:root{
    --primary:#2563eb;
    --primary-dark:#1d4ed8;
    --secondary:#06b6d4;
    --bg:#f4f7fb;
    --surface:#ffffff;
    --text:#0f172a;
    --muted:#64748b;
    --border:#e2e8f0;
    --danger:#dc2626;
    --success:#16a34a;
    --radius:16px;
    --shadow:0 18px 45px rgba(15,23,42,.10);
}
*{box-sizing:border-box}
body{
    margin:0;
    background:linear-gradient(180deg,#eef6ff 0,#f8fafc 260px,#f4f7fb 100%);
    color:var(--text);
    font-family:Arial,"Helvetica Neue",sans-serif;
    line-height:1.55;
}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
.site-nav,.nav,.navbar.bg-primary{
    background:linear-gradient(135deg,var(--primary),var(--secondary)) !important;
    box-shadow:0 10px 30px rgba(37,99,235,.22);
}
.site-nav{position:sticky;top:0;z-index:20}
.site-nav-inner{
    max-width:1120px;margin:0 auto;padding:14px 18px;display:flex;align-items:center;justify-content:space-between;gap:18px;
}
.brand,.navbar-brand{color:#fff!important;font-weight:800;letter-spacing:.4px;text-decoration:none!important}
.nav-links{display:flex;gap:10px;flex-wrap:wrap}
.nav-links a,.nav a,.navbar .nav-link{
    color:#fff!important;padding:8px 12px;border-radius:999px;font-weight:700;text-decoration:none!important;opacity:.92;
}
.nav-links a.active,.nav-links a:hover,.nav a:hover,.navbar .nav-link:hover{background:rgba(255,255,255,.18);opacity:1}
.container,.page-wrap{max-width:1120px;margin:0 auto;padding-left:18px;padding-right:18px}
.page-wrap{padding-top:26px;padding-bottom:40px}
.card,.box,.panel,.login-box,form.card-form{
    background:var(--surface)!important;border:1px solid rgba(226,232,240,.85);border-radius:var(--radius)!important;box-shadow:var(--shadow)!important;
}
.box{max-width:760px!important;width:auto!important;padding:20px!important;margin:22px auto!important}
input,select,textarea{
    border:1px solid var(--border);border-radius:12px;padding:11px 12px;background:#fff;color:var(--text);outline:none;
}
input:focus,select:focus,textarea:focus{border-color:var(--primary);box-shadow:0 0 0 4px rgba(37,99,235,.12)}
textarea{resize:vertical;min-height:110px}
button,.btn, input[type="submit"]{
    border:0;border-radius:12px;padding:10px 16px;background:var(--primary);color:white;font-weight:700;cursor:pointer;transition:.18s ease;
}
button:hover,.btn:hover,input[type="submit"]:hover{background:var(--primary-dark);transform:translateY(-1px)}
.btn-light{background:#eef2ff;color:var(--primary)}
.btn-danger{background:var(--danger)}
.btn-muted{background:#e2e8f0;color:#334155}
.alert{border-radius:14px;padding:12px 14px;margin:12px 0;border:1px solid transparent}
.alert-danger{background:#fef2f2;border-color:#fecaca;color:#991b1b}
.alert-success{background:#f0fdf4;border-color:#bbf7d0;color:#166534}
.post-composer textarea{width:100%}
.upload-panel{border:1px dashed #cbd5e1;background:#f8fafc;border-radius:16px;padding:14px;display:grid;gap:12px;margin-top:12px}
.upload-row{display:grid;gap:8px}
.upload-row label{font-weight:700;color:#334155}
.help-text{font-size:13px;color:var(--muted)}
.post-card{overflow:hidden}
.post-meta{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:13px;margin-bottom:8px}
.post-title{margin:0 0 8px;font-size:22px}
.post-content{white-space:pre-wrap;margin:0 0 14px}
.post-images{display:grid;gap:8px;margin-top:12px;overflow:hidden;border-radius:16px}
.post-images img{width:100%;height:100%;min-height:170px;object-fit:cover;display:block;cursor:pointer;background:#e2e8f0}
.layout-1{grid-template-columns:1fr}.layout-2{grid-template-columns:1fr 1fr}.layout-3{grid-template-columns:2fr 1fr;grid-template-rows:1fr 1fr}.layout-3 img:first-child{grid-row:1/3}.layout-4{grid-template-columns:1fr 1fr}
.media-more{position:relative}.media-more span{position:absolute;inset:0;background:rgba(15,23,42,.65);color:#fff;font-size:28px;font-weight:800;display:flex;align-items:center;justify-content:center}
.post-video{width:100%;border-radius:16px;margin-top:12px;background:#0f172a}
.post-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px;padding-top:14px;border-top:1px solid var(--border)}
#lightbox{display:none;position:fixed;inset:0;background:rgba(2,6,23,.92);z-index:999;align-items:center;justify-content:center;padding:20px}
#lightbox img{max-width:96vw;max-height:92vh;border-radius:14px;box-shadow:0 20px 60px rgba(0,0,0,.45)}
.hero{padding:64px 0 38px;text-align:center}.hero h1{font-size:clamp(34px,6vw,58px);line-height:1.05;margin:0 0 14px}.hero p{max-width:720px;margin:0 auto;color:var(--muted);font-size:18px}.section-title{font-weight:800;color:var(--text)}
.footer{background:#0f172a!important;color:#e2e8f0!important}.footer a{color:#93c5fd!important}
.table-wrap{overflow:auto;background:#fff;border-radius:var(--radius);box-shadow:var(--shadow)}
table{border-collapse:collapse}th{background:#eff6ff;color:#1e3a8a}td,th{border-color:#dbeafe!important}
@media(max-width:640px){.site-nav-inner{align-items:flex-start;flex-direction:column}.nav-links{width:100%}.nav-links a{padding-left:0}.box{margin:16px 12px!important}.layout-2,.layout-3,.layout-4{grid-template-columns:1fr}.layout-3 img:first-child{grid-row:auto}.post-images img{min-height:220px}}


