/* ===== Course Page Styles ===== */

/* --- Hero --- */
.course-hero {
    min-height: 70vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 70px;
    background: linear-gradient(135deg, #0f0c29 0%, #1a1a4e 30%, #302b63 60%, #24243e 100%);
}

.course-hero::before {
    content: '';
    position: absolute;
    top: -30%; right: -20%;
    width: 700px; height: 700px;
    background: radial-gradient(circle, rgba(102,126,234,0.18) 0%, transparent 70%);
    border-radius: 50%;
    animation: coverFloat 15s ease-in-out infinite;
}

.course-hero::after {
    content: '';
    position: absolute;
    bottom: -20%; left: -15%;
    width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(118,75,162,0.12) 0%, transparent 70%);
    border-radius: 50%;
    animation: coverFloat 20s ease-in-out infinite reverse;
}

.course-hero-bg {
    width: 100%;
    position: relative;
    z-index: 1;
}

.course-hero-particles {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background-image:
        radial-gradient(1px 1px at 10% 20%, rgba(255,255,255,0.15), transparent),
        radial-gradient(1px 1px at 30% 60%, rgba(255,255,255,0.1), transparent),
        radial-gradient(1.5px 1.5px at 50% 30%, rgba(255,255,255,0.12), transparent),
        radial-gradient(1px 1px at 70% 80%, rgba(255,255,255,0.1), transparent),
        radial-gradient(1.5px 1.5px at 90% 40%, rgba(255,255,255,0.08), transparent);
    animation: particlesFloat 30s linear infinite;
}

@keyframes particlesFloat {
    0% { transform: translateY(0); }
    100% { transform: translateY(-100px); }
}

@keyframes coverFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

.course-hero-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
    position: relative;
    z-index: 1;
}

.course-hero-text { flex: 1; max-width: 620px; }

.course-hero-text h1 {
    font-size: 2.6rem;
    font-weight: 800;
    color: #fff;
    line-height: 1.25;
    margin-bottom: 16px;
}

.course-hero-hl {
    background: linear-gradient(135deg, #667eea, #a78bfa, #f472b6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.course-hero-text p {
    font-size: 1rem;
    color: rgba(255,255,255,0.7);
    line-height: 1.7;
    margin-bottom: 24px;
}

.course-hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 32px;
}

.course-hero-tags span {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 50px;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.8);
}

.course-hero-stats {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.course-hero-visual {
    flex: 0 0 320px;
}

.course-hero-card {
    background: rgba(255,255,255,0.06);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 24px;
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.course-hero-stat {
    text-align: center;
}

.course-stat-num {
    display: block;
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.course-stat-label {
    display: block;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.6);
    margin-top: 4px;
}
.course-filter-section {
    background: #fff;
    padding: 24px 0;
    border-bottom: 1px solid #f0f0f5;
    position: sticky;
    top: 70px;
    z-index: 100;
}

.course-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.course-filter-btn {
    padding: 8px 20px;
    border: 1.5px solid #e8e5f0;
    border-radius: 50px;
    background: #fff;
    font-size: 0.88rem;
    font-weight: 500;
    color: #666;
    cursor: pointer;
    transition: all 0.3s;
}

.course-filter-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.course-filter-btn.active {
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-color: transparent;
    color: #fff;
}

/* --- Course Grid Section --- */
.course-grid-section {
    padding: 60px 0 80px;
    background: #f8f9fc;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

/* --- Course Card --- */
.course-card {
    background: #fff;
    border-radius: 18px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    border: 1px solid #f0f0f5;
    transition: all 0.4s;
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 16px 40px rgba(102,126,234,0.12);
    border-color: rgba(102,126,234,0.3);
}

.course-card.hidden {
    display: none;
}

.course-card-thumb {
    position: relative;
    height: 140px;
    background: linear-gradient(135deg, #1a1a4e, #302b63);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.course-card-thumb::before {
    content: '';
    position: absolute;
    top: -50%; right: -50%;
    width: 100%; height: 100%;
    background: radial-gradient(circle, rgba(102,126,234,0.2), transparent 60%);
}

.course-card-tag {
    position: absolute;
    top: 12px; left: 12px;
    padding: 4px 10px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 700;
    border-radius: 50px;
    letter-spacing: 0.5px;
}

.course-card-icon {
    font-size: 3rem;
    position: relative;
    z-index: 1;
}

.course-card-overlay {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(15,12,41,0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
    z-index: 2;
}

.course-card:hover .course-card-overlay {
    opacity: 1;
}

.course-card-overlay span {
    padding: 8px 20px;
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 50px;
    color: #fff;
    font-size: 0.85rem;
    backdrop-filter: blur(10px);
}

.course-card-body {
    padding: 20px;
}

.course-card-meta {
    display: flex;
    gap: 12px;
    margin-bottom: 10px;
}

.course-card-level {
    padding: 3px 8px;
    background: #eef1ff;
    color: #667eea;
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: 4px;
}

.course-card-hours {
    font-size: 0.75rem;
    color: #999;
}

.course-card-title {
    font-size: 1rem;
    font-weight: 700;
    color: #1a1a2e;
    margin-bottom: 8px;
    line-height: 1.4;
}

.course-card-desc {
    font-size: 0.8rem;
    color: #888;
    line-height: 1.6;
    margin-bottom: 16px;
}

.course-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px solid #f5f5f8;
}

.course-card-price {
    display: flex;
    flex-direction: column;
}

.price-now {
    font-size: 1.1rem;
    font-weight: 800;
    color: #667eea;
}

.price-original {
    font-size: 0.75rem;
    color: #bbb;
    text-decoration: line-through;
}

.course-card-btn {
    padding: 6px 16px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    font-size: 0.78rem;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s;
}

.course-card-btn:hover {
    opacity: 0.9;
    transform: scale(1.05);
}

/* --- Why Choose Section --- */
.course-why-section {
    padding: 80px 0;
    background: #fff;
}

.course-section-title {
    text-align: center;
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.4rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.course-section-sub {
    text-align: center;
    color: #888;
    font-size: 0.95rem;
    margin-bottom: 44px;
}

.course-why-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.course-why-card {
    text-align: center;
    padding: 36px 24px;
    background: #f8f9fc;
    border-radius: 18px;
    transition: all 0.4s;
}

.course-why-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 32px rgba(102,126,234,0.1);
    border: 1px solid rgba(102,126,234,0.2);
}

.course-why-icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
}

.course-why-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #1a1a2e;
    margin-bottom: 8px;
}

.course-why-card p {
    font-size: 0.85rem;
    color: #888;
    line-height: 1.6;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .course-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .course-hero-inner {
        flex-direction: column;
        text-align: center;
    }
    .course-hero-stats {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }
    .course-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .course-why-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .course-grid {
        grid-template-columns: 1fr;
    }
    .course-why-grid {
        grid-template-columns: 1fr;
    }
}