:root{
  --orange:#ff6a00; --orange-d:#e85f00; --orange-soft:#fff3ea;
  --ink:#0f1b2e; --bg:#ffffff; --card:#fff;
  --text:#16202b; --muted:#72808f; --line:#eceff4; --line-2:#e0e5ec; --soft:#f6f8fb;
  --green:#12a150; --amber:#f5a623;
  --radius:18px; --radius-sm:12px;
  --shadow:0 3px 14px rgba(18,32,54,.06); --shadow-lg:0 18px 44px rgba(18,32,54,.15);
  --t:.18s cubic-bezier(.4,0,.2,1);
}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:Inter,system-ui,-apple-system,Arial,sans-serif;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
#app{min-height:100vh}
a{cursor:pointer;text-decoration:none;color:inherit}
button{font-family:inherit;cursor:pointer}
::selection{background:var(--orange-soft)}
.wrap{max-width:1200px;margin:0 auto;padding:18px 18px 56px}

/* ---- buttons ---- */
.btn{border:0;border-radius:999px;padding:11px 18px;font-weight:600;font-size:14px;display:inline-flex;align-items:center;justify-content:center;gap:7px;transition:transform var(--t),box-shadow var(--t),background var(--t),border-color var(--t),color var(--t);white-space:nowrap;letter-spacing:-.01em}
.btn.sm{padding:8px 15px;font-size:13px}
.btn-primary{background:var(--orange);color:#fff;box-shadow:0 4px 12px rgba(255,106,0,.26)}
.btn-primary:hover{background:var(--orange-d);transform:translateY(-1px);box-shadow:0 8px 18px rgba(255,106,0,.32)}
.btn-primary:active{transform:translateY(0)}
.btn-ghost{background:#fff;border:1.5px solid var(--line-2);color:var(--text)}
.btn-ghost:hover{border-color:var(--orange);color:var(--orange-d);background:var(--orange-soft);transform:translateY(-1px)}

/* ---- explainer hero ---- */
.hero{position:relative;overflow:hidden;border:1px solid #f4ece3;border-radius:24px;background:linear-gradient(120deg,#fff2e4 0%,#fff8f2 40%,#ffffff 100%);padding:32px 28px;box-shadow:var(--shadow)}
.hero:before{content:"";position:absolute;right:-60px;top:-60px;width:280px;height:280px;border-radius:50%;background:radial-gradient(circle,rgba(255,106,0,.14),transparent 70%);pointer-events:none}
.hero-in{position:relative;display:flex;flex-direction:column;gap:26px}
.hero-copy{max-width:580px}
.eyebrow{display:inline-block;font-size:11px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--orange-d);background:#fff;border:1px solid #ffdcc2;padding:7px 13px;border-radius:999px;box-shadow:0 2px 6px rgba(255,106,0,.08)}
.hero h1{font-size:32px;line-height:1.08;margin:16px 0 10px;font-weight:800;letter-spacing:-.025em}
.hero h1 .hl{color:var(--orange)}
.hero p{color:#4a5768;line-height:1.6;margin:0 0 22px;font-size:15.5px}
.hero-cta{display:flex;flex-wrap:wrap;gap:11px;margin-bottom:22px}
.stats{display:flex;gap:14px;flex-wrap:wrap}
.stat{background:rgba(255,255,255,.6);border:1px solid #f2e7db;border-radius:14px;padding:10px 16px;min-width:88px}
.stat b{display:block;font-size:19px;font-weight:800;color:var(--ink);letter-spacing:-.02em}
.stat span{font-size:11.5px;color:var(--muted);font-weight:500}
.hero-illus{align-self:center;width:100%;max-width:330px}
.hero-illus svg{width:100%;height:auto;display:block;filter:drop-shadow(0 12px 24px rgba(18,32,54,.12))}
@media(min-width:880px){
  .hero{padding:48px}
  .hero-in{flex-direction:row;align-items:center;justify-content:space-between;gap:44px}
  .hero h1{font-size:42px}
  .hero-illus{flex:none;width:340px}
}

/* ---- section heads ---- */
.sec-head{display:flex;align-items:center;justify-content:space-between;margin:34px 0 16px;gap:12px}
.sec-head h2{font-size:20px;margin:0;font-weight:800;letter-spacing:-.02em}
.sec-head .link{color:var(--orange);font-weight:700;font-size:14px}

