/* --- Hero Section --- */
.hero {
    background: #fff;
    text-align: center;
    padding: 40px 40px;
    border-radius: 0 0 50px 50px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
    height: 130px;
}

    .hero h1 {
        font-size: clamp(2rem, 5vw, 2.8rem);
        color: #007F66;
        margin-bottom: 5px;
    }

/* --- Controls --- */
.controls-container {
    max-width: 850px;
    margin: -35px auto 30px;
    padding: 0 12px;
}

/* --- Interactive Cards --- */
.card-box {
    background: white;
    border-radius: 24px;
    padding: 1.2rem 0.2rem 0.2rem 0.2rem;
    text-align: center;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    height: 100%;
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 0px #e2e8f0;
    border: 1px solid #eee;
    position: relative;
    overflow: hidden;
}

.card-accent {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 8px;
    background-color: var(--card-color);
}

.card-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 20px rgba(0,0,0,0.08);
}

.icon-circle {
    width: 70px;
    height: 70px;
    background: #f1f5f9;
    border-radius: 20px;
    margin: 0 auto 15px;
    font-size: 32px;
    transition: 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

    .icon-circle i {
        color: #64748b;
        transition: 0.3s;
    }

.card-box:hover .icon-circle {
    background: var(--card-color);
    color: white;
}

    .card-box:hover .icon-circle i {
        color: white;
    }

.card-title {
    font-size: 1.4rem;
    color: #1e293b;
    margin-bottom: 8px;
}

.card-desc {
    font-size: 1.02rem;
    line-height: 1.4;
}

/* --- Mobile --- */
@media (max-width: 576px) {
    .card-box {
        padding: 1.2rem 0.4rem 0.2rem 0.4rem;
        border-radius: 20px;
    }

    .card-title {
        font-size: 1.2rem;
        margin-bottom: 5px;
    }

    .icon-circle {
        width: 55px;
        height: 55px;
        font-size: 24px;
        margin-bottom: 10px;
    }
}
/* WRAPPER */
.tab-wrapper {
    width: 100%;
    margin: auto;
    overflow: hidden;
}

/* RADIO BUTTONS */
input[type=radio] {
    display: none;
}

/* NAV STYLES */
.grade-nav {
    height: 50px;
    display: flex;
    position: relative;
    background: transparent;
    overflow: hidden;
    margin-bottom: 0 !important;
}

    /* BASE LABEL STYLE */
    .grade-nav label {
        flex: 1;
        text-align: center;
        line-height: 50px;
        font-size: 16px;
        font-weight: 600;
        cursor: pointer;
        transition: 0.25s ease;
        z-index: 2;
        margin-left: -1px;
        border: 1px solid #ccc;
        border-radius: 20px 20px 0 0;
        margin-bottom: 0;
    }

        /* INACTIVE COLORS (PASTEL GRADIENTS) */
        .grade-nav label.k {
            background: linear-gradient(135deg, #fcd1e5, #ffa8d1);
        }

        .grade-nav label.g1 {
            background: linear-gradient(135deg, #ffe08a, #ffbe43);
        }

        .grade-nav label.g2 {
            background: linear-gradient(135deg, #b7ffc7, #5fdc8f);
        }

        .grade-nav label.g3 {
            background: linear-gradient(135deg, #fff9a8, #fff05f);
        }

        .grade-nav label.g4 {
            background: linear-gradient(135deg, #82f8f0, #4ce3d3);
        }

        .grade-nav label.g5 {
            background: linear-gradient(135deg, #ffe6d4, #ff9e6a);
        }

        .grade-nav label.g6 {
            background: linear-gradient(135deg, #e6d4ff, #c5a8ff);
        }

        .grade-nav label.g7 {
            background: linear-gradient(135deg, #ffb2cc, #ff7399);
        }

        .grade-nav label.g8 {
            background: linear-gradient(135deg, #b3e5ff, #4db8ff);
        }

/* ACTIVE COLORS */
#k:checked ~ .grade-nav label.k,
#g1:checked ~ .grade-nav label.g1,
#g2:checked ~ .grade-nav label.g2,
#g3:checked ~ .grade-nav label.g3,
#g4:checked ~ .grade-nav label.g4,
#g5:checked ~ .grade-nav label.g5,
#g6:checked ~ .grade-nav label.g6,
#g7:checked ~ .grade-nav label.g7,
#g8:checked ~ .grade-nav label.g8 {
    background: linear-gradient(to bottom, #0b0b0b, #0a0a0a);
    color: white;
}

/* CONTENT PANEL */
.content-box {
    background: #fff;
    padding: 20px 10px;
    padding-left: 0 !important;
    padding-right: 0 !important;
    border-radius: 0 0 20px 20px;
    min-height: 230px;
    border: 1px solid #ccc;
    box-shadow: 0 10px 20px rgba(0,0,0,0.08);
    margin-top: -1px !important;
    overflow: hidden;
}

/* HIDE ALL TAB CONTENT */
.tab-content-section {
    display: none;
}

/* SHOW SELECTED TAB CONTENT */
#k:checked ~ .content-box .k-content {
    display: block;
}

#g1:checked ~ .content-box .g1-content {
    display: block;
}

#g2:checked ~ .content-box .g2-content {
    display: block;
}

#g3:checked ~ .content-box .g3-content {
    display: block;
}

#g4:checked ~ .content-box .g4-content {
    display: block;
}

#g5:checked ~ .content-box .g5-content {
    display: block;
}

#g6:checked ~ .content-box .g6-content {
    display: block;
}

#g7:checked ~ .content-box .g7-content {
    display: block;
}

#g8:checked ~ .content-box .g8-content {
    display: block;
}

/* CARD STYLES */
.exercise-card {
    border-radius: 15px;
    background: #fff;
    border: 1px solid #ccc !important;
    padding: 5px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.08);
    transition: 0.25s ease;
}

    .exercise-card:hover {
        transform: translateY(-2px);
        box-shadow: 0 6px 14px rgba(0,0,0,0.15);
    }

@media (max-width: 480px) {
    .grade-nav label {
        border-radius: 10px 10px 0 0;
    }
}