:root {
  --bg: #f6f7f5;
  --surface: #ffffff;
  --fg: #1d2420;
  --muted: #5f6b64;
  --border: #dde3df;
  --accent: #107c41;
  --accent-fg: #ffffff;
  --accent-soft: #e3f2e9;
  --code-bg: #f1f4f2;
  --danger: #b42318;
  --tok-fn: #0b5cad;
  --tok-ref: #8a3ffc;
  --tok-str: #a15c00;
  --tok-num: #107c41;
  --shadow: 0 1px 2px rgba(20, 30, 25, 0.06), 0 2px 8px rgba(20, 30, 25, 0.05);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121514;
    --surface: #1a1f1d;
    --fg: #e6ebe8;
    --muted: #98a39d;
    --border: #2c3430;
    --accent: #3ccf7f;
    --accent-fg: #0b1a12;
    --accent-soft: #173326;
    --code-bg: #141917;
    --danger: #ff7a6b;
    --tok-fn: #7cb8ff;
    --tok-ref: #c49bff;
    --tok-str: #f2b660;
    --tok-num: #6fdc9f;
    --shadow: none;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.55 "Segoe UI Variable Text", "Segoe UI", system-ui, -apple-system, sans-serif;
}
main { max-width: 820px; margin: 0 auto; padding: 28px 16px 72px; }
h1 { font-size: 1.75rem; line-height: 1.2; margin: 0 0 6px; letter-spacing: -0.01em; }
h2 { font-size: 1.2rem; margin: 1.6em 0 0.4em; }
h3 { font-size: 1.05rem; margin: 1.4em 0 0.3em; }
a { color: var(--accent); }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
button { font: inherit; color: inherit; }
code, pre { font-family: "Cascadia Mono", Consolas, "SF Mono", Menlo, monospace; }

/* Top bar */
.topbar { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 5; }
.topbar-inner { max-width: 820px; margin: 0 auto; padding: 10px 16px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 650; color: var(--fg); text-decoration: none; }
.brand-mark {
  display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 8px;
  background: var(--accent); color: var(--accent-fg); font: italic 700 0.85rem/1 Georgia, serif;
}
.brand-mark.big { width: 52px; height: 52px; border-radius: 14px; font-size: 1.35rem; }
.topbar-actions { display: flex; align-items: center; gap: 14px; }
.topbar-actions form { margin: 0; }
.link-button { background: none; border: 0; padding: 4px 2px; color: var(--muted); cursor: pointer; font-size: 0.9rem; }
.link-button:hover { color: var(--fg); }

.sep-switch { display: inline-flex; align-items: center; gap: 6px; }
.sep-label { color: var(--muted); font-size: 0.85rem; }
.sep-switch button {
  min-width: 34px; padding: 3px 10px; border: 1px solid var(--border); background: var(--surface);
  font: 600 0.95rem/1.4 "Cascadia Mono", Consolas, monospace; cursor: pointer;
}
.sep-switch button:first-of-type { border-radius: 8px 0 0 8px; }
.sep-switch button:last-of-type { border-radius: 0 8px 8px 0; margin-left: -1px; }
.sep-switch button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); }

/* Buttons */
.primary {
  width: 100%; padding: 11px 16px; border: 0; border-radius: 10px; cursor: pointer;
  background: var(--accent); color: var(--accent-fg); font-weight: 600;
}
.primary:hover { filter: brightness(1.06); }
.copy-btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 5px 11px; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface); font-size: 0.85rem; font-weight: 600; white-space: nowrap;
}
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
.copy-btn.done { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* Login */
body.login main { min-height: 100vh; display: grid; place-items: center; padding-top: 16px; }
.login-card {
  width: 100%; max-width: 380px; background: var(--surface); border: 1px solid var(--border);
  border-radius: 16px; padding: 32px 28px; box-shadow: var(--shadow); text-align: center;
}
.login-card h1 { margin-top: 14px; }
.login-card form { margin-top: 22px; text-align: left; }
.login-card label { display: block; font-weight: 600; font-size: 0.9rem; margin-bottom: 6px; }
.login-card input {
  width: 100%; padding: 11px 12px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--bg); color: var(--fg); font: inherit; margin-bottom: 14px;
}
.login-card input:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }
.form-error { color: var(--danger); font-size: 0.9rem; margin: -4px 0 14px; }