/* ---- continue strip ---- */
.continue{display:flex;gap:14px;overflow-x:auto;padding-bottom:8px;scrollbar-width:none}
.continue::-webkit-scrollbar{display:none}
.cont-card{flex:0 0 268px;background:#fff;border:1px solid var(--line);border-radius:15px;padding:12px;display:flex;gap:13px;align-items:center;cursor:pointer;transition:border-color var(--t),box-shadow var(--t),transform var(--t);box-shadow:var(--shadow)}
.cont-card:hover{border-color:var(--line-2);box-shadow:var(--shadow-lg);transform:translateY(-2px)}
.cont-thumb{width:66px;height:50px;border-radius:10px;flex:none;background-size:cover;background-position:center}
.cont-info{min-width:0;flex:1}
.cont-info b{display:block;font-size:14px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.cont-info .bar{height:6px;background:#eef1f5;border-radius:99px;overflow:hidden;margin-top:9px}
.cont-info .bar i{display:block;height:100%;background:linear-gradient(90deg,var(--orange),#ff8c3a)}

/* ---- controls / filters ---- */
.controls{display:flex;flex-direction:column;gap:12px;margin:30px 0 8px}
.chips{display:flex;gap:8px;overflow-x:auto;padding:2px 2px 6px;scrollbar-width:none}
.chips::-webkit-scrollbar{display:none}
.chip{flex:none;height:40px;border:1.5px solid var(--line-2);background:#fff;color:#48566a;border-radius:999px;padding:0 17px;font-size:13.5px;font-weight:600;cursor:pointer;transition:all var(--t);letter-spacing:-.01em}
.chip:hover{border-color:#c9d3df;background:var(--soft)}
.chip.on{background:var(--ink);border-color:var(--ink);color:#fff;box-shadow:0 4px 12px rgba(15,27,46,.22)}
.filters-r{display:flex;gap:10px;align-items:center}
.search{position:relative;flex:1;display:block}
.search input{width:100%;height:40px;padding:0 14px 0 38px;border:1.5px solid var(--line-2);border-radius:11px;font-size:14px;font-family:inherit;background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2372808f' stroke-width='2' stroke-linecap='round'%3E%3Ccircle cx='11' cy='11' r='7'/%3E%3Cpath d='M20 20l-3.2-3.2'/%3E%3C/svg%3E") no-repeat 13px center;transition:border-color var(--t),box-shadow var(--t)}
.search input::-webkit-search-cancel-button{display:none}
.sortsel{height:40px;border:1.5px solid var(--line-2);border-radius:11px;padding:0 34px 0 14px;font-size:14px;font-family:inherit;background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2372808f' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E") no-repeat right 13px center;color:var(--text);font-weight:600;cursor:pointer;-webkit-appearance:none;appearance:none}
input:focus,select:focus{outline:none;border-color:var(--orange);box-shadow:0 0 0 3px rgba(255,106,0,.14)}
@media(min-width:760px){.controls{flex-direction:row;align-items:center;justify-content:space-between}.chips{flex:1}.filters-r{flex:none}.search{width:210px;flex:none}}

/* ---- popular rail ---- */
.rail{display:flex;gap:18px;overflow-x:auto;padding:3px 3px 12px;scroll-snap-type:x mandatory;scrollbar-width:none}
.rail::-webkit-scrollbar{display:none}
.rail .card{flex:0 0 270px;scroll-snap-align:start}

/* ---- grid + cards ---- */
.grid{display:grid;grid-template-columns:1fr;gap:20px}
@media(min-width:560px){.grid{grid-template-columns:repeat(2,1fr)}}
@media(min-width:880px){.grid{grid-template-columns:repeat(3,1fr)}}
@media(min-width:1160px){.grid{grid-template-columns:repeat(4,1fr)}}
.card{background:var(--card);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);border:1px solid var(--line);cursor:pointer;transition:transform var(--t),box-shadow var(--t),border-color var(--t);display:flex;flex-direction:column}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--line-2)}
.thumb{position:relative;aspect-ratio:16/10;display:grid;place-items:center;overflow:hidden}
.thumb:after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(0,0,0,.06) 0%,transparent 30%,transparent 62%,rgba(0,0,0,.32) 100%)}
.thumb .play{position:relative;z-index:1;width:48px;height:48px;border-radius:50%;background:rgba(255,255,255,.16);backdrop-filter:blur(3px);color:#fff;display:grid;place-items:center;font-size:14px;border:1.5px solid rgba(255,255,255,.85);padding-left:3px;transition:transform var(--t),background var(--t)}
.card:hover .thumb .play{transform:scale(1.12);background:var(--orange);border-color:var(--orange)}
.cat-tag{position:absolute;left:10px;top:10px;z-index:1;background:rgba(255,255,255,.9);backdrop-filter:blur(4px);color:var(--ink);font-size:11px;font-weight:700;padding:4px 10px;border-radius:999px;letter-spacing:-.01em}
.thumb-min{position:absolute;right:9px;bottom:9px;z-index:1;background:rgba(15,27,46,.62);backdrop-filter:blur(3px);color:#fff;font-size:11px;font-weight:600;padding:3px 8px;border-radius:7px}
.card-body{padding:14px 15px 16px;display:flex;flex-direction:column;gap:8px;flex:1}
.card-body h3{margin:0;font-size:15.5px;font-weight:700;line-height:1.32;letter-spacing:-.01em;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;min-height:2.64em}
.meta{font-size:12.5px;color:var(--muted);display:flex;align-items:center;gap:8px;font-weight:500}
.rating{color:var(--amber);font-weight:700;display:inline-flex;align-items:center;gap:3px}
.card-foot{margin-top:auto;display:flex;align-items:center;justify-content:space-between;gap:10px;padding-top:4px}
.prog{display:flex;align-items:center;gap:9px;flex:1;min-width:0}
.bar{flex:1;height:6px;background:#eef1f5;border-radius:99px;overflow:hidden}
.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--orange),#ff8c3a);border-radius:99px;transition:width .4s ease}
.prog span{font-size:12px;font-weight:700;color:var(--muted)}
.badge-new{font-size:11px;font-weight:700;color:var(--green);background:#e9f7ef;padding:4px 10px;border-radius:999px;letter-spacing:.01em}
.no-results{grid-column:1/-1;padding:52px 16px;text-align:center;color:var(--muted);font-size:15px}

