/* ============================================================
   JOVANA EDUCATION — Landing Page
   Editorial design system · 3 switchable themes
   ============================================================ */

/* ---------- Fonts ---------- */
:root{
  --font-display: "Cormorant Garamond", "Noto Serif SC", Georgia, serif;
  --font-sans: "Hanken Grotesk", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  --font-cjk-serif: "Noto Serif SC", "Cormorant Garamond", serif;
  --font-mono: "Newsreader", ui-monospace, "SF Mono", monospace;
}

/* CJK pages lean on Noto serif for display */
html[data-lang="zh"]{
  --font-display: "Noto Serif SC", "Cormorant Garamond", serif;
  --font-sans: "Noto Sans SC", "Hanken Grotesk", system-ui, sans-serif;
  --font-cjk-serif: "Noto Serif SC", "Cormorant Garamond", serif;
}
html[data-lang="zhHant"]{
  --font-display: "Noto Serif TC", "Cormorant Garamond", serif;
  --font-sans: "Noto Sans TC", "Hanken Grotesk", system-ui, sans-serif;
  --font-cjk-serif: "Noto Serif TC", "Cormorant Garamond", serif;
}
/* Traditional follows the same CJK display tuning as Simplified */
html[data-lang="zhHant"] .display{ font-weight:600; letter-spacing:0; line-height:1.18; }
html[data-lang="zhHant"] .eyebrow{ letter-spacing:.18em; }
html[data-lang="zhHant"] .hero h1{ font-size:clamp(38px,6.2vw,78px); max-width:14ch; }
html[data-lang="zhHant"] .section-head h2{ line-height:1.2; }
html[data-lang="zhHant"] .brand-name{ letter-spacing:.02em; }
html[data-lang="zhHant"] .founder-quote{ line-height:1.4; }
html[data-lang="zhHant"] .cta-card h2{ line-height:1.22; }
html[data-lang="zhHant"] .field-name .sub-name{ font-size:13px; }

/* ---------- Theme: Editorial (default) ---------- */
:root{
  --bg:        #F4F0E8;
  --bg-warm:   #EFEAE0;
  --surface:   #FBF9F4;
  --surface-2: #FFFFFF;
  --ink:       #1B1813;
  --ink-soft:  #4C463E;
  --ink-faint: #8E877C;
  --line:      rgba(27,24,19,0.13);
  --line-soft: rgba(27,24,19,0.07);

  --accent-1:  #4F5BE3;
  --accent-2:  #8A5CEC;
  --accent-ink:#4a40c9;
  --grad: linear-gradient(118deg, #4F5BE3 0%, #6a59e8 45%, #8A5CEC 100%);
  --grad-soft: linear-gradient(118deg, rgba(79,91,227,0.14), rgba(138,92,236,0.14));
  --aura: radial-gradient(60% 60% at 70% 20%, rgba(138,92,236,0.16), transparent 70%),
          radial-gradient(55% 55% at 15% 80%, rgba(79,91,227,0.13), transparent 70%);

  --shadow-sm: 0 1px 2px rgba(27,24,19,.05), 0 4px 14px rgba(27,24,19,.05);
  --shadow-md: 0 6px 24px rgba(27,24,19,.08), 0 1px 3px rgba(27,24,19,.06);
  --shadow-lg: 0 24px 70px -24px rgba(40,30,70,.30);

  --logo-filter: none;            /* serif logo is black-on-white */
  --logo-blend: multiply;
  --mono-img: url("assets/logo-black.png");
}

/* ---------- Theme: Cosmic (dark) ---------- */
html[data-theme="cosmic"]{
  --bg:        #0B0A12;
  --bg-warm:   #100E1A;
  --surface:   #14121F;
  --surface-2: #1B1830;
  --ink:       #ECEAF4;
  --ink-soft:  #ABA7BE;
  --ink-faint: #6E6A82;
  --line:      rgba(255,255,255,0.14);
  --line-soft: rgba(255,255,255,0.07);

  --accent-1:  #6E78F0;
  --accent-2:  #A982FF;
  --accent-ink:#c9c4ff;
  --grad: linear-gradient(118deg, #6E78F0 0%, #8b7cf5 45%, #A982FF 100%);
  --grad-soft: linear-gradient(118deg, rgba(110,120,240,0.18), rgba(169,130,255,0.18));
  --aura: radial-gradient(60% 60% at 72% 12%, rgba(169,130,255,0.30), transparent 68%),
          radial-gradient(55% 55% at 10% 78%, rgba(79,91,227,0.26), transparent 70%);

  --shadow-sm: 0 1px 2px rgba(0,0,0,.4);
  --shadow-md: 0 8px 30px rgba(0,0,0,.45);
  --shadow-lg: 0 30px 80px -30px rgba(0,0,0,.7);

