/* Custom CSS for Exam Preparation Website */

:root {
    --primary-color: #4e73df;
    --primary-dark: #3a56b0;
    --secondary-color: #1cc88a;
    --secondary-dark: #169a6a;
    --dark-color: #2e3951;
    --light-color: #f8f9fc;
    --danger-color: #e74a3b;
    --warning-color: #f6c23e;
    --info-color: #36b9cc;
    --gray-100: #f8f9fc;
    --gray-200: #eaecf4;
    --gray-300: #dddfeb;
    --gray-400: #d1d3e2;
    --gray-500: #b7b9cc;
    --gray-600: #858796;
    --gray-700: #6e707e;
    --gray-800: #5a5c69;
    --gray-900: #3a3b45;
    --transition-speed: 0.3s;
}

/* General Styles */
body {
    /* Use Poppins across the site; fall back to system fonts if unavailable */
    font-family: 'Poppins', 'Nunito', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--light-color);
    color: var(--gray-800);
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.dark-mode {
    background-color: var(--gray-900);
    color: var(--gray-300);
}

h1, h2, h3, h4, h5, h6 {
    /* Keep headings bold but inherit the Poppins family */
    font-family: inherit;
    font-weight: 700;
    color: var(--dark-color);
}

.dark-mode h1, .dark-mode h2, .dark-mode h3, .dark-mode h4, .dark-mode h5, .dark-mode h6 {
    color: var(--gray-200);
}

a {
    color: var(--primary-color);
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--primary-dark);
    text-decoration: none;
}

.btn {
    font-weight: 600;
    border-radius: 0.35rem;
    padding: 0.5rem 1.2rem;
    transition: all var(--transition-speed);
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
}

.btn-success {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-success:hover {
    background-color: var(--secondary-dark);
    border-color: var(--secondary-dark);
}

.btn-outline-primary {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline-primary:hover {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.text-primary {
    color: var(--primary-color) !important;
}

.bg-primary {
    background-color: var(--primary-color) !important;
}

.text-secondary {
    color: var(--secondary-color) !important;
}

.bg-secondary {
    background-color: var(--secondary-color) !important;
}

/* Navbar */
.navbar {
    box-shadow: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
    background-color: white;
    transition: background-color var(--transition-speed);
}

.dark-mode .navbar {
    background-color: var(--gray-800);
    box-shadow: 0 0.15rem 1.75rem 0 rgba(0, 0, 0, 0.3);
}

.navbar-brand {
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--primary-color) !important;
}

.nav-link {
    font-weight: 600;
    padding: 0.5rem 1rem !important;
    color: var(--gray-700) !important;
}

.dark-mode .nav-link {
    color: var(--gray-300) !important;
}

.nav-link:hover, .nav-link.active {
    color: var(--primary-color) !important;
}

.dark-mode .nav-link:hover, .dark-mode .nav-link.active {
    color: var(--primary-color) !important;
}

/* Cards */
.card {
    border: none;
    border-radius: 0.5rem;
    box-shadow: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.1);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed), background-color var(--transition-speed);
}

.dark-mode .card {
    background-color: var(--gray-800);
    box-shadow: 0 0.15rem 1.75rem 0 rgba(0, 0, 0, 0.2);
}

.hover-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 0.5rem 2rem 0 rgba(58, 59, 69, 0.15);
}

.dark-mode .hover-card:hover {
    box-shadow: 0 0.5rem 2rem 0 rgba(0, 0, 0, 0.3);
}

.card-title {
    font-weight: 700;
    color: var(--dark-color);
}

.dark-mode .card-title {
    color: var(--gray-200);
}

.dark-mode .card-text, .dark-mode .text-muted {
    color: var(--gray-400) !important;
}

/* Icon Box */
.icon-box {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: rgba(78, 115, 223, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
}

/* Footer */
footer {
    background-color: white;
    color: var(--gray-700);
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.dark-mode footer {
    background-color: var(--gray-800);
    color: var(--gray-300);
}

footer a {
    color: var(--gray-700);
    transition: color var(--transition-speed);
}

.dark-mode footer a {
    color: var(--gray-300);
}

footer a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero-section {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
}

/* Subject Cards */
.subject-card {
    border-radius: 0.5rem;
    overflow: hidden;
    height: 100%;
}

.subject-card .card-img-overlay {
    background: linear-gradient(to bottom, rgba(0,0,0,0.1) 0%, rgba(0,0,0,0.8) 100%);
}

/* Quiz Styles */
.question-card {
    border-left: 4px solid var(--primary-color);
}

.options-list .form-check {
    padding: 1rem;
    border: 1px solid var(--gray-300);
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    transition: all var(--transition-speed);
}

.dark-mode .options-list .form-check {
    border-color: var(--gray-700);
}

.options-list .form-check:hover {
    background-color: var(--gray-100);
    border-color: var(--primary-color);
}