/* ===== Bản vá đồng bộ giao diện 06/2026 ===== */
body{overflow-x:hidden;}
.layout{width:100%;}
.content{min-width:0;width:100%;}
.container{max-width:none;width:100%;padding-left:22px;padding-right:22px;}
.content .box, body > .box, .container > .box, .page-wrap .box{
    max-width:none!important;
    width:100%!important;
}
.topbar{
    background:#fff!important;
    color:#0f172a!important;
    border:1px solid #dbeafe!important;
    border-radius:18px!important;
    box-shadow:0 10px 28px rgba(15,23,42,.08)!important;
    display:flex;
    align-items:center;
    justify-content:space-between;
    gap:14px;
}
.topbar a{text-decoration:none!important;}
.topbar-actions{display:flex;align-items:center;justify-content:flex-end;gap:10px;flex-wrap:wrap;}
.btn-home,.topbar .btn-home,.btn-back{
    display:inline-flex!important;
    align-items:center;
    justify-content:center;
    gap:7px;
    background:#2563eb!important;
    color:#fff!important;
    border:0!important;
    border-radius:12px!important;
    padding:10px 15px!important;
    min-height:40px;
    font-size:14px!important;
    font-weight:800!important;
    line-height:1!important;
    text-decoration:none!important;
    box-shadow:0 8px 18px rgba(37,99,235,.18)!important;
    cursor:pointer;
}
.btn-home::before,.btn-back::before{content:"🏠";font-size:15px;}
.btn-home:hover,.btn-back:hover{background:#1d4ed8!important;transform:translateY(-1px);text-decoration:none!important;}
.btn-logout{min-height:40px;border-radius:12px!important;}

