/* --- CSS VARIABLES & RESET --- */
:root {
  /* Ashik's Palette: Deep Blue / Teal Accent */
  --clr-primary: #00bcd4; /* Teal/Cyan */
  --clr-primary-dark: #0097a7;

  /* Dark Theme - Default */
  --clr-text-main: #f0f0f0;
  --clr-text-secondary: #bbb;
  --clr-bg-main: #121212; /* Deep Dark */
  --clr-bg-secondary: #1e1e1e; /* Darker section background */
  --clr-card-bg: rgba(45, 45, 45, 0.7); /* Glass-morphism Base */
  --clr-border: #444;
  --clr-shadow: rgba(0, 0, 0, 0.7);

  /* Light Theme Overrides */
  --light-clr-text-main: #333;
  --light-clr-text-secondary: #666;
  --light-clr-bg-main: #ffffff;
  --light-clr-bg-secondary: #f0f7f9;
  --light-clr-card-bg: rgba(255, 255, 255, 0.9);
  --light-clr-border: #eee;
  --light-clr-shadow: rgba(0, 0, 0, 0.15);

  /* Typography */
  --ff-primary: "Poppins", sans-serif;
  --fs-h1: 5rem;
  --fs-h2: 3.5rem;

  /* Spacing & Transitions */
  --space-sm: 1rem;
  --space-md: 2.5rem;
  --space-lg: 6rem;
  --transition-speed: 0.4s ease-in-out;
}

/* Light Mode Implementation */
body.light-mode {
  --clr-text-main: var(--light-clr-text-main);
  --clr-text-secondary: var(--light-clr-text-secondary);
  --clr-bg-main: var(--light-clr-bg-main);
  --clr-bg-secondary: var(--light-clr-bg-secondary);
  --clr-card-bg: var(--light-clr-card-bg);
  --clr-border: var(--light-clr-border);
  --clr-shadow: var(--light-clr-shadow);
}

/* Global Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  font-size: 62.5%;
  scroll-behavior: smooth;
}
body {
  font-family: var(--ff-primary);
  line-height: 1.7;
  font-size: 1.6rem;
  color: var(--clr-text-main);
  background-color: var(--clr-bg-main);
  transition: background-color var(--transition-speed),
    color var(--transition-speed);
}
a {
  text-decoration: none;
  color: var(--clr-primary);
  transition: color var(--transition-speed), transform var(--transition-speed);
}
img {
  max-width: 100%;
  height: auto;
}

/* --- HEADER / NAVBAR (Glassmorphism Effect) --- */
#header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2rem 5%;
  background-color: var(--clr-card-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--clr-border);
  transition: all var(--transition-speed);
}
#header.scrolled {
  background-color: var(--clr-card-bg);
  box-shadow: 0 4px 15px var(--clr-shadow);
  padding: 1.5rem 5%;
}
.logo {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--clr-primary);
}
.navbar a {
  font-size: 1.7rem;
  margin: 0 1.5rem;
  color: var(--clr-text-main);
  position: relative;
  padding-bottom: 0.5rem;
}
.navbar a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--clr-primary);
  transition: width var(--transition-speed);
}
.navbar a:hover::after,
.navbar a.active::after {
  width: 100%;
}
.nav-controls {
  display: flex;
  align-items: center;
}

/* 🔥 আইকনগুলোর ব্যাকগ্রাউন্ড এবং স্টাইল আপডেট করা হয়েছে */
#theme-toggle,
.github-icon-cta {
  font-size: 2.2rem;
  cursor: pointer;
  color: var(--clr-text-main); /* আইকনের রঙ সাদা */
  margin-left: 1rem;
  background-color: var(--light-clr-text-main); /* 🔥 ব্যাকগ্রাউন্ড কালার */
  border-radius: 50%; /* গোলাকার ব্যাকগ্রাউন্ডের জন্য */
  width: 35px; /* ফিক্সড সাইজ */
  height: 35px; /* ফিক্সড সাইজ */
  display: flex; /* আইকনকে কেন্দ্রে আনতে */
  justify-content: center; /* আইকনকে কেন্দ্রে আনতে */
  align-items: center; /* আইকনকে কেন্দ্রে আনতে */
  transition: all var(--transition-speed);
  border: 1px solid var(--clr-border); /* একটি সূক্ষ্ম বর্ডার যোগ করা হয়েছে */
}

#theme-toggle:hover,
.github-icon-cta:hover {
  background-color: var(--clr-bg-secondary); /* হোভারে সামান্য হালকা কালো */
  transform: scale(1.05); /* হোভারে সামান্য বড় হবে */
  color: var(--clr-primary); /* হোভারে অ্যাকসেন্ট কালার */
  box-shadow: 0 0 10px rgba(0, 188, 212, 0.3); /* অ্যাকোয়া শ্যাডো */
}

#menu-btn {
  font-size: 2.5rem;
  cursor: pointer;
  color: var(--clr-text-main);
  margin-left: 1.5rem;
  display: none;
}

