(--radius);
      font-weight: 500;
      border: 2px solid transparent;
      cursor: pointer;
      transition: all 0.2s;
      text-decoration: none;
    }
    
    .btn-primary {
      background: white;
      color: hsl(var(--primary));
    }
    
    .btn-primary:hover {
      background: rgba(255,255,255,0.9);
      text-decoration: none;
    }
    
    .btn-outline {
      background: transparent;
      border-color: white;
      color: white;
    }
    
    .btn-outline:hover {
      background: white;
      color: hsl(var(--primary));
      text-decoration: none;
    }
    


     /* ============================================
       SECTION STYLES
       ============================================ */
    
    .section {
      padding: 5rem 1rem;
    }
    
    .section-alt {
      background: hsl(var(--muted));
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
    }
    
    .section-title {
      font-size: clamp(1.5rem, 4vw, 2.5rem);
      text-align: center;
      margin-bottom: 1rem;
    }
    
    .section-divider {
      width: 80px;
      height: 4px;
      background: linear-gradient(135deg, hsl(var(--primary)), hsl(var(--secondary)));
      margin: 0 auto 3rem;
      border-radius: 2px;
    }
    



    /* ============================================
       CARD STYLES
       ============================================ */
    
    .card {
      background: hsl(var(--card));
      border: 1px solid hsl(var(--border));
      border-radius: var(--radius);
      padding: 1.5rem;
      box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    }
    
    .card-grid {
      display: grid;
      gap: 1.5rem;
    }
    

 @media (max-width: 768px) {
      .hero-avatar {
        margin: 0 auto 1.5rem;
      }
    }
    

    @media (min-width: 768px) {
      .card-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    
    @media (min-width: 1024px) {
      .card-grid {
        grid-template-columns: repeat(3, 1fr);
      }
    }
    


     /* ============================================
       FOOTER STYLES
       ============================================ */
    
    .footer {
      background: hsl(var(--muted));
      border-top: 1px solid hsl(var(--border));
      padding: 2rem 1rem;
      text-align: center;
      color: hsl(var(--muted-foreground));
    }



     /* ============================================
       UTILITY CLASSES
       ============================================ */
    
    .text-center { text-align: center; }
    .text-muted { color: hsl(var(--muted-foreground)); }
    .mb-1 { margin-bottom: 0.5rem; }
    .mb-2 { margin-bottom: 1rem; }
    .mb-4 { margin-bottom: 2rem; }
    .flex { display: flex; }
    .items-center { align-items: center; }
    .gap-2 { gap: 0.5rem; }
    .gap-4 { gap: 1rem; }
    .hidden { display: none; }
    
    /* ============================================
       BADGE STYLES
       ============================================ */
    
    .badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      background: hsl(var(--accent));
      color: hsl(var(--accent-foreground));
      border-radius: 9999px;
      font-size: 0.875rem;
      font-weight: 500;
    }
    


    /* ============================================
       TIMELINE STYLES
       ============================================ */
    
    .timeline {
      position: relative;
      padding-left: 2rem;
    }
    
    .timeline::before {
      content: '';
      position: absolute;
      left: 0;
      top: 0;
      bottom: 0;
      width: 2px;
      background: linear-gradient(to bottom, hsl(var(--primary)), hsl(var(--secondary)));
    }
    
    .timeline-item {
      position: relative;
      padding-bottom: 2rem;
    }
    
    .timeline-item::before {
      content: '';
      position: absolute;
      left: -2rem;
      top: 0.5rem;
      width: 12px;
      height: 12px;
      background: hsl(var(--primary));
      border-radius: 50%;
      transform: translateX(-5px);
    }
    


     /* ============================================
       CONTACT ICONS
       ============================================ */
    
    .icon-box {
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: linear-gradient(135deg, hsl(var(--primary)), hsl(var(--secondary)));
      border-radius: var(--radius);
      color: white;
    }
    




/* ===== Education box style ===== */
#education .edu-box {
  background: hsl(var(--card));           /* হালকা বক্স */
  padding: 14px 18px;
  border-radius: 8px;
  box-shadow: 0 6px 16px rgba(0,0,0,0.05);
}

/* compact text spacing */
#education .edu-box h2 {
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
}

#education .edu-box h3 {
  margin: 6px 0 4px;
  font-size: 16px;
  font-weight: 600;
}

#education .edu-box p {
  margin: 0;
  font-size: 14px;
  color:hsl(var(--card-foreground));
}

/* reduce gap between timeline items */
#education .timeline-item {
  padding-bottom: 16px;
}







/* ===== Footer ===== */
.site-footer {
  
  padding: 30px 15px;
  margin-top: 60px;
}

.footer-container {
  max-width: 1100px;
  margin: 0 auto;
  text-align: center;
}

