:root {
  /* Color palette - Tetrad color scheme */
  --color-primary: #5a67d8;
  --color-primary-light: #7f9cf5;
  --color-primary-dark: #434190;
  
  --color-secondary: #9f7aea;
  --color-secondary-light: #d6bcfa;
  --color-secondary-dark: #6b46c1;
  
  --color-tertiary: #f6ad55;
  --color-tertiary-light: #fbd38d;
  --color-tertiary-dark: #dd6b20;
  
  --color-quaternary: #68d391;
  --color-quaternary-light: #9ae6b4;
  --color-quaternary-dark: #38a169;
  
  /* Neutral colors */
  --color-white: #ffffff;
  --color-black: #000000;
  --color-gray-100: #f7fafc;
  --color-gray-200: #edf2f7;
  --color-gray-300: #e2e8f0;
  --color-gray-400: #cbd5e0;
  --color-gray-500: #a0aec0;
  --color-gray-600: #718096;
  --color-gray-700: #4a5568;
  --color-gray-800: #2d3748;
  --color-gray-900: #1a202c;
  
  /* Typography */
  --font-heading: 'Poppins', sans-serif;
  --font-body: 'Work Sans', sans-serif;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;
  --spacing-2xl: 8rem;
  
  /* Borders & Shadows */
  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 1rem;
  --border-radius-xl: 1.5rem;
  --border-radius-2xl: 2rem;
  --border-radius-full: 9999px;
  
  /* Shadows for glassmorphism */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Animation Timing */
  --timing-fast: 0.15s;
  --timing-medium: 0.3s;
  --timing-slow: 0.5s;
  
  /* Z-index layers */
  --z-behind: -1;
  --z-normal: 0;
  --z-above: 10;
  --z-modal: 100;
  --z-overlay: 1000;
  --z-highest: 9999;
}

/* Base styles */
html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--color-gray-800);
  line-height: 1.6;
  overflow-x: hidden;
  background-attachment: fixed;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--spacing-md);
  color: var(--color-gray-900);
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--timing-fast) ease;
}

a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
}

/* Buttons */
.btn, 
button:not(.accordion-header):not(.slider-arrow):not(.slider-dot), 
input[type="submit"] {
  display: inline-block;
  font-weight: 500;
  text-align: center;
  vertical-align: middle;
  user-select: none;
  padding: 0.5rem 1.5rem;
  font-size: 1rem;
  line-height: 1.5;
  border-radius: var(--border-radius-full);
  transition: all var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
  cursor: pointer;
  text-decoration: none;
}

.btn:hover, 
button:not(.accordion-header):not(.slider-arrow):not(.slider-dot):hover, 
input[type="submit"]:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}

.btn:active, 
button:not(.accordion-header):not(.slider-arrow):not(.slider-dot):active, 
input[type="submit"]:active {
  transform: translateY(-1px);
}

/* Form elements */
input:not([type="submit"]), 
textarea, 
select {
  display: block;
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  line-height: 1.5;
  background-color: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--border-radius-md);
  transition: all var(--timing-medium) ease;
}

input:not([type="submit"]):focus, 
textarea:focus, 
select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(90, 103, 216, 0.3);
}

/* Glassmorphism effect */
.glass {
  background-color: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: var(--shadow-lg);
}

.glass-dark {
  background-color: rgba(45, 55, 72, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: var(--shadow-lg);
}

/* Header styles */
header {
  transition: background-color var(--timing-medium) ease;
}

header .container {
  height: 80px;
}

#mobile-menu-button {
  cursor: pointer;
  transition: color var(--timing-fast) ease;
}

#mobile-menu {
  transition: all var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
  transform-origin: top center;
}

/* Hero section */
#hero {
  position: relative;
  overflow: hidden;
}

#hero .absolute {
  z-index: var(--z-behind);
}

#hero h1, #hero p {
  color: var(--color-white);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

#hero img {
  transition: transform 15s ease;
}

#hero:hover img {
  transform: scale(1.1);
}

#hero .container {
  position: relative;
  z-index: var(--z-above);
}

/* Mission section */
#mission {
  position: relative;
}

#mission .accordion-item {
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

#mission .accordion-item:hover {
  transform: translateY(-5px);
}

.accordion-header {
  cursor: pointer;
  transition: color var(--timing-fast) ease;
}

.accordion-header svg {
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.accordion-header.active svg {
  transform: rotate(180deg);
}

.accordion-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.accordion-content.show {
  max-height: 500px;
}

/* Research section */
.custom-slider {
  position: relative;
  overflow: hidden;
}

.slider-container {
  width: 100%;
}

.slider-track {
  display: flex;
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.slider-slide {
  flex-shrink: 0;
  width: 100%;
}

