/* ============================================================
   Design system "Hiện đại & thân thiện" — điểm thi THPT
   Thay Pico CSS: tự cấp lại .container/.grid/article/[role=button]...
   ============================================================ */

:root {
  --indigo: #4F46E5;
  --indigo-600: #4338CA;
  --indigo-050: #EEF2FF;
  --indigo-100: #E0E7FF;
  --indigo-200: #C7D2FE;
  --violet: #8B5CF6;
  --teal: #14B8A6;
  --teal-050: #F0FDFA;

  --bg: #F8FAFC;
  --surface: #FFFFFF;
  --surface-2: #F1F5F9;
  --ink: #1E293B;
  --muted: #64748B;
  --faint: #94A3B8;
  --line: #E2E8F0;
  --line-soft: #EEF2F7;

  --green: #10B981; --green-bg: #DCFCE7; --green-ink: #15803D;
  --amber: #F59E0B; --amber-bg: #FEF3C7; --amber-ink: #B45309;
  --red: #EF4444;   --red-bg: #FEE2E2;   --red-ink: #B91C1C;

  --r-sm: 10px; --r: 14px; --r-lg: 16px; --r-pill: 999px;
  --sh-sm: 0 1px 2px rgba(15,23,42,.06);
  --sh: 0 4px 16px rgba(15,23,42,.06);
  --sh-md: 0 8px 24px rgba(15,23,42,.08);
  --sh-lg: 0 16px 40px rgba(15,23,42,.12);
  --ease: 150ms cubic-bezier(.4,0,.2,1);
  --maxw: 1100px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: 'Be Vietnam Pro', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: .95rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
}

h1, h2, h3, h4, h5, h6 { line-height: 1.25; margin: 0 0 .5rem; font-weight: 700; letter-spacing: -.01em; color: var(--ink); }
h1 { font-size: 2rem; font-weight: 800; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.2rem; }
h4 { font-size: 1.05rem; }
h5 { font-size: .98rem; }
p { margin: 0 0 .8rem; }
small { font-size: .82rem; color: var(--muted); }
a { color: var(--indigo); text-decoration: none; }
a:hover { text-decoration: underline; }
hgroup { margin-bottom: 1.2rem; }
hgroup > * { margin-bottom: .25rem; }
hgroup p { color: var(--muted); }

/* ---------- layout ---------- */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 1.1rem; }
.container-fluid { padding: 0 1.1rem; }
main.container { padding-top: 1.4rem; padding-bottom: 2.5rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; }
.stack > * + * { margin-top: 1rem; }
.section { margin: 1.5rem 0; }

/* ---------- top nav ---------- */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.9); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.topnav .nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: .6rem 1.1rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.brand { font-weight: 800; font-size: 1.05rem; color: var(--ink); display: inline-flex; align-items: center; gap: .45rem; }
.brand:hover { text-decoration: none; }
.brand .logo { width: 30px; height: 30px; border-radius: 9px; background: linear-gradient(135deg,#6366F1,#8B5CF6); color: #fff; display: inline-flex; align-items: center; justify-content: center; font-size: 1rem; }
.nav-links { display: flex; align-items: center; gap: .35rem; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  color: var(--muted); font-size: .9rem; font-weight: 500;
  padding: .4rem .7rem; border-radius: var(--r-pill); transition: var(--ease);
}
.nav-links a:hover { background: var(--surface-2); color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--indigo); background: var(--indigo-050); font-weight: 600; }
.nav-toggle { display: none; background: none; border: 1px solid var(--line); border-radius: var(--r-sm); padding: .35rem .5rem; font-size: 1.2rem; color: var(--ink); cursor: pointer; line-height: 1; }

@media (max-width: 820px) {
  .nav-toggle { display: inline-flex; }
  .nav-links {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: .1rem;
    background: var(--surface); border-bottom: 1px solid var(--line);
    padding: .5rem .8rem 1rem; box-shadow: var(--sh-md);
    display: none;
  }
  .topnav.open .nav-links { display: flex; }
  .nav-links a { padding: .6rem .7rem; border-radius: var(--r-sm); }
}

/* ---------- hero ---------- */
.hero {
  background: linear-gradient(135deg,#6366F1,#8B5CF6);
  color: #fff; border-radius: var(--r-lg); padding: 2rem 1.6rem; margin-bottom: 1.4rem;
  box-shadow: var(--sh-md);
}
.hero h1 { color: #fff; font-size: 1.9rem; }
.hero p { color: rgba(255,255,255,.9); margin-bottom: 0; }
.hero .lead { font-size: 1.05rem; }

/* ---------- cards ---------- */
article, .card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg);
  padding: 1.1rem 1.3rem; margin-bottom: 1.1rem; box-shadow: var(--sh);
}
.card-hover { transition: var(--ease); }
.card-hover:hover { transform: translateY(-2px); box-shadow: var(--sh-md); border-color: var(--indigo-200); }
article > :last-child, .card > :last-child { margin-bottom: 0; }

/* feature tiles on landing */
.feature { display: block; text-decoration: none; color: inherit; }
.feature:hover { text-decoration: none; }
.feature .ico { font-size: 1.5rem; }

/* ---------- KPI / stat ---------- */
.kpi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin-bottom: 1.2rem; }
.stat-label { font-size: .78rem; color: var(--muted); font-weight: 600; text-transform: none; }
.stat-value { font-size: 1.7rem; font-weight: 800; color: var(--indigo); letter-spacing: -.02em; line-height: 1.15; }
.stat-value.teal { color: var(--teal); }
.stat-value.violet { color: var(--violet); }