/* Sidebar/cây menu đồng bộ xanh dương, rõ phân nhánh */
.sidebar{
    background:linear-gradient(180deg,#f8fbff 0%,#eef6ff 100%)!important;
    color:#0f172a!important;
    border-right:1px solid #bfdbfe!important;
    box-shadow:4px 0 18px rgba(37,99,235,.08)!important;
}
.logo{
    color:#1e3a8a!important;
    background:#fff!important;
    border:1px solid #dbeafe!important;
    box-shadow:0 8px 20px rgba(37,99,235,.10)!important;
}
.menu{gap:8px!important;}
.menu-section{
    margin:14px 0 8px!important;
    padding:10px 10px 9px!important;
    color:#1d4ed8!important;
    background:#eaf2ff!important;
    border:1px solid #bfdbfe!important;
    border-radius:14px!important;
    font-size:13px!important;
    font-weight:900!important;
    letter-spacing:.25px!important;
    text-transform:uppercase!important;
}
.menu-tree{position:relative;padding-left:18px!important;margin-left:4px;}
.menu-tree::before{content:"";position:absolute;left:6px;top:4px;bottom:8px;width:2px;background:#93c5fd;border-radius:99px;}
.menu a{
    position:relative;
    color:#1d4ed8!important;
    background:#fff!important;
    border:1px solid #dbeafe!important;
    border-radius:12px!important;
    font-weight:800!important;
    box-shadow:0 3px 10px rgba(37,99,235,.06)!important;
}
.menu-tree a::before{content:"";position:absolute;left:-13px;top:50%;width:13px;height:2px;background:#93c5fd;transform:translateY(-50%);}
.menu a:hover{background:#eff6ff!important;color:#1e40af!important;transform:translateX(2px);}
.menu a.active{background:linear-gradient(135deg,#2563eb,#1d4ed8)!important;color:#fff!important;border-color:#2563eb!important;box-shadow:0 8px 18px rgba(37,99,235,.25)!important;}
.menu-group{background:rgba(255,255,255,.74)!important;border:1px solid #dbeafe!important;border-radius:18px!important;padding:10px!important;}

/* Bảng dữ liệu: ưu tiên hiển thị rộng trên máy tính, giảm kéo ngang không cần thiết */
.table-wrap{
    width:100%!important;
    max-width:100%!important;
    overflow:auto!important;
    border-radius:14px!important;
    border:1px solid #cfe0f7!important;
    box-shadow:0 8px 24px rgba(15,23,42,.06)!important;
}
.table-wrap table{width:100%!important;}
.table-wrap th,.table-wrap td{vertical-align:middle;}
.name-col,.sticky-name{text-align:left!important;}

/* Bảng chấm công/tháng: nới rộng khu vực xem và làm cột dễ đọc hơn */
.attendance-page .content,.salary-page .content{padding:22px!important;}
.attendance-page .box,.salary-page .box{max-width:none!important;width:100%!important;margin:0!important;}
.attendance-page .table-wrap{max-height:calc(100vh - 205px)!important;}
.attendance-page table{table-layout:auto!important;width:100%!important;min-width:1180px!important;}
.attendance-page .day-header{width:34px!important;min-width:34px!important;max-width:34px!important;}
.attendance-page .stt-col{width:52px!important;min-width:52px!important;max-width:52px!important;}
.attendance-page .sticky-name{left:52px!important;width:260px!important;min-width:260px!important;max-width:260px!important;white-space:normal!important;}
.attendance-page .teacher-name{white-space:normal!important;overflow:visible!important;text-overflow:clip!important;}
.attendance-page .teacher-meta{white-space:normal!important;overflow:visible!important;text-overflow:clip!important;font-size:11px!important;}
.attendance-page .summary{width:56px!important;min-width:56px!important;max-width:56px!important;}

.salary-page .table-wrap{max-height:calc(100vh - 285px)!important;}
.salary-page table{table-layout:auto!important;min-width:1050px!important;}
.salary-page .name-col{min-width:260px!important;white-space:normal!important;}
.salary-page .teacher-schedule-sub{white-space:normal!important;}

.staff-page,.students-page,.tuition-page,.review-page{padding:18px 22px!important;}
.staff-page .table-wrap table{min-width:960px!important;}
.students-page .table-wrap table{min-width:1120px!important;}
.tuition-page .table-wrap table{min-width:1180px!important;}
.review-page .table-wrap table,.review-page table{min-width:980px!important;}
.review-page .box:last-child{overflow:auto;}

