/* Custom styles for UPES Courses Repository */

:root {
    --primary-color: #4a148c;  /* Deep Purple from logo */
    --secondary-color: #1565c0;  /* Vibrant Blue from logo */
    --accent-color: #ff8f00;  /* Orange/Yellow from logo */
    --text-primary-light: #2c3e50;
    --text-secondary-light: #546e7a;
    --background-light: #f8f9fa;
    --card-background-light: white;
    --card-shadow-light: 0 4px 6px rgba(0, 0, 0, 0.1);
    --hover-shadow-light: 0 8px 15px rgba(0, 0, 0, 0.15);
    --border-color-light: rgba(0, 0, 0, 0.05);
    --navbar-bg-light: linear-gradient(to right, var(--primary-color), var(--secondary-color));

    /* Dark Mode Colors - Updated for better readability */
    --primary-color-dark: #9c7bff; /* Brighter Purple for better visibility */
    --secondary-color-dark: #64b5f6; /* Brighter Blue for better visibility */
    --accent-color-dark: #ffd54f; /* Bright Yellow for emphasis */
    --text-primary-dark: #ffffff; /* Pure white for maximum readability */
    --text-secondary-dark: #e0e0e0; /* Light gray for secondary text */
    --background-dark: #1a1a1a; /* Slightly lighter dark background */
    --card-background-dark: #2d2d2d; /* Distinct card background */
    --card-shadow-dark: 0 4px 12px rgba(0, 0, 0, 0.5);
    --hover-shadow-dark: 0 8px 24px rgba(0, 0, 0, 0.6);
    --border-color-dark: rgba(255, 255, 255, 0.1);
    --navbar-bg-dark: linear-gradient(to right, #2c2c2c, #1a1a1a); /* Subtle gradient */
    --link-color-dark: #90caf9; /* Bright blue for links */
    --footer-bg-dark: #2d2d2d; /* Matching card background */
    --input-bg-dark: #333333; /* Dark input background */
    --input-border-dark: #404040; /* Dark input border */
    --accordion-bg-dark: #2d2d2d; /* Dark accordion background */
    --accordion-hover-dark: #363636; /* Dark accordion hover state */

    /* Additional Colors/Gradients */
    --hero-gradient-light: linear-gradient(135deg, #e0f7fa 0%, #b2ebf2 100%);
    --hero-gradient-dark: linear-gradient(135deg, #2c2c2c 0%, #1a1a1a 100%);
    --navbar-vibrant-gradient: linear-gradient(to right, #0377B7, #24BEE8, #F44669);
}

/* Intro Animation Styles */
.intro-active {
    overflow: hidden;
}

/* Intro Container */
.intro-container {
    position: fixed;
    inset: 0;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    perspective: 1500px;
    overflow: hidden;
    transition: filter 1.4s ease, opacity 1.4s ease;
}

body.dark-mode .intro-container {
    background: var(--background-dark);
}

.intro-container.exit {
    filter: blur(20px);
    opacity: 0;
}

/* Logo Animation */
.logo-intro {
    position: relative;
    width: 60vw;
    max-width: 280px;
    animation: flipZoomFade 4s ease-out forwards;
    z-index: 3;
}

.logo-intro img {
    width: 100%;
    max-width: 100%;
    height: auto;
    display: block;
}

/* Light Flare Effect */
.flare {
    position: fixed;
    top: 0;
    left: -100%;
    width: 300%;
    height: 100vh;
    background: linear-gradient(
        120deg,
        transparent,
        rgba(255, 255, 255, 0.4),
        transparent
    );
    background: linear-gradient(120deg, transparent, rgba(255, 255, 255, 0.121), transparent);
    animation: flareMove 2.8s ease-in-out 1s forwards;
    z-index: 10;
    mix-blend-mode: screen;
    pointer-events: none;
}

/* Grain Texture Motion */
.grain {
    position: absolute;
    inset: 0;
    background: url("https://grainy-gradients.vercel.app/noise.png");
    opacity: 0.04;
    mix-blend-mode: screen;
    z-index: 1;
    animation: grainShift 6s linear infinite;
}

/* Cinematic Vignette */
.vignette {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, rgba(0,0,0,0) 50%, rgba(0,0,0,0.9) 100%);
    pointer-events: none;
    z-index: 2;
}

/* Black Bars */
.letterbox {
    position: absolute;
    width: 100%;
    height: 10vh;
    background: #000;
    z-index: 6;
}

.letterbox.top { top: 0; }
.letterbox.bottom { bottom: 0; }

/* Split Overlays */
.split-overlay {
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200vw;
    height: 200vh;
    background: linear-gradient(
        120deg,
        rgba(255, 0, 51, 0) 0%,
        rgba(252, 210, 3, 0.3) 30%,
        rgba(0, 191, 255, 0.4) 60%,
        rgba(255, 0, 51, 0) 100%
    );
    opacity: 0;
    z-index: 5;
    pointer-events: none;
    mix-blend-mode: screen;
    filter: blur(12px);
}

