/* =====================================================
   HỆ THỐNG THI ĐÁNH GIÁ NĂNG LỰC - BV ĐA KHOA QUANG KHỞI
   Flat Design System v2.0
   ===================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
    --primary: #1976D2;
    --primary-light: #e3f2fd;
    --primary-dark: #1565C0;
    --success: #2e7d32;
    --success-light: #e8f5e9;
    --danger: #c62828;
    --danger-light: #ffebee;
    --warning: #e65100;
    --warning-light: #fff3e0;
    --info: #0277bd;
    --info-light: #e1f5fe;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #eee;
    --gray-300: #e0e0e0;
    --gray-400: #bdbdbd;
    --gray-500: #9e9e9e;
    --gray-600: #757575;
    --gray-700: #616161;
    --gray-800: #424242;
    --gray-900: #212121;
    --white: #fff;
    --body-bg: #f5f6f8;
    --sidebar-width: 240px;
    --header-height: 52px;
    --radius: 4px;
    --border: #ddd;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: var(--font);
    font-size: 13px;
    line-height: 1.5;
    color: var(--gray-900);
    background: var(--body-bg);
    -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Layout ── */
.app-layout { display: flex; min-height: 100vh; }

.sidebar {
    width: var(--sidebar-width);
    background: var(--white);
    border-right: 1px solid var(--border);
    position: fixed;
    top: 0; left: 0; bottom: 0;
    z-index: 100;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 10px;
    height: var(--header-height);
    padding: 0 16px;
    border-bottom: 1px solid var(--border);
}

.logo-sm {
    width: 32px; height: 32px;
    background: var(--primary);
    border-radius: var(--radius);
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.logo-sm svg { width: 18px; height: 18px; }

.brand-text { font-weight: 700; font-size: 14px; color: var(--gray-900); }
.brand-sub { font-size: 11px; color: var(--gray-500); }

.sidebar-nav { flex: 1; padding: 8px 0; }

.nav-section { margin-bottom: 4px; }
.nav-section-title {
    padding: 8px 16px 4px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
}

.nav-item {
    display: flex; align-items: center; gap: 10px;
    padding: 8px 16px;
    color: var(--gray-700);
    font-size: 13px; font-weight: 500;
    text-decoration: none;
    border-left: 3px solid transparent;
    transition: background 0.15s, border-color 0.15s;
}
.nav-item:hover { background: var(--gray-100); text-decoration: none; color: var(--gray-900); }
.nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}

.nav-icon { width: 18px; height: 18px; flex-shrink: 0; }

.sidebar-footer {
    padding: 10px 16px;
    border-top: 1px solid var(--border);
    text-align: center;
}

.sidebar-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.3);
    z-index: 99;
}
.sidebar-overlay.show { display: block; }

/* Main content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.top-header {
    height: var(--header-height);
    background: var(--white);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    position: sticky; top: 0; z-index: 50;
}

.top-header-left { display: flex; align-items: center; gap: 12px; }
.top-header-right { display: flex; align-items: center; gap: 12px; }

.hamburger-btn {
    display: none;
    background: none; border: none; cursor: pointer; padding: 4px;
    color: var(--gray-700);
}

.page-title { font-size: 16px; font-weight: 600; color: var(--gray-900); }

.breadcrumb {
    display: flex; align-items: center; gap: 4px;
    list-style: none; font-size: 12px;
}
.breadcrumb li::before { content: '/'; margin-right: 4px; color: var(--gray-400); }
.breadcrumb li:first-child::before { content: ''; margin: 0; }
.breadcrumb a { color: var(--gray-500); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .active { color: var(--gray-700); }

/* User menu */
.user-menu { position: relative; cursor: pointer; display: flex; align-items: center; gap: 8px; }
.user-info-text { text-align: right; }
.user-info-text .name { font-size: 13px; font-weight: 600; color: var(--gray-800); }
.user-info-text .role { font-size: 11px; color: var(--gray-500); }

.user-avatar {
    width: 32px; height: 32px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: 13px; font-weight: 600;
}

.user-dropdown {
    display: none;
    position: absolute; top: calc(100% + 4px); right: 0;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    min-width: 180px;
    z-index: 200;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.user-menu:focus-within .user-dropdown,
.user-dropdown.show { display: block; }

