:root {
    color-scheme: light;
    --bg: #eef3f8;
    --surface: #ffffff;
    --surface-soft: #f6f9fc;
    --text: #172033;
    --muted: #64748b;
    --border: #dce5ef;
    --primary: #245fac;
    --primary-dark: #174680;
    --primary-soft: #e8f1fb;
    --success: #147a4b;
    --success-soft: #e8f7ef;
    --warning: #9a6200;
    --warning-soft: #fff4d9;
    --danger: #b8323b;
    --danger-soft: #fff0f1;
    --radius: 13px;
    --shadow: 0 12px 30px rgba(30, 50, 80, .08);
}

* { box-sizing: border-box; }
html { font-size: 16px; }
body { margin: 0; color: var(--text); background: var(--bg); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.45; }
a { color: inherit; }
button, input, select { font: inherit; }
button, select { cursor: pointer; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: .35rem; font-size: clamp(1.45rem, 2.3vw, 2rem); font-weight: 650; }
h2 { margin-bottom: .8rem; font-size: 1.08rem; }
small { font-size: .78rem; }

.app-shell { min-height: 100vh; display: grid; grid-template-columns: 245px minmax(0, 1fr); }
.sidebar { position: sticky; top: 0; height: 100vh; padding: 1.25rem 1rem; display: flex; flex-direction: column; gap: 1.5rem; background: #102a43; color: #dce9f7; }
.brand { display: flex; gap: .7rem; align-items: center; padding: 0 .35rem; text-decoration: none; }
.brand strong, .brand small { display: block; }
.brand strong { color: #fff; }
.brand small { margin-top: .1rem; color: #9eb6ce; }
.brand-mark { width: 42px; height: 42px; display: grid; place-items: center; flex: 0 0 auto; border-radius: 11px; background: #4ea1ff; color: #081b2e; font-weight: 800; }
.brand-mark.large { width: 54px; height: 54px; margin-bottom: 1.2rem; font-size: 1.1rem; }
.main-nav { display: flex; flex-direction: column; gap: .28rem; }
.main-nav a { display: flex; align-items: center; gap: .65rem; padding: .7rem .75rem; border-radius: 9px; color: #bcd0e3; text-decoration: none; }
.main-nav a:hover { background: rgba(255,255,255,.07); color: #fff; }
.main-nav a.active { background: #245fac; color: #fff; }
.nav-dot { width: 7px; height: 7px; border-radius: 50%; background: currentColor; opacity: .8; }
.sidebar-footer { margin-top: auto; padding: 1rem .6rem 0; border-top: 1px solid rgba(255,255,255,.12); }
.sidebar-footer small, .sidebar-footer strong { display: block; }
.sidebar-footer small { color: #9eb6ce; }
.app-main { min-width: 0; display: flex; min-height: 100vh; flex-direction: column; }
.topbar { min-height: 70px; padding: .75rem 1.4rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; background: var(--surface); border-bottom: 1px solid var(--border); }
.breadcrumb { color: var(--muted); }
.user-menu { display: flex; gap: .65rem; align-items: center; }
.user-menu strong, .user-menu small { display: block; }
.user-menu small { color: var(--muted); }
.avatar { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; background: var(--primary-soft); color: var(--primary); font-weight: 700; }
.logout-link { margin-left: .5rem; color: var(--primary); text-decoration: none; }
.menu-button { display: none; width: 40px; height: 40px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); }
.content { width: 100%; max-width: 1500px; margin: 0 auto; padding: 1.5rem; flex: 1; }
.site-footer { padding: 1rem 1.5rem; color: var(--muted); text-align: center; font-size: .82rem; }
.page-heading { margin-bottom: 1rem; display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.page-heading p, .panel p { color: var(--muted); }

.panel, .stat-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.panel { padding: 1rem; margin-bottom: 1rem; }
.panel summary { cursor: pointer; }
.panel-heading { display: flex; align-items: center; justify-content: space-between; gap: .75rem; margin-bottom: .75rem; }
.panel-heading h2 { margin: 0; }
.stats-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .85rem; margin-bottom: 1rem; }
.stat-card { padding: 1rem; }
.stat-card span, .stat-card strong, .stat-card small { display: block; }
.stat-card span, .stat-card small { color: var(--muted); }
.stat-card strong { margin: .65rem 0 .15rem; font-size: 1.65rem; }
.two-column { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.side-stack { min-width: 0; }
.empty-state { padding: 1.5rem; color: var(--muted); text-align: center; }
.block-muted { display: block; margin-top: .15rem; color: var(--muted); }
.management-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 1rem; margin-bottom: 1rem; }
.management-card { margin-bottom: 0; }
.management-card.wide { grid-column: 1 / -1; }
.management-card-body { display: grid; grid-template-columns: minmax(240px, 320px) minmax(0, 1fr); gap: 1rem; align-items: start; }
.management-entry { padding: .85rem; border: 1px solid var(--border); border-radius: 10px; background: var(--surface-soft); }
.management-entry h3 { margin: 0 0 .7rem; font-size: .98rem; }
.management-list { min-width: 0; }
.management-form { display: grid; gap: .7rem; }
.compact-check { align-self: start; }

