/* =========================================
   SERIES VARIABLES
========================================= */

:root{
    --series-primary:#2962ff;
    --series-text:#24324a;
    --series-border:#e8edf5;
    --series-bg:#f7f9fc;
    --series-radius:18px;
    --series-shadow:0 12px 35px rgba(30,41,59,.08);
}


/* =========================================
   LAYOUT
========================================= */

.series-layout{
    max-width:1400px;
    margin:0 auto;
    padding:40px 20px;
    display:grid;
    grid-template-columns:minmax(0,1fr) 340px;
    gap:40px;
}

.series-main{
    min-width:0;
}

.series-right{
    position:relative;
}

.series-sidebar{
    position:sticky;
    top:90px;
}


/* =========================================
   CARD
========================================= */

.series-card{
    background:#fff;
    border:1px solid var(--series-border);
    border-radius:var(--series-radius);
    overflow:hidden;
    box-shadow:var(--series-shadow);
}

.series-card-header{
    display:flex;
    align-items:center;
    gap:12px;
    padding:20px;
    border-bottom:1px solid var(--series-border);
}

.series-icon{
    font-size:22px;
}

.series-name{
    flex:1;
    font-size:16px;
    font-weight:500;
    color:var(--series-text);
    line-height:1.4;
}

.series-list-header{
    padding:16px 20px;
    border-bottom:1px solid var(--series-border);
    font-size:12px;
    font-weight:700;
    color:#8b98ad;
    letter-spacing:.08em;
    text-transform:uppercase;
}


/* =========================================
   CHAPTER LIST
========================================= */

.series-list{
    margin:0;
    padding:0;
    list-style:none;
}

.series-list li{
    border-bottom:1px solid #eef2f7;
    transition:.2s;
}

.series-list li:last-child{
    border-bottom:none;
}

.series-list a{
    display:flex;
    align-items:center;
    gap:14px;
    padding:10px 20px;
    text-decoration:none;
    color:inherit;
    transition:.2s;
}

.series-list a:hover{
    background:#f8fbff;
}

.series-number{
    width:34px;
    height:34px;
    border-radius:50%;
    background:#edf4ff;
    color:var(--series-primary);
    display:flex;
    align-items:center;
    justify-content:center;
    flex-shrink:0;
    font-weight:700;
    font-size:13px;
}

.series-title{
    flex:1;
    color:var(--series-text);
    font-size:15px;
    line-height:1.45;
    overflow:hidden;
    display:-webkit-box;
    -webkit-line-clamp:1;
    -webkit-box-orient:vertical;
}

.series-list li.active{
    background:#eef4ff;
}

.series-list li.active .series-number{
    background:var(--series-primary);
    color:#fff;
}

.series-list li.active .series-title{
    color:var(--series-primary);
    font-weight:600;
}


/* =========================================
   FLOAT BUTTON
========================================= */

.series-mobile-toggle{
    display:none;
}

.series-mobile-toggle button{
    border:none;
    background:var(--series-primary);
    color:#fff;
    height:54px;
    padding:0 18px;
    border-radius:999px;
    display:flex;
    align-items:center;
    gap:10px;
    font-size:14px;
    font-weight:600;
    cursor:pointer;
    box-shadow:0 12px 30px rgba(41,98,255,.35);
}


/* =========================================
   MOBILE DRAWER
========================================= */

.series-mobile-panel{
    position:fixed;
    inset:0;
    opacity:0;
    visibility:hidden;
    transition:.25s;
    z-index:99999;
}

.series-mobile-panel.active{
    opacity:1;
    visibility:visible;
}

.series-mobile-overlay{
    position:absolute;
    inset:0;
    background:rgba(0,0,0,.45);
}

.series-mobile-content{
    position:absolute;
    left:0;
    right:0;
    bottom:0;
    max-height:80vh;
    background:#fff;
    border-radius:22px 22px 0 0;
    overflow:hidden;
    transform:translateY(100%);
    transition:.25s;
}

.series-mobile-panel.active .series-mobile-content{
    transform:translateY(0);
}

.series-mobile-handle{
    width:60px;
    height:5px;
    background:#d5dbe5;
    border-radius:999px;
    margin:12px auto;
}

.series-mobile-header{
    display:flex;
    align-items:center;
    justify-content:space-between;
    padding:0 20px 18px;
    border-bottom:1px solid var(--series-border);
}

.series-mobile-title{
    font-size:18px;
    font-weight:700;
}

.series-mobile-count{
    margin-top:5px;
    color:#6b7280;
    font-size:13px;
}