@media(min-width:1200px){
    .attendance-page table{min-width:100%!important;}
    .salary-page table{min-width:100%!important;}
    .students-page .table-wrap table,.tuition-page .table-wrap table{min-width:100%!important;}
}
@media(max-width:900px){
    .topbar{align-items:flex-start;flex-direction:column;}
    .topbar-actions{justify-content:flex-start;}
    .staff-page,.students-page,.tuition-page,.review-page{padding:12px!important;}
}

/* ===== Giao diện điện thoại theo lựa chọn khi đăng nhập ===== */
body.app-mobile {
    background: #f8fafc !important;
    overflow-x: hidden;
    font-size: 16px;
}
body.app-mobile .content,
body.app-mobile .container,
body.app-mobile .staff-page,
body.app-mobile .students-page,
body.app-mobile .tuition-page,
body.app-mobile .review-page,
body.app-mobile .attendance-page .content,
body.app-mobile .salary-page .content {
    width: 100% !important;
    max-width: 100% !important;
    padding: 10px !important;
    margin: 0 !important;
    box-sizing: border-box !important;
}
body.app-mobile .box,
body.app-mobile .content .box,
body.app-mobile .container > .box,
body.app-mobile body > .box {
    width: 100% !important;
    max-width: 100% !important;
    margin: 0 0 12px 0 !important;
    padding: 14px !important;
    border-radius: 14px !important;
    box-sizing: border-box !important;
}
body.app-mobile h1,
body.app-mobile h2,
body.app-mobile h3 {
    line-height: 1.25;
    word-break: break-word;
}
body.app-mobile .topbar {
    flex-direction: column !important;
    align-items: stretch !important;
    gap: 10px !important;
    padding: 12px !important;
    border-radius: 14px !important;
}
body.app-mobile .topbar-actions,
body.app-mobile .actions,
body.app-mobile .filter-row,
body.app-mobile .filters,
body.app-mobile form {
    max-width: 100%;
}
body.app-mobile input,
body.app-mobile select,
body.app-mobile textarea,
body.app-mobile button,
body.app-mobile .btn-home,
body.app-mobile .btn-back,
body.app-mobile .btn-logout,
body.app-mobile a.button,
body.app-mobile .button {
    min-height: 44px;
    font-size: 16px !important;
    max-width: 100%;
    box-sizing: border-box;
}
body.app-mobile input,
body.app-mobile select,
body.app-mobile textarea {
    width: 100%;
}
body.app-mobile button,
body.app-mobile .btn-home,
body.app-mobile .btn-back,
body.app-mobile .btn-logout,
body.app-mobile a.button,
body.app-mobile .button {
    border-radius: 12px !important;
    white-space: normal;
}
body.app-mobile .table-wrap {
    width: 100% !important;
    max-width: 100% !important;
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch;
    border-radius: 14px !important;
    margin-top: 10px !important;
}
body.app-mobile table {
    min-width: 760px !important;
    font-size: 14px !important;
}
body.app-mobile th,
body.app-mobile td {
    padding: 8px 7px !important;
    white-space: nowrap;
}
body.app-mobile .attendance-page table,
body.app-mobile .salary-page table,
body.app-mobile .students-page .table-wrap table,
body.app-mobile .tuition-page .table-wrap table,
body.app-mobile .staff-page .table-wrap table,
body.app-mobile .review-page .table-wrap table {
    min-width: 900px !important;
}
body.app-mobile .attendance-page .sticky-name,
body.app-mobile .salary-page .name-col {
    min-width: 170px !important;
    width: 170px !important;
    max-width: 170px !important;
    white-space: normal !important;
}
body.app-mobile .teacher-name,
body.app-mobile .teacher-meta,
body.app-mobile .teacher-schedule-sub {
    white-space: normal !important;
}
body.app-mobile .hero {
    padding: 28px 12px 20px;
}
body.app-mobile .layout-2,
body.app-mobile .layout-3,
body.app-mobile .layout-4 {
    grid-template-columns: 1fr !important;
}
@media(max-width: 640px) {
    body.app-mobile .box,
    body.app-mobile .content .box {
        padding: 12px !important;
    }
    body.app-mobile table {
        font-size: 13px !important;
    }
}