:root {
    --primary: #2e7d32;
    --accent: #6959CD;
    --muted: #f5f5f5;
    --shadow: 0 4px 24px rgba(0,0,0,0.08);
    --font-sans: 'Segoe UI', 'Open Sans', Arial, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
    background: #fafbfc;
    color: #222;
}

/* ===== HEADER ===== */
.course-header {
    background: #2e7d32;
    color: #fff;
    box-shadow: var(--shadow);
    padding: 10px;
    border-radius: 0 0 70px 70px;
    text-align: center;
}

.course-header h1 {
    font-size: 2.2rem;
    margin: 0;
    letter-spacing: 1px;
}

/* ===== VIDEO + DETAILS ===== */
.video-section {
    display: flex;
    gap: 32px;
    margin: 40px auto;
    max-width: 1100px;
    padding: 0 16px;
    flex-wrap: wrap;
}

.video {
    flex: 1 1 420px;
}

.details {
    flex: 1 1 420px;
    padding: 28px 24px;
    background: var(--muted);
    border-radius: 16px;
    box-shadow: var(--shadow);
}

/* ===== INFO CARDS ===== */
.course-info-icons {
    display: grid;
    grid-template-columns: repeat(2, minmax(160px, 1fr));
    gap: 14px;
    margin-bottom: 20px;
}

.course-info-icons .info-item {
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(46, 125, 50, 0.15);
    padding: 12px 14px;
    border-radius: 12px;
}

.icon {
    font-size: 1.5rem;
}

.text small {
    display: block;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--primary);
}

.text strong {
    font-size: 0.95rem;
    font-weight: 600;
    color: #1b3a24;
}

/* ===== PRICE ===== */
.price-box {
    display: inline-block;
    background: rgba(30, 174, 5, 0.35);
    padding: 16px 22px;
    border-radius: 12px;
    margin-top: 12px;
    font-size: 1.4rem;
    font-weight: 600;
    color: #0f3d2e;
    letter-spacing: 0.5px;
    backdrop-filter: blur(6px);
    box-shadow: 0 0 8px rgba(70, 160, 120, 0.35);
    animation: softGlowGreen 3s ease-in-out infinite;
}

@keyframes softGlowGreen {
    0% { box-shadow: 0 0 6px rgba(70,160,120,0.25); }
    50% { box-shadow: 0 0 12px rgba(70,160,120,0.45); }
    100% { box-shadow: 0 0 6px rgba(70,160,120,0.25); }
}

/* ===== BUTTON ===== */
.custom-button {
    margin-top: 18px;
    padding: 12px 28px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.05rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
}

.custom-button:hover {
    background: #483d8b;
}

/* ===== TABS ===== */
.course-info {
    max-width: 1100px;
    margin: 40px auto 100px;
    padding: 0 16px;
    transition: background 0.22s;
}

.course-info:hover {
    background: #6959CD22;
    box-shadow: 0 4px 24px rgba(105,89,205,0.10);
}

.topic-buttons {
    width: 48%;
    float: left;
}

.topic-button {
    width: 100%;
    margin-bottom: 12px;
    padding: 14px;
    text-align: center;
    cursor: pointer;
    border: 1.5px solid var(--accent);
    background: #fff;
    border-radius: 8px;
    font-weight: 500;
    transition: background 0.22s, color 0.18s, box-shadow 0.18s;
}
.topic-button:hover {
    background: #6959CD;
    color: #fff;
    box-shadow: 0 4px 18px rgba(105,89,205,0.13);
}

.topic-button.selected {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.topic-content {
    width: 50%;
    float: right;
    background: #fff;
    padding: 32px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: background 0.22s;
}

.topic-content:hover {
    background: #6959CD22;
    box-shadow: 0 4px 24px rgba(105,89,205,0.10);
}

/* ===== FOOTER ===== */
.footer-image img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
    .video-section { flex-direction: column; }
    .topic-buttons, .topic-content {
        width: 100%;
        float: none;
    }
}

@media (max-width: 600px) {
    .course-info-icons {
        grid-template-columns: 1fr;
    }
}