/* A Page Wiser · 一页知新 · 学びのしおり
   Palette shared with the I Ching series: ivory, charcoal, vermilion, moss. */
:root {
  --paper: #F5F0E5;
  --paper-2: #EDE6D6;
  --ink: #302D29;
  --ink-2: #6B655C;
  --ink-3: #C9BFAE;
  --seal: #A44736;
  --moss: #626A50;
  --line: #DDD3C1;
  --card: #FBF8F1;
  --serif-zh: "Noto Serif SC", "Songti SC", serif;
  --serif-ja: "Noto Serif JP", "Hiragino Mincho ProN", serif;
  --serif-en: "Source Serif 4", Georgia, serif;
  --sans: "Inter", "Noto Sans JP", "Noto Sans SC", system-ui, sans-serif;
  --serif: var(--serif-en);
  --w: 680px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #1C1A17; --paper-2: #24211D; --ink: #ECE5D8; --ink-2: #A9A094; --ink-3: #4A443C;
    --seal: #C8634F; --moss: #9AA27F; --line: #36312A; --card: #221F1B;
  }
}
:root[data-theme="dark"] {
  --paper: #1C1A17; --paper-2: #24211D; --ink: #ECE5D8; --ink-2: #A9A094; --ink-3: #4A443C;
  --seal: #C8634F; --moss: #9AA27F; --line: #36312A; --card: #221F1B;
}
.lang-zh { --serif: var(--serif-zh); }
.lang-ja { --serif: var(--serif-ja); }

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--serif); font-size: 18px; line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}
.lang-en body, body.lang-en { line-height: 1.7; }
a { color: inherit; }
img, svg { max-width: 100%; }
.wrap { max-width: var(--w); margin: 0 auto; padding: 0 20px; }
.dim { color: var(--ink-2); }
h1, h2, h3 { font-weight: 700; line-height: 1.3; letter-spacing: .01em; }

/* ---------- header ---------- */
.top {
  display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  padding: 14px 20px; border-bottom: 1px solid var(--line); background: var(--paper);
  position: sticky; top: 0; z-index: 10;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-seal {
  width: 34px; height: 34px; display: grid; place-items: center; border-radius: 6px;
  background: var(--seal); color: var(--paper); font-family: var(--serif-zh); font-size: 20px; line-height: 1;
}
.brand-name { font-weight: 700; font-size: 19px; letter-spacing: .04em; }
.nav { display: flex; align-items: center; gap: 16px; font-family: var(--sans); font-size: 14px; flex-wrap: wrap; }
.nav a { text-decoration: none; color: var(--ink-2); }
.nav a:hover { color: var(--ink); }
.langsw { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.langsw a { padding: 4px 10px; font-size: 13px; }
.langsw a.on { background: var(--ink); color: var(--paper); }

/* ---------- shared ---------- */
.eyebrow { font-family: var(--sans); font-size: 13px; letter-spacing: .12em; text-transform: uppercase; color: var(--seal); margin: 0 0 8px; }
.lead { font-size: 19px; color: var(--ink-2); }
.cta, .ghost, .sub-form button {
  font-family: var(--sans); font-size: 15px; font-weight: 600; text-decoration: none; cursor: pointer;
  display: inline-flex; align-items: center; gap: 8px; border-radius: 999px; padding: 12px 22px; border: 1px solid var(--ink);
}
.cta { background: var(--ink); color: var(--paper); }
.cta:hover { background: var(--seal); border-color: var(--seal); }
.ghost { background: transparent; color: var(--ink); }
.ghost:hover { border-color: var(--seal); color: var(--seal); }
.stats { font-family: var(--sans); font-size: 14px; color: var(--moss); min-height: 1.2em; }
.label {
  font-family: var(--sans); font-size: 12px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase;
  color: var(--moss); margin: 0 0 10px; display: block;
}
.label.big { font-size: 13px; color: var(--seal); }