/* Overview */
.overview-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-bottom: 18px; }
.search {
  flex: 0 1 280px; min-width: 0; padding: 9px 12px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--surface); color: var(--fg); font: inherit;
}
.cards { display: grid; gap: 12px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 16px 18px;
  box-shadow: var(--shadow); transition: border-color 0.2s;
}
.card.fresh { border-color: var(--accent); }
.card-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
.card-title { font-size: 1.08rem; font-weight: 650; color: var(--fg); text-decoration: none; }
.card-title:hover { color: var(--accent); }
.badge { display: inline-block; margin-left: 8px; padding: 1px 8px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-size: 0.75rem; font-weight: 700; vertical-align: 2px; }
.card-meta { color: var(--muted); font-size: 0.85rem; margin-top: 2px; }
.card-summary { margin: 8px 0 0; color: var(--muted); font-size: 0.93rem; }
.card .codeblock { margin: 12px 0 0; }
.icon-btn { background: none; border: 0; color: var(--muted); cursor: pointer; padding: 2px 4px; font-size: 0.85rem; }
.icon-btn:hover { color: var(--danger); }
.empty { text-align: center; padding: 48px 16px; }

/* Page */
.back { display: inline-block; margin-bottom: 14px; text-decoration: none; font-size: 0.92rem; }
.page .content { margin-top: 18px; }
.page .content > :first-child { margin-top: 0; }
.content p, .content li { max-width: 68ch; }
.content :not(pre) > code { background: var(--code-bg); border: 1px solid var(--border); padding: 1px 5px; border-radius: 5px; font-size: 0.9em; }

/* Instructions */
.topbar-actions a.link-button { text-decoration: none; }
.lead { font-size: 1.08rem; color: var(--muted); margin: 6px 0 24px; }
.step {
  display: flex; gap: 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 18px 20px; margin: 0 0 14px; box-shadow: var(--shadow);
}
.step-num {
  flex: none; display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%;
  background: var(--accent); color: var(--accent-fg); font-weight: 700;
}
.step-body { flex: 1; min-width: 0; }
.step-body h2 { margin: 3px 0 8px; }
.step-body ol { margin: 8px 0; padding-left: 20px; }
.step-body li { margin: 6px 0; }
.step-body li .muted { display: block; font-size: 0.9rem; }
.step-body .codeblock { margin: 8px 0 4px; }
.guide code { background: var(--code-bg); border: 1px solid var(--border); padding: 1px 5px; border-radius: 5px; font-size: 0.9em; }
.guide pre code { background: none; border: 0; padding: 0; }
.tips { padding-left: 20px; }
.tips li { margin: 8px 0; }

/* Code / formula blocks */
.codeblock {
  display: flex; align-items: flex-start; gap: 10px; margin: 14px 0; padding: 12px 12px 12px 16px;
  background: var(--code-bg); border: 1px solid var(--border); border-left: 4px solid var(--accent); border-radius: 10px;
}
.codeblock pre { flex: 1; min-width: 0; max-width: 100%; margin: 0; overflow-x: auto; white-space: pre-wrap; overflow-wrap: anywhere; font-size: 0.95rem; line-height: 1.6; padding: 3px 0; }
.codeblock pre code { font: inherit; }
.codeblock .copy-btn { flex: none; }
.tok-fn { color: var(--tok-fn); font-weight: 600; }
.tok-ref { color: var(--tok-ref); }
.tok-str { color: var(--tok-str); }
.tok-num { color: var(--tok-num); }

/* Tables */
.tablewrap { margin: 14px 0; }
.tablewrap .copy-btn { margin-bottom: 8px; }
.tablescroll { overflow-x: auto; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: 0.93rem; }
th, td { padding: 8px 12px; text-align: left; border-bottom: 1px solid var(--border); white-space: nowrap; }
th { background: var(--code-bg); font-weight: 650; }
tr:last-child td { border-bottom: 0; }

/* Toast */
.toast {
  position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 20px); opacity: 0; pointer-events: none;
  background: var(--fg); color: var(--bg); padding: 9px 16px; border-radius: 999px; font-size: 0.9rem; font-weight: 600;
  transition: opacity 0.2s, transform 0.2s;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 560px) {
  h1 { font-size: 1.45rem; }
  .sep-label { display: none; }
  .search { flex-basis: 100%; }
  .codeblock { flex-direction: column; align-items: stretch; gap: 8px; }
  .codeblock .copy-btn { align-self: flex-end; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }