/* Tuition Manager — mobile first, no framework. */
:root {
  --bg: #f4f6f9;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #e3e8ef;
  --text: #17212b;
  --muted: #64707d;
  --primary: #1f5f8b;
  --primary-ink: #ffffff;
  --primary-soft: #e8f1f8;
  --success: #1e8a5a;
  --success-soft: #e5f5ed;
  --warn: #b26a00;
  --warn-soft: #fff4e0;
  --danger: #c0392b;
  --danger-soft: #fdecea;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 1px 3px rgba(16, 24, 40, .06);
  --bottomnav-h: 64px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", sans-serif;
  color-scheme: light;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text); font-size: 15px; line-height: 1.45; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.2; margin: 0; }
h1 { font-size: 1.35rem; font-weight: 700; }
h2 { font-size: 1.02rem; font-weight: 650; }
.icon { width: 20px; height: 20px; flex: none; }
.num { font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.right { text-align: right; }
.nowrap { white-space: nowrap; }
.hidden { display: none !important; }
@media (max-width: 599px) { .hide-sm { display: none; } }

/* ---------- Top bar & navigation ---------- */
.topbar { position: sticky; top: 0; z-index: 20; background: var(--surface); border-bottom: 1px solid var(--border); }
.topbar-inner { max-width: 1180px; margin: 0 auto; padding: 0 16px; height: 56px; display: flex; align-items: center; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; min-width: 0; }
.brand:hover { text-decoration: none; }
.brand-mark { width: 32px; height: 32px; border-radius: 9px; background: var(--primary); color: #fff; display: grid; place-items: center; font-size: 17px; flex: none; }
.brand-name { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topnav { display: none; }
.topbar-actions { margin-left: auto; display: flex; gap: 4px; }
.topbar-actions form { margin: 0; }
.icon-btn { width: 40px; height: 40px; border-radius: 10px; border: 0; background: transparent; color: var(--muted); display: grid; place-items: center; cursor: pointer; }
.icon-btn:hover, .icon-btn.active { background: var(--surface-2); color: var(--primary); }

.bottomnav { position: fixed; z-index: 30; left: 0; right: 0; bottom: 0; height: calc(var(--bottomnav-h) + env(safe-area-inset-bottom)); padding-bottom: env(safe-area-inset-bottom); background: var(--surface); border-top: 1px solid var(--border); display: grid; grid-template-columns: repeat(5, 1fr); }
.bottomnav a { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px; color: var(--muted); font-size: 11px; font-weight: 550; }
.bottomnav a:hover { text-decoration: none; }
.bottomnav a.active { color: var(--primary); }
.bottomnav-primary .bn-icon { width: 50px; height: 50px; margin-top: -24px; border-radius: 50%; background: var(--primary); color: #fff; display: grid; place-items: center; box-shadow: 0 6px 16px rgba(31, 95, 139, .35); border: 4px solid var(--bg); }
.bottomnav-primary .bn-icon .icon { width: 22px; height: 22px; }
.bottomnav a.bottomnav-primary { color: var(--primary); }

.page { max-width: 1180px; margin: 0 auto; padding: 16px 16px calc(var(--bottomnav-h) + 28px + env(safe-area-inset-bottom)); }

@media (min-width: 900px) {
  .bottomnav { display: none; }
  .topnav { display: flex; gap: 4px; margin-left: 24px; }
  .topnav a { padding: 8px 12px; border-radius: 9px; color: var(--muted); font-weight: 550; }
  .topnav a:hover { background: var(--surface-2); text-decoration: none; color: var(--text); }
  .topnav a.active { color: var(--primary); background: var(--primary-soft); }
  .topnav a.topnav-primary { background: var(--primary); color: #fff; margin-left: 8px; }
  .topnav a.topnav-primary:hover { background: #194f75; color: #fff; }
  .page { padding: 24px 24px 48px; }
}

/* ---------- Page header ---------- */
.page-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 16px; }
.page-head .sub { color: var(--muted); font-size: .9rem; margin-top: 2px; }
.page-head .actions { margin-left: auto; display: flex; gap: 8px; flex-wrap: wrap; }
.back { display: inline-flex; align-items: center; gap: 4px; color: var(--muted); font-size: .9rem; margin-bottom: 8px; }