  --logo-filter: invert(1) brightness(1.6);   /* black logo -> white */
  --logo-blend: screen;
  --mono-img: url("assets/logo-white.png");
}

/* ---------- Theme: Modern (cool light) ---------- */
html[data-theme="modern"]{
  --bg:        #FFFFFF;
  --bg-warm:   #F5F6F9;
  --surface:   #F7F8FB;
  --surface-2: #FFFFFF;
  --ink:       #13161F;
  --ink-soft:  #474D5C;
  --ink-faint: #8b91a0;
  --line:      rgba(19,22,31,0.10);
  --line-soft: rgba(19,22,31,0.055);

  --accent-1:  #4F5BE3;
  --accent-2:  #8A5CEC;
  --accent-ink:#4a40c9;
  --grad: linear-gradient(118deg, #4F5BE3 0%, #6a59e8 45%, #8A5CEC 100%);
  --grad-soft: linear-gradient(118deg, rgba(79,91,227,0.10), rgba(138,92,236,0.10));
  --aura: radial-gradient(60% 60% at 72% 12%, rgba(138,92,236,0.12), transparent 70%),
          radial-gradient(55% 55% at 10% 80%, rgba(79,91,227,0.10), transparent 72%);

  --shadow-sm: 0 1px 2px rgba(19,22,31,.05), 0 2px 10px rgba(19,22,31,.05);
  --shadow-md: 0 8px 30px rgba(19,22,31,.08);
  --shadow-lg: 0 24px 60px -28px rgba(19,22,31,.22);

  --logo-filter: none;
  --logo-blend: multiply;
  --mono-img: url("assets/logo-black.png");
}

/* ---------- Reset / base ---------- */
*{ box-sizing:border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; -webkit-text-size-adjust:100%; }
body{
  font-family:var(--font-sans);
  background:var(--bg);
  color:var(--ink);
  line-height:1.6;
  font-size:17px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
  transition:background .5s ease, color .5s ease;
}
img{ display:block; max-width:100%; }
a{ color:inherit; text-decoration:none; }
button{ font-family:inherit; cursor:pointer; border:none; background:none; color:inherit; }
::selection{ background:rgba(138,92,236,.22); }

/* ---------- Layout ---------- */
.wrap{ width:min(1200px, 92vw); margin-inline:auto; }
.wrap-narrow{ width:min(900px, 92vw); margin-inline:auto; }
section{ position:relative; }
.section-pad{ padding-block:clamp(72px, 11vh, 140px); }

/* ---------- Typography helpers ---------- */
.display{
  font-family:var(--font-display);
  font-weight:600;
  line-height:1.04;
  letter-spacing:-0.01em;
}
html[data-lang="zh"] .display{ font-weight:600; letter-spacing:0; line-height:1.18; }

.eyebrow{
  font-size:12.5px;
  letter-spacing:.28em;
  text-transform:uppercase;
  font-weight:600;
  color:var(--accent-ink);
}
html[data-lang="zh"] .eyebrow{ letter-spacing:.18em; }

.lede{ font-size:clamp(17px,1.35vw,20px); color:var(--ink-soft); line-height:1.62; }
.kicker-num{ font-family:var(--font-display); font-style:italic; }

.grad-text{
  background:var(--grad);
  -webkit-background-clip:text; background-clip:text;
  -webkit-text-fill-color:transparent; color:transparent;
  padding-bottom:.06em;
}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:.55em;
  padding:.92em 1.5em; border-radius:999px;
  font-size:15px; font-weight:600; letter-spacing:.01em;
  transition:transform .25s cubic-bezier(.2,.7,.2,1), box-shadow .25s, background .25s, color .25s, border-color .25s;
  white-space:nowrap;
}
.btn-primary{ background:var(--grad); color:#fff; box-shadow:0 8px 24px -8px rgba(110,89,232,.6); }
.btn-primary:hover{ transform:translateY(-2px); box-shadow:0 14px 34px -8px rgba(110,89,232,.7); }
.btn-ghost{ border:1px solid var(--line); color:var(--ink); background:var(--surface-2); }
.btn-ghost:hover{ border-color:var(--accent-1); color:var(--accent-ink); transform:translateY(-2px); }
.btn .arrow{ transition:transform .25s; }
.btn:hover .arrow{ transform:translateX(3px); }