/* ---------- ink art ---------- */
.art-wrap { margin: 24px 0; position: relative; border-radius: 14px; overflow: hidden; border: 1px solid var(--line); background: var(--paper); }
.art { display: block; width: 100%; height: auto; }
.art .p { fill: var(--paper); }
.art .k { fill: var(--ink); }
.art .k2 { fill: var(--ink-2); }
.art .k3 { fill: var(--ink-3); }
.art .r { fill: var(--seal); }
.art .g { fill: var(--moss); }
.art .stroke-k { stroke: var(--ink); }
.art .stroke-k2 { stroke: var(--ink-2); }
.art .stroke-k3 { stroke: var(--ink-3); }
.art .stroke-r { stroke: var(--seal); }
.art .stroke-g { stroke: var(--moss); }
.art .stroke-p { stroke: var(--paper); }
.art .wave { fill: none; stroke: var(--ink-2); stroke-width: 2; opacity: .55; }
.art .lbl { fill: var(--ink); font-family: var(--serif); font-weight: 600; }
.art .lbl.dim { fill: var(--ink-2); font-weight: 400; }
.art .lbl.inv { fill: var(--paper); }
.art .sealtxt { fill: var(--paper); font-family: var(--serif-zh); font-weight: 700; }
.replay {
  position: absolute; right: 10px; top: 10px; width: 34px; height: 34px; border-radius: 50%;
  border: 1px solid var(--line); background: var(--card); color: var(--ink-2); cursor: pointer; font-size: 16px;
}

/* Kun → Peng animation (12s). Fish rises, dissolves; bird surges up out of the sea. */
.kunpeng .kp-fish, .kunpeng .kp-bird, .kunpeng .kp-wind, .kunpeng .lab-fish, .kunpeng .lab-bird { transform-box: view-box; }
.kunpeng.anim .kp-fish { animation: kp-fish 12s ease-in-out both; }
.kunpeng.anim .lab-fish { animation: kp-labfish 12s ease-in-out both; }
.kunpeng.anim .kp-wind { animation: kp-wind 12s ease-in-out both; }
.kunpeng.anim .kp-bird { animation: kp-bird 12s cubic-bezier(.3,.1,.2,1) both; }
.kunpeng.anim .lab-bird { animation: kp-labbird 12s ease both; }
.kunpeng.anim .peng-wings { animation: kp-flap 2.4s ease-in-out 6s 3; transform-origin: 400px 220px; transform-box: view-box; }
@keyframes kp-fish {
  0% { opacity: 0; transform: translate(0, 40px); }
  12% { opacity: 1; transform: translate(0, 0); }
  32% { opacity: 1; transform: translate(40px, -6px); }
  46% { opacity: 0; transform: translate(80px, -30px) scale(1.15, .7); }
  100% { opacity: 0; }
}
@keyframes kp-labfish { 0%, 6% { opacity: 0; } 14%, 32% { opacity: 1; } 42%, 100% { opacity: 0; } }
@keyframes kp-wind {
  0%, 34% { opacity: 0; stroke-dashoffset: 400; }
  40% { opacity: 1; }
  60% { opacity: .8; }
  80%, 100% { opacity: 0; }
}
@keyframes kp-bird {
  0%, 36% { opacity: 0; transform: translate(0, 170px) scale(.35); }
  52% { opacity: 1; transform: translate(0, 60px) scale(.7); }
  72% { opacity: 1; transform: translate(0, 0) scale(1); }
  100% { opacity: 1; transform: translate(0, -6px) scale(1.02); }
}
@keyframes kp-labbird { 0%, 66% { opacity: 0; } 78%, 100% { opacity: 1; } }
@keyframes kp-flap { 0%, 100% { transform: scaleY(1); } 50% { transform: scaleY(.82); } }
/* static default (before JS / reduced motion): show the bird */
.kunpeng:not(.anim) .kp-fish, .kunpeng:not(.anim) .lab-fish, .kunpeng:not(.anim) .kp-wind { opacity: .0; }
.kunpeng:not(.anim) .kp-fish { opacity: .18; }
@media (prefers-reduced-motion: reduce) {
  .kunpeng.anim * { animation: none !important; }
  .replay { display: none; }
}
.butterfly .bfly { animation: bf 3.2s ease-in-out infinite; transform-box: fill-box; }
@keyframes bf { 0%, 100% { transform: translate(560px, 230px) scaleX(1); } 50% { transform: translate(560px, 222px) scaleX(.55); } }
@media (prefers-reduced-motion: reduce) { .butterfly .bfly { animation: none; } }