/* ---------- Cards & grids ---------- */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 16px; }
.card + .card { margin-top: 16px; }
.grid > .card + .card, .grid > * + .card { margin-top: 0; }
.card-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 12px; }
.card-head a { font-size: .88rem; }
.card.flush { padding: 0; overflow: hidden; }
.card.flush .card-head { padding: 16px 16px 0; }
.grid { display: grid; gap: 16px; }
.grid > * { min-width: 0; } /* let wide tables scroll inside their card instead of stretching the page */
.stack > * + * { margin-top: 16px; }
@media (min-width: 900px) {
  .grid-2 { grid-template-columns: 1fr 1fr; }
  .grid-3-1 { grid-template-columns: 2fr 1fr; }
  .grid-1-2 { grid-template-columns: 1fr 2fr; }
}

/* ---------- Stat tiles ---------- */
.stats { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 16px; }
@media (min-width: 900px) { .stats { grid-template-columns: repeat(4, 1fr); gap: 16px; } }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; box-shadow: var(--shadow); min-width: 0; }
.stat-label { color: var(--muted); font-size: .8rem; font-weight: 550; }
.stat-value { font-size: 1.4rem; font-weight: 700; margin-top: 4px; font-variant-numeric: tabular-nums; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.stat-foot { color: var(--muted); font-size: .78rem; margin-top: 4px; }
.stat.accent { background: var(--primary); border-color: var(--primary); color: #fff; }
.stat.accent .stat-label, .stat.accent .stat-foot { color: rgba(255, 255, 255, .8); }
.stat.warn .stat-value { color: var(--warn); }
.progress { height: 6px; border-radius: 99px; background: var(--border); overflow: hidden; margin-top: 8px; }
.progress > span { display: block; height: 100%; background: var(--success); border-radius: 99px; }
.stat.accent .progress { background: rgba(255, 255, 255, .25); }
.stat.accent .progress > span { background: #fff; }

/* ---------- Buttons & forms ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 42px; padding: 0 16px; border-radius: var(--radius-sm); border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-weight: 600; cursor: pointer; white-space: nowrap; }
.btn:hover { text-decoration: none; background: var(--surface-2); }
.btn-primary { background: var(--primary); border-color: var(--primary); color: var(--primary-ink); }
.btn-primary:hover { background: #194f75; }
.btn-success { background: var(--success); border-color: var(--success); color: #fff; }
.btn-success:hover { background: #18724a; }
.btn-danger { color: var(--danger); }
.btn-danger:hover { background: var(--danger-soft); }
.btn-lg { min-height: 52px; font-size: 1.05rem; border-radius: 12px; }
.btn-sm { min-height: 34px; padding: 0 12px; font-size: .88rem; }
.btn-block { width: 100%; }
.btn .icon { width: 18px; height: 18px; }

label { display: block; font-weight: 600; font-size: .88rem; margin-bottom: 6px; }
.field { margin-bottom: 14px; }
.field .hint { color: var(--muted); font-size: .8rem; margin-top: 4px; }
input, select, textarea { width: 100%; min-height: 44px; padding: 10px 12px; font: inherit; font-size: 16px; color: var(--text); background: var(--surface); border: 1px solid #cfd6df; border-radius: var(--radius-sm); }
textarea { min-height: 80px; resize: vertical; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(31, 95, 139, .15); }
.form-row { display: grid; gap: 0 14px; }
@media (min-width: 600px) { .form-row { grid-template-columns: 1fr 1fr; } }
.form-narrow { max-width: 640px; }
.errors { background: var(--danger-soft); color: var(--danger); border-radius: var(--radius-sm); padding: 10px 14px; margin-bottom: 14px; }
.errors ul { margin: 0; padding-left: 18px; }

.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.filters > * { flex: 1 1 140px; }
.filters .btn { flex: 0 0 auto; }
.search { position: relative; }
.search .icon { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--muted); }
.search input { padding-left: 40px; }

/* Segmented choice (payment mode, status) built from radio inputs */
.segmented { display: grid; grid-template-columns: repeat(auto-fit, minmax(70px, 1fr)); gap: 8px; }
.segmented input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.segmented label { margin: 0; min-height: 46px; display: grid; place-items: center; border: 1px solid #cfd6df; border-radius: var(--radius-sm); cursor: pointer; font-weight: 600; background: var(--surface); }
.segmented input:checked + label { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); }
.segmented input:focus-visible + label { box-shadow: 0 0 0 3px rgba(31, 95, 139, .25); }