/* ============================================================
   NAV
   ============================================================ */
.nav{
  position:fixed; top:0; left:0; right:0; z-index:80;
  transition:background .35s, box-shadow .35s, border-color .35s, padding .35s;
  border-bottom:1px solid transparent;
}
.nav.scrolled{
  background:color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter:saturate(1.4) blur(14px);
  -webkit-backdrop-filter:saturate(1.4) blur(14px);
  border-bottom:1px solid var(--line-soft);
}
.nav-inner{ display:flex; align-items:center; justify-content:space-between; height:74px; }
.brand{ display:flex; align-items:center; gap:12px; }
.brand-mono{
  width:30px; height:32px;
  background:var(--mono-img) center/contain no-repeat;
}
.brand-text{ display:flex; flex-direction:column; line-height:1; }
.brand-name{ font-family:var(--font-display); font-weight:600; font-size:23px; letter-spacing:.06em; }
.brand-sub{ font-size:9.5px; letter-spacing:.42em; text-transform:uppercase; color:var(--ink-faint); margin-top:3px; padding-left:2px; }
html[data-lang="zh"] .brand-name{ letter-spacing:.02em; }

.nav-links{ display:flex; align-items:center; gap:34px; }
.nav-link{ font-size:14.5px; font-weight:500; color:var(--ink-soft); position:relative; padding:6px 0; transition:color .2s; }
.nav-link::after{ content:""; position:absolute; left:0; bottom:0; height:1.5px; width:0; background:var(--grad); transition:width .28s ease; }
.nav-link:hover{ color:var(--ink); }
.nav-link:hover::after{ width:100%; }

.nav-right{ display:flex; align-items:center; gap:18px; }

/* language dropdown */
.lang-menu{ position:relative; }
.lang-trigger{
  display:inline-flex; align-items:center; gap:7px;
  padding:8px 11px; border-radius:999px;
  border:1px solid var(--line); background:var(--surface-2);
  font-size:13px; font-weight:600; color:var(--ink-soft); letter-spacing:.02em;
  transition:border-color .2s, color .2s, background .2s;
}
.lang-trigger:hover{ border-color:var(--accent-1); color:var(--ink); }
.lang-trigger .globe{ opacity:.8; }
.lang-trigger .lang-code{ min-width:1.4em; text-align:center; }
.lang-trigger .chev{ opacity:.6; transition:transform .25s; }
.lang-menu.open .lang-trigger{ border-color:var(--accent-1); color:var(--ink); }
.lang-menu.open .chev{ transform:rotate(180deg); }
.lang-pop{
  position:absolute; top:calc(100% + 10px); right:0; z-index:90;
  min-width:208px; padding:7px; border-radius:14px;
  background:color-mix(in srgb, var(--surface-2) 92%, transparent);
  -webkit-backdrop-filter:blur(20px) saturate(1.5); backdrop-filter:blur(20px) saturate(1.5);
  border:1px solid var(--line); box-shadow:var(--shadow-lg);
  display:flex; flex-direction:column; gap:2px;
  opacity:0; transform:translateY(-6px) scale(.98); transform-origin:top right;
  pointer-events:none; transition:opacity .2s ease, transform .2s ease;
}
.lang-menu.open .lang-pop{ opacity:1; transform:none; pointer-events:auto; }
.lang-pop .lang-opt{
  display:flex; align-items:center; justify-content:space-between;
  width:100%; text-align:left; padding:10px 12px; border-radius:9px;
  font-size:14px; font-weight:500; color:var(--ink-soft); letter-spacing:.01em;
  transition:background .18s, color .18s;
}
.lang-pop .lang-opt:hover{ background:var(--grad-soft); color:var(--ink); }
.lang-pop .lang-opt.active{ color:var(--accent-ink); font-weight:600; }
.lang-pop .lang-opt.active::after{ content:"\2713"; font-size:13px; color:var(--accent-ink); }

/* mobile language segmented control */
.m-langs{ display:flex; gap:6px; flex:1; }
.m-langs .lang-opt{
  flex:1; padding:11px 6px; border-radius:11px; border:1px solid var(--line);
  background:var(--surface-2); font-size:13px; font-weight:600; color:var(--ink-faint);
  text-align:center; transition:color .2s, background .2s, border-color .2s;
}
.m-langs .lang-opt.active{ color:#fff; background:var(--grad); border-color:transparent; }

.nav-cta{ padding:.62em 1.15em; font-size:14px; }

.menu-btn{ display:none; width:42px; height:42px; align-items:center; justify-content:center; border-radius:10px; border:1px solid var(--line); }

