/* ui.css: a design system for single-file web pages, written by Claude for LFM3 (general purpose).
   Themes: <body data-theme="warm|forest|ocean|dark"> (default: indigo on light grey). */
:root {
  --bg: #f6f7fb; --surface: #ffffff; --surface-2: #eff1f7; --text: #1c2030; --muted: #5c6378; --border: #e2e5ee;
  --primary: #4f46e5; --primary-ink: #ffffff; --accent: #f59e0b; --success: #16a34a; --warning: #d97706;
  --danger: #dc2626; --radius: 14px; --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(20, 24, 40, .06), 0 8px 24px rgba(20, 24, 40, .08);
  --shadow-lg: 0 18px 48px rgba(20, 24, 40, .18);
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --serif: Georgia, "Times New Roman", serif; --mono: ui-monospace, "Cascadia Code", Consolas, monospace;
  --max: 1120px;
}
body[data-theme="warm"] { --bg: #fdf8f2; --surface-2: #f7ede1; --text: #2a2019; --muted: #75645a; --border: #ead9c8;
  --primary: #c2410c; --accent: #d97706; }
body[data-theme="forest"] { --bg: #f4f8f3; --surface-2: #e7f0e5; --border: #d6e3d3; --primary: #15803d; --accent: #ca8a04; }
body[data-theme="ocean"] { --bg: #f2f8fb; --surface-2: #e3f0f7; --border: #d3e4ee; --primary: #0369a1; --accent: #06b6d4; }
body[data-theme="dark"] { --bg: #0f1218; --surface: #171b24; --surface-2: #1f2431; --text: #e8ebf3; --muted: #9aa3b6;
  --border: #2a3142; --primary: #818cf8; --primary-ink: #0f1218; --accent: #fbbf24;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .35); }

*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.6 var(--font); -webkit-font-smoothing: antialiased; }
img, svg, video { max-width: 100%; }
h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 .5em; font-weight: 750; letter-spacing: -.015em; }
h1 { font-size: clamp(2.1rem, 4.2vw, 3.3rem); } h2 { font-size: clamp(1.6rem, 3vw, 2.25rem); }
h3 { font-size: 1.25rem; } h4 { font-size: 1.05rem; }
p { margin: 0 0 1em; } a { color: var(--primary); text-decoration: none; } a:hover { text-decoration: underline; }
.lead { font-size: 1.2rem; color: var(--muted); } .muted { color: var(--muted); } .small { font-size: .875rem; }
.center { text-align: center; } .serif { font-family: var(--serif); } .mono { font-family: var(--mono); }
.eyebrow { font-size: .8rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--primary); }

/* layout */
.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: 760px; }
.section { padding: 72px 0; } .section-alt { background: var(--surface-2); }
.section-title { text-align: center; max-width: 640px; margin: 0 auto 40px; }
.stack > * + * { margin-top: var(--gap, 16px); }
.row { display: flex; gap: var(--gap, 16px); align-items: center; flex-wrap: wrap; }
.between { justify-content: space-between; } .end { justify-content: flex-end; } .top { align-items: flex-start; }
.grow { flex: 1; }
.grid { display: grid; gap: var(--gap, 24px); grid-template-columns: repeat(auto-fit, minmax(var(--min, 240px), 1fr)); }
.grid-2 { grid-template-columns: repeat(2, 1fr); } .grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 800px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }
.layout-sidebar { display: grid; grid-template-columns: 240px 1fr; min-height: 100vh; }
.sidebar { background: var(--surface); border-right: 1px solid var(--border); padding: 20px 14px; }
.sidebar .brand { display: block; padding: 6px 12px 18px; }
.sidebar a { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: var(--radius-sm);
  color: var(--muted); font-weight: 500; }
.sidebar a:hover { background: var(--surface-2); color: var(--text); text-decoration: none; }
.sidebar a.active { background: color-mix(in srgb, var(--primary) 12%, transparent); color: var(--primary); font-weight: 650; }
.main { padding: 28px 32px; min-width: 0; }