.button, .icon-button { border: 1px solid var(--border); background: var(--surface); color: var(--text); text-decoration: none; }
.button { min-height: 40px; padding: .55rem .85rem; display: inline-flex; align-items: center; justify-content: center; border-radius: 9px; font-weight: 600; }
.button:hover { border-color: var(--primary); }
.button.primary { border-color: var(--primary); background: var(--primary); color: #fff; }
.button.primary:hover { background: var(--primary-dark); }
.button.small { min-height: 32px; padding: .35rem .55rem; font-size: .82rem; }
.button.wide { width: 100%; }
.icon-button { width: 36px; height: 36px; display: inline-grid; place-items: center; border-radius: 8px; }
.danger-text { color: var(--danger); }
.inline-actions, .form-footer, .attendance-summary { display: flex; align-items: center; gap: .55rem; flex-wrap: wrap; }
.inline-form { display: flex; align-items: center; gap: .35rem; }
.inline-form select { width: auto; min-height: 34px; margin-top: 0; padding: .35rem .5rem; }
.form-footer { margin-top: 1rem; justify-content: flex-end; }

label { color: var(--muted); font-size: .88rem; }
input, select { width: 100%; min-height: 41px; margin-top: .3rem; padding: .55rem .65rem; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--text); }
input:focus, select:focus { outline: 3px solid rgba(36,95,172,.16); border-color: var(--primary); }
.stack-form { display: grid; gap: .8rem; }
.form-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .8rem; align-items: end; }
.form-grid.compact { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.form-action { align-self: end; }
.span-2 { grid-column: span 2; }
.top-space { margin-top: 1rem; }
.filter-bar { display: flex; align-items: end; gap: .7rem; flex-wrap: wrap; }
.filter-bar label { min-width: 155px; }
.filter-bar .grow { flex: 1; min-width: 240px; }
.check-row, .attendance-check { display: flex; align-items: center; gap: .55rem; color: var(--text); }
.check-row input, .attendance-check input { width: 19px; height: 19px; min-height: 0; margin: 0; accent-color: var(--primary); }

.table-wrap { width: 100%; overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: .72rem .65rem; border-bottom: 1px solid var(--border); text-align: left; vertical-align: middle; white-space: nowrap; }
th { background: var(--surface-soft); color: var(--muted); font-size: .82rem; }
tbody tr:last-child td { border-bottom: 0; }
.badge { padding: .25rem .5rem; display: inline-flex; border-radius: 999px; font-size: .78rem; font-weight: 650; }
.badge.success { background: var(--success-soft); color: var(--success); }
.badge.warning { background: var(--warning-soft); color: var(--warning); }
.badge.danger { background: var(--danger-soft); color: var(--danger); }
.alert { margin-bottom: 1rem; padding: .75rem .9rem; border-radius: 9px; }
.alert.success { background: var(--success-soft); color: var(--success); }
.alert.error { background: var(--danger-soft); color: var(--danger); }
.attendance-summary { margin: 1rem 0; }
.attendance-summary > span { padding: .5rem .65rem; border-radius: 8px; background: var(--surface-soft); }

.calendar-layout { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(280px, .75fr); gap: 1rem; }
.calendar-weekdays, .calendar-grid { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: .35rem; }
.calendar-weekdays { margin-bottom: .35rem; color: var(--muted); text-align: center; font-size: .8rem; }
.calendar-day { min-height: 82px; padding: .45rem; border: 1px solid var(--border); border-radius: 8px; background: var(--surface-soft); }
.calendar-day strong, .calendar-day small { display: block; }
.calendar-day small { margin-top: .35rem; color: var(--muted); white-space: normal; }
.calendar-day.empty { opacity: .25; }
.calendar-day.has-class { border-color: var(--primary); background: var(--primary-soft); }
.calendar-day.weekend-off { border-style: dashed; background: #edf0f3; color: var(--muted); }
.calendar-day.holiday { border-color: var(--danger); background: var(--danger-soft); color: var(--danger); }
.calendar-day.leave { border-color: var(--warning); background: var(--warning-soft); color: var(--warning); }
.calendar-legend { margin-bottom: .8rem; display: flex; gap: .8rem; flex-wrap: wrap; color: var(--muted); font-size: .8rem; }
.calendar-legend span { display: inline-flex; align-items: center; gap: .35rem; }
.legend-dot { width: 9px; height: 9px; border-radius: 3px; display: inline-block; }
.class-dot { background: var(--primary); }.weekend-dot { background: #8b98a7; }.holiday-dot { background: var(--danger); }.leave-dot { background: var(--warning); }
.event-list { display: grid; gap: .6rem; }
.event-item { padding-bottom: .6rem; display: flex; justify-content: space-between; gap: .5rem; border-bottom: 1px solid var(--border); }
.event-item strong, .event-item small { display: block; }
.event-item small { margin-top: .2rem; color: var(--muted); }
.profile-list { margin: 0; }
.profile-list div { padding: .7rem 0; display: grid; grid-template-columns: 120px 1fr; border-bottom: 1px solid var(--border); }
.profile-list dt { color: var(--muted); }.profile-list dd { margin: 0; font-weight: 600; }

