/* ===== VARIABLES ===== */
:root {
  /* Main Colors */
  --primary: #6c5ce7;
  --primary-light: #a29bfe;
  --secondary: #00cec9;
  --secondary-light: #81ecec;
  --accent: #fd79a8;
  --accent-light: #fab1c9;

  /* Neutral Colors */
  --dark: #2d3436;
  --dark-light: #636e72;
  --light: #dfe6e9;
  --white: #ffffff;

  /* Text Colors */
  --text-dark: #2d3436;
  --text-light: #b2bec3;

  /* Status Colors */
  --success: #00b894;
  --warning: #fdcb6e;
  --danger: #d63031;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  --gradient-secondary: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-light) 100%);
  --gradient-accent: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);

  /* Shadows */
  --shadow-sm: 0 2px 5px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 5px 15px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 15px 35px rgba(0, 0, 0, 0.1);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-md: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  /* Font Weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Z-index */
  --z-negative: -1;
  --z-normal: 1;
  --z-tooltip: 10;
  --z-fixed: 100;
  --z-modal: 1000;
}

/* Dark Theme Variables */
.dark-theme {
  --primary: #a29bfe;
  --primary-light: #6c5ce7;
  --secondary: #81ecec;
  --secondary-light: #00cec9;

  --dark: #f5f6fa;
  --dark-light: #dfe4ea;
  --light: #2f3542;
  --white: #1e272e;

  --text-dark: #f5f6fa;
  --text-light: #a4b0be;

  --gradient-primary: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
  --gradient-secondary: linear-gradient(135deg, var(--secondary-light) 0%, var(--secondary) 100%);

  --shadow-sm: 0 2px 5px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 5px 15px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 15px 35px rgba(0, 0, 0, 0.3);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Poppins", sans-serif;
  color: var(--text-dark);
  background-color: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: var(--font-bold);
  line-height: 1.3;
  margin-bottom: var(--spacing-md);
}

p {
  margin-bottom: var(--spacing-md);
}

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

ul,
ol {
  list-style-position: inside;
  margin-bottom: var(--spacing-md);
}

img {
  max-width: 100%;
  height: auto;
}

code {
  font-family: "Fira Code", monospace;
  background-color: var(--light);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  font-size: 0.9em;
}

/* ===== THEME TOGGLE ===== */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  width: 60px;
  height: 30px;
  background-color: var(--light);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 5px;
  cursor: pointer;
  z-index: var(--z-fixed);
  box-shadow: var(--shadow-md);
}

.theme-toggle i {
  font-size: var(--text-md);
  color: var(--text-dark);
  z-index: 1;
}

.theme-toggle .fa-sun {
  color: #f1c40f;
}

.theme-toggle .fa-moon {
  color: #34495e;
}

.toggle-ball {
  position: absolute;
  width: 24px;
  height: 24px;
  background-color: var(--white);
  border-radius: 50%;
  left: 3px;
  transition: transform var(--transition-normal);
}

.dark-theme .toggle-ball {
  transform: translateX(30px);
}

/* ===== PARTICLES BACKGROUND ===== */
#particles-js {
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  z-index: var(--z-negative);
  opacity: 0.5;
}

/* ===== HEADER ===== */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: var(--spacing-md) 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: rgba(var(--white-rgb), 0.9);
  backdrop-filter: blur(10px);
  z-index: var(--z-fixed);
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal);
}

.dark-theme header {
  background-color: rgba(30, 39, 46, 0.9);
}

.logo {
  display: flex;
  align-items: center;
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--primary);
}

.logo-icon {
  margin-right: var(--spacing-sm);
  font-size: var(--text-2xl);
  color: var(--secondary);
}

nav ul {
  display: flex;
  gap: var(--spacing-lg);
  margin: 0;
}

nav a {
  font-weight: var(--font-medium);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

nav a:hover {
  color: var(--primary);
  transform: translateY(-2px);
}

nav a.active {
  background-color: var(--primary);
  color: var(--white);
}

nav a i {
  font-size: var(--text-lg);
}

.menu-toggle {
  display: none;
  font-size: var(--text-2xl);
  cursor: pointer;
}

/* ===== HERO SECTION ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 8rem 5% 5rem;
  position: relative;
  overflow: hidden;
}

.hero-content {
  flex: 1;
  max-width: 600px;
}

.hero h1 {
  font-size: var(--text-5xl);
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
}

