/* ============================================================
   AI for Startups — Lecture Series · design system
   Side Quest Strategies × Five by Five Labs
   Light/dark theme, mint accent. Shared by the hub SPA and the
   standalone experiences (slides / pitch / data-room).
   ============================================================ */

:root {
  --bg:       #f7f9fc;
  --bg-grad:  radial-gradient(1200px 600px at 75% -10%, #dcfce7 0%, rgba(220,252,231,0) 58%),
              radial-gradient(900px 500px at 10% 0%, #dbeafe 0%, rgba(219,234,254,0) 54%);
  --panel:    #ffffff;
  --panel-2:  #f1f5f9;
  --panel-3:  #e2e8f080;
  --ink:      #17202c;
  --muted:    #5d6978;
  --faint:    #7a8796;
  --accent:   #047857;   /* mint  */
  --accent-2: #2563eb;   /* blue  */
  --accent-3: #b45309;   /* amber */
  --pink:     #be185d;
  --border:   #dbe3ef;
  --border-2: #c7d2e1;
  --good:     #047857;
  --warn:     #b45309;
  --bad:      #dc2626;
  --accent-ink: #ecfdf5;
  --topbar-bg: rgba(247,249,252,0.86);
  --code-bg: #eef4f8;
  --code-ink: #115e59;
  --active-bg: #dcfce7;
  --accent-soft: #dcfce7;
  --accent-border: #86efac;
  --blue-soft: #dbeafe;
  --blue-border: #93c5fd;
  --amber-soft: #fef3c7;
  --amber-border: #fcd34d;
  --pink-soft: #fce7f3;
  --pink-border: #f9a8d4;
  --thumb-border: #f7f9fc;
  --chart-grid: rgba(23,32,44,0.08);
  --chart-tick: #5d6978;
  --radius:   14px;
  --radius-sm: 9px;
  --max:      1080px;
  --shadow:   0 18px 50px -34px rgba(23,32,44,0.45);
  color-scheme: light;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;
}

:root[data-theme="dark"] {
  --bg:       #0b0e13;
  --bg-grad:  radial-gradient(1200px 600px at 75% -10%, #12202a 0%, rgba(18,32,42,0) 55%),
              radial-gradient(900px 500px at 10% 0%, #161427 0%, rgba(22,20,39,0) 50%);
  --panel:    #141922;
  --panel-2:  #1a2029;
  --panel-3:  #20283340;
  --ink:      #e8ebef;
  --muted:    #93a0b1;
  --faint:    #62707f;
  --accent:   #6ee7b7;
  --accent-2: #7aa2ff;
  --accent-3: #f7b955;
  --pink:     #f178b6;
  --border:   #232b38;
  --border-2: #2e3947;
  --good:     #6ee7b7;
  --warn:     #f7b955;
  --bad:      #ff6f6f;
  --accent-ink: #06231a;
  --topbar-bg: rgba(11,14,19,0.82);
  --code-bg: #0d1117;
  --code-ink: #cfe9dd;
  --active-bg: #112019;
  --accent-soft: #0f1d18;
  --accent-border: #2b5446;
  --blue-soft: #111626;
  --blue-border: #2c3a63;
  --amber-soft: #1d180f;
  --amber-border: #5a4a25;
  --pink-soft: #1d1018;
  --pink-border: #5a2c46;
  --thumb-border: #0b0e13;
  --chart-grid: rgba(255,255,255,0.05);
  --chart-tick: #8b95a3;
  --shadow:   0 18px 50px -24px rgba(0,0,0,0.7);
  color-scheme: dark;
}
* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  background-image: var(--bg-grad);
  background-attachment: fixed;
  color: var(--ink);
  font-family: var(--font);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1, h2, h3, h4 { line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 0.4em; font-weight: 700; }
h1 { font-size: clamp(1.9rem, 4vw, 3rem); }
h2 { font-size: clamp(1.4rem, 2.6vw, 2rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }
code, kbd { font-family: var(--mono); font-size: 0.86em; }
code { background: var(--code-bg); border: 1px solid var(--border); padding: 1px 6px; border-radius: 6px; color: var(--code-ink); }
kbd {
  background: var(--code-bg); border: 1px solid var(--border-2); border-bottom-width: 2px;
  border-radius: 6px; padding: 1px 7px; color: var(--ink); font-size: 0.78em;
}
hr { border: none; border-top: 1px solid var(--border); margin: 28px 0; }

