/* =====================================================================
   PrepKing Online — app.css (base layout, tokens, components)
   Design tokens follow the supplied prototype (§24).
   ===================================================================== */

:root {
    --bg-color: #f4f6f9;
    --card-bg: #ffffff;
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --correct-bg: #dcfce7;
    --correct-border: #16a34a;
    --correct-text: #14532d;
    --wrong-bg: #fee2e2;
    --wrong-border: #dc2626;
    --wrong-text: #7f1d1d;
    --warning: #f59e0b;
    --urgent: #ef4444;
    --radius: 14px;
    --shadow: 0 1px 3px rgba(0,0,0,.08), 0 8px 24px rgba(0,0,0,.05);
    --maxw: 800px;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg-color);
    color: var(--text-main);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    -webkit-text-size-adjust: 100%;
}

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

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5rem; }
h1 { font-size: 1.6rem; }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.1rem; }

.muted { color: var(--text-muted); }
.small { font-size: .85rem; }
.center { text-align: center; }
.hidden { display: none !important; }

/* ---- Layout ---- */
.app-shell { min-height: 100vh; display: flex; flex-direction: column; }

.topbar {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky; top: 0; z-index: 20;
}
.topbar-inner {
    max-width: 1100px; margin: 0 auto; padding: .7rem 1rem;
    display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
}
.brand { font-weight: 800; font-size: 1.15rem; color: var(--text-main); letter-spacing: -.02em; }
.brand span { color: var(--primary); }
.nav { display: flex; gap: .25rem; flex-wrap: wrap; margin-left: auto; }
.nav a {
    padding: .45rem .8rem; border-radius: 8px; color: var(--text-muted);
    font-weight: 600; font-size: .92rem;
}
.nav a:hover { background: var(--bg-color); text-decoration: none; color: var(--text-main); }
.nav a.active { background: #eaf1ff; color: var(--primary); }
.nav .nav-user { color: var(--text-main); font-weight: 700; }

.container { width: 100%; max-width: 1100px; margin: 0 auto; padding: 1.25rem 1rem 3rem; flex: 1; }
.container.narrow { max-width: var(--maxw); }

/* ---- Cards ---- */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.25rem;
    margin-bottom: 1rem;
}
.card-title { font-weight: 700; margin-bottom: .75rem; }

/* ---- Forms ---- */
.field { margin-bottom: 1rem; }
.field label { display: block; font-weight: 600; margin-bottom: .35rem; font-size: .92rem; }
.field .hint { color: var(--text-muted); font-size: .8rem; margin-top: .25rem; }
input[type=text], input[type=email], input[type=password], input[type=number],
select, textarea {
    width: 100%; padding: .65rem .8rem; border: 1px solid var(--border-color);
    border-radius: 10px; font-size: 1rem; background: #fff; color: var(--text-main);
    transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus, textarea:focus {
    outline: none; border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,.15);
}
textarea { min-height: 90px; resize: vertical; }

/* ---- Buttons ---- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
    padding: .7rem 1.2rem; border-radius: 10px; border: 1px solid transparent;
    font-size: 1rem; font-weight: 700; cursor: pointer; background: var(--primary);
    color: #fff; transition: background .15s, transform .05s;
    min-height: 44px; /* touch friendly (§99) */
}
.btn:hover { background: var(--primary-hover); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .6; cursor: not-allowed; }
.btn.secondary { background: #fff; color: var(--text-main); border-color: var(--border-color); }
.btn.secondary:hover { background: var(--bg-color); }
.btn.danger { background: var(--urgent); }
.btn.danger:hover { background: #dc2626; }
.btn.success { background: var(--correct-border); }
.btn.ghost { background: transparent; color: var(--primary); }
.btn.ghost:hover { background: #eaf1ff; }
.btn.block { width: 100%; }
.btn.sm { padding: .4rem .8rem; font-size: .88rem; min-height: 38px; }
.btn-row { display: flex; gap: .6rem; flex-wrap: wrap; }

