:root {
    --primary-color: #6a11cb;
    --secondary-color: #2575fc;
    --background-color: #f0f2f5;
    --card-background-color: #ffffff;
    --text-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --danger-color: #e74c3c;
    --danger-hover-color: #c0392b;
    --github-color: #333;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 2rem;
    font-size: 18px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    padding-bottom: 1.5rem;
    border-bottom: 3px solid transparent;
    border-image: linear-gradient(to right, var(--primary-color), var(--secondary-color)) 1;
}

header h1 {
    margin: 0;
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
}

.primary-btn {
    background-image: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 14px 28px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

#certificate-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    gap: 2.5rem;
}

.certificate-card {
    background-color: var(--card-background-color);
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
    padding: 2.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 5px solid var(--secondary-color);
    display: flex;
    flex-direction: column;
    animation: fadeInUp 0.5s ease forwards;
    opacity: 0;
}

.certificate-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.certificate-card h3 {
    margin-top: 0;
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.certificate-card p {
    line-height: 1.8;
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.certificate-link-btn {
    display: inline-block;
    padding: 12px 24px;
    background-color: var(--github-color);
    color: #fff;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    text-align: center;
    transition: background-color 0.3s ease, transform 0.3s ease;
    margin-top: 1rem;
}

.certificate-link-btn:hover {
    background-color: #555;
    transform: translateY(-2px);
}

.card-actions {
    display: flex;
    justify-content: flex-end;
    margin-top: auto;
    padding-top: 1.5rem;
    gap: 0.75rem;
}

.card-actions button {
    background: none;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.card-actions .delete-btn {
    border-color: var(--danger-color);
    color: var(--danger-color);
}

.card-actions button:hover {
    color: white;
    background-color: var(--secondary-color);
}

.card-actions .delete-btn:hover {
    background-color: var(--danger-color);
    border-color: var(--danger-color);
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.6);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: #fefefe;
    margin: 8% auto;
    padding: 3rem;
    border: 1px solid #888;
    width: 90%;
    max-width: 650px;
    border-radius: 12px;
    position: relative;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.2);
}

.modal-content h2 {
    text-align: center;
    font-size: 2.2rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
}

.close-button {
    color: #aaa;
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    font-size: 2.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.close-button:hover,
.close-button:focus {
    color: black;
}

.form-group {
    margin-bottom: 1.75rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 600;
    font-size: 1.25rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
    font-size: 1.2rem;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 8px rgba(37, 117, 252, 0.5);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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