body {
    margin: 0;
    font-family: 'Poppins', sans-serif;
    background: #f4f6f9;
}

/* ================= HERO ================= */

.hero {
    background: linear-gradient(135deg, #1e73e8, #2c5cc5);
    padding: 30px 20px 90px;
    text-align: center;
    color: white;
}

.hero h1 {
    margin: 0;
    font-size: 40px;
    font-weight: 700;
}

.hero h6 {
    margin-top: 12px;
    font-size: 16px;
    opacity: 0.9;
    font-weight: 400;
}

.card-section {
    margin-top: -80px;
    padding: 0 5% 60px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

/* ================= BREADCRUMB + STAGE HEADING ================= */

.browse-topbar {
    background: white;
    border-radius: 14px;
    padding: 18px 24px;
    margin-bottom: 25px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
}

.browse-breadcrumb {
    font-size: 14px;
    color: #667;
    margin-bottom: 6px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    row-gap: 4px;
}

.browse-breadcrumb .crumb {
    cursor: pointer;
    color: #1e73e8;
    font-weight: 500;
}

.browse-breadcrumb .crumb:hover {
    text-decoration: underline;
}

.browse-breadcrumb .crumb.active {
    color: #333;
    cursor: default;
    font-weight: 600;
}

.browse-breadcrumb .crumb.active:hover {
    text-decoration: none;
}

.browse-breadcrumb .crumb-sep {
    color: #bbb;
    font-size: 11px;
    margin: 0 4px;
}

.stage-heading {
    margin: 0;
    font-size: 22px;
    font-weight: 700;
    color: #1a2b4c;
}

/* ================= GRID ================= */

.quiz-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 35px;
}

.quiz-container.browse-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 24px;
    justify-content: initial;
}

.empty-msg {
    width: 100%;
    text-align: center;
    color: #777;
    font-size: 16px;
    padding: 40px 0;
}

/* ================= BROWSE CARDS (Course / Paper / Chapter) ================= */

.browse-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.browse-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.browse-thumb-wrap {
    width: 100%;
    height: 170px;
    overflow: hidden;
    background: #e8f0ff;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
}

.browse-thumb {
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    object-fit: contain;
    display: block;
}

.browse-card-body {
    padding: 18px 20px 22px;
}

.browse-card-body h3 {
    margin: 0 0 8px;
    font-size: 19px;
    font-weight: 600;
    color: #1e73e8;
}

.browse-subtitle {
    font-size: 13px;
    color: #666;
    margin: 0 0 14px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.browse-btn {
    width: 100%;
    border: none;
    background: #eaf1ff;
    color: #1e73e8;
    padding: 10px;
    border-radius: 8px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    pointer-events: none;
}

.browse-card:hover .browse-btn {
    background: #1e73e8;
    color: white;
}

/* ================= QUIZ CARD (final level) ================= */

.quiz-card {
    width: 320px;
    background: #ffffff;
    border-radius: 16px;
    padding: 25px;
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    display: flex;
    flex-direction: column;
    will-change: transform;
}

.quiz-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

/* Ribbon */
.ribbon {
    position: absolute;
    top: 20px;
    right: -45px;
    background: #e63946;
    color: white;
    padding: 6px 50px;
    transform: rotate(45deg);
    font-size: 12px;
    font-weight: bold;
}

.quiz-card h3 {
    margin: 10px 0;
    font-size: 17px;
    font-weight: 600;
    color: #1e73e8;
}

.quiz-card p {
    margin: 6px 0;
    font-size: 14px;
    color: #444;
}

/* Status */
.status {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: bold;
    width: fit-content;
    margin-bottom: 10px;
}

.status.upcoming {
    background: #fff3cd;
    color: #856404;
}

.status.live {
    background: #d4edda;
    color: #155724;
}

.status.ended {
    background: #f8d7da;
    color: #721c24;
}

/* Button */
.quiz-card button {
    margin-top: auto;
    padding: 12px;
    border-radius: 8px;
    border: 2px solid transparent;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.quiz-card button.active-btn {
    background: #1e73e8;
    color: white;
}

.quiz-card button.active-btn:hover {
    background: #155bb5;
    border-color: #155bb5;
}

.quiz-card button.disabled-btn {
    background: #ccc;
    color: #666;
    cursor: not-allowed;
}

.course-badge {
    display: inline-block;
    background: #1e73e8;
    color: #ffffff;
    font-size: 16px;
    padding: 5px 12px;
    border-radius: 20px;
    font-weight: 600;
    margin: 10px 0;
}

/* ================= RESPONSIVE ================= */

@media (max-width: 991px) {
    .card-section {
        margin-top: -60px;
    }
}

@media (max-width: 768px) {
    .hero {
        padding: 25px 16px 70px;
    }

    .hero h1 {
        font-size: 30px;
    }

    .hero h6 {
        font-size: 14px;
    }

    .card-section {
        padding: 0 16px 50px;
    }

    .quiz-container.browse-grid {
        grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
        gap: 18px;
    }

    .browse-thumb-wrap {
        height: 140px;
    }

    .quiz-container {
        gap: 20px;
    }
}

@media (max-width: 600px) {
    .hero h1 {
        font-size: 24px;
    }

    .browse-topbar {
        padding: 12px 14px;
    }

    .stage-heading {
        font-size: 17px;
    }

    .quiz-card {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .card-section {
        margin-top: -45px;
        padding: 0 10px 40px;
    }

    .quiz-container.browse-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .browse-thumb-wrap {
        height: 160px;
    }

    .quiz-card {
        padding: 20px;
    }
}