.user-dropdown a {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 14px;
    color: var(--gray-700); font-size: 13px;
    text-decoration: none;
}
.user-dropdown a:hover { background: var(--gray-100); }
.user-dropdown a.danger { color: var(--danger); }
.dropdown-divider { border-top: 1px solid var(--gray-200); margin: 2px 0; }

/* Page content */
.page-content { padding: 20px; flex: 1; }

/* ── Cards ── */
.card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 16px;
}

.card-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    background: var(--gray-50);
    font-weight: 600; font-size: 14px;
}

.card-body { padding: 16px; }
.card-body.p-0 { padding: 0; }

/* ── Buttons ── */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 6px;
    padding: 7px 14px;
    border: 1px solid transparent;
    border-radius: var(--radius);
    font-size: 13px; font-weight: 500;
    cursor: pointer; font-family: var(--font);
    text-decoration: none;
    transition: background 0.15s, border-color 0.15s;
    line-height: 1.4;
}

.btn-primary { background: var(--primary); color: var(--white); border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); text-decoration: none; color: var(--white); }

.btn-success { background: var(--success); color: var(--white); border-color: var(--success); }
.btn-success:hover { background: #1b5e20; text-decoration: none; color: var(--white); }

.btn-danger { background: var(--danger); color: var(--white); border-color: var(--danger); }
.btn-danger:hover { background: #b71c1c; text-decoration: none; color: var(--white); }

.btn-warning { background: var(--warning); color: var(--white); border-color: var(--warning); }
.btn-warning:hover { background: #bf360c; text-decoration: none; color: var(--white); }

.btn-outline {
    background: var(--white); color: var(--gray-700);
    border-color: var(--border);
}
.btn-outline:hover { background: var(--gray-100); text-decoration: none; }

.btn-ghost {
    background: transparent;
    color: var(--gray-700);
    border-color: transparent;
}
.btn-ghost:hover {
    background: var(--gray-100);
    text-decoration: none;
}

/* Ensure clicks on icons inside buttons pass through to the button itself */
button i.fi, a.btn i.fi {
    pointer-events: none;
}

.btn-sm { padding: 4px 10px; font-size: 12px; }
.btn-lg { padding: 10px 20px; font-size: 14px; }
.btn-block { width: 100%; }
.btn:disabled, .btn.disabled { opacity: 0.5; pointer-events: none; }
.btn svg { width: 16px; height: 16px; }

.btn-group { display: flex; gap: 4px; }

/* ── Tables ── */
.table {
    width: 100%; border-collapse: collapse;
    font-size: 13px;
}
.table th {
    text-align: left;
    padding: 10px 14px;
    font-weight: 600; font-size: 12px;
    color: var(--gray-600);
    background: var(--gray-50);
    border-bottom: 1px solid var(--border);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}
.table td {
    padding: 10px 14px;
    border-bottom: 1px solid var(--gray-200);
    vertical-align: middle;
}
.table tbody tr:hover { background: var(--gray-50); }
.table tbody tr:last-child td { border-bottom: none; }

/* ── Forms ── */
.form-group { margin-bottom: 14px; }
.form-group label {
    display: block;
    font-size: 13px; font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 4px;
}
.form-control {
    width: 100%;
    padding: 7px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px; font-family: var(--font);
    color: var(--gray-900);
    background: var(--white);
    transition: border-color 0.15s;
    outline: none;
}
.form-control:focus { border-color: var(--primary); }
.form-control::placeholder { color: var(--gray-400); }

textarea.form-control { min-height: 80px; resize: vertical; }
select.form-control { cursor: pointer; }

.form-text { font-size: 11px; color: var(--gray-500); margin-top: 2px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.form-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }
.required { color: var(--danger); }

.input-group { position: relative; display: flex; align-items: center; }
.input-icon {
    position: absolute; left: 10px;
    color: var(--gray-400); display: flex;
}
.input-icon svg { width: 16px; height: 16px; }
.input-group .form-control { padding-left: 34px; }
.toggle-password {
    position: absolute; right: 10px;
    background: none; border: none; cursor: pointer;
    color: var(--gray-400); display: flex;
}

.form-check {
    display: flex; align-items: center; gap: 6px;
    font-size: 13px; cursor: pointer;
}
.form-check input[type="checkbox"] { width: 16px; height: 16px; cursor: pointer; }