.slider-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--border-radius-full);
  background: rgba(255, 255, 255, 0.8);
  border: none;
  cursor: pointer;
  transition: all var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.slider-arrow:hover {
  background: rgba(237, 242, 247, 1);
  box-shadow: var(--shadow-md);
}

.slider-dot {
  width: 12px;
  height: 12px;
  border-radius: var(--border-radius-full);
  background-color: var(--color-gray-300);
  border: none;
  cursor: pointer;
  transition: all var(--timing-medium) ease;
}

.slider-dot.active, .slider-dot:hover {
  background-color: var(--color-primary);
}

/* Instructors section */
#instructors .card {
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow var(--timing-medium) ease;
}

#instructors .card-image {
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

#instructors .card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--timing-medium) ease;
}

#instructors .card:hover {
  box-shadow: var(--shadow-xl);
}

#instructors .card:hover .card-image img {
  transform: scale(1.05);
}

#instructors .card-content {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

/* Resources section */
#resources .card {
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow var(--timing-medium) ease;
}

#resources .card-image {
  height: 200px;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

#resources .card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--timing-medium) ease;
}

#resources .card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

#resources .card:hover .card-image img {
  transform: scale(1.05);
}

#resources .card-content {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

/* History section */
.timeline {
  position: relative;
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

@media (min-width: 768px) {
  .timeline-item {
    display: flex;
    align-items: flex-start;
  }
  
  .timeline-item div {
    width: 50%;
  }
  
  .timeline-item:nth-child(odd) div:first-child {
    padding-right: 3rem;
    text-align: right;
  }
  
  .timeline-item:nth-child(even) div:first-child {
    order: 2;
    padding-left: 3rem;
  }
  
  .timeline-item:nth-child(even) div:last-child {
    order: 1;
    text-align: right;
    padding-right: 3rem;
  }
  
  .timeline-item:nth-child(odd) div:last-child {
    padding-left: 3rem;
  }
  
  .timeline::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    width: 4px;
    background-color: var(--color-primary-light);
    transform: translateX(-2px);
  }
}

/* Behind the Scenes section */
#behind-scenes img {
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1);
}

#behind-scenes img:hover {
  transform: scale(1.03);
}

/* Contact section */
#contact .flex-shrink-0 {
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1), background-color var(--timing-medium) ease;
}

#contact .flex:hover .flex-shrink-0 {
  transform: scale(1.1);
  background-color: var(--color-primary-light);
}

#contact input[type="checkbox"] {
  cursor: pointer;
}

/* Footer */
footer {
  position: relative;
  overflow: hidden;
}

footer a {
  color: var(--color-indigo-100);
  transition: color var(--timing-fast) ease;
}

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

/* Social media links in footer */
footer ul li a {
  display: inline-flex;
  align-items: center;
  transition: transform var(--timing-medium) cubic-bezier(0.34, 1.56, 0.64, 1), color var(--timing-fast) ease;
}

footer ul li a:hover {
  transform: translateX(5px);
}

/* Success page */
.success-page {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 2rem;
  text-align: center;
}

.success-icon {
  font-size: 4rem;
  color: var(--color-quaternary);
  margin-bottom: 2rem;
}

/* Privacy and Terms pages */
.privacy-page, 
.terms-page {
  padding-top: 100px;
  padding-bottom: 4rem;
}

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

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

@keyframes float {
  0% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-10px);
  }
  100% {
    transform: translateY(0px);
  }
}

.animate-fadeIn {
  animation: fadeIn var(--timing-slow) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.34, 1.56, 0.64, 1) infinite;
}

.animate-float {
  animation: float 3s ease-in-out infinite;
}

/* Media queries */
@media (max-width: 768px) {
  h1 {
    font-size: 2.5rem;
  }
  
  h2 {
    font-size: 2rem;
  }
  
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }
  
  .timeline::before {
    left: 1rem;
  }
  
  .slider-arrow {
    width: 36px;
    height: 36px;
  }
}

@media (max-width: 640px) {
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.75rem;
  }
  
  #hero .flex {
    flex-direction: column;
  }
  
  .timeline-item > div {
    width: 100%;
  }
}

/* AOS initialization styles */
[data-aos] {
  opacity: 0;
  transition-property: opacity, transform;
  
  &.aos-animate {
    opacity: 1;
  }
}

[data-aos="fade-up"] {
  transform: translateY(30px);
  
  &.aos-animate {
    transform: translateY(0);
  }
}

[data-aos="fade-down"] {
  transform: translateY(-30px);
  
  &.aos-animate {
    transform: translateY(0);
  }
}

[data-aos="fade-left"] {
  transform: translateX(-30px);
  
  &.aos-animate {
    transform: translateX(0);
  }
}

[data-aos="fade-right"] {
  transform: translateX(30px);
  
  &.aos-animate {
    transform: translateX(0);
  }
}

html,body{
  overflow-x: hidden;
}