:root{
    /* Virtual University navy family */
    --vu-navy:#0E2A52;
    --vu-navy-2:#16386B;
    --vu-blue:#1D5CA8;
    --vu-sky:#E9F1FB;

    --ink:var(--vu-navy);
    --ink-soft:#4A5E78;
    --paper:#F6F9FD;
    --paper-2:#ECF2FA;
    --card:#FFFFFF;

    --orange:#F2932B;
    --orange-dark:#D97706;
    --orange-soft:#FDEBD3;
    --green-stamp:#1F7A4D;
    --line:#D9E3F0;

    /* aliases — keep old pages from breaking */
    --maroon:var(--orange);
    --maroon-dark:var(--orange-dark);
    --gold:var(--vu-navy-2);
    --gold-soft:var(--orange-soft);
    --ink-2:var(--vu-navy-2);

    --shadow-sm:0 2px 8px rgba(14,42,82,.07);
    --shadow-md:0 8px 24px rgba(14,42,82,.11);
    --shadow-lg:0 16px 40px rgba(14,42,82,.16);
    --radius:14px;
    --ease-out:cubic-bezier(.22,.68,0,1.01);
}

*{ box-sizing:border-box; margin:0; padding:0; }

html{ scroll-behavior:smooth; overflow-x:hidden; width:100%; }

body{
    background:var(--paper);
    color:var(--ink);
    font-family:'Inter',sans-serif;
    line-height:1.5;
    -webkit-font-smoothing:antialiased;
    overflow-x:hidden;
    width:100%;
}

.mono{ font-family:'IBM Plex Mono',monospace; }
.slab{ font-family:'Zilla Slab',serif; }

a{ color:inherit; text-decoration:none; }

.wrap{ max-width:1180px; margin:0 auto; padding:0 24px; }

/* ===== HEADER ===== */
header{
    background:rgba(255,255,255,.92);
    backdrop-filter:blur(10px);
    position:sticky; top:0;
    z-index:110;
    box-shadow:var(--shadow-sm);
    border-bottom:1px solid var(--line);
}
.header-inner{
    display:flex;
    align-items:center;
    justify-content:space-between;
    padding-top:8px;
    padding-bottom:8px;
}
.logo{ display:flex; align-items:center; flex-shrink:0; }
.logo-img{ height:72px; width:auto; display:block; transition:transform .2s; }
.logo-img:hover{ transform:scale(1.05); }

@media (max-width:768px){ .logo-img{ height:64px; } }
@media (max-width:480px){ .logo-img{ height:52px; } }

header nav{
    display:flex; gap:30px;
    font-size:.92rem; font-weight:600;
}
header nav a{
    color:var(--ink); opacity:.72;
    position:relative; padding-bottom:4px;
    transition:opacity .2s, color .2s;
}
header nav a::after{
    content:''; position:absolute;
    left:0; bottom:0; width:0; height:2px;
    background:linear-gradient(90deg,var(--orange),var(--vu-blue));
    transition:width .3s var(--ease-out);
}
header nav a:hover{ opacity:1; }
header nav a:hover::after{ width:100%; }

.header-right{ display:flex; align-items:center; gap:16px; }
.cart-pill{
    display:flex; align-items:center; gap:8px;
    background:linear-gradient(135deg,var(--vu-navy-2),var(--vu-navy));
    color:#fff; padding:9px 16px;
    border-radius:24px; font-size:.85rem; font-weight:700;
    transition:transform .2s, box-shadow .2s;
}
.cart-pill:hover{ transform:translateY(-2px); box-shadow:var(--shadow-md); }
.faq-link{ font-size:.85rem; font-weight:700; opacity:.75; transition:opacity .2s, color .2s; }
.faq-link:hover{ opacity:1; color:var(--orange); }

/* ===== HAMBURGER ===== */
.menu-toggle{
    display:none;
    flex-direction:column; justify-content:center; align-items:center;
    gap:5px;
    background:var(--vu-sky);
    border:1.5px solid var(--line);
    border-radius:10px;
    cursor:pointer;
    padding:10px;
    width:44px; height:44px;
    transition:background .25s, border-color .25s, transform .2s;
}
.menu-toggle:hover{ background:var(--orange-soft); border-color:var(--orange); }
.menu-toggle:active{ transform:scale(.92); }

.menu-toggle-bar{
    display:block;
    width:20px; height:2.5px;
    background:var(--vu-navy);
    border-radius:4px;
    transform-origin:center;
    transition:transform .38s var(--ease-out), opacity .25s ease, background .3s;
    animation:bar-in .5s var(--ease-out) backwards;
}
.menu-toggle-bar:nth-child(2){ animation-delay:.08s; }
.menu-toggle-bar:nth-child(3){ animation-delay:.16s; }
@keyframes bar-in{ from{ transform:scaleX(0); opacity:0; } }

.menu-toggle:hover .menu-toggle-bar:nth-child(1){ transform:translateX(2.5px); }
.menu-toggle:hover .menu-toggle-bar:nth-child(3){ transform:translateX(-2.5px); }