.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
  position: relative;
}

.subtitle {
  font-size: var(--text-xl);
  color: var(--text-light);
  margin-bottom: var(--spacing-lg);
  font-weight: var(--font-medium);
}

.description {
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-xl);
  max-width: 90%;
}

.cta-buttons {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.hero-image {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

/* Algorithm Visualization in Hero */
.algo-visual {
  position: relative;
  width: 300px;
  height: 300px;
  margin: 0 auto;
}

.node {
  position: absolute;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  animation: pulse 3s infinite alternate;
}

.edge {
  position: absolute;
  height: 3px;
  background: var(--primary-light);
  transform-origin: left center;
}

.n1 {
  top: 20px;
  left: 130px;
  animation-delay: 0s;
}
.n2 {
  top: 100px;
  left: 50px;
  animation-delay: 0.5s;
}
.n3 {
  top: 100px;
  left: 210px;
  animation-delay: 1s;
}
.n4 {
  top: 180px;
  left: 20px;
  animation-delay: 1.5s;
}
.n5 {
  top: 180px;
  left: 130px;
  animation-delay: 2s;
}
.n6 {
  top: 180px;
  left: 240px;
  animation-delay: 2.5s;
}

.e1 {
  width: 90px;
  top: 40px;
  left: 130px;
  transform: rotate(45deg);
}

.e2 {
  width: 90px;
  top: 40px;
  left: 150px;
  transform: rotate(-45deg);
}

.e3 {
  width: 60px;
  top: 120px;
  left: 50px;
  transform: rotate(70deg);
}

.e4 {
  width: 60px;
  top: 120px;
  left: 130px;
  transform: rotate(45deg);
}

.e5 {
  width: 60px;
  top: 120px;
  left: 210px;
  transform: rotate(70deg);
}

@keyframes pulse {
  0% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(108, 92, 231, 0.7);
  }
  70% {
    transform: scale(1.1);
    box-shadow: 0 0 0 10px rgba(108, 92, 231, 0);
  }
  100% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(108, 92, 231, 0);
  }
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.8rem 1.8rem;
  border-radius: var(--radius-full);
  font-weight: var(--font-semibold);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: none;
  outline: none;
  text-align: center;
  font-size: var(--text-md);
}

.primary-btn {
  background: var(--gradient-primary);
  color: var(--white);
  box-shadow: 0 4px 15px rgba(108, 92, 231, 0.4);
}

.primary-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(108, 92, 231, 0.6);
}

.secondary-btn {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.secondary-btn:hover {
  background-color: rgba(108, 92, 231, 0.1);
  transform: translateY(-3px);
}

.small-btn {
  padding: 0.5rem 1.2rem;
  font-size: var(--text-sm);
}

/* ===== SECTION STYLES ===== */
.section {
  padding: 6rem 5%;
  position: relative;
}

.dark-section {
  background-color: var(--dark);
  color: var(--white);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  position: relative;
}

.section-header h2 {
  font-size: var(--text-4xl);
  margin-bottom: var(--spacing-md);
  display: inline-block;
}

.section-header.light h2 {
  color: var(--white);
}

.section-number {
  color: var(--primary);
  font-size: var(--text-2xl);
  font-weight: var(--font-light);
  margin-right: var(--spacing-sm);
  opacity: 0.8;
}

.underline {
  width: 80px;
  height: 4px;
  background: var(--gradient-primary);
  margin: 0 auto;
  border-radius: var(--radius-full);
}

.section-intro {
  text-align: center;
  max-width: 800px;
  margin: 0 auto var(--spacing-xl);
  font-size: var(--text-lg);
}

/* ===== INTRODUCTION SECTION ===== */
.intro-content {
  display: flex;
  gap: var(--spacing-xl);
  align-items: center;
  flex-wrap: wrap;
}

.text-content {
  flex: 1;
  min-width: 300px;
}

.text-content p {
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-md);
}

.feature-list {
  list-style: none;
  margin: var(--spacing-lg) 0;
}

.feature-list li {
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  font-size: var(--text-md);
}

.feature-list i {
  color: var(--primary);
  font-size: var(--text-xl);
}

.stats-grid {
  flex: 1;
  min-width: 300px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
}

.stat-card {
  background-color: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: all var(--transition-normal);
}

.dark-theme .stat-card {
  background-color: var(--light);
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.stat-value {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.stat-label {
  color: var(--text-light);
  font-size: var(--text-sm);
}

