:root{
    --primary:#635bff;
    --primary-dark:#4338ca;
    --secondary:#ec4899;
    --accent:#14b8a6;
    --accent-2:#f59e0b;
    --bg:#f8fbff;
    --bg-soft:#eef4ff;
    --bg-card:rgba(255,255,255,0.78);
    --text:#122033;
    --muted:#66758a;
    --white:#ffffff;
    --border:rgba(99,91,255,0.12);
    --shadow:0 18px 60px rgba(67, 56, 202, 0.12);
    --shadow-lg:0 30px 80px rgba(17, 24, 39, 0.16);
    --radius-xl:32px;
    --radius-lg:24px;
    --radius-md:18px;
    --max:1280px;
    --student-workspace-width:calc(100% - clamp(24px, 4vw, 72px));
}

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:'Nunito',sans-serif;
}

html{
    scroll-behavior:smooth;
}

body{
    background:
        radial-gradient(circle at top left, rgba(99,91,255,0.16), transparent 28%),
        radial-gradient(circle at top right, rgba(236,72,153,0.16), transparent 24%),
        radial-gradient(circle at 20% 80%, rgba(20,184,166,0.10), transparent 26%),
        linear-gradient(180deg, #f7faff 0%, #fdfcff 42%, #f7fbff 100%);
    color:var(--text);
    overflow-x:hidden;
}

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

img{
    max-width:100%;
    display:block;
}

.container{
    width:min(var(--max), calc(100% - 40px));
    margin:0 auto;
}

.student-workspace > .container,
.student-workspace > .unit-page-container{
    width:var(--student-workspace-width) !important;
    max-width:none !important;
    margin-right:auto;
    margin-left:auto;
}

/* ===== Floating blobs ===== */
.page-blob{
    position:fixed;
    z-index:-1;
    border-radius:999px;
    filter:blur(50px);
    opacity:0.5;
    pointer-events:none;
}

.blob-1{
    width:320px;height:320px;
    background:rgba(99,91,255,0.16);
    top:40px;left:-90px;
}

.blob-2{
    width:260px;height:260px;
    background:rgba(236,72,153,0.14);
    top:380px;right:-90px;
}

.blob-3{
    width:240px;height:240px;
    background:rgba(20,184,166,0.12);
    bottom:120px;left:8%;
}

/* ===== Buttons ===== */
.btn{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    gap:10px;
    padding:14px 24px;
    border-radius:999px;
    font-weight:800;
    transition:all .25s ease;
    border:1px solid transparent;
}

.btn-primary{
    color:#fff;
    background:linear-gradient(135deg, var(--primary), var(--secondary));
    box-shadow:0 12px 28px rgba(99,91,255,0.28);
}

.btn-primary:hover{
    transform:translateY(-2px);
    box-shadow:0 18px 34px rgba(99,91,255,0.34);
}

.btn-secondary{
    color:var(--primary);
    background:rgba(255,255,255,0.78);
    border-color:rgba(99,91,255,0.18);
    backdrop-filter:blur(10px);
}

.btn-secondary:hover{
    transform:translateY(-2px);
    background:#fff;
}

/* ===== Navbar ===== */
.site-nav{
    position:sticky;
    top:0;
    z-index:1000;
    padding:16px 0;
    backdrop-filter:blur(16px);
    background:rgba(248,251,255,0.74);
    border-bottom:1px solid rgba(255,255,255,0.55);
}

.nav-inner{
    width:min(var(--max), calc(100% - 40px));
    margin:0 auto;
    display:flex;
    align-items:center;
    justify-content:space-between;
    gap:20px;
    padding:8px 0;
}

.logo{
    display:block;
    width:212px;
    height:42px;
    flex:0 0 212px;
    overflow:hidden;
    background:url("/static/img/co-tutoring-logo.png") left center / contain no-repeat;
    color:transparent;
    font-size:0;
    line-height:0;
}

.logo-badge{
    display:none;
}

.logo span{
    display:none;
}

.nav-links{
    display:flex;
    align-items:center;
    gap:14px;
    flex-wrap:wrap;
}

.nav-links a.nav-link{
    padding:10px 14px;
    border-radius:999px;
    color:var(--muted);
    font-weight:700;
    transition:all .2s ease;
}

.nav-links a.nav-link:hover{
    background:rgba(99,91,255,0.08);
    color:var(--primary);
}

.nav-item{
    position:relative;
    padding-bottom:10px;
    margin-bottom:-10px;
}

.nav-item .nav-link{
    display:inline-flex;
    align-items:center;
    gap:6px;
}

.submenu{
    position:absolute;
    top:100%;
    left:0;
    min-width:200px;
    background:#fff;
    border:1px solid rgba(99,91,255,0.12);
    border-radius:14px;
    box-shadow:var(--shadow);
    padding:8px;
    display:none;
    z-index:20;
}

.submenu a{
    display:block;
    padding:10px 12px;
    border-radius:10px;
    color:var(--text);
    font-weight:700;
}

.submenu a:hover{
    background:rgba(99,91,255,0.08);
    color:var(--primary);
}

.nav-item:hover .submenu,
.nav-item:focus-within .submenu{
    display:block;
}

@media (max-width:900px){
    .nav-links{ display:none; }
}