/* ---------- layout ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 18px;
  padding: 12px 22px;
  background: var(--topbar-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 11px; font-weight: 700; letter-spacing: -0.01em; }
.brand .logo {
  width: 30px; height: 30px; border-radius: 8px; flex: none;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--accent-ink); display: grid; place-items: center; font-weight: 800; font-size: 0.95rem;
  box-shadow: 0 6px 18px -6px var(--accent);
}
.brand small { color: var(--muted); font-weight: 500; font-size: 0.72rem; display: block; letter-spacing: 0.02em; }
.topnav { margin-left: auto; display: flex; gap: 4px; flex-wrap: wrap; }

.menu-toggle {
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border-2);
  border-radius: 999px;
  color: var(--ink);
  cursor: pointer;
  display: none;
  font: inherit;
  font-size: 0.86rem;
  font-weight: 650;
  gap: 8px;
  padding: 7px 12px;
  transition: border-color 120ms, color 120ms, transform 120ms;
}
.menu-toggle:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.menu-toggle__icon,
.menu-toggle__icon::before,
.menu-toggle__icon::after {
  background: currentColor;
  border-radius: 999px;
  content: "";
  display: block;
  height: 2px;
  transition: transform 160ms, opacity 160ms;
  width: 16px;
}
.menu-toggle__icon { position: relative; }
.menu-toggle__icon::before,
.menu-toggle__icon::after { position: absolute; left: 0; }
.menu-toggle__icon::before { top: -5px; }
.menu-toggle__icon::after { top: 5px; }
.menu-toggle[aria-expanded="true"] .menu-toggle__icon { background: transparent; }
.menu-toggle[aria-expanded="true"] .menu-toggle__icon::before { transform: translateY(5px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] .menu-toggle__icon::after { transform: translateY(-5px) rotate(-45deg); }

.theme-toggle {
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border-2);
  border-radius: 999px;
  color: var(--ink);
  cursor: pointer;
  display: inline-flex;
  font: inherit;
  font-size: 0.86rem;
  font-weight: 650;
  gap: 6px;
  padding: 7px 12px;
  transition: border-color 120ms, color 120ms, transform 120ms;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }

.topnav a {
  color: var(--muted); padding: 7px 12px; border-radius: 8px; font-size: 0.9rem; font-weight: 500;
  transition: background 120ms, color 120ms;
}
.topnav a:hover { color: var(--ink); background: var(--panel); text-decoration: none; }
.topnav a.active { color: var(--accent); background: var(--active-bg); }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 22px; width: 100%; }
.view { padding: 40px 0 88px; animation: fade 240ms ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

footer {
  border-top: 1px solid var(--border); color: var(--muted); font-size: 0.85rem;
  padding: 26px 22px; display: flex; gap: 14px; justify-content: space-between; flex-wrap: wrap;
  max-width: var(--max); margin: 0 auto;
}

/* ---------- hero ---------- */
.hero { padding: 56px 0 18px; }
.eyebrow { color: var(--accent); font-weight: 600; font-size: 0.8rem; letter-spacing: 0.16em; text-transform: uppercase; margin-bottom: 14px; }
.hero h1 { max-width: 16ch; }
.hero .lede { color: var(--muted); font-size: 1.18rem; max-width: 60ch; }
.hosts { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 22px; color: var(--muted); font-size: 0.92rem; }
.hosts b { color: var(--ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; cursor: pointer;
  background: var(--accent); color: var(--accent-ink); border: 1px solid transparent;
  padding: 10px 18px; border-radius: 10px; font-weight: 650; font-size: 0.95rem;
  font-family: inherit; transition: transform 120ms, box-shadow 120ms, background 120ms;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 10px 24px -10px var(--accent); text-decoration: none; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--border-2); }
.btn.ghost:hover { border-color: var(--accent); box-shadow: none; color: var(--accent); }
.btn.sm { padding: 6px 12px; font-size: 0.85rem; border-radius: 8px; }
.btn-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 26px; }