.split-overlay.left {
    left: 0;
    animation: splitLeft 1.2s ease 3.4s forwards;
}

.split-overlay.right {
    right: 0;
    animation: splitRight 1.2s ease 3.4s forwards;
}

/* Main Content Wrapper for Intro */
.main-content-wrapper {
    display: none;
    overflow-y: auto;
    min-height: 100vh;
    background: var(--background-light);
    color: var(--text-primary-light);
    transition: background-color 0.5s ease, color 0.5s ease;
}

body.dark-mode .main-content-wrapper {
    background: var(--background-dark);
    color: var(--text-primary-dark);
}

/* Intro Animation Keyframes */
@keyframes flareMove {
    0% { transform: translateX(-100%); opacity: 0; }
    50% { opacity: 1; }
    100% { transform: translateX(100%); opacity: 0; }
}

@keyframes flipZoomFade {
    0%   { opacity: 0; transform: rotateY(180deg) scale(0.08); }
    35%  { opacity: 1; transform: rotateY(90deg) scale(0.5); }
    55%  { transform: rotateY(0deg) scale(1); }
    85%  { transform: scale(1.25); opacity: 1; }
    100% { transform: scale(4); opacity: 0; }
}

@keyframes splitLeft {
    0% { opacity: 0; transform: translateX(0); }
    100% { opacity: 1; transform: translateX(-100vw); }
}

@keyframes splitRight {
    0% { opacity: 0; transform: translateX(0); }
    100% { opacity: 1; transform: translateX(100vw); }
}

@keyframes grainShift {
    0% { background-position: 0 0; }
    100% { background-position: 100px 100px; }
}

/* Responsive Fix for Intro */
@media (max-width: 600px) {
    .logo-intro {
        width: 80vw;
    }
    .letterbox {
        height: 8vh;
    }
}

body {
    font-family: 'Poppins', 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--background-light) 0%, #e4e8eb 100%);
    color: var(--text-primary-light);
    min-height: 100vh;
    transition: background-color 0.5s ease, color 0.5s ease;
}

body.dark-mode {
    background: var(--background-dark);
    color: var(--text-primary-dark);
}

/* Navbar customization */
.navbar {
    background: var(--navbar-vibrant-gradient) !important; /* Use the new vibrant gradient */
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
    transition: background 0.5s ease, box-shadow 0.5s ease;
}

body.dark-mode .navbar {
    background: var(--navbar-bg-dark) !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.8); /* Darker and more spread shadow in dark mode */
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: 0.5px;
    color: white !important;
}

.navbar-brand i {
    color: var(--accent-color);
    transition: color 0.5s ease;
}

body.dark-mode .navbar-brand i {
     color: var(--accent-color-dark);
}

.nav-link {
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    transition: all 0.3s ease;
    color: rgba(255, 255, 255, 0.9) !important;
}

.nav-link:hover {
    color: var(--accent-color) !important;
    transform: translateY(-1px);
}

body.dark-mode .nav-link {
    color: var(--text-primary-dark) !important;
}

body.dark-mode .nav-link:hover {
     color: var(--accent-color-dark) !important;
}

/* Hero Section Styling */
.hero-section {
    background: var(--hero-gradient-light);
    padding: 6rem 20px;
    margin-bottom: 3rem;
    transition: background 0.5s ease;
    text-align: center;
    width: 100%;
    box-sizing: border-box;
    position: relative;
    overflow: hidden;
}

body.dark-mode .hero-section {
    background: var(--hero-gradient-dark);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.8);
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0) 100%);
    pointer-events: none;
}

body.dark-mode .hero-section::before {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0) 100%);
}

.hero-section .container {
    /* Keep container for content alignment but override its default padding */
    padding: 0;
}

.hero-section h1 {
    color: var(--primary-color);
    transition: color 0.5s ease;
}

body.dark-mode .hero-section h1 {
    color: var(--primary-color-dark);
}

.hero-section p {
    color: var(--text-secondary-light);
    transition: color 0.5s ease;
    max-width: 800px;
    margin: 0 auto 1.5rem auto;
}

body.dark-mode .hero-section p {
    color: var(--text-secondary-dark);
}

/* Main Content Section Styling */
.main-content-section {
    background-color: var(--background-light);
    padding: 3rem 0; /* Adjust vertical padding as needed */
    transition: background-color 0.5s ease;
}

body.dark-mode .main-content-section {
    background-color: var(--card-background-dark); /* Use card background for dark mode */
}