.menu-toggle.active{ background:var(--vu-navy); border-color:var(--vu-navy); }
.menu-toggle.active .menu-toggle-bar{ background:var(--orange); }
.menu-toggle.active .menu-toggle-bar:nth-child(1){ transform:translateY(7.5px) rotate(45deg); }
.menu-toggle.active .menu-toggle-bar:nth-child(2){ opacity:0; transform:scaleX(.2); }
.menu-toggle.active .menu-toggle-bar:nth-child(3){ transform:translateY(-7.5px) rotate(-45deg); }

/* ===== MOBILE DRAWER OVERLAY ===== */
.nav-overlay{
    display:none;
    position:fixed; inset:0;
    background:rgba(14,42,82,.55);
    backdrop-filter:blur(3px);
    z-index:95;
    opacity:0;
    transition:opacity .35s ease;
}
.nav-overlay.active{ display:block; opacity:1; }

/* ===== SECTIONS ===== */
.section{ padding:76px 0; }
.section-head{
    display:flex;
    justify-content:space-between;
    align-items:flex-end;
    margin-bottom:40px;
    gap:20px;
    flex-wrap:wrap;
}
.section-head h2{
    font-family:'Zilla Slab',serif;
    font-size:2rem;
    font-weight:700;
}
.section-head .tag{
    font-family:'IBM Plex Mono',monospace;
    font-size:.7rem;
    text-transform:uppercase;
    letter-spacing:.1em;
    color:var(--maroon);
    margin-bottom:8px;
    display:block;
}

/* ===== SEARCH BOX ===== */
.search-slip{
    background:var(--card);
    border:1.5px solid var(--ink);
    border-radius:6px;
    padding:18px 20px;
    box-shadow:6px 6px 0 var(--maroon);
}
.search-slip .label-row{
    display:flex;
    justify-content:space-between;
    font-family:'IBM Plex Mono',monospace;
    font-size:.68rem;
    letter-spacing:.08em;
    text-transform:uppercase;
    color:var(--ink-soft);
    margin-bottom:10px;
}
.search-row{ display:flex; gap:10px; }
.search-row input{
    flex:1;
    min-width:0;
    border:1px solid var(--line);
    border-radius:4px;
    padding:12px 14px;
    font-family:'Inter',sans-serif;
    font-size:.95rem;
    background:var(--paper);
}
.search-row input:focus{ outline:2px solid var(--maroon); outline-offset:1px; }

/* ===== BUTTONS ===== */
.btn{
    border:none;
    cursor:pointer;
    font-weight:700;
    font-size:.92rem;
    border-radius:4px;
    padding:12px 20px;
    transition:transform .15s ease, background .2s;
}
.btn:focus-visible{ outline:3px solid var(--ink); outline-offset:2px; }
.btn:active{ transform:translateY(1px); }
.btn-primary{ background:var(--maroon); color:#fff; }
.btn-primary:hover{ background:var(--maroon-dark); }
.btn-add{
    background:var(--ink);
    color:var(--paper);
    font-size:.78rem;
    padding:8px 14px;
}
.btn-add:hover{ background:var(--maroon); }

/* ===== BOOK GRID ===== */
.book-grid{
    display:grid;
    grid-template-columns:repeat(auto-fill, minmax(230px, 1fr));
    gap:22px;
}
.book-card{
    background:var(--card);
    border:1.5px solid var(--ink);
    border-radius:8px;
    padding:18px;
    position:relative;
    transition:transform .18s ease, box-shadow .18s ease;
}
.book-card:hover{
    transform:translateY(-4px);
    box-shadow:5px 8px 0 var(--gold);
}
.book-card .hole{
    position:absolute;
    top:14px; right:14px;
    width:14px; height:14px;
    border-radius:50%;
    background:var(--paper);
    border:1.5px solid var(--line);
}
.book-card .code{
    font-family:'IBM Plex Mono',monospace;
    font-size:.72rem;
    font-weight:600;
    color:var(--maroon-dark);
    letter-spacing:.04em;
    margin-bottom:8px;
    display:inline-block;
    background:var(--gold-soft);
    padding:2px 8px;
    border-radius:2px;
}
.book-card h3{
    font-family:'Zilla Slab',serif;
    font-size:1.08rem;
    font-weight:600;
    margin:4px 0 14px;
    line-height:1.3;
    min-height:2.6em;
}
.book-card .price-row{
    display:flex;
    justify-content:space-between;
    align-items:center;
    border-top:1px dashed var(--line);
    padding-top:12px;
}

/* ===== PAGINATION ===== */
nav[role="navigation"]{ display:flex; justify-content:center; }

/* ===== RESPONSIVE ===== */
@media (max-width:900px){
    header nav{ display:none; }
    .menu-toggle{ display:flex; }
    .section{ padding:48px 0; }
}

@media (max-width:400px){
    .book-grid{ grid-template-columns:1fr; }
}