/* สไตล์กลางของหน้าย่อย (คลังความรู้ และเครื่องมือ) — โทนเดียวกับหน้าแรก index.html */
:root{
  --bg:#f7f8fc; --surface:rgba(255,255,255,.78); --line:rgba(99,102,241,.16);
  --ink:#0f172a; --ink-2:#475569; --ink-3:#64748b;
  --a1:#6366f1; --a2:#06b6d4; --a3:#a855f7; --a4:#f472b6;
  --grad:linear-gradient(120deg,var(--a1),var(--a2) 45%,var(--a3) 80%,var(--a4));
  --r:22px; --shadow:0 10px 40px -12px rgba(79,70,229,.18),0 2px 6px rgba(15,23,42,.04);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;overflow-x:clip;scroll-padding-top:80px}
body{font-family:"IBM Plex Sans Thai",system-ui,sans-serif;background:var(--bg);color:var(--ink);line-height:1.7;overflow-x:clip}
a{color:inherit;text-decoration:none}
.en{font-family:"Space Grotesk","IBM Plex Sans Thai",sans-serif;letter-spacing:-.01em}

.bg{position:fixed;inset:0;z-index:-1;overflow:hidden;pointer-events:none}
.bg::before{content:"";position:absolute;inset:0;background-image:radial-gradient(rgba(99,102,241,.13) 1px,transparent 1px);background-size:26px 26px;mask-image:radial-gradient(ellipse at 50% 20%,#000 30%,transparent 75%)}
.blob{position:absolute;border-radius:50%;filter:blur(70px);opacity:.5}
.b1{width:520px;height:520px;background:#c7d2fe;top:-140px;left:-120px}
.b2{width:460px;height:460px;background:#a5f3fc;top:120px;right:-160px}

.wrap{width:min(1120px,100% - 32px);margin-inline:auto}
nav{position:sticky;top:0;z-index:20;backdrop-filter:blur(14px);background:rgba(247,248,252,.75);border-bottom:1px solid var(--line)}
nav .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;height:64px}
.logo{font-weight:700;font-size:1.15rem;display:flex;align-items:center;gap:.55rem}
.logo i{width:30px;height:30px;border-radius:9px;background:var(--grad);display:grid;place-items:center;color:#fff;font-style:normal;font-size:.8rem}
.menu{display:flex;gap:1.6rem;font-size:.95rem;color:var(--ink-2)}
.menu a:hover,.menu a.on{color:var(--a1)}
@media (max-width:760px){.menu{display:none}}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.7rem 1.2rem;border-radius:999px;font:inherit;font-weight:600;font-size:.95rem;border:0;cursor:pointer;transition:transform .2s,box-shadow .2s}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 8px 24px -8px rgba(99,102,241,.6)}
.btn-ghost{background:#fff;border:1px solid var(--line);color:var(--ink)}
.btn:hover{transform:translateY(-2px)}
.btn:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,.tab:focus-visible{outline:3px solid rgba(99,102,241,.45);outline-offset:2px}

section{padding:56px 0}
.eyebrow{font-size:.85rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--a1)}
h1{font-size:clamp(1.9rem,4.4vw,3rem);line-height:1.2;margin:.4rem 0 .7rem}
h2{font-size:clamp(1.5rem,3vw,2.1rem);line-height:1.25;margin:.4rem 0 .6rem}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.sub{color:var(--ink-2);max-width:44em}
.card{background:var(--surface);backdrop-filter:blur(12px);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow)}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:20px;margin-top:28px}
.lesson{padding:24px;display:flex;flex-direction:column;gap:10px;transition:transform .25s}
a.lesson:hover{transform:translateY(-4px)}
.lesson .ico{width:44px;height:44px;border-radius:13px;display:grid;place-items:center;color:#fff;font-size:1.2rem}
.lesson h3{font-size:1.08rem;line-height:1.45}
.lesson p{color:var(--ink-2);font-size:.93rem}
.lesson .more{margin-top:auto;color:var(--a1);font-weight:600;font-size:.92rem}
.soon{opacity:.75;border-style:dashed}
.pill{display:inline-block;align-self:flex-start;font-size:.75rem;padding:.15rem .6rem;border-radius:999px;background:#eef2ff;color:#4338ca;font-weight:600}
.pill.new{background:#dcfce7;color:#166534}
footer{padding:28px 0 40px;text-align:center;color:var(--ink-3);font-size:.85rem}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}