/* ---- Flash messages (§144) ---- */
.flashes { margin-bottom: 1rem; }
.flash {
    padding: .8rem 1rem; border-radius: 10px; margin-bottom: .6rem;
    border: 1px solid transparent; font-weight: 600; font-size: .95rem;
}
.flash.success { background: var(--correct-bg); border-color: var(--correct-border); color: var(--correct-text); }
.flash.error   { background: var(--wrong-bg); border-color: var(--wrong-border); color: var(--wrong-text); }
.flash.warning { background: #fef3c7; border-color: var(--warning); color: #92400e; }
.flash.info    { background: #e0f2fe; border-color: #0284c7; color: #075985; }

/* ---- Auth pages ---- */
.auth-wrap {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    padding: 1rem; background: linear-gradient(160deg, #eef2ff 0%, #f4f6f9 45%, #eff6ff 100%);
}
.auth-card { width: 100%; max-width: 420px; }
.auth-brand { text-align: center; margin-bottom: 1rem; }
.auth-brand h1 { font-size: 1.7rem; }
.auth-alt { text-align: center; margin-top: 1rem; font-size: .92rem; }
.divider { display: flex; align-items: center; gap: .75rem; color: var(--text-muted); margin: 1rem 0; font-size: .85rem; }
.divider::before, .divider::after { content: ""; height: 1px; background: var(--border-color); flex: 1; }
.btn-google { background: #fff; color: #1f2937; border: 1px solid var(--border-color); }
.btn-google:hover { background: var(--bg-color); }

/* ---- Loading / spinner (§145) ---- */
.spinner {
    width: 18px; height: 18px; border: 3px solid rgba(255,255,255,.4);
    border-top-color: #fff; border-radius: 50%; animation: spin .8s linear infinite;
    display: inline-block;
}
.spinner.dark { border-color: rgba(0,0,0,.15); border-top-color: var(--primary); }
@keyframes spin { to { transform: rotate(360deg); } }
.loading-overlay {
    position: fixed; inset: 0; background: rgba(244,246,249,.86);
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    gap: 1rem; z-index: 100; text-align: center; padding: 1rem;
}
.loading-overlay .msg { font-weight: 700; color: var(--text-main); }
.loading-overlay .sub { color: var(--text-muted); font-size: .9rem; }

/* ---- Tables ---- */
.table-wrap { overflow-x: auto; }
table.data { width: 100%; border-collapse: collapse; font-size: .92rem; }
table.data th, table.data td { text-align: left; padding: .6rem .7rem; border-bottom: 1px solid var(--border-color); }
table.data th { background: var(--bg-color); font-weight: 700; white-space: nowrap; }
table.data tr:hover td { background: #fafbff; }

/* ---- Badges ---- */
.badge {
    display: inline-block; padding: .15rem .55rem; border-radius: 999px;
    font-size: .75rem; font-weight: 700; border: 1px solid var(--border-color);
    background: #f9fafb; color: var(--text-muted);
}
.badge.primary { background: #eaf1ff; color: var(--primary); border-color: #c7dbff; }
.badge.success { background: var(--correct-bg); color: var(--correct-text); border-color: var(--correct-border); }
.badge.danger  { background: var(--wrong-bg); color: var(--wrong-text); border-color: var(--wrong-border); }
.badge.warning { background: #fef3c7; color: #92400e; border-color: var(--warning); }

/* ---- Grid helpers ---- */
.grid { display: grid; gap: 1rem; }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
.stat { text-align: center; }
.stat .value { font-size: 1.8rem; font-weight: 800; }
.stat .label { color: var(--text-muted); font-size: .85rem; }

/* ---- Responsive (§99) ---- */
@media (max-width: 720px) {
    .grid.cols-3, .grid.cols-4 { grid-template-columns: repeat(2, 1fr); }
    .topbar-inner { gap: .5rem; }
    .nav { width: 100%; margin-left: 0; }
    h1 { font-size: 1.4rem; }
}
@media (max-width: 420px) {
    .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; }
    .container { padding: 1rem .75rem 2rem; }
}

/* ---- Print (§152) ---- */
@media print {
    .topbar, .nav, .btn, .btn-row, .no-print, .flashes { display: none !important; }
    body { background: #fff; }
    .card { box-shadow: none; border-color: #ccc; break-inside: avoid; }
    a { color: #000; text-decoration: none; }
}