/* ========== 1. CSS Variables ========== */
:root {
    --primary: #0a4d8c;
    --primary-dark: #042449;
    --primary-light: #e8f2fb;
    --secondary: #1e3a5f;
    --accent: #2563eb;
    --accent-light: #60a5fa;
    --gold: #d4af37;
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --text: #0f172a;
    --text-light: #64748b;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --gradient-primary: linear-gradient(135deg, #0a4d8c 0%, #1e3a5f 100%);
    --gradient-accent: linear-gradient(135deg, #2563eb 0%, #60a5fa 100%);
    --gradient-gold: linear-gradient(135deg, #d4af37 0%, #f59e0b 100%);
}

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

body {
    background: linear-gradient(180deg, var(--gray-50) 0%, var(--gray-100) 100%);
    font-family: 'Prompt', 'Inter', system-ui, -apple-system, sans-serif;
    overflow-x: hidden;
}

/* ========== 2. Background Orbs ========== */
.bg-orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    z-index: 0;
    pointer-events: none;
}

.bg-orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-light), transparent);
    top: -200px;
    right: -100px;
}

.bg-orb-2 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--primary-light), transparent);
    bottom: -200px;
    left: -150px;
}

.bg-orb-3 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(212, 175, 55, 0.2), transparent);
    top: 40%;
    right: 10%;
}

/* ========== 3. Hero Section ========== */
.hero-section {
    position: relative;
    background: var(--gradient-primary);
    padding: 60px 0 80px;
    overflow: hidden;
    z-index: 1;
}

.hero-section::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 80px;
    background: linear-gradient(to top, var(--gray-50), transparent);
    z-index: 2;
}

.hero-floating {
    position: absolute;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(255,255,255,0.08), transparent);
    border-radius: 50%;
    top: -150px;
    left: -100px;
    animation: float 20s infinite ease-in-out;
}

.hero-floating-2 {
    position: absolute;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(255,255,255,0.05), transparent);
    border-radius: 50%;
    bottom: -80px;
    right: 10%;
    animation: float 15s infinite ease-in-out reverse;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    50% { transform: translate(30px, 20px) rotate(5deg); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(25px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content {
    position: relative;
    z-index: 3;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
    opacity: 0;
    animation: fadeInUp 1s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.hero-title span {
    background: linear-gradient(135deg, var(--accent-light), var(--gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1rem;
    color: rgba(255,255,255,0.85);
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.6;
    opacity: 0;
    animation: fadeInUp 1s cubic-bezier(0.4, 0, 0.2, 1) 0.3s forwards;
}

/* ========== 4. Certificate Section ========== */
.cert-section {
    position: relative;
    padding: 60px 0 80px;
    z-index: 2;
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-tag {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-light), rgba(37, 99, 235, 0.1));
    color: var(--primary);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 16px;
    opacity: 0;
    animation: fadeInUp 1s cubic-bezier(0.4, 0, 0.2, 1) 0.5s forwards;
}

.section-divider {
    width: 80px;
    height: 4px;
    background: var(--gradient-accent);
    margin: 0 auto;
    border-radius: 4px;
}

/* ========== 5. Certificate Cards ========== */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
    max-width: 400px;
    margin: 0 auto;
}

.cert-card {
    background: var(--white);
    border-radius: 24px;
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow-md);
    cursor: pointer;
    display: flex;
    flex-direction: column;
}

.cert-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-2xl);
}

.cert-card.fade-in {
    animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.cert-image-wrapper {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--gray-50), var(--white));
    padding: 20px;
    text-align: center;
    cursor: pointer;
    flex-shrink: 0;
}

.cert-image {
    width: 100%;
    height: 250px;
    object-fit: contain;
    transition: var(--transition);
}

.cert-card:hover .cert-image {
    transform: scale(1.03);
}

.zoom-icon-cert {
    position: absolute;
    bottom: 15px;
    right: 15px;
    background: rgba(10, 77, 140, 0.8);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 18px;
    opacity: 0;
    transition: var(--transition);
    backdrop-filter: blur(4px);
}

.cert-card:hover .zoom-icon-cert {
    opacity: 1;
}

.cert-body {
    padding: 20px 24px 24px;
    text-align: center;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.cert-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.cert-desc {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.5;
    flex: 1;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 12px 20px;
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
    border-radius: 60px;
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    text-align: center;
    min-height: 48px;
    margin-top: auto;
}

.btn-download i {
    font-size: 1rem;
    flex-shrink: 0;
}

.btn-download span {
    flex: 1;
    text-align: center;
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
    color: var(--white);
}

/* ========== 6. Filter Buttons ========== */
.filter-btn {
    padding: 10px 24px;
    background: var(--white);
    border: 2px solid var(--primary);
    color: var(--primary);
    border-radius: 60px;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
    font-family: 'Prompt', sans-serif;
    text-decoration: none;
    display: inline-block;
}

.filter-btn:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-2px);
    text-decoration: none;
}

.filter-btn.active {
    background: var(--primary);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

/* ========== 7. Lightbox Modal ========== */
.lightbox-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 1000;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.lightbox-modal.active {
    display: flex !important;
    align-items: center;
    justify-content: center;
    opacity: 1;
}

.lightbox-content {
    max-width: 100%;
    max-height: 100%;
    position: relative;
    animation: zoomIn 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

@keyframes zoomIn {
    from {
        transform: scale(0.8);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.lightbox-image {
    max-width: 95vw;
    max-height: 95vh;
    width: auto;
    height: auto;
    object-fit: contain;
    border-radius: 12px;
    box-shadow: var(--shadow-2xl);
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 30px;
    color: var(--white);
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    z-index: 1001;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
}

.lightbox-close:hover {
    background: rgba(255,255,255,0.2);
    transform: scale(1.1);
}

/* ========== 8. Responsive ========== */
@media (max-width: 991px) {
    .hero-title { font-size: 2rem; }
    .hero-section { padding: 50px 0 70px; }
    .section-title { font-size: 1.5rem; }
}

@media (max-width: 767px) {
    .hero-section { padding: 40px 0 60px; }
    .hero-title { font-size: 1.4rem; }
    .hero-subtitle { font-size: 0.85rem; }
    .cert-section { padding: 40px 0 60px; }
    .cert-grid { grid-template-columns: 1fr; max-width: 350px; }
    .cert-image { height: 200px; }
    .cert-body { padding: 16px 20px 20px; }
    .cert-title { font-size: 1rem; }
    .cert-desc { font-size: 0.8rem; }
    .btn-download { padding: 10px 16px; font-size: 0.8rem; min-height: 42px; }
    .zoom-icon-cert { width: 30px; height: 30px; font-size: 14px; bottom: 10px; right: 10px; }
    .lightbox-close { font-size: 30px; width: 40px; height: 40px; top: 15px; right: 20px; }
    .lightbox-image { max-width: 98vw; max-height: 90vh; }
    .filter-btn { padding: 8px 18px; font-size: 0.8rem; }
}

@media (max-width: 480px) {
    .hero-title { font-size: 1.2rem; }
    .cert-image { height: 170px; }
    .zoom-icon-cert { width: 28px; height: 28px; font-size: 12px; }
    .btn-download { padding: 8px 14px; font-size: 0.75rem; min-height: 38px; }
}