/* The inner container will provide horizontal padding and centering */
/* .main-content-section .container {   
}
 */

/* Search section styling */
.search-container {
    background: var(--card-background-light);
    border-radius: 15px;
    padding: 2rem;
    box-shadow: var(--card-shadow-light);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.18);
    transition: all 0.5s ease;
}

body.dark-mode .search-container {
    background: var(--card-background-dark);
    box-shadow: var(--card-shadow-dark);
    border: 1px solid var(--border-color-dark);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
}

#searchInput {
    border-radius: 25px 0 0 25px;
    padding: 1rem 1.5rem;
    border: 2px solid #e9ecef;
    font-size: 1rem;
    transition: all 0.3s ease;
}

#searchInput:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(74, 20, 140, 0.15);
    transform: scaleX(1.01);
    outline: none;
}

body.dark-mode #searchInput {
    background-color: var(--input-bg-dark);
    color: var(--text-primary-dark);
    border-color: var(--input-border-dark);
}

body.dark-mode #searchInput:focus {
    border-color: var(--primary-color-dark);
    box-shadow: 0 0 0 0.2rem rgba(156, 123, 255, 0.25);
}

#searchButton {
    border-radius: 0 25px 25px 0;
    padding: 1rem 2rem;
    background: var(--primary-color);
    border: none;
    font-weight: 500;
    transition: all 0.3s ease;
    color: white;
}

#searchButton:hover {
    background: var(--secondary-color);
    transform: translateX(2px);
}

body.dark-mode #searchButton {
    background: var(--primary-color-dark);
    color: var(--text-primary-dark);
}

body.dark-mode #searchButton:hover {
    background: var(--secondary-color-dark);
}

/* Accordion customization */
.accordion {
    margin-top: 2rem;
}

.accordion-button {
    font-weight: 600;
    padding: 1.25rem;
    background: var(--card-background-light);
    border: none;
    box-shadow: var(--card-shadow-light);
    margin-bottom: 0.5rem;
    border-radius: 10px !important;
    transition: background 0.5s ease, color 0.5s ease, box-shadow 0.5s ease;
    color: var(--text-primary-light);
}

body.dark-mode .accordion-button {
    background: var(--accordion-bg-dark);
    color: var(--text-primary-dark);
    border-color: var(--border-color-dark);
}

.accordion-button:not(.collapsed) {
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: white; /* Ensure text is light on dark gradient */
}

body.dark-mode .accordion-button:not(.collapsed) {
     background: linear-gradient(to right, var(--primary-color-dark), var(--secondary-color-dark));
     color: var(--text-primary-dark);
}

.accordion-button:focus {
    box-shadow: none;
    border-color: transparent;
}

.accordion-button::after {
    background-size: 1.2rem;
    transition: all 0.3s ease;
    filter: brightness(0) invert(0); /* Default filter for light mode */
}

body.dark-mode .accordion-button::after {
    filter: brightness(0) invert(1); /* Invert for dark mode */
}

.accordion-button:not(.collapsed)::after {
    filter: brightness(0) invert(1);
}

body.dark-mode .accordion-button:not(.collapsed)::after {
     filter: brightness(0) invert(0); /* Invert back for dark mode active */
}

.accordion-collapse {
    transition: all 0.5s ease;
}

.accordion-body {
    background-color: var(--background-light);
    transition: background-color 0.5s ease;
    color: var(--text-primary-light);
}

body.dark-mode .accordion-body {
    background-color: var(--card-background-dark);
    color: var(--text-primary-dark);
}

/* Course cards */
.course-card {
    background: var(--card-background-light);
    border-radius: 15px;
    border: none;
    box-shadow: var(--card-shadow-light);
    transition: all 0.3s ease;
    overflow: hidden;
    backdrop-filter: blur(10px); /* Enhanced Glassmorphism effect */
    -webkit-backdrop-filter: blur(10px); /* For Safari */
    border: 1px solid rgba(255, 255, 255, 0.18); /* Glassmorphism border */
}

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

body.dark-mode .course-card {
    background: var(--card-background-dark);
    box-shadow: var(--card-shadow-dark);
    border: 1px solid var(--border-color-dark);
}

body.dark-mode .course-card:hover {
     box-shadow: var(--hover-shadow-dark);
}

.course-card .card-body {
    padding: 1.5rem;
}

.course-card .card-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1.2rem;
    transition: color 0.5s ease;
}

body.dark-mode .course-card .card-title {
    color: var(--primary-color-dark);
}

.course-card .card-text a {
    color: var(--secondary-color);
    font-weight: 500;
    transition: all 0.3s ease;
}

