:root{
  --ink:#e9eef4; --ink-2:#aebac9; --muted:#7b8798; --line:#222c39; --bg:#0b1017; --card:#121a24;
  --accent:#0abab5; --accent-ink:#7ce6df; --accent-soft:#0e2b30;
  --ok:#3ddc97; --ok-soft:#0e2a22; --lock:#5d6875;
  --radius:14px; --shadow:0 1px 2px rgba(0,0,0,.4),0 6px 20px rgba(0,0,0,.28);
  --font:"Noto Sans JP",system-ui,-apple-system,"Hiragino Sans",sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);font-size:15px;line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:inherit}
button{font:inherit;cursor:pointer}
input,textarea,select{font:inherit;color:inherit}
img{max-width:100%}

/* layout */
.shell{display:grid;grid-template-columns:248px 1fr;min-height:100vh}
.side{position:sticky;top:0;height:100vh;background:#080d13;color:#e9edf3;border-right:1px solid var(--line);padding:22px 14px;display:flex;flex-direction:column;gap:4px;overflow:auto}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px;letter-spacing:.02em;padding:4px 10px 18px}
.brand-mark{width:32px;height:32px;display:grid;place-items:center;color:var(--accent)}
.brand-mark svg{width:32px;height:32px}
.nav-label{font-size:11px;color:#8a95a8;letter-spacing:.12em;padding:14px 10px 4px}
.nav a{display:flex;align-items:center;gap:10px;padding:9px 12px;border-radius:10px;text-decoration:none;color:#9fadbe;font-size:14px}
.nav a:hover{background:rgba(255,255,255,.06);color:#fff}
.nav a.on{background:rgba(10,186,181,.16);color:#fff}
.nav a.on .ico{color:var(--accent)}
.ico{width:18px;text-align:center;opacity:.95}
.side-foot{margin-top:auto;padding:12px 10px 0;border-top:1px solid rgba(255,255,255,.08);font-size:13px;color:#aab3c2}
.main{min-width:0;padding:28px clamp(16px,4vw,44px) 60px}
.topbar{display:none}
.tabbar{display:none}

@media (max-width:860px){
  .shell{grid-template-columns:1fr}
  .side{display:none}
  .topbar{display:flex;position:sticky;top:0;z-index:10;align-items:center;justify-content:space-between;background:#080d13;color:#fff;padding:10px 16px;border-bottom:1px solid var(--line)}
  .topbar .brand{padding:0;font-size:16px}
  .main{padding:18px 16px 96px}
  .tabbar{display:grid;grid-auto-flow:column;position:fixed;bottom:0;left:0;right:0;z-index:10;background:#0e151d;border-top:1px solid var(--line);padding:6px 4px calc(6px + env(safe-area-inset-bottom))}
  .tabbar a{position:relative;display:flex;flex-direction:column;align-items:center;gap:1px;font-size:10.5px;color:var(--muted);text-decoration:none;padding:4px 0}
  .tabbar a .ico{font-size:18px}
  .tabbar a.on{color:var(--accent)}
}

/* type */
h1{font-size:clamp(20px,2.4vw,26px);margin:0 0 4px;letter-spacing:.01em}
h2{font-size:17px;margin:0 0 10px}
h3{font-size:15px;margin:0}
.sub{color:var(--muted);font-size:13.5px;margin:0 0 22px}
.muted{color:var(--muted)}
.small{font-size:12.5px}

/* cards */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px}
.grid{display:grid;gap:14px}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.stat{display:flex;flex-direction:column;gap:2px}
.stat b{font-size:26px;line-height:1.2}
.row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.between{justify-content:space-between}
.stack{display:flex;flex-direction:column;gap:10px}
.mt{margin-top:18px}