/* ---------- home ---------- */
.hero { padding: 40px 0 16px; }
.hero .wrap { max-width: 1120px; }
.hero-grid { display: grid; gap: 28px; align-items: center; }
@media (min-width: 900px) { .hero-grid { grid-template-columns: 1fr 1.15fr; } }
.hero h1 { font-size: clamp(30px, 4.6vw, 46px); margin: 0 0 14px; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin: 22px 0 10px; }
.how, .keys, .map, .shelf { padding-top: 36px; }
.how h2, .keys h2, .map h2, .shelf h2 { font-size: 24px; }
.how-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
@media (min-width: 640px) { .how-list { grid-template-columns: 1fr 1fr; } }
.how-list li { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; display: grid; gap: 4px; }
.how-list li span:last-child { color: var(--ink-2); font-size: 16px; }
.how-n { font-family: var(--sans); font-size: 12px; color: var(--seal); font-weight: 700; }
.keys-list { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; }
.keys-list li { border-top: 3px solid var(--seal); background: var(--card); padding: 14px; border-radius: 0 0 10px 10px; display: grid; gap: 4px; }
.key-zh { font-family: var(--serif-zh); font-size: 21px; font-weight: 700; }
.key-tr { font-size: 15px; color: var(--ink-2); }
.shelf-list { list-style: none; padding: 0; margin: 0; display: flex; gap: 12px; flex-wrap: wrap; }
.shelf-list li { width: 116px; height: 170px; border-radius: 6px 10px 10px 6px; padding: 14px 10px; display: flex; flex-direction: column; justify-content: space-between; border: 1px solid var(--line); background: var(--card); }
.shelf-list li.open { background: var(--moss); color: var(--paper); border-color: var(--moss); }
.shelf-list .spine { font-size: 22px; font-weight: 700; writing-mode: vertical-rl; }
.lang-en .shelf-list .spine { writing-mode: horizontal-tb; font-size: 18px; }
.shelf-list small { font-family: var(--sans); font-size: 12px; opacity: .8; }

/* ---------- course map ---------- */
.course-head { padding-top: 40px; }
.course-head h1 { font-size: 38px; margin: 0 0 8px; }
.map .wrap, .map { max-width: 860px; }
.theme { margin: 26px 0; }
.theme h3 { font-size: 19px; margin: 0 0 12px; display: flex; gap: 10px; align-items: baseline; flex-wrap: wrap; }
.theme h3 small { font-weight: 400; font-size: 14px; color: var(--ink-2); font-family: var(--sans); }
.cells { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; }
.cell { border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; text-decoration: none; display: grid; gap: 2px; background: var(--card); position: relative; }
.cell .n { font-family: var(--sans); font-size: 12px; color: var(--ink-2); }
.cell .nm { font-size: 16px; line-height: 1.35; }
.cell.open:hover { border-color: var(--seal); }
.cell.locked { opacity: .5; background: transparent; }
.cell.done::after {
  content: "印"; position: absolute; right: 8px; top: 8px; width: 22px; height: 22px; display: grid; place-items: center;
  background: var(--seal); color: var(--paper); border-radius: 4px; font-size: 13px; font-family: var(--serif-zh); transform: rotate(-8deg);
}