.dark-mode .options-list .form-check:hover {
    background-color: var(--gray-800);
    border-color: var(--primary-color);
}

.options-list .form-check-input:checked ~ .form-check-label {
    color: var(--primary-color);
    font-weight: 600;
}

.question-nav-btn {
    width: 40px;
    height: 40px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Notes Styles */
.note-body {
    line-height: 1.8;
}

.note-body h2, .note-body h3 {
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.note-body img {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    margin: 1.5rem 0;
}

/* Dark Mode Toggle */
.dark-mode-toggle {
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color var(--transition-speed);
}

.dark-mode-toggle:hover {
    background-color: var(--gray-200);
}

.dark-mode .dark-mode-toggle:hover {
    background-color: var(--gray-700);
}

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

.animated-element {
    animation: fadeIn 0.8s ease-out forwards;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .navbar-brand {
        font-size: 1.2rem;
    }

    .hero-section {
        padding: 4rem 0;
    }
}

/* Empty State */
.empty-state {
    padding: 3rem;
    text-align: center;
}

.empty-state i {
    color: var(--gray-400);
}

.dark-mode .empty-state i {
    color: var(--gray-600);
}

/* Newsletter */
.newsletter-form .form-control {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
    height: 50px;
}

.newsletter-form .btn {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    height: 50px;
}

.newsletter-success-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: success-fade 3s forwards;
    z-index: 10;
}

@keyframes success-fade {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    20% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
    80% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
    100% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
}

.animate-message {
    animation: message-highlight 0.5s ease-in-out;
}

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

/* Search Results */
.list-group-item-action {
    transition: all var(--transition-speed);
}

.list-group-item-action:hover {
    transform: translateY(-2px);
    box-shadow: 0 0.25rem 0.75rem rgba(0, 0, 0, 0.05);
    z-index: 1;
}

/* Typing Effect */
.typing-effect {
    display: inline-block;
    min-height: 1.2em;
    position: relative;
}

.typing-text {
    display: inline-block;
}

.typing-cursor {
    display: inline-block;
    margin-left: 2px;
    font-weight: 400;
    animation: blink 0.8s step-end infinite;
    position: relative;
    top: -1px;
}

@keyframes blink {
    from, to { opacity: 1; }
    50% { opacity: 0; }
}

/* Error Pages Styling */
.error-page {
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.error-page::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(78, 115, 223, 0.05) 0%, rgba(28, 200, 138, 0.05) 100%);
    z-index: -1;
}

.dark-mode .error-page::before {
    background: linear-gradient(135deg, rgba(78, 115, 223, 0.1) 0%, rgba(28, 200, 138, 0.1) 100%);
}

.error-icon {
    position: relative;
    display: inline-block;
    animation: float 3s ease-in-out infinite;
}

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

.error-page .display-1 {
    font-size: 8rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(78, 115, 223, 0.3);
}

.dark-mode .error-page .display-1 {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.error-page h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.dark-mode .error-page h2 {
    color: var(--gray-200);
}

.error-page .lead {
    font-size: 1.25rem;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

.error-page .btn {
    padding: 0.75rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.error-page .btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.error-page .btn:hover::before {
    left: 100%;
}

.error-page .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.dark-mode .error-page .btn:hover {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.error-page .btn-outline-primary {
    border-width: 2px;
}

.error-page .btn-outline-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(78, 115, 223, 0.3);
}

/* Error page specific animations */
.error-page [data-aos] {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.error-page [data-aos].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive error page adjustments */
@media (max-width: 768px) {
    .error-page .display-1 {
        font-size: 6rem;
    }
    
    .error-page h2 {
        font-size: 2rem;
    }
    
    .error-page .lead {
        font-size: 1.1rem;
    }
    
    .error-page .btn {
        padding: 0.6rem 1.5rem;
        font-size: 1rem;
    }
}

@media (max-width: 576px) {
    .error-page .display-1 {
        font-size: 4rem;
    }
    
    .error-page h2 {
        font-size: 1.5rem;
    }
    
    .error-page .lead {
        font-size: 1rem;
    }
}

/* Error page alert styling */
.error-page .alert {
    border: none;
    border-radius: 15px;
    padding: 1.5rem;
    background: linear-gradient(135deg, rgba(54, 185, 204, 0.1), rgba(78, 115, 223, 0.1));
    border-left: 4px solid var(--info-color);
}

.dark-mode .error-page .alert {
    background: linear-gradient(135deg, rgba(54, 185, 204, 0.2), rgba(78, 115, 223, 0.2));
}

/* Popular pages section */
.error-page .btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    border-radius: 25px;
    transition: all 0.3s ease;
}

.error-page .btn-sm:hover {
    transform: translateY(-1px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.dark-mode .error-page .btn-sm:hover {
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}