.series-mobile-close{
    width:40px;
    height:40px;
    border:none;
    border-radius:50%;
    background:#f5f5f5;
    cursor:pointer;
    font-size:18px;
}

.series-mobile-list{
    max-height:60vh;
    overflow:auto;
}

.series-mobile-item{
    display:flex;
    align-items:center;
    gap:14px;
    padding:16px 20px;
    text-decoration:none;
    color:#222;
    border-bottom:1px solid #f2f2f2;
}

.series-mobile-item.active{
    background:#eef4ff;
}

.series-mobile-item.active .series-mobile-number{
    background:var(--series-primary);
    color:#fff;
}

.series-mobile-number{
    width:36px;
    height:36px;
    border-radius:50%;
    background:#edf4ff;
    color:var(--series-primary);
    display:flex;
    justify-content:center;
    align-items:center;
    flex-shrink:0;
    font-weight:700;
}

.series-mobile-text{
    flex:1;
    line-height:1.45;
}

.series-lock{
    overflow:hidden;
}
/* =========================================
   HEADER
========================================= */

.series-header{
    margin-bottom:40px;
}

.series-breadcrumb{
    display:flex;
    align-items:center;
    gap:8px;
    font-size:14px;
    color:#6b7280;
    margin-bottom:18px;
}

.series-breadcrumb a{
    color:inherit;
    text-decoration:none;
}

.series-breadcrumb a:hover{
    color:var(--series-primary);
}

.series-header h1{
    font-size:40px;
    line-height:1.3;
    color:var(--series-text);
    margin:0 0 20px;
}

.series-meta{
    display:flex;
    flex-wrap:wrap;
    gap:15px;
    margin-bottom:20px;
    color:#6b7280;
    font-size:14px;
}

.series-progress{
    width:100%;
    height:6px;
    border-radius:999px;
    background:#edf2f7;
    overflow:hidden;
}

.series-progress span{
    display:block;
    height:100%;
    background:var(--series-primary);
}


/* =========================================
   ARTICLE
========================================= */

.series-main article{
    font-size:17px;
    line-height:1.85;
    color:#374151;
}

.series-main img{
    max-width:100%;
    height:auto;
    border-radius:12px;
}

.series-main table{
    width:100%;
    overflow:auto;
    display:block;
}


/* =========================================
   PREVIOUS / NEXT
========================================= */

.series-navigation{
    display:grid;
    grid-template-columns:repeat(2,minmax(0,1fr));
    gap:20px;
    margin-top:50px;
    padding-top:30px;
    border-top:1px solid var(--series-border);
}

.series-nav-col{
    display:flex;
}

.series-nav{
    width:100%;
}

.series-nav.next{
    text-align:right;
}

.series-nav:hover{
    transform:translateY(-4px);
    box-shadow:0 12px 25px rgba(0,0,0,.08);
}

.series-nav-label{
    display:block;
    margin-bottom:8px;
    font-size:13px;
    color:#6b7280;
}

.series-nav strong{
    display:block;
    color:#111827;
    line-height:1.5;
    font-size:15px;
}

.series-nav.center{
    text-align:center;
}

.series-nav.next{
    text-align:right;
}


/* =========================================
   TABLET
========================================= */

@media (max-width:1200px){

    .series-layout{
        grid-template-columns:minmax(0,1fr) 300px;
        gap:30px;
    }

}


/* =========================================
   MOBILE
========================================= */

@media (max-width:991px){

    .series-layout{
        grid-template-columns:1fr;
        gap:0;
        padding:25px 15px 90px;
    }

    .series-right{
        display:none;
    }

    .series-header{
        margin-bottom:25px;
    }

    .series-header h1{
        font-size:30px;
        line-height:1.35;
    }

    .series-main article{
        font-size:16px;
        line-height:1.8;
    }

    .series-navigation{
        grid-template-columns:1fr;
        gap:15px;
        margin-top:40px;
    }

    .series-nav.center{
        order:-1;
    }

    .series-nav.next{
        text-align:left;
    }

    .series-mobile-toggle{
        display:block;
        position:fixed;
        right:18px;
        bottom:18px;
        z-index:9999;
    }

}


/* =========================================
   SMALL MOBILE
========================================= */

@media (max-width:576px){

    .series-layout{
        padding:20px 12px 90px;
    }

    .series-header h1{
        font-size:26px;
    }

    .series-card-header{
        padding:16px;
    }

    .series-list a{
        padding:14px 16px;
    }

    .series-navigation{
        grid-template-columns:1fr;
    }

    .series-nav.next{
        text-align:left;
    }

    .series-nav{
        padding:16px;
    }

}