/* ============================================================
   HERO
   ============================================================ */
.hero{ position:relative; padding-top:150px; padding-bottom:clamp(60px,9vh,110px); overflow:hidden; }
.hero-aura{ position:absolute; inset:0; background:var(--aura); pointer-events:none; z-index:0; }
.hero-grid-lines{ position:absolute; inset:0; z-index:0; opacity:.5;
  background-image:linear-gradient(var(--line-soft) 1px, transparent 1px);
  background-size:100% 34px;
  -webkit-mask-image:linear-gradient(transparent, #000 30%, #000 75%, transparent);
          mask-image:linear-gradient(transparent, #000 30%, #000 75%, transparent);
}
.hero-inner{ position:relative; z-index:2; max-width:960px; }
.hero .eyebrow{ display:inline-flex; align-items:center; gap:12px; margin-bottom:26px; }
.hero .eyebrow::before{ content:""; width:34px; height:1px; background:var(--accent-1); display:inline-block; }
.hero h1{ font-size:clamp(44px, 7.4vw, 92px); margin-bottom:28px; max-width:16ch; }
html[data-lang="zh"] .hero h1{ font-size:clamp(38px,6.2vw,78px); max-width:14ch; }
.hero h1 .ln2{ display:block; }
.hero-sub{ max-width:60ch; margin-bottom:40px; }
.hero-actions{ display:flex; flex-wrap:wrap; gap:16px; align-items:center; }
.hero-note{ font-size:13.5px; color:var(--ink-faint); display:inline-flex; align-items:center; gap:8px; }
.hero-note .dot{ width:7px; height:7px; border-radius:50%; background:var(--grad); display:inline-block; }

/* hero meta strip */
.hero-meta{ position:relative; z-index:2; margin-top:clamp(48px,7vh,86px); display:grid; grid-template-columns:repeat(3,1fr); gap:1px; background:var(--line-soft); border-block:1px solid var(--line); }
.hero-meta .cell{ background:var(--bg); padding:24px 6px 22px; }
.hero-meta .n{ font-family:var(--font-display); font-size:clamp(34px,4vw,48px); font-weight:600; line-height:1.12; }
.hero-meta .l{ font-size:13px; color:var(--ink-faint); margin-top:8px; letter-spacing:.04em; }

/* ============================================================
   DEMO (three levels)
   ============================================================ */
.demo{ background:var(--bg-warm); border-block:1px solid var(--line); }
.section-head{ max-width:680px; margin-bottom:clamp(40px,6vh,68px); }
.section-head.center{ margin-inline:auto; text-align:center; }
.section-head h2{ font-size:clamp(34px,4.6vw,58px); margin:18px 0 18px; line-height:1.05; }
html[data-lang="zh"] .section-head h2{ line-height:1.2; }

.demo-card{
  background:var(--surface-2); border:1px solid var(--line);
  border-radius:22px; box-shadow:var(--shadow-lg); overflow:hidden;
}
.demo-card.swap .demo-meta, .demo-card.swap .paper-formula{ opacity:0; transform:translateY(6px); }
.demo-meta, .paper-formula{ transition:opacity .3s ease, transform .3s ease; }

/* paper switcher strip */
.demo-switch{
  display:flex; align-items:center; justify-content:space-between;
  padding:14px clamp(24px,3.5vw,44px); border-bottom:1px solid var(--line-soft);
  background:var(--grad-soft);
}
.ds-label{ display:inline-flex; align-items:center; gap:9px; font-size:12px; font-weight:700; letter-spacing:.16em; text-transform:uppercase; color:var(--accent-ink); }
html[data-lang="zh"] .ds-label, html[data-lang="zhHant"] .ds-label{ letter-spacing:.08em; }
.ds-dot{ width:7px; height:7px; border-radius:50%; background:var(--grad); box-shadow:0 0 0 4px color-mix(in srgb, var(--accent-1) 18%, transparent); }
.ds-right{ display:flex; align-items:center; gap:14px; }
.ds-count{ font-family:var(--font-display); font-style:italic; font-size:16px; color:var(--ink-faint); }
.ds-nav{ display:flex; gap:6px; }
.ds-nav button{
  width:34px; height:34px; display:flex; align-items:center; justify-content:center;
  border-radius:9px; border:1px solid var(--line); background:var(--surface-2); color:var(--ink-soft);
  transition:border-color .2s, color .2s, transform .15s, background .2s;
}
.ds-nav button:hover{ border-color:var(--accent-1); color:var(--accent-ink); transform:translateY(-1px); }
.ds-nav button:active{ transform:translateY(0); }
.demo-top{ display:flex; flex-wrap:wrap; gap:20px 28px; align-items:flex-start; justify-content:space-between; padding:clamp(24px,3.5vw,40px) clamp(24px,3.5vw,44px) 0; }
.demo-top > div:first-child{ flex:1 1 60%; min-width:0; }
.paper-tag{ display:inline-flex; align-items:center; gap:9px; font-size:12.5px; font-weight:700; letter-spacing:.12em; text-transform:uppercase; color:var(--accent-ink); }
.paper-tag .glyph{ width:18px; height:18px; }
.paper-title{ font-family:var(--font-display); font-weight:600; font-size:clamp(24px,3vw,36px); line-height:1.12; margin:12px 0 6px; max-width:24ch; }
.paper-byline{ font-size:14px; color:var(--ink-faint); font-style:italic; font-family:var(--font-display); }
.paper-formula{
  flex-shrink:0; font-family:var(--font-display); font-style:italic; white-space:nowrap;
  font-size:clamp(30px,3.6vw,46px); line-height:1; padding-top:10px;
  background:var(--grad); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; color:transparent;
}