.footer-text {
  margin: 0 0 10px;
  font-size: 14px;
color:black;
}
.dark .footer-text {
color:white;
}

.footer-links a {
  color: #94a3b8;
  margin: 0 10px;
  font-size: 14px;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: #38bdf8; /* accent color */
}


.social-icons {
  margin-top: 15px;
  display: flex;
  justify-content: center;
  gap: 15px;
  flex-wrap: wrap;
}

.social-icons a {
  width: 42px;
  height: 42px;
  background: rgba(255,255,255,0.85);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0b3c5d;
  font-size: 18px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.social-icons a:hover {
  background: #0b3c5d;
  color: #ffffff;
  transform: translateY(-4px);
}





#live-clock-wrapper{
  text-align:center;
  padding:30px 10px;
  background:hsl(var(--muted));
}

#live-date{
  font-size:15px;
  color:#666;
  margin-bottom:6px;
  font-family: Arial, sans-serif;
}

#live-clock{
  font-family: 'DSDigital' !important;
  font-size: 72px;
  font-weight: normal;
  
  letter-spacing: 8px;
  line-height: 1;
  display: inline-block;

 color: #2ecc71;
text-shadow:
  0 0 3px rgba(46,204,113,.5),
  0 0 8px rgba(46,204,113,.3);

}



/* Dark mode support */
body.dark #live-clock-wrapper{
  background:hsl(var(--muted-background));
}
body.dark #live-date{
  color:#aaa;
}
body.dark #live-clock{
  color:#00e5ff;
  text-shadow:
    0 0 6px rgba(0,229,255,.8),
    0 0 14px rgba(0,229,255,.6);
}



@font-face {
  font-family: 'DSDigital';
  src: url('https://static.wfonts.com/data/2014/11/02/ds-digital/DS-Digital%20Normal.ttf') format('truetype');
  font-display: swap;
}



.navbar.scrolled {
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.nav-link.active,
.mobile-nav-link.active {
  color: var(--primary);
  font-weight: 600;
}

html {
  position: relative;
}

#scrollTopBtn {
  position: fixed;

  right: 24px;
  bottom: 24px;

  width: 48px;
  height: 48px;

  display: flex;
  align-items: center;
  justify-content: center;

  border-radius: 50%;
  border: none;
  cursor: pointer;

  z-index: 100000;

  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

#scrollTopBtn.show {
  opacity: 1;
  pointer-events: auto;
}


/* ===============================
   Section Reveal Animation
   =============================== */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.6s ease,
    transform 0.6s ease;
}

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

/* Accessibility: reduce motion */
@media (prefers-reduced-motion: reduce) {
  .reveal {
    transition: none;
    transform: none;
  }
}

/* ===============================
   Button Micro-interactions
   =============================== */

.btn {
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease,
    background-color 0.2s ease,
    color 0.2s ease;
}

/* Hover: lift */
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(0,0,0,0.18);
}

/* Active: press */
.btn:active {
  transform: translateY(0);
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

/* Dark mode tweak */
body.dark .btn:hover {
  box-shadow: 0 10px 22px rgba(0,0,0,0.35);
}

/* ===============================
   Card Micro-interactions
   =============================== */

.card {
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease;
}

/* Hover: gentle elevation */
.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 30px rgba(0,0,0,0.18);
}

/* Dark mode depth */
body.dark .card:hover {
  box-shadow: 0 18px 34px rgba(0,0,0,0.45);
}

.icon-box {
  transition: transform 0.25s ease;
}

.card:hover .icon-box {
  transform: scale(1.08);
}

@media (prefers-reduced-motion: reduce) {
  .btn,
  .card,
  .icon-box {
    transition: none;
    transform: none;
  }
}

/* ===============================
   Navbar Animated Underline (FIXED)
   =============================== */

.nav-links {
  position: relative;
}

.nav-underline {
  position: absolute;

  bottom: -6px;              /* 🔥 navbar-এর নিচে আনলাম */
  height: 3px;               /* একটু মোটা */
  width: 0;

  background: hsl(var(--primary));
  border-radius: 2px;

  transition:
    left 0.3s ease,
    width 0.3s ease;

  opacity: 1;
  z-index: 999;              /* 🔥 always on top */
}



/* ===============================
   Navbar Active Cleanup
   =============================== */

.nav-link.active {
  background: transparent !important;
  color: hsl(var(--primary));
  font-weight: 600;
}



/* ===============================
   Hero Micro Motion
   =============================== */

/* floating avatar */
.hero-avatar {
  animation: hero-float 6s ease-in-out infinite;
}

/* page load fade */
.hero .container {
  animation: hero-fade 0.8s ease-out both;
}

/* subtle floating */
@keyframes hero-float {
  0%   { transform: translateY(0); }
  50%  { transform: translateY(-6px); }
  100% { transform: translateY(0); }
}