/* navigation */
.navbar { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--surface) 90%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.navbar .container { display: flex; align-items: center; justify-content: space-between; gap: 24px; height: 66px; }
.brand { font-weight: 800; font-size: 1.25rem; color: var(--text); letter-spacing: -.02em; }
.nav-links { display: flex; gap: 26px; align-items: center; }
.nav-links a { color: var(--muted); font-weight: 550; }
.nav-links a:hover, .nav-links a.active { color: var(--text); text-decoration: none; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px 28px;
  background: var(--surface); border-bottom: 1px solid var(--border); }

/* hero */
.hero { padding: 104px 0 88px; text-align: center;
  background: radial-gradient(1100px 480px at 50% -12%, color-mix(in srgb, var(--primary) 20%, transparent), transparent), var(--bg); }
.hero h1 { max-width: 18ch; margin: 0 auto 18px; }
.hero .lead { max-width: 58ch; margin: 0 auto 30px; }
.hero-dark { color: #fff; background: linear-gradient(135deg, #1e1b4b, var(--primary)); }
.hero-dark .lead { color: rgba(255, 255, 255, .85); }

/* cards */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 24px; }
.card-hover { transition: transform .2s ease, box-shadow .2s ease; }
.card-hover:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.media { aspect-ratio: 16 / 10; border-radius: calc(var(--radius) - 4px); margin-bottom: 16px; }
.card.featured { border: 2px solid var(--primary); box-shadow: var(--shadow-lg); }

/* gradient placeholders instead of images */
.ph { background: linear-gradient(135deg, #a5b4fc, #f0abfc); } .ph-1 { background: linear-gradient(135deg, #fcd34d, #f97316); }
.ph-2 { background: linear-gradient(135deg, #6ee7b7, #0ea5e9); } .ph-3 { background: linear-gradient(135deg, #f9a8d4, #8b5cf6); }
.ph-4 { background: linear-gradient(135deg, #93c5fd, #4f46e5); } .ph-5 { background: linear-gradient(135deg, #bef264, #16a34a); }
.ph-6 { background: linear-gradient(135deg, #fda4af, #e11d48); } .ph-7 { background: linear-gradient(135deg, #fde68a, #a16207); }
.ph-8 { background: linear-gradient(135deg, #cbd5e1, #334155); }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 22px; border-radius: 999px;
  border: 1px solid transparent; font: 650 1rem/1 var(--font); cursor: pointer; background: var(--primary);
  color: var(--primary-ink); transition: filter .15s, transform .15s; text-decoration: none; white-space: nowrap; }
.btn:hover { filter: brightness(1.08); text-decoration: none; } .btn:active { transform: translateY(1px); }
.btn-outline { background: transparent; color: var(--primary); border-color: currentColor; }
.btn-ghost { background: transparent; color: var(--text); } .btn-accent { background: var(--accent); color: #1f1300; }
.btn-light { background: var(--surface); color: var(--text); border-color: var(--border); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-lg { padding: 16px 30px; font-size: 1.1rem; } .btn-sm { padding: 8px 14px; font-size: .875rem; }
.btn-block { width: 100%; }

/* badges, tags, avatars, icons */
.badge { display: inline-block; padding: 3px 10px; border-radius: 999px; font-size: .78rem; font-weight: 650;
  background: var(--surface-2); color: var(--muted); }
.badge-primary { background: color-mix(in srgb, var(--primary) 14%, transparent); color: var(--primary); }
.badge-success { background: #dcfce7; color: #166534; } .badge-warning { background: #fef3c7; color: #92400e; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag { padding: 6px 12px; border-radius: 999px; background: var(--surface-2); border: 1px solid var(--border); font-size: .875rem; }
.avatar { width: 44px; height: 44px; border-radius: 50%; display: inline-grid; place-items: center; font-weight: 700;
  color: #fff; background: linear-gradient(135deg, var(--primary), var(--accent)); flex: none; }
.avatar-lg { width: 104px; height: 104px; font-size: 2.1rem; } .avatar-sm { width: 32px; height: 32px; font-size: .8rem; }
.icon { width: 48px; height: 48px; border-radius: 12px; display: inline-grid; place-items: center; font-size: 1.4rem;
  background: color-mix(in srgb, var(--primary) 12%, transparent); color: var(--primary); }