.level-tabs{ display:flex; gap:8px; padding:clamp(20px,3vw,30px) clamp(24px,3.5vw,44px) 0; flex-wrap:wrap; }
.level-tab{
  position:relative; padding:13px 20px; border-radius:13px; border:1px solid var(--line);
  background:var(--surface); text-align:left; transition:border-color .25s, background .25s, transform .2s;
  flex:1; min-width:150px;
}
.level-tab .lt-k{ font-size:11px; letter-spacing:.16em; text-transform:uppercase; color:var(--ink-faint); font-weight:700; }
.level-tab .lt-t{ font-family:var(--font-display); font-size:20px; font-weight:600; margin-top:3px; display:block; }
.level-tab:hover{ transform:translateY(-2px); border-color:var(--accent-1); }
.level-tab.active{ border-color:transparent; background:var(--grad-soft); }
.level-tab.active::before{ content:""; position:absolute; inset:0; border-radius:13px; padding:1.5px; background:var(--grad); -webkit-mask:linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0); -webkit-mask-composite:xor; mask-composite:exclude; }
.level-tab.active .lt-k{ color:var(--accent-ink); }

.demo-body{ padding:clamp(24px,3.2vw,40px) clamp(24px,3.5vw,44px) clamp(28px,3.6vw,46px); }
.demo-reading{ display:grid; grid-template-columns:auto 1fr; gap:0 26px; }
.reading-rail{ width:2px; background:var(--grad); border-radius:2px; }
.reading-text{ font-size:clamp(17px,1.5vw,21px); line-height:1.7; color:var(--ink); transition:opacity .35s ease, transform .35s ease; }
.reading-text.swap{ opacity:0; transform:translateY(8px); }
.demo-foot{ display:flex; align-items:center; justify-content:space-between; flex-wrap:wrap; gap:14px; margin-top:26px; padding-top:22px; border-top:1px solid var(--line-soft); }
.demo-foot-right{ display:flex; align-items:center; gap:20px; flex-wrap:wrap; }
.read-time{ font-size:13.5px; color:var(--ink-faint); display:flex; align-items:center; gap:8px; }
.demo-langflip{ font-size:13.5px; color:var(--accent-ink); font-weight:600; display:inline-flex; align-items:center; gap:7px; }
.demo-langflip:hover{ text-decoration:underline; }
.demo-readfull{ display:inline-flex; align-items:center; gap:8px; font-size:14px; font-weight:600; color:#fff; background:var(--grad); padding:9px 18px; border-radius:999px; box-shadow:0 6px 18px -8px rgba(110,89,232,.6); transition:transform .2s, box-shadow .2s; }
.demo-readfull:hover{ transform:translateY(-2px); box-shadow:0 12px 26px -8px rgba(110,89,232,.7); }
.demo-readfull .arrow{ transition:transform .25s; }
.demo-readfull:hover .arrow{ transform:translateX(3px); }
.lib-browse-cta{ display:flex; justify-content:center; margin-top:40px; }

/* ============================================================
   FIELDS
   ============================================================ */
.fields-grid{ display:grid; grid-template-columns:repeat(auto-fill, minmax(230px,1fr)); gap:1px; background:var(--line-soft); border:1px solid var(--line); border-radius:18px; overflow:hidden; }
.field-card{ background:var(--surface); padding:30px 26px 28px; transition:background .3s, transform .3s; position:relative; min-height:188px; display:flex; flex-direction:column; }
.field-card > *{ flex-shrink:0; }
.field-card:hover{ background:var(--surface-2); }
.field-glyph{ width:34px; height:34px; color:var(--accent-1); margin-bottom:auto; }
.field-name{ font-family:var(--font-display); font-weight:600; font-size:25px; margin-top:18px; }
.field-name .sub-name{ display:block; font-size:14px; color:var(--ink-faint); font-family:var(--font-sans); font-weight:500; margin-top:3px; letter-spacing:.02em; }
.field-name .sub-name:empty{ display:none; }
html[data-lang="zh"] .field-name .sub-name{ font-size:13px; }
.field-more{ display:flex; align-items:flex-end; }
.field-desc{ font-size:13.5px; color:var(--ink-soft); margin-top:10px; line-height:1.5; }
.field-card .corner{ position:absolute; top:26px; right:26px; font-family:var(--font-display); font-style:italic; color:var(--ink-faint); font-size:15px; opacity:.7; }