/* ===== COMPETENCY GRID ===== */
.competency-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.competency-card {
  background-color: rgba(255, 255, 255, 0.1);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: all var(--transition-normal);
  backdrop-filter: blur(5px);
}

.competency-card:hover {
  transform: translateY(-10px);
  background-color: rgba(255, 255, 255, 0.15);
}

.competency-icon {
  font-size: var(--text-4xl);
  color: var(--secondary);
  margin-bottom: var(--spacing-lg);
}

.competency-card h3 {
  margin-bottom: var(--spacing-md);
  font-size: var(--text-xl);
}

.competency-card p {
  font-size: var(--text-md);
  opacity: 0.9;
}

/* ===== TABS SYSTEM ===== */
.tabs-container {
  background-color: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.dark-theme .tabs-container {
  background-color: var(--light);
}

.tabs {
  display: flex;
  border-bottom: 1px solid var(--light);
  overflow-x: auto;
  scrollbar-width: none;
}

.tabs::-webkit-scrollbar {
  display: none;
}

.tab-btn {
  padding: var(--spacing-lg) var(--spacing-xl);
  background: none;
  border: none;
  cursor: pointer;
  font-weight: var(--font-semibold);
  color: var(--text-light);
  position: relative;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.tab-btn.active {
  color: var(--primary);
}

.tab-btn.active::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-primary);
}

.tab-content {
  padding: var(--spacing-lg);
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
}

.tab-image {
  flex: 1;
  min-width: 300px;
}

.tab-info {
  flex: 1;
  min-width: 300px;
}

.tab-info h3 {
  font-size: var(--text-2xl);
  margin-bottom: var(--spacing-md);
  color: var(--primary);
}

.tab-info p {
  margin-bottom: var(--spacing-md);
  font-size: var(--text-md);
}

.paradigm-list {
  list-style: none;
  margin-bottom: var(--spacing-lg);
}

.paradigm-list li {
  margin-bottom: var(--spacing-sm);
  position: relative;
  padding-left: var(--spacing-lg);
}

.paradigm-list li::before {
  content: "▹";
  position: absolute;
  left: 0;
  color: var(--primary);
}

/* Algorithm Animations */
.algo-animation {
  width: 100%;
  height: 300px;
  background-color: rgba(var(--light-rgb), 0.3);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* Divide & Conquer Animation */
.array-container {
  display: flex;
  align-items: flex-end;
  height: 100px;
  gap: 5px;
}

.array-element {
  width: 20px;
  background: var(--gradient-primary);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  transition: all var(--transition-normal);
}

.division-line {
  position: absolute;
  width: 2px;
  height: 0;
  background-color: var(--accent);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation: divideHeight 3s infinite;
}

.division-line.second {
  animation-delay: 1.5s;
  left: 25%;
}

@keyframes divideHeight {
  0% {
    height: 0;
  }
  50% {
    height: 100px;
  }
  100% {
    height: 0;
  }
}

/* Dynamic Programming Animation */
.dp-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(4, 1fr);
  gap: 5px;
  width: 200px;
  height: 200px;
}

.dp-cell {
  background-color: rgba(var(--primary-rgb), 0.2);
  border-radius: var(--radius-sm);
  transition: all var(--transition-normal);
}

.dp-cell:nth-child(1) {
  animation: fillCell 3s infinite;
  animation-delay: 0.1s;
}
.dp-cell:nth-child(2) {
  animation: fillCell 3s infinite;
  animation-delay: 0.2s;
}
.dp-cell:nth-child(3) {
  animation: fillCell 3s infinite;
  animation-delay: 0.3s;
}
.dp-cell:nth-child(4) {
  animation: fillCell 3s infinite;
  animation-delay: 0.4s;
}
.dp-cell:nth-child(5) {
  animation: fillCell 3s infinite;
  animation-delay: 0.5s;
}
.dp-cell:nth-child(6) {
  animation: fillCell 3s infinite;
  animation-delay: 0.6s;
}
.dp-cell:nth-child(7) {
  animation: fillCell 3s infinite;
  animation-delay: 0.7s;
}
.dp-cell:nth-child(8) {
  animation: fillCell 3s infinite;
  animation-delay: 0.8s;
}
.dp-cell:nth-child(9) {
  animation: fillCell 3s infinite;
  animation-delay: 0.9s;
}
.dp-cell:nth-child(10) {
  animation: fillCell 3s infinite;
  animation-delay: 1.0s;
}
.dp-cell:nth-child(11) {
  animation: fillCell 3s infinite;
  animation-delay: 1.1s;
}
.dp-cell:nth-child(12) {
  animation: fillCell 3s infinite;
  animation-delay: 1.2s;
}
.dp-cell:nth-child(13) {
  animation: fillCell 3s infinite;
  animation-delay: 1.3s;
}
.dp-cell:nth-child(14) {
  animation: fillCell 3s infinite;
  animation-delay: 1.4s;
}
.dp-cell:nth-child(15) {
  animation: fillCell 3s infinite;
  animation-delay: 1.5s;
}
.dp-cell:nth-child(16) {
  animation: fillCell 3s infinite;
  animation-delay: 1.6s;
}

