/******************************************
/* BASE COLOR VARIABLES - (easy color management)
/******************************************/

:root {
  /* main colors */
  --clr-bg-main: #1e293b;        /* dark background */
  --clr-text-main: #e2e8f0;      /* light text */
  --clr-accent: #3b82f6;         /* blue accent */
  --clr-accent-hover: #2563eb;   /* darker blue for hover */
  --clr-accent-light: #60a5fa;   /* light blue */
  --clr-white: #ffffff;          /* white */
  
  /* card colors */
  --clr-card-bg: #334155;         /* card background */
  --clr-card-shadow: rgba(0,0,0,0.25); /* shadows */
  --clr-card-border: #475569;    /* borders */
  
  /* header colors for different screens */
  --clr-header-lg: #1e40af;      /* desktop large-screen*/
  --clr-header-md: #2563eb;      /* tablet */
  --clr-header-sm: #dc2626;      /* mobile small-screen*/
  
  /* gradients */
  --gradient-primary: linear-gradient(135deg, #3b82f6, #1e40af);
  --gradient-accent: linear-gradient(135deg, #60a5fa, #3b82f6);
}

/******************************************
/* GLOBAL RESET + BASE STYLES
/******************************************/

* {
  box-sizing: border-box; /* includes padding + border in width/height */
}

.clearfix::after {
  content: "";
  display: block;
  clear: both;
}

.clear {
  clear: both;
}

/* main body */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
  background-color: var(--clr-bg-main);
  background-image: 
    radial-gradient(circle at 25% 25%, rgba(59, 130, 246, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(96, 165, 250, 0.05) 0%, transparent 50%);
  font-size: 16px;
  color: var(--clr-text-main);
  line-height: 1.6;
  min-height: 100vh;
}

/******************************************
/* NAVIGATION STYLES
/******************************************/
.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.navbar {
  background-color: var(--clr-header-lg);
  color: #fff;
  padding: 10px 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
}

/* Logo section */
.navbar .logo {
  display: flex;
  align-items: center;
}

.navbar .logo img {
  height: 50px;
  margin-right: 10px;
  
}

.navbar .logo a {
  color: #fff;
  text-decoration: none;
  font-size: 24px;
  font-weight: bold;
  background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4, #feca57);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s ease-in-out infinite;
}

/* Hamburger (hidden by default) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  padding: 10px;
}

.nav-toggle-icon {
  width: 25px;
  height: 3px;
  background-color: #fff;
  border-radius: 2px;
}

/* Main nav menu */
.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-menu > li {
  margin-left: 20px;
}

/* Shared link styles */
.nav-menu a {
  position: relative;
  color: #fff;
  font-size: 16px;
  padding: 10px 16px;
  text-decoration: none;
  transition: color 0.3s ease;
}

/* Hover color */
.nav-menu > li > a:hover {
  color: var(--clr-accent);
}

/* Hover underline animation */
.nav-menu a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 100%;
  background: var(--clr-accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s ease;
  background: linear-gradient(to right, rgb(176, 36, 36), rgb(170, 170, 255));
  /* New 2 colored underline */

}

.nav-menu a:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}


/******************************************
/* MOBILE NAVIGATION (≤768px)
/******************************************/

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    background-color: var(--clr-header-lg);
  }

  .nav-menu.show {
    display: flex;
  }

  .nav-menu > li {
    margin: 10px 0;
    text-align: center;
  }
}

/******************************************
/* HEADER + INTRO SECTION
/******************************************/

header {
  background-color: var(--clr-header-lg); /* dynamic from :root */
  color: #fff;
  padding: 60px 0;
  text-align: center;
}

.header-content h1 {
  margin: 0;
  font-size: 36px;
}

header p {
  margin-top: 10px;
  font-size: 20px;
}

/* fade in animation on load */
.header-content {
  opacity: 0;
  animation: fadeIn 1s ease-in-out forwards;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/******************************************
/* MAIN SECTION
/******************************************/

main {
  padding: 60px 0;
  max-width: 1200px;
  margin: 0 auto;
}

/* section headings */
section h2 {
  color: var(--clr-accent-light);
  font-size: 32px;
  margin-bottom: 30px;
  text-align: center;
  font-weight: 600;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  position: relative;
}