/* ── Alerts ── */
.alert {
    display: flex; align-items: center; justify-content: space-between;
    padding: 10px 14px;
    border: 1px solid;
    border-radius: var(--radius);
    font-size: 13px;
    margin-bottom: 12px;
}
.alert-success { background: var(--success-light); border-color: #c8e6c9; color: var(--success); }
.alert-danger { background: var(--danger-light); border-color: #ffcdd2; color: var(--danger); }
.alert-warning { background: var(--warning-light); border-color: #ffe0b2; color: var(--warning); }
.alert-info { background: var(--info-light); border-color: #b3e5fc; color: var(--info); }
.alert-close {
    background: none; border: none; cursor: pointer;
    font-size: 18px; line-height: 1; color: inherit; opacity: 0.6;
}
.alert-close:hover { opacity: 1; }

/* ── Badges ── */
.badge {
    display: inline-block;
    padding: 2px 8px;
    font-size: 11px; font-weight: 600;
    border-radius: 3px;
    line-height: 1.5;
}
.badge-success { background: var(--success-light); color: var(--success); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-warning { background: var(--warning-light); color: var(--warning); }
.badge-info { background: var(--info-light); color: var(--info); }
.badge-gray { background: var(--gray-200); color: var(--gray-700); }
.badge-primary { background: var(--primary-light); color: var(--primary); }

/* ── Stats Grid ── */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}
.stat-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 16px;
}
.stat-card .stat-label {
    font-size: 12px; color: var(--gray-600);
    margin-bottom: 4px;
}
.stat-card .stat-value {
    font-size: 24px; font-weight: 700;
    color: var(--gray-900);
}
.stat-card .stat-icon {
    float: right;
    width: 36px; height: 36px;
    border-radius: var(--radius);
    display: flex; align-items: center; justify-content: center;
    font-size: 18px;
}

/* ── Empty State ── */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--gray-500);
}
.empty-state svg { color: var(--gray-300); margin-bottom: 12px; }
.empty-state h3 { font-size: 15px; color: var(--gray-700); margin-bottom: 4px; }
.empty-state p { font-size: 13px; }

/* ── Pagination ── */
.pagination {
    display: flex; align-items: center; justify-content: center;
    gap: 2px; list-style: none;
    padding: 12px;
}
.pagination a, .pagination span {
    display: flex; align-items: center; justify-content: center;
    min-width: 32px; height: 32px;
    padding: 0 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px; color: var(--gray-700);
    text-decoration: none;
}
.pagination a:hover { background: var(--gray-100); text-decoration: none; }
.pagination .active { background: var(--primary); color: var(--white); border-color: var(--primary); }
.pagination .disabled { opacity: 0.4; pointer-events: none; }

/* ── Utilities ── */
.d-flex { display: flex; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.ml-auto { margin-left: auto; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--gray-500); }
.text-sm { font-size: 12px; }
.text-xs { font-size: 11px; }
.fw-500 { font-weight: 500; }
.fw-600 { font-weight: 600; }
.fw-700 { font-weight: 700; }
.text-danger { color: var(--danger); }
.text-success { color: var(--success); }
.text-primary { color: var(--primary); }
.p-0 { padding: 0; }
.p-3 { padding: 12px; }
.w-100 { width: 100%; }
.hidden { display: none !important; }

/* ── Filter bar ── */
.filter-bar {
    display: flex; flex-wrap: wrap; gap: 8px;
    padding: 12px 16px;
    background: var(--gray-50);
    border-bottom: 1px solid var(--border);
    align-items: center;
}
.filter-bar .form-group { margin: 0; }
.filter-bar .form-control { font-size: 12px; padding: 5px 8px; }
.filter-bar label { font-size: 11px; margin-bottom: 2px; }

/* ── Auth Page ── */
.auth-page {
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    background: var(--body-bg);
    padding: 20px;
}
.auth-card {
    width: 100%; max-width: 400px;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
}
.auth-logo { text-align: center; margin-bottom: 24px; }
.auth-logo .logo-icon {
    width: 48px; height: 48px;
    background: var(--primary);
    border-radius: var(--radius);
    display: inline-flex; align-items: center; justify-content: center;
    margin-bottom: 12px;
}
.auth-logo .logo-icon svg { width: 24px; height: 24px; }
.auth-logo h1 { font-size: 16px; color: var(--gray-900); margin-bottom: 4px; }
.auth-logo p { font-size: 13px; color: var(--gray-500); }