/* ============================================================
   HOW IT WORKS
   ============================================================ */
.how{ background:var(--bg-warm); border-block:1px solid var(--line); }
.steps{ display:grid; grid-template-columns:repeat(3,1fr); gap:clamp(24px,3vw,48px); }
.step{ position:relative; }
.step-num{ font-family:var(--font-display); font-style:italic; font-size:64px; font-weight:600; line-height:1; color:transparent; -webkit-text-stroke:1.3px var(--accent-1); }
html[data-theme="cosmic"] .step-num{ -webkit-text-stroke-color:var(--accent-2); }
.step h3{ font-family:var(--font-display); font-weight:600; font-size:27px; margin:18px 0 12px; }
.step p{ color:var(--ink-soft); font-size:15.5px; line-height:1.62; }
.step-line{ position:absolute; top:30px; left:84px; right:-24px; height:1px; background:repeating-linear-gradient(90deg, var(--line) 0 8px, transparent 8px 16px); }
.step:last-child .step-line{ display:none; }

/* ============================================================
   FEATURED PAPERS
   ============================================================ */
/* library toolbar: search + field filters */
.lib-toolbar{ display:flex; align-items:center; gap:18px 24px; flex-wrap:wrap; justify-content:space-between; margin-bottom:26px; }
.lib-search{ position:relative; display:flex; align-items:center; flex:0 1 340px; min-width:240px; }
.lib-search-ic{ position:absolute; left:15px; color:var(--ink-faint); pointer-events:none; }
.lib-search input{
  width:100%; padding:12px 38px 12px 42px; border-radius:999px;
  border:1px solid var(--line); background:var(--surface-2); color:var(--ink);
  font-family:inherit; font-size:14.5px; transition:border-color .2s, box-shadow .2s;
}
.lib-search input::placeholder{ color:var(--ink-faint); }
.lib-search input:focus{ outline:none; border-color:var(--accent-1); box-shadow:0 0 0 3px var(--grad-soft); }
.lib-search input::-webkit-search-cancel-button{ -webkit-appearance:none; }
.lib-search #libClear{ position:absolute; right:13px; width:22px; height:22px; display:flex; align-items:center; justify-content:center; border-radius:50%; color:var(--ink-faint); opacity:0; transition:opacity .2s, color .2s, background .2s; }
.lib-search input:not(:placeholder-shown) + #libClear{ opacity:1; }
.lib-search #libClear:hover{ color:var(--ink); background:var(--line-soft); }
.lib-filters{ display:flex; gap:8px; flex-wrap:wrap; }
.lib-chip{
  padding:8px 15px; border-radius:999px; border:1px solid var(--line);
  background:var(--surface-2); font-size:13px; font-weight:600; color:var(--ink-soft);
  letter-spacing:.01em; transition:color .2s, background .2s, border-color .2s, transform .15s;
}
.lib-chip:hover{ border-color:var(--accent-1); color:var(--ink); transform:translateY(-1px); }
.lib-chip.on{ color:#fff; background:var(--grad); border-color:transparent; }
.lib-empty{ text-align:center; color:var(--ink-faint); font-size:15px; padding:40px 0; }

.papers-grid{ display:grid; grid-template-columns:repeat(auto-fill,minmax(330px,1fr)); gap:18px; }
.paper-card{ position:relative; background:var(--surface-2); border:1px solid var(--line); border-radius:16px; padding:28px 28px 24px; transition:transform .3s, box-shadow .3s, border-color .3s; display:flex; flex-direction:column; min-height:248px; cursor:pointer; }
.paper-card > *{ flex-shrink:0; }
.paper-card:hover{ transform:translateY(-4px); box-shadow:var(--shadow-md); border-color:var(--accent-1); }
.paper-card:focus-visible{ outline:none; border-color:var(--accent-1); box-shadow:0 0 0 3px var(--grad-soft); }
.paper-card.active{ border-color:transparent; box-shadow:0 0 0 1.5px var(--accent-1), var(--shadow-md); }
.paper-card.active::before{ content:""; position:absolute; left:0; top:22px; bottom:22px; width:3px; border-radius:3px; background:var(--grad); }
.pc-top{ display:flex; align-items:center; justify-content:space-between; gap:10px; margin-bottom:0; }
.pc-field{ font-size:11px; font-weight:700; letter-spacing:.13em; text-transform:uppercase; color:var(--accent-ink); }
.pc-year{ font-family:var(--font-display); font-style:italic; color:var(--ink-faint); font-size:16px; }
.pc-title{ font-family:var(--font-display); font-weight:600; font-size:23px; line-height:1.18; margin:18px 0 8px; }
.pc-author{ font-size:13.5px; color:var(--ink-soft); }
.pc-foot{ margin-top:auto; padding-top:20px; }
.pc-badges{ display:flex; gap:8px; flex-wrap:wrap; }
.pc-go{ display:inline-flex; align-items:center; gap:7px; margin-top:16px; font-size:13px; font-weight:600; color:var(--accent-ink); opacity:.55; transition:opacity .25s, gap .25s; }
.paper-card:hover .pc-go, .paper-card.active .pc-go{ opacity:1; gap:11px; }
.pc-arrow{ transition:transform .25s; }
.paper-card:hover .pc-arrow{ transform:translateX(3px); }
.paper-card.active .pc-go .pc-arrow{ transform:rotate(0); }
.badge{ font-size:11.5px; font-weight:600; letter-spacing:.03em; padding:5px 11px; border-radius:999px; border:1px solid var(--line); color:var(--ink-soft); display:inline-flex; align-items:center; gap:6px; }
.badge .lv-dots{ display:inline-flex; gap:3px; }
.badge .lv-dots i{ width:5px; height:5px; border-radius:50%; background:var(--accent-1); display:inline-block; }
.badge.lang{ color:var(--accent-ink); border-color:color-mix(in srgb,var(--accent-1) 35%, transparent); }

