:root {
    --c-primary: #023A64;
    --c-secondary: #628EB4;
    --c-accent: #96BABE;
    --c-dark: #4B5056;
    --c-muted: #9FA7AE;
    --sidebar-w: 260px;
}

* { box-sizing: border-box; }

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: #f4f6f9;
    color: var(--c-dark);
}

/* ===== Sidebar ===== */
.app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-w);
    height: 100vh;
    background: var(--c-primary);
    color: #fff;
    overflow-y: auto;
    z-index: 1040;
    transition: transform .25s ease;
    /* Thin, subtle scrollbar (Firefox) */
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,.25) transparent;
}
/* Thin, subtle scrollbar (WebKit/Chromium) */
.app-sidebar::-webkit-scrollbar { width: 5px; }
.app-sidebar::-webkit-scrollbar-track { background: transparent; }
.app-sidebar::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,.22);
    border-radius: 4px;
}
.app-sidebar:hover::-webkit-scrollbar-thumb { background: rgba(255,255,255,.4); }
.app-sidebar .brand {
    padding: 18px 20px;
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: .5px;
    border-bottom: 1px solid rgba(255,255,255,.12);
    display: flex;
    align-items: center;
    gap: 10px;
}
.app-sidebar .nav-section {
    padding: 14px 20px 6px;
    font-size: .68rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--c-accent);
}
.app-sidebar a.nav-link {
    color: #d7e2ec;
    padding: 10px 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-left: 3px solid transparent;
    font-size: .92rem;
}
.app-sidebar a.nav-link i { width: 20px; text-align: center; }
.app-sidebar a.nav-link:hover { background: rgba(255,255,255,.08); color: #fff; }
.app-sidebar a.nav-link.active {
    background: rgba(98,142,180,.35);
    border-left-color: var(--c-accent);
    color: #fff;
    font-weight: 600;
}

/* ===== Topbar ===== */
.app-main {
    margin-left: var(--sidebar-w);
    min-height: 100vh;
    transition: margin .25s ease;
}
.app-topbar {
    background: #fff;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 22px;
    box-shadow: 0 1px 4px rgba(0,0,0,.06);
    position: sticky;
    top: 0;
    z-index: 1030;
}
.app-content { padding: 22px; }
.app-footer {
    padding: 14px 22px;
    color: var(--c-muted);
    font-size: .82rem;
    border-top: 1px solid #e6e9ee;
}

/* ===== Components ===== */
.btn-primary {
    background: var(--c-primary);
    border-color: var(--c-primary);
}
.btn-primary:hover { background: #022d4e; border-color: #022d4e; }
.btn-outline-primary { color: var(--c-primary); border-color: var(--c-primary); }
.btn-outline-primary:hover { background: var(--c-primary); border-color: var(--c-primary); }
a { color: var(--c-primary); }

.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 1px 6px rgba(0,0,0,.06);
}
.card-header {
    background: #fff;
    border-bottom: 1px solid #eef1f5;
    font-weight: 600;
    color: var(--c-primary);
    border-radius: 12px 12px 0 0 !important;
}

.stat-card { color: #fff; border-radius: 12px; }
.stat-card .stat-icon { font-size: 2rem; opacity: .35; }
.stat-card .stat-value { font-size: 1.7rem; font-weight: 700; }
.bg-c-primary { background: var(--c-primary); }
.bg-c-secondary { background: var(--c-secondary); }
.bg-c-accent { background: var(--c-accent); }
.bg-c-dark { background: var(--c-dark); }
.bg-c-muted { background: var(--c-muted); }
.text-c-primary { color: var(--c-primary) !important; }

table.dataTable thead th { background: #f1f5f9; color: var(--c-primary); }

.badge-stage { font-weight: 600; font-size: .72rem; }

/* Compact circular progress gauge */
.progress-gauge {
    --p: 0;
    --size: 64px;
    width: var(--size);
    height: var(--size);
    border-radius: 50%;
    background: conic-gradient(var(--c-primary) calc(var(--p) * 1%), #e3e7ec 0);
    display: flex;
    align-items: center;
    justify-content: center;
    flex: none;
}
.progress-gauge > span {
    width: calc(var(--size) - 14px);
    height: calc(var(--size) - 14px);
    background: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: .8rem;
    color: var(--c-primary);
}
.student-header .meta-label { font-size: .68rem; color: var(--c-muted); text-transform: uppercase; letter-spacing: .3px; }
.student-header .meta-value { font-size: .85rem; font-weight: 600; color: var(--c-dark); }

.login-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
    padding: 20px;
}
.login-card {
    width: 100%;
    max-width: 420px;
    border-radius: 16px;
    overflow: hidden;
}
.login-card .login-head {
    background: var(--c-primary);
    color: #fff;
    padding: 26px;
    text-align: center;
}

/* ===== Mobile ===== */
.sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.45);
    z-index: 1035;
}
@media (max-width: 991.98px) {
    .app-sidebar { transform: translateX(-100%); }
    .app-sidebar.open { transform: translateX(0); }
    .app-main { margin-left: 0; }
    .sidebar-backdrop.show { display: block; }
}