/* ---- course detail view ---- */
.course-view{padding-bottom:12px}
.back{background:transparent;border:0;color:var(--muted);font-weight:700;font-size:14px;padding:6px 0;margin-bottom:10px;transition:color var(--t)}
.back:hover{color:var(--orange)}
.course-grid{display:flex;flex-direction:column;gap:24px}
.player-wrap{display:flex;flex-direction:column;gap:13px;align-items:stretch}
.player-frame{width:100%;aspect-ratio:16/9;border-radius:16px;overflow:hidden;background:#000;box-shadow:var(--shadow-lg)}
.player-frame iframe,.player-frame video{width:100%;height:100%;border:0;display:block}
.player{aspect-ratio:16/9;width:100%;border-radius:16px;display:grid;place-items:center;color:#fff;position:relative;text-align:center;padding:16px;box-shadow:var(--shadow-lg)}
.play-lg{width:66px;height:66px;border-radius:50%;background:rgba(0,0,0,.32);display:grid;place-items:center;font-size:20px;border:2px solid rgba(255,255,255,.85);padding-left:4px}
.player-cap{position:absolute;left:16px;bottom:14px;font-weight:700}
.player-note{position:absolute;right:14px;top:12px;font-size:11px;opacity:.72;max-width:45%}
.course-side h2{margin:0 0 8px;font-size:23px;font-weight:800;letter-spacing:-.02em}
.course-desc{color:var(--muted);margin:0 0 18px;line-height:1.6}
.lessons{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}
.lesson{display:flex;align-items:center;gap:13px;padding:13px;border:1px solid var(--line);border-radius:13px;background:#fff;cursor:pointer;transition:border-color var(--t),background var(--t),transform var(--t);box-shadow:var(--shadow)}
.lesson:hover{border-color:var(--line-2);transform:translateX(2px)}
.lesson.active{border-color:var(--orange);background:var(--orange-soft)}
.ls-n{width:30px;height:30px;border-radius:50%;background:#f0f3f7;display:grid;place-items:center;font-weight:700;font-size:13px;flex:none}
.lesson.active .ls-n{background:var(--orange);color:#fff}
.ls-info{display:flex;flex-direction:column;flex:1;min-width:0;gap:2px}
.ls-info b{font-size:14.5px;font-weight:600}
.ls-info small{color:var(--muted);font-size:12px}
.ls-done{color:var(--green);font-weight:800;flex:none}
.ls-pct{color:var(--muted);font-weight:700;font-size:12px;flex:none}
.ls-play{color:var(--orange);flex:none}
@media(min-width:900px){.course-grid{display:grid;grid-template-columns:1.5fr 1fr;align-items:start;gap:32px}}

/* ---- 404 + misc ---- */
.notfound{min-height:100vh;display:grid;place-content:center;text-align:center;gap:8px;padding:24px;max-width:560px;margin:auto}
.nf-code{font-size:84px;font-weight:900;color:var(--orange);line-height:1;letter-spacing:-.03em}
.notfound h1{margin:6px 0;font-size:24px;font-weight:800}
.notfound p{color:var(--muted);line-height:1.65;margin:0 0 18px}
.empty,.loading{padding:64px 16px;text-align:center;color:var(--muted)}