/* ---------- buttons ---------- */
button, [role="button"], .btn, input[type="submit"] {
  display: inline-flex; align-items: center; justify-content: center; gap: .4rem;
  font-family: inherit; font-size: .9rem; font-weight: 600; line-height: 1;
  padding: .62rem 1.1rem; border-radius: var(--r-pill); border: 1.5px solid transparent;
  background: var(--indigo); color: #fff; cursor: pointer; transition: var(--ease);
  text-decoration: none;
}
button:hover, [role="button"]:hover, .btn:hover { background: var(--indigo-600); text-decoration: none; }
button:active, [role="button"]:active, .btn:active { transform: scale(.98); }
.outline, [role="button"].outline, .btn.outline {
  background: var(--surface); color: var(--indigo); border-color: var(--indigo-200);
}
.outline:hover, [role="button"].outline:hover { background: var(--indigo-050); }
.secondary, [role="button"].secondary, .btn.secondary {
  background: var(--surface-2); color: var(--ink); border-color: var(--line);
}
.secondary:hover, [role="button"].secondary:hover { background: #E2E8F0; }
.btn-teal { background: var(--teal); }
.btn-teal:hover { background: #0D9488; }
.btn-sm { padding: .35rem .7rem; font-size: .8rem; }

/* ---------- forms ---------- */
label { display: block; font-size: .85rem; font-weight: 600; color: var(--ink); margin-bottom: .9rem; }
input, select, textarea {
  font-family: inherit; font-size: .9rem; color: var(--ink); width: 100%;
  padding: .55rem .75rem; border: 1px solid var(--line); border-radius: var(--r-sm);
  background: var(--surface); margin-top: .3rem; transition: var(--ease);
}
input:focus, select:focus, textarea:focus {
  outline: none; border-color: var(--indigo); box-shadow: 0 0 0 3px var(--indigo-050);
}
select { cursor: pointer; }
.form-row { display: flex; gap: .8rem; flex-wrap: wrap; align-items: end; }
.form-row > label { flex: 1; min-width: 150px; margin-bottom: 0; }
.form-row button { white-space: nowrap; }

/* ---------- badges ---------- */
.badge { display: inline-block; padding: .18rem .6rem; border-radius: var(--r-pill); font-size: .78rem; font-weight: 700; }
.badge-xanh { background: var(--green-bg); color: var(--green-ink); }
.badge-vang { background: var(--amber-bg); color: var(--amber-ink); }
.badge-do   { background: var(--red-bg);   color: var(--red-ink); }
.badge-info { background: var(--indigo-050); color: var(--indigo-600); }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; border-radius: var(--r); border: 1px solid var(--line); }
table { width: 100%; border-collapse: collapse; font-size: .9rem; }
thead th {
  position: sticky; top: 0; background: var(--surface-2); color: var(--muted);
  font-weight: 700; font-size: .8rem; text-align: left; padding: .6rem .75rem;
  border-bottom: 1px solid var(--line); white-space: nowrap;
}
tbody td { padding: .55rem .75rem; border-bottom: 1px solid var(--line-soft); }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: var(--indigo-050); }
table.compact td, table.compact th { padding: .4rem .6rem; font-size: .86rem; }

/* ---------- details/summary (chiến lược) ---------- */
details { border: 1px solid var(--line); border-radius: var(--r); margin-bottom: .7rem; background: var(--surface); overflow: hidden; }
summary { cursor: pointer; padding: .7rem 1rem; font-weight: 600; list-style: none; display: flex; align-items: center; gap: .5rem; }
summary::-webkit-details-marker { display: none; }
summary::before { content: "▸"; color: var(--muted); transition: var(--ease); }
details[open] summary::before { transform: rotate(90deg); }
details > *:not(summary) { padding: 0 1rem 1rem; }
details .table-wrap { margin: 0 1rem 1rem; }

/* ---------- charts ---------- */
.chart { min-height: 380px; }

/* ---------- skeleton loading (HTMX) ---------- */
.htmx-indicator { opacity: 0; transition: opacity 200ms; }
.htmx-request .htmx-indicator, .htmx-request.htmx-indicator { opacity: 1; }
.htmx-request.skeleton-target { position: relative; min-height: 70px; }
.skeleton { background: linear-gradient(90deg,#F1F5F9 25%,#E2E8F0 37%,#F1F5F9 63%); background-size: 400% 100%; animation: shimmer 1.4s ease infinite; border-radius: var(--r-sm); height: 1rem; }
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* ---------- auth / centered card ---------- */
.auth-wrap { max-width: 440px; margin: 2.5rem auto; }

/* ---------- alerts ---------- */
.alert { border-radius: var(--r); padding: .8rem 1rem; margin-bottom: 1rem; font-size: .9rem; border: 1px solid; }
.alert-ok { background: var(--green-bg); border-color: #A7F3D0; color: var(--green-ink); }
.alert-err { background: var(--red-bg); border-color: #FCA5A5; color: var(--red-ink); }
.alert-warn { background: var(--amber-bg); border-color: #FDE68A; color: var(--amber-ink); }

/* ---------- footer ---------- */
footer.site { border-top: 1px solid var(--line); margin-top: 2rem; padding: 1.4rem 1.1rem; }
footer.site .container { color: var(--muted); font-size: .8rem; }

/* ---------- utilities ---------- */
.muted { color: var(--muted); }
.center { text-align: center; }
.fade-in { animation: fadein var(--ease); }
@keyframes fadein { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
.pill-note { display: inline-block; background: var(--indigo-050); color: var(--indigo-600); font-size: .78rem; font-weight: 600; padding: .2rem .7rem; border-radius: var(--r-pill); }