.course-card .card-text a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

body.dark-mode .course-card .card-text a {
    color: var(--link-color-dark);
}

body.dark-mode .course-card .card-text a:hover {
    color: var(--primary-color-dark);
}

.course-card .card-text i {
    color: var(--accent-color);
    transition: color 0.5s ease;
}

body.dark-mode .course-card .card-text i {
    color: var(--accent-color-dark);
}

/* Resource cards */
.resource-card {
    background: var(--card-background-light);
    border-radius: 15px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--card-shadow-light);
    transition: all 0.3s ease;
    border: 1px solid rgba(0, 0, 0, 0.05);
    backdrop-filter: blur(10px); /* Enhanced Glassmorphism effect */
    -webkit-backdrop-filter: blur(10px); /* For Safari */
    border: 1px solid rgba(255, 255, 255, 0.18); /* Glassmorphism border */
}

.resource-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow-light);
}

body.dark-mode .resource-card {
    background: var(--card-background-dark);
    box-shadow: var(--card-shadow-dark);
    border: 1px solid var(--border-color-dark);
}

body.dark-mode .resource-card:hover {
     box-shadow: var(--hover-shadow-dark);
}

.resource-card .card-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
    transition: color 0.5s ease;
}

body.dark-mode .resource-card .card-title {
    color: var(--primary-color-dark);
}

.resource-card .card-text a {
    color: var(--secondary-color);
    font-weight: 500;
    transition: all 0.3s ease;
}

.resource-card .card-text a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

body.dark-mode .resource-card .card-text a {
    color: var(--link-color-dark);
}

body.dark-mode .resource-card .card-text a:hover {
    color: var(--primary-color-dark);
}

/* Section headers */
h2 {
    color: var(--primary-color);
    font-weight: 700;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
    transition: color 0.5s ease;
}

body.dark-mode h2 {
    color: var(--primary-color-dark);
}

h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--accent-color);
    border-radius: 2px;
    transition: background 0.5s ease;
}

body.dark-mode h2::after {
    background: var(--accent-color-dark);
}

/* Footer styling */
footer {
    background: white;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    padding: 1.5rem 0;
    margin-top: 4rem;
    transition: background-color 0.5s ease, border-color 0.5s ease;
}

body.dark-mode footer {
    background: var(--footer-bg-dark); /* Use soft dark gray for footer */
    border-top: 1px solid var(--border-color-dark);
}

footer p {
    color: var(--text-secondary-light);
    font-weight: 500;
    transition: color 0.5s ease;
}

body.dark-mode footer p {
    color: var(--text-secondary-dark);
}

footer a {
    color: var(--text-secondary-light);
    transition: color 0.5s ease;
}

body.dark-mode footer a {
     color: var(--text-secondary-dark) !important;
}

body.dark-mode footer a:hover {
     color: var(--primary-color-dark) !important;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 5px;
}

body.dark-mode ::-webkit-scrollbar-track {
    background: var(--card-background-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
    transition: background 0.5s ease;
}

body.dark-mode ::-webkit-scrollbar-thumb {
    background: var(--primary-color-dark);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color-dark);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .navbar-brand {
        font-size: 1.3rem;
    }
    
    .search-container {
        padding: 1rem;
    }
    
    #searchInput, #searchButton {
        padding: 0.8rem 1.2rem;
    }
    
    .course-card, .resource-card {
        margin-bottom: 1rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
}

/* Animation classes */
.fade-in {
    animation: fadeIn 0.8s ease-out;
    animation-fill-mode: both;
}

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

.slide-in-left {
    animation: slideInLeft 0.6s ease-out;
    animation-fill-mode: both;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-right {
    animation: slideInRight 0.6s ease-out;
    animation-fill-mode: both;
}

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

.scale-up {
    animation: scaleUp 0.5s ease-out;
    animation-fill-mode: both;
}

@keyframes scaleUp {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.accordion-button:hover {
    box-shadow: var(--hover-shadow-light);
}

body.dark-mode .accordion-button:hover {
    box-shadow: var(--hover-shadow-dark);
}

/* Adjustments for Hero Section Layout */
.hero-content {
    margin: 0 auto; /* Center content within its column */
    max-width: 800px; /* Limit width for better readability */
}

/* Resources Section */
#resources {
    background: var(--background-light);
    border-radius: 15px;
    transition: all 0.5s ease;
}

body.dark-mode #resources {
    background: var(--card-background-dark);
    box-shadow: var(--card-shadow-dark);
}

#refreshResources {
    background: var(--primary-color);
    color: white;
    border: none;
    transition: all 0.3s ease;
}

body.dark-mode #refreshResources {
    background: var(--primary-color-dark);
    color: var(--text-primary-dark);
}

#refreshResources:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

body.dark-mode #refreshResources:hover {
    background: var(--secondary-color-dark);
}