/* numbers, prices, ratings, check lists */
.price { font-size: 2.6rem; font-weight: 800; letter-spacing: -.02em; }
.price small { font-size: 1rem; color: var(--muted); font-weight: 500; }
.stars { color: #f59e0b; letter-spacing: 2px; }
.list-check { list-style: none; padding: 0; margin: 0 0 1.2em; }
.list-check li { padding: 6px 0 6px 28px; position: relative; }
.list-check li::before { content: "\2713"; position: absolute; left: 0; color: var(--success); font-weight: 800; }
.list-check li.no { color: var(--muted); } .list-check li.no::before { content: "\2715"; color: var(--danger); }
.kpi { display: grid; gap: 4px; } .kpi .value { font-size: 2rem; font-weight: 800; letter-spacing: -.02em; }
.kpi .label { color: var(--muted); font-size: .9rem; } .up { color: var(--success); } .down { color: var(--danger); }
.progress { height: 8px; background: var(--surface-2); border-radius: 999px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: var(--primary); border-radius: inherit; }

/* forms */
.field { display: grid; gap: 6px; margin-bottom: 16px; }
label { font-weight: 600; font-size: .92rem; }
.input, input[type=text], input[type=email], input[type=password], input[type=search], input[type=number],
input[type=date], input[type=tel], select, textarea { width: 100%; padding: 12px 14px; border: 1px solid var(--border);
  border-radius: var(--radius-sm); background: var(--surface); color: var(--text); font: inherit; }
input:focus, select:focus, textarea:focus { outline: 3px solid color-mix(in srgb, var(--primary) 30%, transparent);
  border-color: var(--primary); }
.error { color: var(--danger); font-size: .85rem; min-height: 1em; } .is-invalid { border-color: var(--danger) !important; }
.check { display: flex; align-items: center; gap: 10px; font-weight: 500; }
input[type=checkbox], input[type=radio], input[type=range] { accent-color: var(--primary); }
input[type=checkbox], input[type=radio] { width: 18px; height: 18px; }
input[type=range] { width: 100%; }
.switch { position: relative; display: inline-block; width: 46px; height: 26px; flex: none; }
.switch input { opacity: 0; width: 0; height: 0; }
.switch span { position: absolute; inset: 0; background: #c7ccd8; border-radius: 999px; transition: .2s; cursor: pointer; }
.switch span::before { content: ""; position: absolute; width: 20px; height: 20px; left: 3px; top: 3px; background: #fff;
  border-radius: 50%; transition: .2s; box-shadow: 0 1px 3px rgba(0, 0, 0, .3); }
.switch input:checked + span { background: var(--primary); }
.switch input:checked + span::before { transform: translateX(20px); }

/* tables */
.table { width: 100%; border-collapse: collapse; background: var(--surface); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow); }
.table th, .table td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
.table th { background: var(--surface-2); font-size: .8rem; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); }
.table tbody tr:nth-child(even) { background: color-mix(in srgb, var(--surface-2) 50%, transparent); }
.table tbody tr:hover { background: var(--surface-2); }
.table .num { text-align: right; font-variant-numeric: tabular-nums; }
.table-wrap { max-height: 70vh; overflow: auto; border-radius: var(--radius); }
.table-wrap thead th { position: sticky; top: 0; z-index: 1; }
th[data-sort] { cursor: pointer; user-select: none; } th[data-sort]::after { content: " \2195"; opacity: .45; }
th.asc::after { content: " \2191"; opacity: 1; } th.desc::after { content: " \2193"; opacity: 1; }