/* underline for headings */
section h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--gradient-accent);
  border-radius: 2px;
}

section p {
  line-height: 1.6;
  margin-bottom: 20px;
  color: var(--clr-text-main);
  font-size: 16px;
}

ul {
  list-style-type: none;
  padding: 0;
}
li {
  margin-bottom: 10px;
}

section {
  border-bottom: 1px solid #ccc;
  padding-bottom: 20px;
  margin-bottom: 20px;
}

h1, h2, p, li {
  margin: 20px;
}

/* === CERTIFICATIONS SECTION STYLING === */
#certifications li {
  background: var(--clr-card-bg);     /* Warm gray background */
  padding: 25px;                      /* generous spacing */
  margin: 25px 0;                     /* Better spacing between items */
  border-radius: 12px;                /* Softer corners */
  box-shadow: 0 4px 20px var(--clr-card-shadow); /* depth */
  border: 1px solid var(--clr-card-border); /* border */
  border-left: 4px solid var(--clr-accent); /* Professional blue accent */
  transition: all 0.3s ease;          /* Smooth animations */
  position: relative;                 /* hover effects */
  overflow: hidden;                   /* gradient overlay */
}

#certifications li:hover {
  transform: translateY(-3px);        /* card Lift effect */
  box-shadow: 0 8px 30px rgba(59, 130, 246, 0.15); /* Blue glow */
  border-left-color: var(--clr-accent-light); /* Lighter accent */
}

#certifications li strong {
  color: var(--clr-accent-light);     /* Bright blue for program names */
  font-size: 1.1em;                   /* Slightly larger size */
  display: inline;                    /* Inline display to keep dates on same line */
  margin-bottom: 8px;                 /* Space below program name */
}

#certifications li ul {
  margin-top: 10px;                   /* Space above sub-items */
}

#certifications li ul li {
  background: transparent;              /* No background for sub-items */
  padding: 5px 0;                     /* Minimal padding */
  margin: 5px 0;                      /* Minimal margin */
  border: none;                       /* No borders */
  box-shadow: none;                   /* No shadows */
  border-left: none;                  /* No accent border */
  font-size: 0.95em;                  /* Slightly smaller text */
  color: var(--clr-text-main);        /* text color */
}

#certifications li ul li:hover {
  transform: none;                    /* No hover effect for sub-items */
  box-shadow: none;                   /* No hover shadow */
}

/* Ensure Further Learning keeps its special styling */
#certifications .currently-learning li {
  background: var(--gradient-accent) !important; /* Beautiful gradient background */
  color: var(--clr-white) !important;          /* White text for readability */
  padding: 8px 12px !important;               /* More generous padding */
  border-radius: 8px !important;              /* Softer corners */
  font-size: 0.95rem !important;
  font-weight: 500 !important;                /* Slightly bolder text */
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3) !important; /* Blue shadow */
  transition: all 0.3s ease !important;       /* Smooth hover effect */
  display: inline-block !important;
  margin: 8px 8px 8px 0 !important;           /* Better spacing */
}

#certifications .currently-learning li:hover {
  transform: translateY(-2px) !important;      /* lift on hover */
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4) !important; /* Enhanced shadow */
}

#certifications li a {
  color: var(--clr-accent-light);     /* Blue color for links */
  text-decoration: none;              /* No underline */
  font-weight: 500;                  /* Medium weight */
  transition: color 0.3s ease;       /* Smooth color transition */
}

#certifications li a:hover {
  color: var(--clr-white);           /* White on hover */
  text-decoration: underline;         /* Underline on hover */
}

/* === ABOUT ME SECTION STYLING === */
#about {
  background: var(--clr-card-bg);     /* gray background */
  padding: 40px;                     
  margin: 30px 0;                     /* Better spacing */
  border-radius: 16px;               
  box-shadow: 0 4px 20px var(--clr-card-shadow); /* depth */
  border: 1px solid var(--clr-card-border); 
  border-left: 4px solid var(--clr-accent); /* Professional blue accent */
  position: relative;                 /* decorative elements */
  overflow: hidden;                   /* gradient overlay */
}