/* ---------- cards / grid ---------- */
.grid { display: grid; gap: 16px; }
.grid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); }

.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; transition: border-color 140ms, transform 140ms, box-shadow 140ms;
}
.card.link { cursor: pointer; }
.card.link:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.card h3 { margin-bottom: 6px; }
.card p { color: var(--muted); font-size: 0.92rem; margin: 0; }

/* module cards */
.mod { display: flex; flex-direction: column; gap: 10px; position: relative; }
.mod .mod-no {
  position: absolute; top: 16px; right: 18px; font-family: var(--mono);
  font-size: 0.8rem; color: var(--faint);
}
.mod .ico { font-size: 1.7rem; }
.mod .meta { display: flex; gap: 8px; flex-wrap: wrap; margin-top: auto; }

/* ---------- badges / tags ---------- */
.tag {
  display: inline-flex; align-items: center; gap: 5px; font-size: 0.72rem; font-weight: 600;
  padding: 3px 9px; border-radius: 999px; border: 1px solid var(--border-2);
  color: var(--muted); letter-spacing: 0.01em;
}
.tag.accent { color: var(--accent); border-color: var(--accent-border); background: var(--accent-soft); }
.tag.blue { color: var(--accent-2); border-color: var(--blue-border); background: var(--blue-soft); }
.tag.amber { color: var(--accent-3); border-color: var(--amber-border); background: var(--amber-soft); }
.tag.pink { color: var(--pink); border-color: var(--pink-border); background: var(--pink-soft); }

/* ---------- section heads ---------- */
.section-head { display: flex; align-items: baseline; gap: 12px; margin: 8px 0 18px; flex-wrap: wrap; }
.section-head h2 { margin: 0; }
.section-head .sub { color: var(--muted); font-size: 0.95rem; }
.kicker { color: var(--accent); font-weight: 600; font-size: 0.78rem; letter-spacing: 0.14em; text-transform: uppercase; margin-bottom: 8px; }

/* ---------- prose blocks ---------- */
.prose { max-width: 70ch; }
.prose p, .prose li { color: var(--ink); }
.prose ul, .prose ol { padding-left: 1.2em; }
.prose li { margin-bottom: 0.4em; }
.callout {
  display: flex; gap: 12px; background: var(--panel); border: 1px solid var(--border);
  border-left: 3px solid var(--accent); border-radius: var(--radius-sm); padding: 14px 16px; margin: 16px 0;
}
.callout.warn { border-left-color: var(--warn); }
.callout .c-ico { font-size: 1.1rem; }
.callout p { margin: 0; color: var(--muted); font-size: 0.92rem; }
.callout p b { color: var(--ink); }

/* ---------- steps ---------- */
.steps { counter-reset: step; display: grid; gap: 12px; }
.step { display: flex; gap: 14px; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 14px 16px; }
.step::before {
  counter-increment: step; content: counter(step);
  flex: none; width: 28px; height: 28px; border-radius: 8px; background: var(--active-bg); color: var(--accent);
  display: grid; place-items: center; font-weight: 700; font-family: var(--mono); font-size: 0.85rem;
  border: 1px solid var(--accent-border);
}
.step h4 { margin: 2px 0 4px; font-size: 1rem; }
.step p { margin: 0; color: var(--muted); font-size: 0.9rem; }

/* ---------- tables ---------- */
table.data { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
table.data th, table.data td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--border); }
table.data th { color: var(--muted); font-weight: 600; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
table.data tr:hover td { background: var(--panel); }
table.data td.num, table.data th.num { text-align: right; font-family: var(--mono); }