@keyframes fillCell {
  0% {
    background-color: rgba(var(--primary-rgb), 0.2);
  }
  50% {
    background-color: rgba(var(--primary-rgb), 0.8);
  }
  100% {
    background-color: rgba(var(--primary-rgb), 0.2);
  }
}

/* Greedy Animation */
.coin-container {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.coin {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: var(--font-bold);
  color: var(--white);
}

.c25 {
  background-color: var(--primary);
}
.c10 {
  background-color: var(--secondary);
}
.c5 {
  background-color: var(--accent);
}
.c1 {
  background-color: var(--success);
}

.target-amount {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  margin: 20px 0;
}

.solution {
  display: flex;
  gap: 5px;
}

.coin-selected {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
  color: var(--white);
  animation: selectCoin 3s infinite;
}

.coin-selected.c25 {
  animation-delay: 0.5s;
}
.coin-selected.c10 {
  animation-delay: 1.5s;
}
.coin-selected.c5 {
  animation-delay: 2.5s;
}
.coin-selected.c1 {
  animation-delay: 3.5s;
}

@keyframes selectCoin {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.3);
  }
  100% {
    transform: scale(1);
  }
}

/* Backtracking Animation */
.chess-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(4, 1fr);
  width: 200px;
  height: 200px;
  position: relative;
}

.chess-row {
  display: flex;
}

.chess-cell {
  width: 50px;
  height: 50px;
  background-color: var(--white);
}

.chess-cell.dark {
  background-color: var(--primary-light);
}

.queen {
  position: absolute;
  width: 30px;
  height: 30px;
  background-color: var(--accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: var(--text-xs);
  transform: translate(-50%, -50%);
}

.queen::after {
  content: "♕";
  font-size: 20px;
}

.q1 {
  top: 25px;
  left: 75px;
  animation: placeQueen 4s infinite;
}

.q2 {
  top: 75px;
  left: 175px;
  animation: placeQueen 4s infinite;
  animation-delay: 1s;
}

.q3 {
  top: 125px;
  left: 25px;
  animation: placeQueen 4s infinite;
  animation-delay: 2s;
}

.q4 {
  top: 175px;
  left: 125px;
  animation: placeQueen 4s infinite;
  animation-delay: 3s;
}

@keyframes placeQueen {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0);
  }
  10% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1.2);
  }
  20% {
    transform: translate(-50%, -50%) scale(1);
  }
  100% {
    transform: translate(-50%, -50%) scale(1);
  }
}

/* ===== PROJECTS SECTION ===== */
.projects-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.project-card {
  display: flex;
  background-color: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.dark-theme .project-card {
  background-color: var(--light);
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.project-badge {
  width: 80px;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: var(--text-3xl);
}

.project-content {
  flex: 1;
  padding: var(--spacing-lg);
}

.project-content h3 {
  font-size: var(--text-xl);
  margin-bottom: var(--spacing-sm);
  color: var(--primary);
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.tech-tag {
  background-color: var(--light);
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
}

.dark-theme .tech-tag {
  background-color: var(--dark);
}

.project-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.feature {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--text-sm);
}

.feature i {
  color: var(--primary);
}

/* ===== CTA SECTION ===== */
.cta-section {
  padding: var(--spacing-xl) 5%;
  background: var(--gradient-primary);
  color: var(--white);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before,
.cta-section::after {
  content: "";
  position: absolute;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.1);
}