#about::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 100px;
  height: 100px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

#about p {
  font-size: 1.1em;                   /* larger for readability */
  line-height: 1.7;                   /* line spacing */
  margin-bottom: 20px;                /* Space between paragraphs */
  color: var(--clr-text-main);        /* text color */
}

#about p:first-child {
  font-size: 1.2em;                   /* Slightly larger first paragraph */
  font-weight: 500;                   /* Medium weight for emphasis */
}

#about strong {
  color: var(--clr-text-main);        /* Same color as rest of paragraph */
  font-weight: 600;                   /* Bold weight */
}

/* === PROJECT CARDS STYLING (Professional) === */
#projects li {
  background: var(--clr-card-bg);     /* gray background */
  padding: 25px;                     /* generous spacing */
  margin: 25px 0;                     /* Better spacing between cards */
  border-radius: 12px;                /* Softer corners */
  box-shadow: 0 4px 20px var(--clr-card-shadow); /* Subtle depth */
  border: 1px solid var(--clr-card-border); /* Subtle border */
  border-left: 4px solid var(--clr-accent); /* Professional blue accent */
  transition: all 0.3s ease;          /* Smooth animations */
  position: relative;                 /* hover effects */
  overflow: hidden;                   /* gradient overlay */
}

/* Add subtle gradient overlay on hover */
#projects li:hover {
  transform: translateY(-5px);        /* Lift effect */
  box-shadow: 0 8px 30px rgba(59, 130, 246, 0.15); /* Blue glow */
  border-left-color: var(--clr-accent-light); /* Lighter accent */
}

#projects li::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

#projects li:hover::before {
  opacity: 1;
}


#projects li strong {
  color: var(--clr-accent-light);     /* blue for project titles */
  font-size: 20px;                   /* Slightly larger for better hierarchy */
  font-weight: 600;                  /* Medium weight for emphasis */
  display: block;
  margin-bottom: 12px;               /* More space below title */
  line-height: 1.3;                  /* Better line spacing */
}

#projects li {
  font-size: 1.05em;                 /* Slightly larger text for readability */
  line-height: 1.6;                  /* Better line spacing */
}

#projects li a {
  color: var(--clr-accent-light);    /* Blue color for links */
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;       /* Smooth color transition */
}

#projects li a:hover {
  color: var(--clr-white);           /* White on hover */
  text-decoration: underline;         /* Underline on hover */
}
/******************************************
/* CURRENTLY LEARNING Section 
/******************************************/

.currently-learning {
  list-style: disc inside;
  padding-left: 1.5rem;
  margin: 10px 0 20px;
}

.currently-learning li {
  display: inline-block;
  margin: 8px 8px 8px 0;           /* Better spacing */
  background: var(--gradient-accent); /* Beautiful gradient background */
  color: var(--clr-white);          /* White text */
  padding: 8px 12px;               /* generous padding */
  border-radius: 8px;              /* Softer corners */
  font-size: 0.95rem;
  font-weight: 500;                /* Slightly bolder text */
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3); /* Blue shadow */
  transition: all 0.3s ease;       /* Smooth hover effect */
}

.currently-learning li:hover {
  transform: translateY(-2px);      /* lift on hover */
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4); /* Enhanced shadow */
}

/******************************************
/* SKILLS SECTION
/******************************************/

.skill-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  position: relative;
}

/* === SKILL CARDS STYLING (Interactive) === */
.skill-list li {
  margin: 12px;                        /* Better spacing */
  position: relative;                  /* tooltip positioning */
  background: var(--clr-card-bg);      /* gray background */
  padding: 18px;                       /* generous padding */
  border-radius: 10px;                 /* Softer corners */
  box-shadow: 0 3px 12px var(--clr-card-shadow); /* Subtle depth */
  border: 1px solid var(--clr-card-border); /* Subtle border */
  transition: all 0.3s ease;          /* Smooth animations */
  cursor: pointer;                     /* Indicates interactivity */
}

.skill-list li:hover {
  transform: translateY(-3px);         /* Lift effect */
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.2); /* Blue glow */
  border-color: var(--clr-accent-light); /* Accent border */
}


.skill-link {
  display: block;
  text-decoration: none;
  transition: transform 0.3s;
}

