html {
    scroll-behavior: smooth;
}
.gradient-bg {
    background: linear-gradient(135deg, #F8FAFC 0%, #FFFFFF 100%);
}
.hero-gradient {
    background: linear-gradient(135deg, #2563EB 0%, #06B6D4 100%);
}
.card-hover {
    transition: all 0.3s ease;
}
.card-hover:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(37, 99, 235, 0.15);
}
.thumbnail-container {
    position: relative;
    width: 100%;
    aspect-ratio: 16/9;
}
.thumbnail-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(0, 0, 0, 0.7);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}
.play-button svg {
    width: 30px;
    height: 30px;
    fill: white;
    margin-left: 2px;
}
.thumbnail-container:hover .play-button {
    background: rgba(37, 99, 235);
}

/* Base label styling */
label {
    color: #64748B;
}

/* Fix floating labels when input/select/textarea has content */
.has-content + label,
input:focus + label,
select:focus + label,
textarea:focus + label {
    font-size: 0.75rem !important;
    transform: translateY(-0.75rem) !important;
    color: #1d4ed8 !important;
}
.nav-link {
    position: relative;
}
.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #2563EB, #06B6D4);
    transition: width 0.3s ease;
}
.nav-link:hover::after {
    width: 100%;
}
.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}
.accordion-content.active {
    max-height: 500px;
}
.btn-primary {
    background: linear-gradient(135deg, #2563EB 0%, #06B6D4 100%);
    transition: all 0.3s ease;
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.3);
}
.btn-secondary {
    border: 2px solid #2563EB;
    transition: all 0.3s ease;
}
.btn-secondary:hover {
    background: #2563EB;
    color: white;
}
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
.animate-fadeInUp {
    animation: fadeInUp 0.6s ease forwards;
}
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}
.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0);
}
#backToTop {
    transition: all 0.3s ease;
}
.mobile-menu {
    transform: translateX(100%);
    transition: transform 0.3s ease;
}
.mobile-menu.active {
    transform: translateX(0);
}
/* Reading Progress Bar */
#reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, #2563EB, #06B6D4);
    z-index: 1000;
    width: 0%;
}
/* Table of Contents Sticky */
.toc-sticky {
    position: sticky;
    top: 100px;
}