/* ---------- lesson ---------- */
.lesson { padding-top: 28px; }
.meta { display: flex; gap: 14px; flex-wrap: wrap; align-items: center; font-family: var(--sans); font-size: 13px; }
.pill { background: var(--moss); color: var(--paper); padding: 3px 10px; border-radius: 999px; }
.progress { height: 3px; background: var(--line); border-radius: 3px; margin: 14px 0 0; overflow: hidden; }
.progress span { display: block; height: 100%; background: var(--seal); }
.l-title { font-size: clamp(34px, 7vw, 52px); margin: 22px 0 6px; }
.hook { font-size: 20px; color: var(--ink-2); margin: 0; }
.block { margin: 34px 0; }
.original {
  margin: 0; padding: 22px 24px; background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  font-family: var(--serif-zh); font-size: 21px; line-height: 2; letter-spacing: .06em;
}
.lang-ja .original { font-family: var(--serif-ja); }
@media (min-width: 760px) {
  .original.vertical {
    writing-mode: vertical-rl; height: 360px; overflow-x: auto; line-height: 2.1; padding: 26px 28px;
    border-right: 4px solid var(--seal);
  }
}
.kundoku { margin-top: 16px; padding: 16px 20px; border-left: 3px solid var(--moss); background: var(--paper-2); border-radius: 0 10px 10px 0; }
.kundoku p { margin: 0; font-size: 17px; }
.translation { font-size: 18px; }
.words { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.words li { display: grid; grid-template-columns: auto 1fr; gap: 2px 14px; padding: 12px 14px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; }
.w-t { font-family: var(--serif-zh); font-size: 22px; font-weight: 700; grid-row: span 2; align-self: center; color: var(--seal); }
.lang-ja .w-t { font-family: var(--serif-ja); }
.w-r { font-family: var(--sans); font-size: 12px; color: var(--ink-2); }
.w-m { font-size: 16px; line-height: 1.6; }
.teach p { margin: 0 0 1.05em; }
.teach strong { color: var(--ink); background: linear-gradient(transparent 62%, color-mix(in srgb, var(--seal) 18%, transparent) 62%); }
.takeaway { margin: 40px -4px; padding: 30px 26px; border-radius: 16px; background: var(--ink); color: var(--paper); position: relative; }
.takeaway .label { color: var(--ink-3); }
.take-q { font-size: clamp(22px, 4vw, 28px); line-height: 1.5; margin: 0 0 18px; font-weight: 700; }
.takeaway .ghost { border-color: var(--ink-3); color: var(--paper); padding: 8px 16px; font-size: 13px; }
.prompt { font-size: 18px; }
textarea {
  width: 100%; font: inherit; font-size: 17px; line-height: 1.7; color: var(--ink); background: var(--card);
  border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; resize: vertical;
  background-image: repeating-linear-gradient(transparent, transparent calc(1.7em - 1px), var(--line) calc(1.7em - 1px), var(--line) 1.7em);
  background-attachment: local; background-position: 0 14px;
}
textarea:focus, input:focus { outline: 2px solid var(--moss); outline-offset: 1px; }
.j-status { font-family: var(--sans); font-size: 12px; color: var(--moss); }
.opts { display: grid; gap: 8px; }
.opt { text-align: left; font: inherit; font-size: 16px; color: var(--ink); background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; cursor: pointer; }
.opt:hover { border-color: var(--ink-2); }
.opt.right { border-color: var(--moss); background: color-mix(in srgb, var(--moss) 14%, var(--card)); }
.opt.wrong { border-color: var(--seal); opacity: .7; }
.explain { margin-top: 12px; color: var(--moss); font-size: 16px; }
.deeper-link { display: flex; gap: 14px; align-items: center; padding: 14px 16px; border: 1px solid var(--line); border-radius: 12px; text-decoration: none; background: var(--card); }
.deeper-link:hover { border-color: var(--moss); }
.deeper-link small { font-family: var(--sans); color: var(--ink-2); }
.play { width: 40px; height: 40px; flex: none; border-radius: 50%; display: grid; place-items: center; background: var(--moss); color: var(--paper); font-size: 14px; }
.deeper p { font-size: 15px; color: var(--ink-2); }