/* --- HERO SECTION --- */
#home {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 8rem;
  background: var(--clr-bg-secondary);
}
.hero-content {
  max-width: 55%;
  padding-left: 5%;
}
.greeting {
  font-size: 2rem;
  color: var(--clr-text-secondary);
}
.main-heading {
  font-size: var(--fs-h1);
  color: var(--clr-primary);
  margin: 0.5rem 0;
}
.typing-text-wrapper {
  font-size: var(--fs-h2);
  color: var(--clr-text-main);
  display: flex;
  align-items: flex-end;
  height: 4rem;
}
.cursor {
  animation: blink 0.7s infinite;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}
.intro-text {
  margin-top: 2rem;
  font-size: 1.7rem;
  color: var(--clr-text-secondary);
}

.hero-image img {
  max-width: 450px;
  border-radius: 50%;
  object-fit: cover;
  border: 5px solid var(--clr-primary);
  box-shadow: 0 0 20px var(--clr-primary);
  transition: transform var(--transition-speed),
    box-shadow var(--transition-speed);
}
.hero-image img:hover {
  transform: scale(1.05) rotate(1deg);
}

.social-hero {
  margin-top: 3rem;
}
.social-hero a {
  font-size: 3rem;
  margin-right: 2.5rem;
  color: var(--clr-text-secondary);
  /* filter: drop-shadow(0 2px 5px rgba(47, 71, 80, 0.5)); */
  transition: all var(--transition-speed);
}
.social-hero a:hover {
  color: var(--clr-primary);
  transform: scale(1.2);
}

/* --- GLOBAL SECTIONS & COMPONENTS --- */
.section-padding {
  padding: var(--space-lg) 5%;
  min-height: 80vh;
}
.section-title {
  font-size: 4rem;
  text-align: center;
  margin-bottom: var(--space-lg);
  background: linear-gradient(
    90deg,
    var(--clr-primary),
    var(--clr-primary-dark)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 800;
}
.section-title::after {
  content: "";
  display: block;
  width: 60px;
  height: 4px;
  background: var(--clr-primary);
  margin: 1rem auto 0;
  border-radius: 2px;
  box-shadow: 0 0 10px var(--clr-primary);
}

/* Buttons (Shadow reduced) */
.btn {
  display: inline-block;
  padding: 1.2rem 3rem;
  margin-top: 2rem;
  border-radius: 5px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-speed);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 1.5rem;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.3); /* 🔥 Shadow Reduced */
}
.primary-btn {
  background: linear-gradient(
    45deg,
    var(--clr-primary),
    var(--clr-primary-dark)
  );
  color: #fff;
  border: none;
}
.primary-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px var(--clr-primary); /* 🔥 Hover Shadow Reduced */
}
.secondary-btn {
  background: transparent;
  color: var(--clr-primary);
  border: 2px solid var(--clr-primary);
  margin-left: var(--space-sm);
}
.secondary-btn:hover {
  background: var(--clr-primary);
  color: var(--clr-bg-main);
}
.small-btn {
  padding: 0.8rem 1.8rem;
  font-size: 1.4rem;
  margin: 0.5rem 0.5rem 0 0;
}

/* --- ABOUT SECTION --- */
.about-container {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}
.about-image img {
  border-radius: 1rem;
  max-width: 350px;
  object-fit: cover;
  box-shadow: 0 10px 40px var(--clr-shadow);
  transition: transform var(--transition-speed);
}
.about-image img:hover {
  transform: rotate(-2deg) scale(1.02);
}
.bio-text {
  margin-bottom: 2rem;
  font-size: 1.8rem;
}

.highlights-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
  margin-top: 2rem;
}
.highlight-card {
  padding: 1.5rem;
  background: var(--clr-card-bg);
  border: 1px solid rgba(var(--clr-primary), 0.5);
  backdrop-filter: blur(5px);
  border-radius: 5px;
  font-size: 1.5rem;
  transition: all var(--transition-speed);
}
.highlight-card:hover {
  transform: scale(1.03);
  background: rgba(0, 188, 212, 0.15);
}

/* --- SKILLS SECTION (High-Contrast Bars) --- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-md);
}
.skill-item {
  background: var(--clr-card-bg);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.4),
    inset 0 0 5px rgba(255, 255, 255, 0.1);
  padding: var(--space-md);
  border-radius: 1rem;
  text-align: center;
  transition: transform var(--transition-speed);
}
.skill-item:hover {
  transform: translateY(-5px);
}
.skill-icon {
  font-size: 5rem;
  color: var(--clr-primary);
  margin-bottom: 1rem;
}
.skill-item h3 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

.progress-bar-container {
  height: 12px;
  background: #333;
  border-radius: 5px;
  overflow: hidden;
  margin-top: 0.5rem;
  display: flex;
}
.progress-bar-container span {
  display: flex;
  justify-self: center;
  align-self: center;
}
.progress-bar-container span {
  font-size: 1.2rem;
  margin-top: 0.5rem;
  color: var(--clr-text-secondary);
  display: block;
  text-align: right;
  width: 100%;
}
.progress-bar {
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--clr-primary),
    var(--clr-primary-dark)
  );
  box-shadow: 0 0 10px var(--clr-primary);
  width: 0;
  transition: width 1s ease-out;
  border-radius: 5px;
}

/* --- PROJECTS SECTION --- */
.project-filters {
  text-align: center;
  margin-bottom: var(--space-md);
}
.filter-btn {
  background: var(--clr-bg-secondary);
  color: var(--clr-text-main);
  border: none;
  padding: 0.8rem 1.5rem;
  margin: 0 0.5rem;
  border-radius: 5px;
  cursor: pointer;
  transition: background var(--transition-speed), color var(--transition-speed);
  font-size: 1.5rem;
}
.filter-btn:hover,
.filter-btn.active {
  background: var(--clr-primary);
  color: var(--clr-bg-main);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}
.project-card {
  background: var(--clr-card-bg);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: 0 5px 30px var(--clr-shadow);
  transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275),
    box-shadow 0.6s;
}
.project-card img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}
.project-info {
  padding: var(--space-md);
}
.project-info h3 {
  font-size: 2rem;
  margin-bottom: 1rem;
}
.project-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.6);
}

/* --- CONTACT SECTION --- */
.contact-container {
  display: flex;
  justify-content: space-between;
  gap: var(--space-lg);
  max-width: 1000px;
  margin: 0 auto;
}
.contact-intro {
  text-align: center;
  margin-bottom: 3rem;
  font-size: 1.8rem;
}
.contact-form {
  flex: 2;
}
.form-group {
  margin-bottom: 2rem;
}
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 1.5rem;
  border: 1px solid #555;
  background: #252525;
  color: var(--clr-text-main);
  border-radius: 5px;
  font-size: 1.6rem;
  transition: border-color var(--transition-speed);
}
.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--clr-primary);
  outline: none;
}
.contact-form textarea {
  resize: vertical;
}

.social-links {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.social-links a {
  display: flex;
  align-items: center;
  padding: 1.5rem;
  border-radius: 5px;
  background: var(--clr-card-bg);
  border: 1px solid rgba(0, 188, 212, 0.3);
  box-shadow: 0 2px 10px var(--clr-shadow);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.social-links a i {
  font-size: 2.5rem;
  color: var(--clr-primary);
  margin-right: 1.5rem;
}
.social-links a span {
  color: var(--clr-text-main);
  font-size: 1.7rem;
}
.social-links a:hover {
  background: rgba(0, 188, 212, 0.15);
  transform: translateX(10px) scale(1.02);
}

/* Form Message */
.form-message {
  margin-top: 1rem;
  padding: 1rem;
  border-radius: 5px;
  font-weight: 600;
  text-align: center;
}
.form-message.success {
  background: #4caf504d;
  color: #4caf50;
}
.form-message.error {
  background: #f443364d;
  color: #f44336;
}

/* --- FOOTER & BACK TO TOP --- */
#footer {
  text-align: center;
  padding: var(--space-md) 5%;
  background: var(--clr-bg-secondary);
  border-top: 1px solid var(--clr-border);
}

#back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--clr-primary);
  color: #fff;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  font-size: 2.2rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-speed), transform 0.3s;
  box-shadow: 0 0 15px var(--clr-primary);
  z-index: 900;
}
#back-to-top:hover {
  background: var(--clr-primary-dark);
  transform: translateY(-3px);
}

/* --- PRELOADER --- */
#preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--clr-bg-main);
  z-index: 9999;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.5s ease-out;
}
.spinner {
  border: 5px solid #333;
  border-top: 5px solid var(--clr-primary);
  border-radius: 50%;
  width: 50px;
  height: 50px;
  animation: spin 1s linear infinite;
}
@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* --- MEDIA QUERIES (Menu Blur Fix) --- */
@media (max-width: 768px) {
  html {
    font-size: 55%;
  }
  #home {
    flex-direction: column-reverse;
    text-align: center;
    padding-top: 10rem;
  }
  .hero-content {
    padding: 0 5%;
  }
  .hero-image img {
    max-width: 250px;
  }
  #menu-btn {
    display: inline-block;
  }

  .navbar {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(
      18,
      18,
      18,
      0.95
    ); /* 🔥 Deep Dark BG with slight transparency */
    backdrop-filter: blur(8px); /* 🔥 Blur added for readability */
    border-top: 1px solid var(--clr-border);
    flex-direction: column;
    padding: 1rem 0;
    clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
    transition: clip-path 0.4s ease-out;
  }
  .navbar.active {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  }
  .navbar a {
    display: block;
    margin: 1rem 0;
    text-align: center;
    padding: 1rem 0;
  }
  .typing-text-wrapper {
    justify-content: center;
    font-size: 2.5rem;
  }
  .highlights-grid {
    grid-template-columns: 1fr;
  }
}