.chips { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 4px; margin-bottom: 12px; scrollbar-width: none; }
.chips::-webkit-scrollbar { display: none; }
.chip { flex: none; padding: 7px 14px; border-radius: 99px; border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-size: .88rem; font-weight: 550; cursor: pointer; }
.chip.active, .chip:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); text-decoration: none; }

/* ---------- Badges ---------- */
.badge { display: inline-block; padding: 2px 9px; border-radius: 99px; font-size: .76rem; font-weight: 650; white-space: nowrap; background: var(--surface-2); color: var(--muted); border: 1px solid var(--border); }
.badge-due { background: var(--danger-soft); color: var(--danger); border-color: transparent; }
.badge-partial { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.badge-paid { background: var(--success-soft); color: var(--success); border-color: transparent; }
.badge-class { background: var(--primary-soft); color: var(--primary); border-color: transparent; }

/* ---------- Lists & tables ---------- */
.list { list-style: none; margin: 0; padding: 0; }
.list-item { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-top: 1px solid var(--border); color: var(--text); }
.list-item:first-child { border-top: 0; }
a.list-item:hover { background: var(--surface-2); text-decoration: none; }
.list-main { flex: 1; min-width: 0; }
.list-title { font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.list-sub { color: var(--muted); font-size: .82rem; }
.list-end { text-align: right; flex: none; }
.avatar { width: 38px; height: 38px; border-radius: 50%; background: var(--primary-soft); color: var(--primary); display: grid; place-items: center; font-weight: 700; flex: none; font-size: .9rem; }
.empty { padding: 28px 16px; text-align: center; color: var(--muted); }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: .9rem; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: middle; }
th { font-size: .76rem; text-transform: uppercase; letter-spacing: .03em; color: var(--muted); font-weight: 650; background: var(--surface-2); white-space: nowrap; }
tbody tr:last-child td { border-bottom: 0; }
tfoot td { font-weight: 700; background: var(--surface-2); border-top: 1px solid var(--border); border-bottom: 0; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
tr.voided td { color: var(--muted); text-decoration: line-through; }

/* ---------- Flash ---------- */
.flash { padding: 12px 14px; border-radius: var(--radius-sm); margin-bottom: 16px; font-weight: 550; }
.flash-success { background: var(--success-soft); color: var(--success); }
.flash-error { background: var(--danger-soft); color: var(--danger); }

/* ---------- Dashboard ---------- */
.quick-collect { display: flex; align-items: center; gap: 14px; background: linear-gradient(135deg, #1f5f8b, #2b7bb0); color: #fff; border-radius: var(--radius); padding: 16px; margin-bottom: 16px; box-shadow: 0 8px 20px rgba(31, 95, 139, .25); }
.quick-collect:hover { text-decoration: none; filter: brightness(1.05); }
.quick-collect .qc-icon { width: 48px; height: 48px; border-radius: 12px; background: rgba(255, 255, 255, .18); display: grid; place-items: center; flex: none; }
.quick-collect .qc-icon .icon { width: 26px; height: 26px; }
.quick-collect strong { display: block; font-size: 1.1rem; }
.quick-collect span { opacity: .85; font-size: .88rem; }
.quick-collect .chev { margin-left: auto; }
.chart-box { position: relative; height: 240px; }
.mode-row { display: flex; align-items: center; gap: 10px; padding: 8px 0; border-top: 1px solid var(--border); }
.mode-row:first-child { border-top: 0; }
.mode-bar { flex: 1; height: 8px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.mode-bar span { display: block; height: 100%; background: var(--primary); border-radius: 99px; }

/* ---------- Student profile ---------- */
.profile-head { display: flex; align-items: center; gap: 14px; }
.profile-head .avatar { width: 56px; height: 56px; font-size: 1.2rem; }
.balance-card { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.balance-card .amount { font-size: 1.8rem; font-weight: 750; font-variant-numeric: tabular-nums; }
.balance-card .actions { margin-left: auto; }
.amount.due { color: var(--danger); }
.amount.clear { color: var(--success); }
.kv { display: grid; grid-template-columns: auto 1fr; gap: 6px 16px; margin: 0; font-size: .92rem; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; font-weight: 550; overflow-wrap: anywhere; }
.inline-form { display: inline; margin: 0; }
.link-btn { white-space: nowrap; background: none; border: 0; padding: 0; color: var(--primary); font: inherit; font-size: .82rem; cursor: pointer; }
.link-btn:hover { text-decoration: underline; }