.stamp-row { text-align: center; margin: 44px 0 20px; }
.stamp-btn {
  font-family: var(--sans); font-size: 15px; font-weight: 600; display: inline-flex; align-items: center; gap: 12px;
  padding: 10px 22px 10px 10px; border-radius: 999px; border: 1px dashed var(--seal); background: transparent; color: var(--seal); cursor: pointer;
}
.stamp-ico { width: 38px; height: 38px; border-radius: 6px; display: grid; place-items: center; border: 2px solid var(--seal); font-family: var(--serif-zh); font-size: 20px; transition: transform .3s; }
.stamp-btn.done { border-style: solid; background: var(--seal); color: var(--paper); }
.stamp-btn.done .stamp-ico { background: var(--paper); color: var(--seal); border-color: var(--paper); transform: rotate(-10deg) scale(1.05); }
.streak-line { font-family: var(--sans); font-size: 14px; color: var(--moss); min-height: 1.2em; }
.tomorrow { display: grid; gap: 2px; text-decoration: none; padding: 20px 22px; border-radius: 14px; border: 1px solid var(--line); background: var(--paper-2); margin: 20px 0; }
.tomorrow .tm-t { font-size: 24px; font-weight: 700; }
.tomorrow .tm-s { font-family: var(--sans); font-size: 13px; color: var(--ink-2); }
a.tomorrow:hover { border-color: var(--seal); }
.pn-row { display: flex; justify-content: space-between; font-family: var(--sans); font-size: 14px; margin: 18px 0; }
.pn { text-decoration: none; color: var(--ink-2); }
.source { font-size: 14px; color: var(--ink-2); margin-top: 30px; }
.source .label { display: inline; margin-right: 6px; }
.theme-note { font-size: 14px; }

/* ---------- subscribe ---------- */
.subscribe { margin: 60px 0 0; background: var(--moss); color: var(--paper); padding: 48px 20px; }
.sub-inner { max-width: var(--w); margin: 0 auto; }
.subscribe h2 { margin: 0 0 8px; font-size: 26px; }
.subscribe p { margin: 0 0 16px; opacity: .92; }
.sub-form { display: flex; gap: 8px; flex-wrap: wrap; }
.sub-form input { flex: 1 1 220px; font: inherit; font-family: var(--sans); font-size: 16px; padding: 12px 16px; border-radius: 999px; border: 0; background: var(--paper); color: var(--ink); }
.sub-form button { background: var(--seal); border-color: var(--seal); color: #fff; }
.sub-bonus { font-size: 14px; margin-top: 12px !important; }
.sub-msg { font-family: var(--sans); font-size: 14px; min-height: 1.2em; }

/* ---------- prose / footer ---------- */
.prose { padding-top: 36px; }
.prose h1 { font-size: 36px; }
.fine { font-family: var(--sans); font-size: 12px; color: var(--ink-2); line-height: 1.6; }
.foot { border-top: 1px solid var(--line); padding: 26px 0 40px; background: var(--paper); }
.subscribe + .foot { border-top: 0; }
.foot-brand { font-weight: 700; margin: 0 0 8px; }

@media (max-width: 560px) {
  body { font-size: 17px; }
  .top { padding: 10px 16px; }
  .wrap { padding: 0 16px; }
  .nav { gap: 10px; font-size: 13px; }
  .original { font-size: 19px; padding: 18px; }
  .takeaway { margin: 34px 0; padding: 24px 20px; }
}
.deeper-list { display: grid; gap: 8px; }
.deeper-link.alt .play { background: var(--ink-3); color: var(--ink); }
.fu-videos { padding-top: 36px; }
.fu-videos h2 { font-size: 24px; margin-bottom: 4px; }
.kunpeng .kp-bird { transform-origin: 400px 240px; }
.kunpeng .kp-fish { transform-origin: 400px 330px; }

/* concept diagrams inside the teaching section */
.diagram-wrap { margin: 22px 0 26px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--paper); }
.diagram-wrap .art { width: 100%; height: auto; }
.art .lbl.r-txt { fill: var(--seal); font-weight: 500; }