.cta-section::before {
  top: -150px;
  left: -150px;
}

.cta-section::after {
  bottom: -150px;
  right: -150px;
}

.cta-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.cta-content h2 {
  font-size: var(--text-3xl);
  margin-bottom: var(--spacing-md);
}

.cta-content p {
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-lg);
  opacity: 0.9;
}

.cta-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
}

/* ===== FOOTER ===== */
footer {
  background-color: var(--dark);
  color: var(--white);
  padding-top: var(--spacing-xl);
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  padding: 0 5% var(--spacing-xl);
  max-width: 1200px;
  margin: 0 auto;
}

.footer-section {
  flex: 1;
  min-width: 250px;
}

.footer-logo {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.footer-section.about p {
  margin-bottom: var(--spacing-md);
  opacity: 0.8;
}

.contact span {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  opacity: 0.8;
}

.contact i {
  color: var(--primary);
}

.footer-section h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-md);
  position: relative;
  padding-bottom: var(--spacing-sm);
}

.footer-section h3::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 50px;
  height: 3px;
  background: var(--primary);
}

.footer-section.links ul {
  list-style: none;
}

.footer-section.links li {
  margin-bottom: var(--spacing-sm);
}

.footer-section.links a {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: all var(--transition-fast);
  opacity: 0.8;
}

.footer-section.links a:hover {
  opacity: 1;
  color: var(--primary);
  transform: translateX(5px);
}

.footer-section.links i {
  color: var(--primary);
  font-size: var(--text-sm);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  transition: all var(--transition-normal);
}

.social-links a:hover {
  background-color: var(--primary);
  transform: translateY(-3px);
}

.newsletter h4 {
  margin-bottom: var(--spacing-md);
  font-size: var(--text-md);
}

.newsletter form {
  display: flex;
}

.newsletter input {
  flex: 1;
  padding: 0.8rem;
  border: none;
  border-radius: var(--radius-full) 0 0 var(--radius-full);
  outline: none;
}

.newsletter button {
  padding: 0 var(--spacing-md);
  background-color: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.newsletter button:hover {
  background-color: var(--primary-light);
}

.footer-bottom {
  text-align: center;
  padding: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: var(--text-sm);
  opacity: 0.7;
}

/* ===== BACK TO TOP BUTTON ===== */
#backToTopBtn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: var(--white);
  border: none;
  cursor: pointer;
  font-size: var(--text-lg);
  z-index: var(--z-tooltip);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: scale(0.8);
  pointer-events: none;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
}

#backToTopBtn:hover {
  transform: translateY(-5px) scale(1.1);
  box-shadow: var(--shadow-lg);
}

/* ===== PAGE SPECIFIC STYLES ===== */
/* Page Hero */
.page-hero {
  min-height: 50vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8rem 5% 5rem;
  text-align: center;
  background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.1) 0%, rgba(var(--secondary-rgb), 0.1) 100%);
}

.page-hero .hero-content {
  max-width: 800px;
}

/* Concepts Page */
.concepts-intro {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.concepts-intro p {
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-xl);
}

.concept-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.concept-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-md);
  background-color: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  width: 120px;
  text-align: center;
}

.dark-theme .concept-nav-item {
  background-color: var(--light);
}

.concept-nav-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  color: var(--primary);
}

.concept-icon {
  font-size: var(--text-2xl);
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.concept-sections {
  max-width: 1000px;
  margin: 0 auto;
  padding: var(--spacing-xl) 0;
}

.concept-section {
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-xl);
  background-color: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.dark-theme .concept-section {
  background-color: var(--light);
}

.concept-section:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.concept-header {
  display: flex;
  align-items: center;
  margin-bottom: var(--spacing-lg);
}

.concept-number {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  color: var(--primary);
  opacity: 0.5;
  margin-right: var(--spacing-md);
}

.concept-header h2 {
  font-size: var(--text-2xl);
  margin-bottom: 0;
  color: var(--primary);
}

.algorithm-list {
  list-style: none;
  margin: var(--spacing-lg) 0;
}

.algorithm-list li {
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--light);
}

.algorithm-list li:last-child {
  border-bottom: none;
}

.algorithm-name {
  font-weight: var(--font-bold);
  font-size: var(--text-lg);
  color: var(--primary);
  margin-bottom: var(--spacing-xs);
}

.algorithm-desc {
  margin-bottom: var(--spacing-xs);
}

.complexity {
  font-family: "Fira Code", monospace;
  color: var(--accent);
  font-size: var(--text-sm);
}

.concept-note {
  background-color: var(--light);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin-top: var(--spacing-lg);
}

.dark-theme .concept-note {
  background-color: var(--dark);
}

.concept-note h4 {
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.code-block {
  background-color: var(--dark);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
}

.dark-theme .code-block {
  background-color: #1a1a1a;
}

.code-block pre {
  font-family: "Fira Code", monospace;
  color: var(--white);
  font-size: var(--text-sm);
  line-height: 1.5;
}

.table-container {
  overflow-x: auto;
  margin: var(--spacing-lg) 0;
}

.complexity-table {
  width: 100%;
  border-collapse: collapse;
  text-align: center;
}

.complexity-table th {
  background-color: var(--primary);
  color: var(--white);
  padding: var(--spacing-md);
  border: 1px solid var(--light);
}

.complexity-table td {
  padding: var(--spacing-md);
  border: 1px solid var(--light);
}

.complexity-table tr:nth-child(even) {
  background-color: var(--light);
}

.dark-theme .complexity-table tr:nth-child(even) {
  background-color: var(--dark);
}

.quote-block {
  background-color: var(--light);
  padding: var(--spacing-lg);
  border-left: 5px solid var(--primary);
  margin: var(--spacing-xl) 0;
  font-style: italic;
  position: relative;
}

.dark-theme .quote-block {
  background-color: var(--dark);
}

.quote-block.large {
  text-align: center;
  padding: var(--spacing-xl);
  font-size: var(--text-xl);
  border-left: none;
  border-radius: var(--radius-lg);
}

.quote-icon {
  font-size: var(--text-4xl);
  color: var(--primary);
  opacity: 0.2;
  position: absolute;
  top: 20px;
  left: 20px;
}

.quote-author {
  font-weight: var(--font-bold);
  text-align: right;
  margin-top: var(--spacing-md);
}

.lab-brief {
  background-color: var(--light);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
}

.dark-theme .lab-brief {
  background-color: var(--dark);
}

.lab-brief h2 {
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.lab-brief p {
  margin-bottom: var(--spacing-lg);
}

/* Lab Page */
.lab-hero {
  background: linear-gradient(135deg, rgba(var(--secondary-rgb), 0.1) 0%, rgba(var(--primary-rgb), 0.1) 100%);
}

.lab-highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.highlight-card {
  background-color: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: all var(--transition-normal);
}

.dark-theme .highlight-card {
  background-color: var(--light);
}

.highlight-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.highlight-icon {
  font-size: var(--text-3xl);
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.highlight-card h3 {
  font-size: var(--text-xl);
  margin-bottom: var(--spacing-sm);
  color: var(--primary);
}

.lab-methodology {
  background-color: var(--light);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  margin-top: var(--spacing-xl);
}

.dark-theme .lab-methodology {
  background-color: var(--dark);
}

.lab-methodology h3 {
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.methodology-steps {
  list-style-type: decimal;
  padding-left: var(--spacing-xl);
}

.methodology-steps li {
  margin-bottom: var(--spacing-sm);
}

.filter-section {
  text-align: center;
}

.filter-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-sm);
  margin: var(--spacing-lg) 0;
}

.filter-btn {
  padding: 0.5rem 1rem;
  background-color: var(--light);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.dark-theme .filter-btn {
  background-color: var(--dark);
}

.filter-btn.active {
  background-color: var(--primary);
  color: var(--white);
}

.filter-btn:hover:not(.active) {
  background-color: var(--primary-light);
  color: var(--white);
}

/* Accordion */
.accordion-section {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 5% var(--spacing-xl);
}

.accordion {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.accordion-item {
  background-color: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.dark-theme .accordion-item {
  background-color: var(--light);
}

.accordion-header {
  padding: var(--spacing-lg);
  display: flex;
  align-items: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.accordion-header:hover {
  background-color: rgba(var(--primary-rgb), 0.05);
}

.exp-number {
  width: 40px;
  height: 40px;
  background-color: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: var(--font-bold);
  margin-right: var(--spacing-md);
}

.exp-title {
  flex: 1;
  font-weight: var(--font-semibold);
  font-size: var(--text-lg);
}

.exp-complexity {
  font-family: "Fira Code", monospace;
  color: var(--accent);
  margin-right: var(--spacing-md);
}