/* ---------- KPI ---------- */
.kpis { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
.kpi { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 16px; }
.kpi .label { color: var(--muted); font-size: 0.76rem; text-transform: uppercase; letter-spacing: 0.05em; }
.kpi .val { font-size: 1.7rem; font-weight: 750; font-family: var(--mono); letter-spacing: -0.02em; margin-top: 4px; }
.kpi .val.good { color: var(--good); }
.kpi .val.warn { color: var(--warn); }
.kpi .val.bad { color: var(--bad); }
.kpi .sub { color: var(--faint); font-size: 0.78rem; margin-top: 2px; }

/* ---------- controls (sliders) ---------- */
.controls { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.ctrl label { display: flex; justify-content: space-between; font-size: 0.85rem; color: var(--muted); margin-bottom: 6px; }
.ctrl label b { color: var(--ink); font-family: var(--mono); }
input[type=range] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 5px; border-radius: 999px;
  background: var(--border-2); outline: none;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 17px; height: 17px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: 3px solid var(--thumb-border); box-shadow: 0 0 0 1px var(--accent);
}
input[type=range]::-moz-range-thumb {
  width: 14px; height: 14px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 3px solid var(--thumb-border);
}

.seg { display: inline-flex; background: var(--panel); border: 1px solid var(--border); border-radius: 10px; padding: 3px; gap: 3px; }
.seg button {
  background: transparent; color: var(--muted); border: none; cursor: pointer; font-family: inherit;
  padding: 6px 14px; border-radius: 7px; font-size: 0.88rem; font-weight: 600; transition: all 120ms;
}
.seg button.active { background: var(--active-bg); color: var(--accent); }
.seg button:hover:not(.active) { color: var(--ink); }

/* ---------- panel layout for model/sales ---------- */
.split { display: grid; gap: 22px; grid-template-columns: 1fr; }
@media (min-width: 920px) { .split.wide-right { grid-template-columns: 320px 1fr; } }
.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px;
}
.panel h3 { margin-top: 0; }
.chart-box { position: relative; height: 300px; }
.chart-box.tall { height: 360px; }

/* ---------- chips row ---------- */
.chips { display: flex; gap: 8px; flex-wrap: wrap; }

/* ---------- misc ---------- */
.muted { color: var(--muted); }
.center { text-align: center; }
.divider-label { display: flex; align-items: center; gap: 14px; color: var(--faint); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.1em; margin: 34px 0 18px; }
.divider-label::before, .divider-label::after { content: ""; flex: 1; height: 1px; background: var(--border); }
.notice { font-size: 0.82rem; color: var(--faint); }

/* ---------- Module 9: To-Do case study ---------- */
/* copyable prompt block */
.prompt {
  position: relative; background: #0d1117; border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 14px 16px; margin: 8px 0 4px;
  white-space: pre-wrap; font-family: var(--mono);
}
.prompt pre {
  margin: 0; color: #cfe9dd; font-size: 0.82rem; line-height: 1.55;
  white-space: pre-wrap; word-break: break-word; overflow-x: auto;
  font-family: var(--mono);
}
.prompt .copy {
  position: absolute; top: 8px; right: 8px; cursor: pointer;
  background: var(--panel-2); color: var(--muted); border: 1px solid var(--border-2);
  border-radius: 7px; padding: 3px 10px; font-size: 0.74rem; font-weight: 600;
  font-family: inherit; transition: color 120ms, border-color 120ms, background 120ms;
}
.prompt .copy:hover { color: var(--accent); border-color: var(--accent); }
.prompt-label { font-size: 0.72rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); margin-top: 14px; }

/* phase cards */
.phases { display: grid; gap: 14px; }
.phase { padding: 18px 20px; }
.phase-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.phase-head h3 { margin: 0; }
.phase-ico { font-size: 1.5rem; line-height: 1; }
.phase-done {
  margin-left: auto; display: inline-flex; align-items: center; gap: 7px;
  color: var(--muted); font-size: 0.82rem; font-weight: 600; cursor: pointer; white-space: nowrap;
}
.phase-done input { width: 16px; height: 16px; accent-color: var(--accent); cursor: pointer; }
.phase > p.muted { font-size: 0.92rem; margin: 0; }
.branch {
  margin-top: 12px; padding-left: 12px; border-left: 2px solid #2b5446;
  color: var(--muted); font-size: 0.82rem;
}

/* progress bar */
.tut-progress { display: flex; align-items: center; gap: 14px; }
.tut-bar { flex: 1; height: 8px; border-radius: 999px; background: var(--border-2); overflow: hidden; }
.tut-bar > span { display: block; height: 100%; width: 0; border-radius: 999px; background: var(--accent); transition: width 280ms ease; }
.tut-progress .notice { white-space: nowrap; }

/* live to-do demo widget */
.todo-demo { margin: 14px 0 4px; }
.td-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.td-input {
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px;
  color: var(--ink); padding: 9px 12px; font-family: inherit; font-size: 0.92rem;
}
#tdTitle { flex: 1; min-width: 180px; }
.td-select { cursor: pointer; }
.td-list { display: flex; flex-direction: column; gap: 8px; }
.td-item {
  display: flex; align-items: center; gap: 11px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 10px 12px;
}
.td-item .td-check { width: 17px; height: 17px; flex: none; accent-color: var(--accent); cursor: pointer; }
.td-title { flex: 1; font-size: 0.92rem; color: var(--ink); word-break: break-word; }
.td-item.done .td-title { text-decoration: line-through; color: var(--faint); }
.td-prio {
  flex: none; font-size: 0.68rem; font-weight: 700; letter-spacing: 0.02em;
  padding: 2px 8px; border-radius: 999px; border: 1px solid var(--border-2); color: var(--muted);
}
.td-prio.urgent { color: var(--bad); border-color: #5a2c2c; background: #1d1010; }
.td-prio.high { color: var(--accent-3); border-color: #5a4a25; background: #1d180f; }
.td-prio.medium { color: var(--accent-2); border-color: #2c3a63; background: #111626; }
.td-prio.low { color: var(--faint); border-color: var(--border-2); background: var(--panel); }
.td-del {
  flex: none; background: transparent; border: none; cursor: pointer; color: var(--faint);
  font-size: 0.95rem; line-height: 1; padding: 4px 6px; border-radius: 6px;
  font-family: inherit; transition: color 120ms, background 120ms;
}
.td-del:hover { color: var(--bad); background: var(--panel); }

@media (max-width: 560px) {
  .td-row { flex-direction: column; align-items: stretch; }
  .td-row .btn.sm { width: 100%; justify-content: center; }
  .phase-done { margin-left: 0; }
}

/* hide elements before JS hydrates */
[data-cloak] { visibility: hidden; }

@media (max-width: 760px) {
  .topbar {
    gap: 10px;
    padding: 10px 14px;
  }
  .brand {
    flex: 1 1 auto;
    min-width: 0;
  }
  .brand > span:last-child {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .brand small { display: none; }
  .menu-toggle {
    display: inline-flex;
    order: 2;
  }
  .theme-toggle {
    font-size: 0.8rem;
    order: 3;
    padding: 7px 10px;
  }
  .topnav {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: none;
    flex-direction: column;
    gap: 4px;
    left: 14px;
    margin-left: 0;
    max-height: min(70vh, 420px);
    overflow-y: auto;
    padding: 8px;
    position: absolute;
    right: 14px;
    top: calc(100% + 8px);
  }
  .topnav.open { display: flex; }
  .topnav a {
    border-radius: 10px;
    font-size: 1rem;
    padding: 11px 12px;
    width: 100%;
  }
  .wrap { padding: 0 16px; }
  .view { padding-top: 26px; }
}