/* soft entrance */
@keyframes hero-fade {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  .hero-avatar,
  .hero .container {
    animation: none;
  }
}

#research .card h3 {
  margin-bottom: 0.25rem;
}
#certifications .card h3 {
  margin-bottom: 0.25rem;
}



/* ===============================
   Achievements Section Styling
   =============================== */

.achievement-card {
  position: relative;
  overflow: hidden;
}

/* subtle color accent */
.achievement-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.12),
    rgba(255,255,255,0)
  );
  pointer-events: none;
}

/* individual themes */
.achievement-card.scholarship {
  background: linear-gradient(135deg, #e0f2fe, #f8fafc);
}

.achievement-card.certificate {
  background: linear-gradient(135deg, #ecfeff, #f8fafc);
}

.achievement-card.competition {
  background: linear-gradient(135deg, #fef3c7, #f8fafc);
}

/* tags for PSC/JSC/SSC/HSC */
.achievement-tags {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.achievement-tags span {
  background: rgba(0,0,0,0.05);
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
  font-size: 0.85rem;
}

/* ===============================
   Achievements Dark Mode Fix
   =============================== */

body.dark .achievement-card.scholarship {
  background: linear-gradient(135deg, #0f172a, #020617);
}

body.dark .achievement-card.certificate {
  background: linear-gradient(135deg, #022c22, #020617);
}

body.dark .achievement-card.competition {
  background: linear-gradient(135deg, #3f2d00, #020617);
}

/* tags visibility fix */
body.dark .achievement-tags span {
  background: rgba(255,255,255,0.08);
  color: #e5e7eb;
}

/* ===============================
   About Section – Design Only
   (Content unchanged)
   =============================== */

.about-single {
  position: relative;
  overflow: hidden;
}

/* soft overlay like achievements */
.about-single::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.16),
    rgba(255,255,255,0)
  );
  pointer-events: none;
}

/* info grid polish (existing content) */
#about .card-grid > div {
  background: rgba(0,0,0,0.04);
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
}

/* spacing refinement */
#about p {
  line-height: 1.75;
}

/* About Section – Dark Mode */

body.dark .about-single::before {
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.05),
    rgba(255,255,255,0)
  );
}

body.dark #about .card-grid > div {
  background: rgba(255,255,255,0.06);
}

/* ===============================
   About Section – Colorful Design
   (Same style as Achievements)
   =============================== */

.about-colorful {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #eef2ff, #f8fafc);
}

/* glossy overlay */
.about-colorful::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.25),
    rgba(255,255,255,0)
  );
  pointer-events: none;
}

/* inner info blocks polish */


/* spacing & readability */
#about p {
  line-height: 1.8;
}

/* ===============================
   About Section – Dark Mode Colors
   =============================== */

body.dark .about-colorful {
  background: linear-gradient(135deg, #1e1b4b, #020617);
}

body.dark .about-colorful::before {
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.06),
    rgba(255,255,255,0)
  );
}

body.dark #about .card-grid > div {
  background: rgba(255,255,255,0.07);
}

/* ===============================
   Education – Colorful Design
   =============================== */

.edu-colorful {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #eef2ff, #f8fafc);
}

/* soft glossy overlay */
.edu-colorful::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.22),
    rgba(255,255,255,0)
  );
  pointer-events: none;
}

/* spacing polish */
.edu-colorful h2 {
  margin-bottom: 4px;
}

.edu-colorful h3 {
  margin-bottom: 2px;
}

/* optional variations */
#education .timeline-item:nth-child(1) .edu-colorful {
  background: linear-gradient(135deg, #e0f2fe, #f8fafc);
}

#education .timeline-item:nth-child(2) .edu-colorful {
  background: linear-gradient(135deg, #f0fdf4, #f8fafc);
}

#education .timeline-item:nth-child(3) .edu-colorful {
  background: linear-gradient(135deg, #fff7ed, #f8fafc);
}

/* ===============================
   Education – Dark Mode
   =============================== */

body.dark .edu-colorful {
  background: linear-gradient(135deg, #020617, #020617);
}

body.dark .edu-colorful::before {
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.05),
    rgba(255,255,255,0)
  );
}


/* =====================================
   About section – REMOVE inner backgrounds (FINAL FIX)
   ===================================== */

#about .card-grid > div {
  background: transparent !important;
  padding: 0 !important;
  border-radius: 0 !important;
}

/* =====================================
   Education – Dark Mode FIX (University)
   ===================================== */

/* override level-wise gradients in dark mode */
body.dark #education .timeline-item .edu-colorful {
  background: linear-gradient(135deg, #020617, #020617) !important;
}

/* keep overlay subtle */
body.dark #education .edu-colorful::before {
  background: linear-gradient(
    135deg,
    rgba(255,255,255,0.05),
    rgba(255,255,255,0)
  );
}