/* tooltips on hover */
.skill-link .skill-tooltip {
  position: absolute;
  top: -50px;
  left: 50%;
  transform: translateX(-50%);
  background-color: rgba(0, 0, 0, 0.9);  /* Dark background for contrast */
  color: var(--clr-white);               /* White text for readability */
  font-size: 0.8rem;                    /* Slightly larger for readability */
  padding: 8px 12px;
  border-radius: 6px;                   /* Softer corners */
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
  z-index: 1000;                        /* Higher z-index */
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3); /* Better shadow */
  width: max-content;
}

.skill-link.active .skill-tooltip {
  opacity: 1;
  pointer-events: auto;
}

.skill-link:hover {
  transform: scale(1.1);
}

/* Responsive adjustments for tooltips */
@media (max-width: 768px) {
  .skill-link .skill-tooltip {
    max-width: 300px;
    padding: 10px 12px;
    white-space: normal;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .skill-link .skill-tooltip {
    max-width: 150px;
    padding: 8px 10px;
    text-align: center;
  }
}
/******************************************
/* CONTACT SECTION
/******************************************/

/* === CONTACT SECTION STYLING (Professional) === */
#contact {
  padding: 80px 0;                      /* generous spacing */
  background: var(--gradient-primary);  /* gradient background */
  border-radius: 16px;                  /* Softer corners */
  margin: 30px 0;                       /* Better spacing */
  box-shadow: 0 8px 32px rgba(59, 130, 246, 0.2); /* Blue-tinted shadow */
  position: relative;                   /* decorative elements */
  overflow: hidden;                     /* gradient effects */
}

/* Add subtle pattern overlay */
#contact::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 80%, rgba(96, 165, 250, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, rgba(59, 130, 246, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

#contact h2 {
  position: relative;
  z-index: 1;
  color: var(--clr-white);
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

#contact h2 {
  text-align: center;
  margin-bottom: 40px;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--clr-dark);
}

.contact-list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: 0;
  padding: 0;
  list-style: none;
}

.contact-list li {
  margin: 0 12px;
}

.contact-link {
  display: block;
  text-decoration: none;
  color: var(--clr-accent);
  transition: color 0.3s;
}

.contact-link i {
  font-size: 1.3rem;
  border: 2px solid var(--clr-accent);
  border-radius: 50%;
  padding: 8px;
  width: 35px;
  height: 35px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s, box-shadow 0.3s;
  background: var(--clr-white);
}

.contact-link:hover {
  color: var(--clr-white);           /* White text for readability */
}

.contact-link:hover i {
  transform: scale(1.1);
  box-shadow: 0 0 10px rgba(63, 162, 246, 0.5);
  background: linear-gradient(to right, rgb(228, 195, 206), rgb(178, 223, 234));
/* New update */
}

/* shows small text below icons on hover */
.contact-link[title] {
  position: relative;
}

.contact-link[title]::after {
  content: attr(title);
  position: absolute;
  bottom: -20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.8rem;               /* Slightly larger for readability */
  color: var(--clr-white);         /* White text for readability */
  background: rgba(0, 0, 0, 0.9);  /* Dark background for contrast */
  padding: 4px 8px;                /* Padding for better appearance */
  border-radius: 4px;              /* Rounded corners */
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.3s;
  z-index: 10;                     /* Ensure tooltip appears above other elements */
}

.contact-link[title]:hover::after {
  opacity: 1;
}

/******************************************
/* RESPONSIVE STYLES - CONTACT
/******************************************/

@media (max-width: 428px) {
  .contact-section {
    padding: 40px 0;
  }

  .contact-section h2 {
    font-size: 2rem;
    margin-bottom: 30px;
  }

  .contact-list li {
    margin: 0 10px;
  }

  .contact-link i {
    font-size: 1.2rem;
    padding: 8px;
    width: 35px;
    height: 35px;
  }
}

@media (min-width: 429px) and (max-width: 1279px) {
  .contact-section {
    padding: 50px 0;
  }

  .contact-section h2 {
    font-size: 2.2rem;
    margin-bottom: 35px;
  }

  .contact-link i {
    font-size: 1.4rem;
    padding: 10px;
    width: 40px;
    height: 40px;
  }
}