/* ============================================================
   FOUNDER
   ============================================================ */
.founder{ background:var(--bg-warm); border-block:1px solid var(--line); overflow:hidden; }
.founder-grid{ display:grid; grid-template-columns:0.85fr 1.15fr; gap:clamp(36px,5vw,80px); align-items:center; }
.founder-portrait{ position:relative; }
.founder-portrait .frame{ position:relative; border-radius:18px; overflow:hidden; border:1px solid var(--line); background:linear-gradient(160deg,#f0eee9,#e7e3da); box-shadow:var(--shadow-lg); }
html[data-theme="cosmic"] .founder-portrait .frame{ background:linear-gradient(160deg,#1a1830,#121022); }
.founder-portrait img{ width:100%; mix-blend-mode:multiply; }
html[data-theme="cosmic"] .founder-portrait img{ mix-blend-mode:normal; }
.founder-portrait .pf-tag{ position:absolute; left:18px; bottom:18px; z-index:2; background:color-mix(in srgb,var(--surface-2) 86%, transparent); backdrop-filter:blur(6px); border:1px solid var(--line); border-radius:12px; padding:11px 16px; }
.founder-portrait .pf-tag .nm{ font-family:var(--font-display); font-weight:600; font-size:18px; white-space:nowrap; }
.founder-portrait .pf-tag .rl{ font-size:12px; color:var(--ink-faint); letter-spacing:.04em; white-space:nowrap; }
.founder-quote{ font-family:var(--font-display); font-weight:500; font-size:clamp(26px,3.2vw,42px); line-height:1.22; letter-spacing:-.01em; }
html[data-lang="zh"] .founder-quote{ line-height:1.4; }
.founder-quote em{ font-style:italic; }
.founder-quote .hl{ background:var(--grad); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.founder-body{ margin-top:26px; color:var(--ink-soft); font-size:16px; line-height:1.7; max-width:54ch; }
.founder-sign{ margin-top:28px; display:flex; align-items:center; gap:16px; }
.founder-sign .sig{ font-family:var(--font-display); font-style:italic; font-size:30px; }
.founder-sign .meta{ font-size:13px; color:var(--ink-faint); border-left:1px solid var(--line); padding-left:16px; }

/* ============================================================
   CTA
   ============================================================ */
.cta{ position:relative; overflow:hidden; }
.cta-card{ position:relative; border-radius:26px; overflow:hidden; padding:clamp(46px,7vw,90px) clamp(28px,5vw,80px); background:var(--ink); color:#fff; }
html[data-theme="cosmic"] .cta-card{ background:#16142a; border:1px solid var(--line); }
.cta-card .cta-aura{ position:absolute; inset:0; background:radial-gradient(70% 120% at 85% 10%, rgba(138,92,236,.6), transparent 60%), radial-gradient(60% 120% at 10% 90%, rgba(79,91,227,.5), transparent 60%); opacity:.85; }
.cta-card .inner{ position:relative; z-index:2; max-width:640px; }
.cta-card h2{ font-family:var(--font-display); font-weight:600; font-size:clamp(32px,4.4vw,56px); line-height:1.08; color:#fff; }
html[data-lang="zh"] .cta-card h2{ line-height:1.22; }
.cta-card p{ color:rgba(255,255,255,.78); margin:18px 0 32px; font-size:17px; max-width:48ch; }
.join-form{ display:flex; gap:10px; flex-wrap:wrap; max-width:480px; }
.join-form input{ flex:1; min-width:220px; padding:15px 20px; border-radius:999px; border:1px solid rgba(255,255,255,.22); background:rgba(255,255,255,.08); color:#fff; font-size:15px; font-family:inherit; }
.join-form input::placeholder{ color:rgba(255,255,255,.55); }
.join-form input:focus{ outline:none; border-color:#fff; background:rgba(255,255,255,.14); }
.join-form .btn-primary{ background:#fff; color:#2a2350; box-shadow:none; }
.join-form .btn-primary:hover{ background:#f0eeff; }
.cta-fine{ color:rgba(255,255,255,.6); font-size:13px; margin-top:16px; }