.accordion-icon {
  transition: transform var(--transition-fast);
}

.accordion-item.active .accordion-icon {
  transform: rotate(180deg);
}

.accordion-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.accordion-item.active .accordion-content {
  max-height: 2000px;
}

.experiment-details {
  padding: 0 var(--spacing-lg) var(--spacing-lg);
}

.experiment-description h3 {
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.algorithm-details {
  margin-bottom: var(--spacing-lg);
}

.algorithm-details h4 {
  color: var(--secondary);
  margin-bottom: var(--spacing-sm);
}

.algorithm-properties {
  list-style: none;
  background-color: var(--light);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin: var(--spacing-md) 0;
}

.dark-theme .algorithm-properties {
  background-color: var(--dark);
}

.implementation-insight {
  background-color: rgba(var(--secondary-rgb), 0.1);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--secondary);
}

.experiment-analysis {
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--light);
}

.experiment-analysis h4 {
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.key-findings {
  background-color: rgba(var(--primary-rgb), 0.1);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin-top: var(--spacing-md);
}

.key-findings h5 {
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.optimization-note {
  background-color: rgba(var(--success-rgb), 0.1);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin-top: var(--spacing-md);
  border-left: 3px solid var(--success);
}

.optimization-note h5 {
  color: var(--success);
  margin-bottom: var(--spacing-sm);
}

/* Conclusion Page */
.conclusion-hero {
  background: linear-gradient(135deg, rgba(var(--accent-rgb), 0.1) 0%, rgba(var(--primary-rgb), 0.1) 100%);
}

.conclusion-section {
  max-width: 900px;
  margin: 0 auto;
}

.conclusion-content {
  font-size: var(--text-lg);
}

.highlight-paragraph {
  font-size: var(--text-xl);
  color: var(--primary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
}

.conclusion-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.conclusion-card {
  background-color: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.dark-theme .conclusion-card {
  background-color: var(--light);
}

.conclusion-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.card-icon {
  font-size: var(--text-3xl);
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.conclusion-card h3 {
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.future-directions {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-lg);
  background-color: var(--light);
  border-radius: var(--radius-lg);
}

.dark-theme .future-directions {
  background-color: var(--dark);
}

.future-directions h3 {
  color: var(--primary);
  margin-bottom: var(--spacing-md);
}

.future-list {
  list-style: none;
}

.future-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.future-list i {
  color: var(--primary);
  margin-top: 5px;
}

/* ===== RESPONSIVE STYLES ===== */
@media (max-width: 1024px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2rem;
    --text-3xl: 1.75rem;
    --text-2xl: 1.5rem;
  }

  .hero {
    flex-direction: column;
    text-align: center;
    padding-top: 6rem;
  }

  .hero-content {
    margin-bottom: var(--spacing-xl);
    padding-right: 0;
  }

  .description {
    max-width: 100%;
  }

  .cta-buttons {
    justify-content: center;
  }

  .tab-pane.active {
    flex-direction: column;
  }

  .tab-image {
    margin-bottom: var(--spacing-lg);
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-xl: 2rem;
    --spacing-lg: 1.5rem;
  }

  header {
    padding: var(--spacing-md) 5%;
  }

  .logo {
    font-size: var(--text-lg);
  }

  .logo-icon {
    font-size: var(--text-xl);
  }

  nav {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background-color: var(--white);
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-xl) 0;
    transition: left var(--transition-normal);
    z-index: var(--z-fixed);
  }

  .dark-theme nav {
    background-color: var(--dark);
  }

  nav.show {
    left: 0;
  }

  nav ul {
    flex-direction: column;
    width: 100%;
  }

  nav a {
    width: 100%;
    text-align: center;
    padding: var(--spacing-md);
  }

  .menu-toggle {
    display: block;
  }

  .intro-content {
    flex-direction: column;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .tabs {
    flex-wrap: wrap;
  }

  .tab-btn {
    flex: 1;
    min-width: 120px;
    text-align: center;
  }

  .project-badge {
    width: 60px;
  }

  .cta-buttons {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .footer-content {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  :root {
    --text-5xl: 2rem;
    --text-4xl: 1.75rem;
    --text-3xl: 1.5rem;
    --text-2xl: 1.25rem;
    --text-xl: 1.125rem;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .competency-grid {
    grid-template-columns: 1fr;
  }

  .exp-complexity {
    display: none;
  }

  .conclusion-grid {
    grid-template-columns: 1fr;
  }
}