@media (min-width: 1280px) {
  .contact-section h2 {
    font-size: 2.5rem;
    margin-bottom: 40px;
  }

  .contact-link i {
    font-size: 1.6rem;
    padding: 12px;
    width: 45px;
    height: 45px;
  }
}
/******************************************
/* FOOTER + BACK TO TOP
/******************************************/

footer {
  background-color: var(--clr-footer-lg); /* corrected var name */
  color: #fff;
  padding: 20px 0;
  text-align: center;
  font-size: 14px;
}

/* GitHub link hover */
footer a {
  color: inherit;
  text-decoration: underline;
  font-weight: 600;
}

footer a:hover {
  color: var(--clr-accent);
  text-decoration: none;
}

/* Back to top button */
.btt {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #4CAF50;
  color: white;
  font-size: 1.5rem;        /* icon size */
  border-radius: 50%;       /* round button */
  padding: 0.75rem;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  opacity: 0;               /* hidden by default (new/js) */
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease, background 0.2s ease;
  z-index: 1000;            /* above other content */
  text-decoration: none;
}

.btt:hover {
  background: #388E3C;
}

.btt.show {
  opacity: 1;
  visibility: visible;
}


/******************************************
/* MEDIA QUERY - COLOR SCHEME ADJUSTMENTS
/******************************************/

/* === DESKTOP SCREENS (1280px+) === */
@media (min-width: 1280px) {
  header {
    background-color: var(--clr-header-lg); /* Deep navy-blue */
  }

  footer {
    background-color: var(--clr-header-lg); /* Match header */
  }

  body {
    background-color: var(--clr-bg-main); /* Deep dark background */
    color: var(--clr-text-main);          /* Bright white text */
  }
}

/* === TABLET SCREENS (600px - 1279px) === */
@media (max-width: 1279px) and (min-width: 600px) {
  header {
    background-color: var(--clr-header-md); /* Medium blue */
  }

  footer {
    background-color: var(--clr-header-md); /* Match header */
  }

  body {
    background-color: var(--clr-bg-main); /* Deep dark background */
    color: var(--clr-text-main);          /* Bright white text */
  }

  /* Fix navigation underline for medium screens */
  .nav-menu a {
    padding: 12px 18px;                   /* Slightly more padding */
  }

  .nav-menu a::after {
    width: calc(100% + 36px);             /* Extend beyond padding */
    left: -18px;                           /* Start before padding */
    bottom: 0;                             /* Position at bottom */
  }
}

/* === MOBILE SCREENS (under 600px) === */
@media (max-width: 599px) {
  header {
    background-color: var(--clr-header-sm); /* Orange-red */
  }

  footer {
    background-color: var(--clr-header-sm); /* Match header */
  }

  body {
    background-color: var(--clr-bg-main); /* Deep dark background */
    color: var(--clr-text-main);          /* Bright white text */
  }
}

/* ======================================
   HAMBURGER MENU GLOW EFFECT
   Animated pulse glow (teal/blue hue)
   scoped to nav-toggle-icon only
   ====================================== */

.nav-toggle-icon {
  display: inline-block;
  width: 30px;
  height: 3px;
  background-color: white;
  position: relative;
  border-radius: 2px;

  /* Glowing pulse animation */
  animation: glowPulse 2.5s ease-in-out infinite;
}

/* Top and bottom lines of hamburger */
.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: '';
  position: absolute;
  width: 30px;
  height: 3px;
  background-color: white;
  border-radius: 2px;
  left: 0;
}

/* Top bar */
.nav-toggle-icon::before {
  top: -8px;
}

/* Bottom bar */
.nav-toggle-icon::after {
  top: 8px;
}

/* Pulse animation - subtle glow */
@keyframes glowPulse {
  0%, 100% {
    box-shadow: 0 0 5px rgba(0, 255, 255, 0.3);
  }
  50% {
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.8);
  }
}

/* enhancement: glow intensifies on hover */
.nav-toggle-icon:hover {
  box-shadow: 0 0 20px rgba(0, 255, 255, 1);
  transition: box-shadow 0.2s ease-in-out;
}