/* ============================================================
   FOOTER
   ============================================================ */
.footer{ padding-block:clamp(60px,8vh,90px) 40px; }
.footer-top{ display:grid; grid-template-columns:1.4fr 1fr 1fr 1fr; gap:40px 32px; padding-bottom:48px; border-bottom:1px solid var(--line); }
.footer-logo{ height:120px; width:auto; filter:var(--logo-filter); mix-blend-mode:var(--logo-blend); margin-bottom:18px; margin-left:-6px; }
.footer-blurb{ color:var(--ink-soft); font-size:14.5px; max-width:34ch; line-height:1.6; }
.footer-col h4{ font-size:12px; letter-spacing:.16em; text-transform:uppercase; color:var(--ink-faint); margin-bottom:18px; font-weight:700; }
.footer-col a{ display:block; color:var(--ink-soft); font-size:14.5px; padding:6px 0; transition:color .2s; }
.footer-col a:hover{ color:var(--accent-ink); }
.footer-col a.lang-opt.active{ color:var(--accent-ink); font-weight:700; }
.footer-bottom{ display:flex; align-items:center; justify-content:space-between; flex-wrap:wrap; gap:16px; padding-top:28px; }
.footer-bottom .copy{ font-size:13px; color:var(--ink-faint); }
.footer-bottom .mantra{ font-family:var(--font-display); font-style:italic; font-size:16px; color:var(--ink-soft); }

/* ============================================================
   Reveal on scroll — robust against background-tab throttling.
   Default state is VISIBLE. Above-fold uses a timeline animation
   (resolves even when unpainted); below-fold uses a scroll
   transition (only armed once JS confirms it's off-screen).
   ============================================================ */
@keyframes jvRise{ from{ opacity:0; transform:translateY(22px); } to{ opacity:1; transform:none; } }
.reveal.lift{ animation:jvRise .8s cubic-bezier(.2,.7,.2,1) both; }
.reveal.lift[data-d="1"]{ animation-delay:.09s; }
.reveal.lift[data-d="2"]{ animation-delay:.18s; }
.reveal.lift[data-d="3"]{ animation-delay:.27s; }
.reveal.lift[data-d="4"]{ animation-delay:.36s; }

.reveal.armed{ opacity:0; transform:translateY(26px); }
.reveal.armed.in{ opacity:1; transform:none;
  transition:opacity .8s cubic-bezier(.2,.7,.2,1), transform .8s cubic-bezier(.2,.7,.2,1); }
.reveal.armed.in[data-d="1"]{ transition-delay:.08s; }
.reveal.armed.in[data-d="2"]{ transition-delay:.16s; }
.reveal.armed.in[data-d="3"]{ transition-delay:.24s; }
.reveal.armed.in[data-d="4"]{ transition-delay:.32s; }
@media (prefers-reduced-motion: reduce){
  .reveal.armed, .reveal.lift{ opacity:1 !important; transform:none !important; animation:none !important; }
  html{ scroll-behavior:auto; }
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px){
  body{ font-size:16px; }
  .nav-links{ display:none; }
  .menu-btn{ display:flex; }
  .founder-grid{ grid-template-columns:1fr; }
  .founder-portrait{ max-width:420px; }
  .steps{ grid-template-columns:1fr; gap:34px; }
  .step-line{ display:none; }
  .footer-top{ grid-template-columns:1fr 1fr; }
  .hero h1{ font-size:clamp(40px,10vw,60px); }
  .paper-formula{ display:none; }
}
@media (max-width: 560px){
  .hero-meta{ grid-template-columns:1fr; }
  .hero-meta .cell{ display:flex; align-items:baseline; gap:14px; padding:18px 4px; }
  .hero-meta .l{ margin-top:0; }
  .footer-top{ grid-template-columns:1fr; }
  .level-tab{ min-width:120px; }
  .nav-cta{ display:none; }
}

/* mobile menu sheet */
.m-sheet{ position:fixed; inset:0; z-index:90; background:var(--bg); transform:translateX(100%); transition:transform .4s cubic-bezier(.4,0,.1,1); display:flex; flex-direction:column; padding:26px; }
.m-sheet.open{ transform:none; }
.m-sheet .m-head{ display:flex; justify-content:space-between; align-items:center; margin-bottom:40px; }
.m-sheet a{ font-family:var(--font-display); font-size:34px; font-weight:600; padding:14px 0; border-bottom:1px solid var(--line-soft); }
.m-sheet .m-foot{ margin-top:auto; display:flex; flex-direction:column; gap:14px; align-items:stretch; }
.m-sheet .m-foot .btn{ justify-content:center; }