/*=============== GOOGLE FONTS ===============*/
@import url("https://fonts.googleapis.com/css2?family=Grechen+Fuemen&family=Montserrat+Alternates:wght@400;500;600&display=swap");

/*=============== VARIABLES CSS ===============*/
:root {
    /*========== Colors ==========*/
    --hue: 215;
    --first-color: hsl(var(--hue), 80%, 49%);
    --first-color-alt: hsl(var(--hue), 76%, 45%);
    --black-color: hsl(0, 0%, 1%);

    /*========== Main Body Color ==========*/
    --body-color: hsl(var(--hue), 100%, 1%); /* Keep this as it was for certificates.html */
    --main-body-color: #092241; /* Added for clarity if main styles.css uses it differently */


    --container-color: #092241; /* Original container color from your CSS */
    --modal-background: rgba(0, 0, 0, 0.9); /* Darker background for modal */


    /*========== Text ==========*/
    --white-color: hsl(0, 0%, 98%);
    --text-color: hsl(var(--hue), 2%, 66%);


    /*========== Font and typography ==========*/
    --body-font: "Montserrat Alternates", sans-serif;
    --second-font: "Grechen Fuemen", cursive;
    --biggest-font-size: 2.5rem;
    --h1-font-size: 1.5rem;
    --h2-font-size: 1.25rem;
    --h3-font-size: 1rem;
    --normal-font-size: .938rem;
    --small-font-size: .813rem;
    --smaller-font-size: .75rem;

    /*========== Font weight ==========*/
    --font-regular: 400;
    --font-medium: 500;
    --font-semi-bold: 600;

    /*========== z index ==========*/
    --z-tooltip: 10;
    --z-fixed: 100;
    --z-modal: 1000; /* New z-index for modal */
}

/*========== Responsive typography ==========*/
@media screen and (min-width: 1168px) {
    :root {
        --biggest-font-size: 3.5rem;
        --h1-font-size: 2.25rem;
        --h2-font-size: 1.5rem;
        --h3-font-size: 1.25rem;
        --normal-font-size: 1rem;
        --small-font-size: .875rem;
        --smaller-font-size: .813rem;
    }
}

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

html {
    scroll-behavior: smooth;
}

body,
input,
textarea,
button {
    font-family: var(--body-font);
    font-size: var(--normal-font-size);
}

body {
    background-color: var(--body-color);
    color: var(--white-color);
}

/*=============== ANIMATION CLASSES ===============*/
/* Hidden state for scroll reveal */
.hidden {
    opacity: 0;
    transform: translateY(20px);
}

/* Animation for fade-in effect */
.fade-in.show,
.certificate-card.show { /* Apply 'show' class to trigger animation */
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

/* For staggered effect */
.fade-in:nth-child(even) {
    transition-delay: 0.1s;
}
.fade-in:nth-child(odd) {
    transition-delay: 0s;
}

/*=============== FILTER BUTTONS ===============*/
.filter-buttons-section {
    padding: 2rem 1rem;
    background-color: var(--container-color);
    text-align: center;
    border-bottom: 1px solid hsla(0, 0%, 98%, .1);
}

.filter-buttons-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap; /* Allows buttons to wrap on smaller screens */
    max-width: 800px;
    margin: 0 auto;
}

.filter-btn {
    background-color: var(--black-color);
    color: var(--white-color);
    border: 2px solid var(--first-color);
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    cursor: pointer;
    font-weight: var(--font-medium);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, transform 0.2s ease;
}

.filter-btn:hover {
    background-color: var(--first-color-alt);
    transform: translateY(-2px);
}

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

/* Certificates Section */
.certificates-section {
    padding: 4rem 2rem;
    background-color: var(--container-color);
    text-align: center;
    margin-bottom: 2rem;
}

.section-title {
    font-size: var(--h1-font-size);
    margin-bottom: 2rem;
    font-weight: var(--font-semi-bold);
    color: var(--first-color);
}

.certificates-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(175px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;

    /* For filter transition */
    transition: all 0.5s ease-out;
}

.certificate-card {
    background-color: var(--body-color);
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 4px 15px var(--first-color);
    cursor: pointer; /* Indicates clickability for modal */

    /* For 3D hover effect */
    transform-style: preserve-3d;
    transition: transform 0.3s ease, opacity 0.5s ease; /* Added opacity transition for filtering */

    /* Hidden by default for filtering */
    opacity: 1; /* Default to visible for initial load, JS handles hiding */
}

/* 3D Hover Effect */
.certificate-card:hover {
    transform: perspective(1000px) rotateY(5deg) rotateX(-5deg) scale(1.05); /* Combined 3D tilt with existing scale */
    box-shadow: 0 8px 25px var(--first-color); /* More pronounced shadow on hover */
}

.certificate-card img {
    width: 100%;
    height: auto;
    display: block;
}

.certificate-card h3 {
    font-size: var(--normal-font-size);
    margin: 1rem 0.5rem;
}

.certificate-card p {
    font-size: var(--small-font-size);
    color: var(--text-color);
    margin-bottom: 1rem;
}

.certificate-card h3 a {
    color: var(--white-color);
    text-decoration: none;
}

.certificate-card h3 a:hover {
    color: var(--first-color);
    text-decoration: underline;
}

/* Filtering Animations (CSS-driven) */
.certificate-card.hide {
    opacity: 0;
    height: 0; /* Collapse height to remove from layout flow */
    margin: 0; /* Remove margin to prevent empty gaps */
    padding: 0; /* Remove padding */
    transition: opacity 0.5s ease, height 0.5s ease, margin 0.5s ease, padding 0.5s ease;
}
.certificate-card:not(.hide) {
    height: auto; /* Restore height when not hidden */
    padding: 1rem; /* Adjust padding as per your design. Assuming 1rem based on original card padding. Adjust if necessary. */
    margin: 0; /* Reset margin */
}


.back-btn {
    display: block;
    width: fit-content;
    margin: 2rem auto;
    padding: 0.75rem 1.5rem;
    background-color: var(--first-color);
    color: var(--white-color);
    font-size: 1rem;
    font-weight: bold;
    text-decoration: none;
    border-radius: 1rem;
    transition: background-color 0.3s, transform 0.2s;
}

.back-btn:hover {
    background-color: var(--first-color-alt);
    transform: translateY(-.25rem);
}

/*=============== MODAL STYLES (for click-to-enlarge) ===============*/
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--modal-background);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background-color: var(--body-color);
    padding: 2rem;
    border-radius: 1rem;
    max-width: 90vw;
    max-height: 90vh;
    overflow-y: auto; /* Enable scrolling for large images */
    position: relative;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.5);
    transform: scale(0.5); /* Initial state for entry animation */
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1); /* Final state for entry animation */
}

.modal-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto 1rem;
    border-radius: 0.5rem;
}

.modal-title {
    font-size: var(--h2-font-size);
    margin-bottom: 0.5rem;
    color: var(--white-color);
}

.modal-description {
    font-size: var(--normal-font-size);
    color: var(--text-color);
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 20px;
    color: var(--white-color);
    font-size: 2.5rem;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-btn:hover {
    color: var(--first-color);
}

/*=============== Responsive Adjustments for Modal ===============*/
@media screen and (max-width: 768px) {
    .modal-content {
        padding: 1.5rem;
    }
    .close-btn {
        font-size: 2rem;
        top: 5px;
        right: 15px;
    }
}