/* ── Tabs ── */
.tabs {
    display: flex; gap: 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 16px;
}
.tab-item {
    padding: 8px 16px;
    font-size: 13px; font-weight: 500;
    color: var(--gray-600);
    border-bottom: 2px solid transparent;
    cursor: pointer;
    text-decoration: none;
}
.tab-item:hover { color: var(--gray-900); text-decoration: none; }
.tab-item.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }

/* ── Modal ── */
.modal-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 1000;
    align-items: center; justify-content: center;
}
.modal-overlay.show { display: flex; }
.modal {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 90%; max-width: 560px;
    max-height: 80vh; overflow-y: auto;
}
.modal-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    font-weight: 600;
}
.modal-body { padding: 16px; }
.modal-footer {
    display: flex; justify-content: flex-end; gap: 8px;
    padding: 12px 16px;
    border-top: 1px solid var(--border);
}
.modal-close { background: none; border: none; cursor: pointer; font-size: 20px; color: var(--gray-500); }

/* ── Exam Taking ── */
.exam-container {
    display: flex; min-height: 100vh;
    background: var(--white);
}
.exam-sidebar {
    width: 260px;
    background: var(--gray-50);
    border-right: 1px solid var(--border);
    padding: 16px;
    position: fixed; top: 0; left: 0; bottom: 0;
    overflow-y: auto;
}
.exam-main {
    flex: 1; margin-left: 260px;
    padding: 24px 32px;
}
.exam-timer {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 12px;
    text-align: center;
    margin-bottom: 16px;
}
.exam-timer .time { font-size: 28px; font-weight: 700; font-variant-numeric: tabular-nums; }
.exam-timer .time.warning { color: var(--warning); }
.exam-timer .time.danger { color: var(--danger); }

.question-nav {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 4px;
    margin-top: 12px;
}
.question-nav .q-btn {
    width: 100%; aspect-ratio: 1;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--white);
    font-size: 12px; font-weight: 600;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
}
.question-nav .q-btn.answered { background: var(--primary-light); border-color: var(--primary); color: var(--primary); }
.question-nav .q-btn.flagged { background: #fff3e0; border-color: var(--warning); color: var(--warning); }
.question-nav .q-btn.active { background: var(--primary); color: var(--white); border-color: var(--primary); }

.question-block {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
}
.question-block .q-number {
    font-size: 12px; font-weight: 600; color: var(--primary);
    margin-bottom: 8px;
}
.question-block .q-content { font-size: 14px; line-height: 1.7; margin-bottom: 16px; }

.answer-option {
    display: flex; align-items: flex-start; gap: 10px;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 6px;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s;
}
.answer-option:hover { background: var(--gray-50); }
.answer-option.selected { background: var(--primary-light); border-color: var(--primary); }
.answer-option.correct { background: var(--success-light); border-color: var(--success); }
.answer-option.wrong { background: var(--danger-light); border-color: var(--danger); }
.answer-option input[type="radio"],
.answer-option input[type="checkbox"] { margin-top: 2px; flex-shrink: 0; }

/* ── Progress bar ── */
.progress { height: 6px; background: var(--gray-200); border-radius: 3px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--primary); border-radius: 3px; transition: width 0.3s; }
.progress-bar.success { background: var(--success); }
.progress-bar.danger { background: var(--danger); }

/* ── Action bar ── */
.action-bar {
    display: flex; align-items: center; justify-content: space-between;
    flex-wrap: wrap; gap: 8px;
    margin-bottom: 12px;
}

/* ── Spinner ── */
.spinner {
    display: inline-block;
    width: 16px; height: 16px;
    border: 2px solid var(--gray-300);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Responsive ── */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.2s;
    }
    .sidebar.open { transform: translateX(0); }
    .main-content { margin-left: 0; }
    .hamburger-btn { display: block; }
    .form-row, .form-row-3 { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .exam-sidebar { display: none; }
    .exam-main { margin-left: 0; }
    .filter-bar { flex-direction: column; }
}

@media (max-width: 480px) {
    .stats-grid { grid-template-columns: 1fr; }
    .page-content { padding: 12px; }
    .auth-card { padding: 24px 16px; }
}