.classes-table td { min-width: 130px; max-width: 330px; white-space: normal; overflow-wrap: anywhere; }
.classes-table td:first-child { min-width: 200px; }
.class-assignment + .class-assignment { margin-top: .6rem; padding-top: .6rem; border-top: 1px solid var(--border); }
.button:disabled { opacity: .55; cursor: not-allowed; }

.login-body { min-height: 100vh; display: grid; place-items: center; padding: 1.2rem; background: linear-gradient(135deg, #0f2941, #174b78); }
.login-page-shell { width: min(960px, 100%); }
.login-layout { width: min(960px, 100%); display: grid; grid-template-columns: 1.1fr .9fr; overflow: hidden; border-radius: 18px; box-shadow: 0 28px 70px rgba(0,0,0,.3); }
.login-intro { padding: clamp(1.8rem, 5vw, 4rem); background: #102a43; color: #fff; }
.login-intro p { max-width: 550px; color: #bdd1e5; font-size: 1.05rem; }
.login-card { padding: clamp(1.8rem, 5vw, 3.3rem); background: var(--surface); }
.login-card > p { color: var(--muted); }
.login-maintainer-note { margin-top: 2rem; padding-top: 1.2rem; display: grid; gap: .35rem; border-top: 1px solid rgba(255,255,255,.15); color: #cfe0f0; font-size: .84rem; line-height: 1.45; }
.login-maintainer-note strong { color: #fff; }
.login-maintainer-note a { color: #fff; font-weight: 600; }

@media (max-width: 1000px) {
    .stats-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .form-grid.compact { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .calendar-layout { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
    .app-shell { grid-template-columns: 1fr; }
    .sidebar { position: fixed; z-index: 20; width: 260px; transform: translateX(-105%); transition: transform .2s ease; box-shadow: 20px 0 40px rgba(0,0,0,.18); }
    .sidebar.open { transform: translateX(0); }
    .menu-button { display: grid; place-items: center; }
    .breadcrumb { display: none; }
    .user-menu > span:not(.avatar) { display: none; }
    .content { padding: 1rem; }
    .two-column, .login-layout { grid-template-columns: 1fr; }
    .login-intro { display: none; }
    .form-grid { grid-template-columns: 1fr; }
    .form-grid.compact { grid-template-columns: 1fr; }
    .management-grid, .management-card-body { grid-template-columns: 1fr; }
    .span-2 { grid-column: auto; }
    .calendar-day { min-height: 58px; }
    .calendar-day small { font-size: .67rem; }
}
@media (max-width: 480px) {
    .stats-grid { grid-template-columns: 1fr; }
    .topbar { padding: .65rem .8rem; }
    .logout-link { font-size: .8rem; }
    .calendar-weekdays, .calendar-grid { gap: .15rem; }
    .calendar-day { min-height: 48px; padding: .3rem; }
    .calendar-day small { display: none; }
}

/* Compact typography for the Attendance module. */
.attendance-page { font-size: .8125rem; }
.attendance-page .page-heading h1 { font-size: 1.4rem; }
.attendance-page .page-heading p,
.attendance-page label,
.attendance-page input,
.attendance-page select,
.attendance-page .button { font-size: .8125rem; }
.attendance-page th, .attendance-page .badge { font-size: .75rem; }
.attendance-page th, .attendance-page td { padding: .5rem .6rem; }
.attendance-columns { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; align-items: start; }
.attendance-table { width: 100%; }
@media (max-width: 1000px) {
    .attendance-columns { grid-template-columns: minmax(0, 1fr); }
}
.attendance-table th, .attendance-table td { padding: .28rem .35rem; }
.attendance-table tbody tr:nth-child(even) { background: var(--surface-soft); }
.attendance-table tbody tr:hover { background: var(--primary-soft); }
.attendance-table th:first-child, .attendance-table td:first-child { width: 58px; text-align: center; }
.attendance-table th:nth-child(3), .attendance-table td:nth-child(3),
.attendance-table th:nth-child(4), .attendance-table td:nth-child(4) { width: 96px; }
.attendance-table .attendance-check { gap: .25rem; }
.attendance-table .attendance-check input { width: 17px; height: 17px; }

/* Dense student list with readable controls. */
.students-table { font-size: .78rem; }
.students-table th { font-size: .73rem; }
.students-table th, .students-table td { padding: .3rem .4rem; }
.students-table .button.small { padding: .25rem .45rem; min-height: 28px; font-size: .73rem; }
.students-table .badge { padding: .15rem .35rem; font-size: .7rem; }
.students-table .inline-actions { gap: .3rem; flex-wrap: nowrap; }
.students-table .check-row input { width: 16px; height: 16px; }