/* tabs, accordion, modal, toast */
[data-tabs] .tab-list { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: 20px; }
[data-tabs] .tab-list button { background: none; border: 0; padding: 12px 18px; font: 650 1rem var(--font);
  color: var(--muted); cursor: pointer; border-bottom: 3px solid transparent; margin-bottom: -1px; }
[data-tabs] .tab-list button.active { color: var(--primary); border-bottom-color: var(--primary); }
[data-tabs] .tab-panel { display: none; } [data-tabs] .tab-panel.active { display: block; }
details.accordion { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 0 18px; margin-bottom: 10px; }
details.accordion summary { cursor: pointer; padding: 16px 0; font-weight: 650; list-style: none; display: flex;
  justify-content: space-between; gap: 16px; }
details.accordion summary::-webkit-details-marker { display: none; }
details.accordion summary::after { content: "+"; font-size: 1.35rem; line-height: 1; color: var(--primary); }
details.accordion[open] summary::after { content: "\2212"; }
details.accordion > :not(summary) { padding-bottom: 16px; margin: 0; color: var(--muted); }
.modal { position: fixed; inset: 0; display: none; place-items: center; background: rgba(10, 12, 20, .55); z-index: 50;
  padding: 20px; }
.modal.open { display: grid; }
.modal-box { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow-lg); padding: 28px;
  width: min(480px, 100%); position: relative; }
.close { position: absolute; top: 10px; right: 14px; border: 0; background: none; font-size: 1.6rem; cursor: pointer;
  color: var(--muted); line-height: 1; }
.toasts { position: fixed; top: 20px; right: 20px; display: grid; gap: 10px; z-index: 60; }
.toast { min-width: 260px; padding: 14px 18px; border-radius: var(--radius-sm); color: #fff; background: #334155;
  box-shadow: var(--shadow-lg); animation: ui-toast-in .3s ease-out; font-weight: 550; }
.toast.success { background: var(--success); } .toast.warning { background: var(--warning); }
.toast.error { background: var(--danger); }
@keyframes ui-toast-in { from { transform: translateX(120%); opacity: 0; } to { transform: none; opacity: 1; } }

/* timeline, steps, chat */
.timeline { position: relative; max-width: 920px; margin: 0 auto; }
.timeline::before { content: ""; position: absolute; left: 50%; top: 0; bottom: 0; width: 3px; background: var(--border);
  transform: translateX(-50%); }
.timeline .item { position: relative; width: 50%; padding: 10px 40px; }
.timeline .item:nth-child(odd) { left: 0; text-align: right; } .timeline .item:nth-child(even) { left: 50%; }
.timeline .item::before { content: ""; position: absolute; top: 22px; width: 16px; height: 16px; border-radius: 50%;
  background: var(--primary); border: 3px solid var(--bg); }
.timeline .item:nth-child(odd)::before { right: -8px; } .timeline .item:nth-child(even)::before { left: -8px; }
.steps { display: flex; gap: 8px; counter-reset: step; }
.steps .step { flex: 1; text-align: center; color: var(--muted); font-weight: 600; font-size: .9rem; }
.steps .step::before { counter-increment: step; content: counter(step); display: grid; place-items: center; width: 36px;
  height: 36px; margin: 0 auto 8px; border-radius: 50%; background: var(--surface-2); border: 2px solid var(--border); }
.steps .step.active { color: var(--primary); }
.steps .step.active::before, .steps .step.done::before { background: var(--primary); color: #fff; border-color: var(--primary); }
.bubble { max-width: 70%; width: fit-content; padding: 10px 14px; border-radius: 16px; background: var(--surface-2); margin: 6px 0; }
.bubble.me { margin-left: auto; background: var(--primary); color: var(--primary-ink); border-bottom-right-radius: 4px; }
.bubble.them { border-bottom-left-radius: 4px; }

/* article typography, footer, misc */
.prose { max-width: 70ch; } .prose p { font-size: 1.08rem; } .prose h2 { margin-top: 1.6em; }
blockquote { margin: 1.5em 0; padding: 14px 22px; border-left: 4px solid var(--primary); background: var(--surface-2);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; font-style: italic; }
pre { background: #0f172a; color: #e2e8f0; padding: 16px 18px; border-radius: var(--radius-sm); overflow: auto;
  font: .9rem/1.55 var(--mono); }
:not(pre) > code { background: var(--surface-2); padding: 2px 6px; border-radius: 6px; font: .9em var(--mono); }
figure { margin: 1.5em 0; } figcaption { color: var(--muted); font-size: .9rem; text-align: center; margin-top: 8px; }
.footer { background: #111827; color: #cbd5e1; padding: 52px 0 28px; }
.footer a { color: #e5e7eb; } .footer h4 { color: #fff; } .footer ul { list-style: none; padding: 0; margin: 0; }
.footer li { margin: 6px 0; }
.divider { height: 1px; background: var(--border); margin: 24px 0; }