/* ---------- Collect fee ---------- */
.amount-input { font-size: 1.8rem; font-weight: 700; min-height: 60px; text-align: left; font-variant-numeric: tabular-nums; }
.amount-wrap { position: relative; }
.amount-wrap::before { content: "₹"; position: absolute; left: 14px; top: 50%; transform: translateY(-50%); font-size: 1.5rem; font-weight: 700; color: var(--muted); }
.amount-wrap .amount-input { padding-left: 38px; }
.pending-months { display: flex; flex-wrap: wrap; gap: 6px; }
.sticky-submit { position: sticky; bottom: calc(var(--bottomnav-h) + 12px + env(safe-area-inset-bottom)); }
@media (min-width: 900px) { .sticky-submit { position: static; } }

/* ---------- Receipt ---------- */
.receipt { max-width: 520px; margin: 0 auto; }
.receipt-success { text-align: center; padding: 8px 0 16px; }
.receipt-success .tick { width: 64px; height: 64px; border-radius: 50%; margin: 0 auto 10px; background: var(--success-soft); color: var(--success); display: grid; place-items: center; }
.receipt-success .tick .icon { width: 34px; height: 34px; stroke-width: 2.4; }
.receipt-amount { font-size: 2.2rem; font-weight: 750; font-variant-numeric: tabular-nums; }
.void-banner { background: var(--danger-soft); color: var(--danger); padding: 10px 14px; border-radius: var(--radius-sm); margin-bottom: 12px; font-weight: 600; }
details summary { cursor: pointer; color: var(--muted); font-size: .88rem; }

/* ---------- Attendance ---------- */
.class-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
@media (min-width: 600px) { .class-grid { grid-template-columns: repeat(4, 1fr); } }
.class-tile { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; color: var(--text); box-shadow: var(--shadow); display: block; }
.class-tile:hover { text-decoration: none; border-color: var(--primary); }
.class-tile .ct-name { font-size: 1.25rem; font-weight: 750; }
.class-tile .ct-meta { color: var(--muted); font-size: .82rem; margin-top: 2px; }
.class-tile.done { border-color: #bfe3cf; background: #f6fcf8; }
.class-group + .class-group { margin-top: 18px; }
.class-group h2 { margin-bottom: 10px; color: var(--muted); font-size: .85rem; text-transform: uppercase; letter-spacing: .04em; }

.att-list { list-style: none; margin: 0; padding: 0; }
.att-item input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.att-item label { margin: 0; display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-top: 1px solid var(--border); cursor: pointer; font-weight: 550; font-size: 1rem; user-select: none; -webkit-tap-highlight-color: transparent; }
.att-item:first-child label { border-top: 0; }
.att-item .roll { width: 34px; height: 34px; border-radius: 50%; background: var(--surface-2); color: var(--muted); display: grid; place-items: center; font-size: .85rem; font-weight: 700; flex: none; }
.att-item .name { flex: 1; min-width: 0; }
.att-toggle { flex: none; width: 92px; text-align: center; padding: 7px 0; border-radius: 99px; font-size: .85rem; font-weight: 700; background: var(--danger-soft); color: var(--danger); }
.att-toggle::after { content: "Absent"; }
.att-item input:checked + label .att-toggle { background: var(--success-soft); color: var(--success); }
.att-item input:checked + label .att-toggle::after { content: "Present"; }
.att-item input:not(:checked) + label { background: #fff8f7; }
.att-item input:focus-visible + label { box-shadow: inset 0 0 0 2px var(--primary); }
.att-summary { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

/* ---------- Login ---------- */
.login-page { min-height: 100vh; display: grid; place-items: center; padding: 16px; }
.login-card { width: 100%; max-width: 380px; }
.login-card .brand { justify-content: center; margin-bottom: 18px; font-size: 1.1rem; }

/* ---------- Print ---------- */
@media print {
  .topbar, .bottomnav, .no-print, .flash { display: none !important; }
  body { background: #fff; }
  .page { padding: 0; }
  .card { box-shadow: none; }
}