/* buttons & inputs */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1px solid var(--line);background:#182231;color:var(--ink);padding:8px 14px;border-radius:10px;font-size:14px;font-weight:600;text-decoration:none}
.btn:hover{border-color:#313e4f}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#04231f;font-weight:700}
.btn.primary:hover{filter:brightness(.96)}
.btn.dark{background:#e9eef4;border-color:#e9eef4;color:#0b1017}
.btn.ghost{background:transparent;border-color:transparent;color:var(--ink-2)}
.btn.sm{padding:5px 10px;font-size:12.5px;border-radius:8px}
.btn:disabled{opacity:.5;cursor:default}
.field{display:flex;flex-direction:column;gap:5px;font-size:13px;color:var(--ink-2)}
.input,textarea.input,select.input{width:100%;border:1px solid var(--line);background:#0e151d;border-radius:10px;padding:9px 12px;font-size:14.5px;outline:none}
.input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(10,186,181,.25)}
textarea.input{resize:vertical;min-height:84px;line-height:1.6}
.err{color:#ff8f6b;font-size:13px}
.note{background:var(--accent-soft);color:var(--accent-ink);border:1px solid rgba(10,186,181,.25);border-radius:10px;padding:10px 14px;font-size:13.5px}

/* badges */
.badge{display:inline-flex;align-items:center;gap:4px;font-size:11.5px;font-weight:700;padding:2px 9px;border-radius:999px;background:#1b2534;color:var(--ink-2)}
.badge.ok{background:var(--ok-soft);color:var(--ok)}
.badge.accent{background:var(--accent-soft);color:var(--accent-ink)}
.badge.lock{background:#1b2534;color:var(--lock)}

/* stages */
.stage{border-radius:var(--radius);background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);overflow:hidden}
.stage-head{display:flex;gap:14px;align-items:center;padding:16px 18px;border-bottom:1px solid var(--line)}
.stage-num{flex:none;width:44px;height:44px;border-radius:12px;display:grid;place-items:center;font-weight:800;background:var(--accent-soft);color:var(--accent)}
.stage.locked .stage-num{background:#1b2534;color:#5d6875}
.stage-bar{height:6px;background:#1b2534;border-radius:99px;overflow:hidden;margin-top:6px;width:160px;max-width:100%}
.stage-bar i{display:block;height:100%;background:var(--accent)}
.lesson{display:flex;align-items:center;gap:12px;padding:11px 18px;border-top:1px solid #1a2330;text-decoration:none}
.lesson:first-child{border-top:0}
.lesson:hover{background:#161f2b}
.lesson .dot{flex:none;width:22px;height:22px;border-radius:50%;border:2px solid #2c3849;display:grid;place-items:center;font-size:12px;color:#04231f}
.lesson .dot.done{background:var(--ok);border-color:var(--ok)}
.lesson.locked{color:var(--lock);pointer-events:none}
.lesson-title{flex:1;min-width:0}
.video{position:relative;aspect-ratio:16/9;max-width:100%;border-radius:12px;overflow:hidden;background:#000}
.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.thumbs{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(230px,1fr))}
.thumb{background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden;text-decoration:none;box-shadow:var(--shadow)}
.thumb .img{aspect-ratio:16/9;background:#161f2b center/cover no-repeat;display:grid;place-items:center;color:#fff;font-size:28px}
.thumb .t{padding:10px 12px;font-size:13.5px;font-weight:600;line-height:1.5}
.thumb.locked{opacity:.55;pointer-events:none}

/* chat */
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:16px}
.tab{padding:7px 14px;border-radius:999px;border:1px solid var(--line);background:#182231;text-decoration:none;font-size:13.5px;font-weight:600;color:var(--ink-2)}
.tab.on{background:var(--accent);border-color:var(--accent);color:#04231f}
.thread-item{display:flex;align-items:center;gap:12px;padding:14px 16px;border-top:1px solid var(--line);text-decoration:none}
.thread-item:first-child{border-top:0}
.thread-item:hover{background:#161f2b}
.post{display:flex;gap:12px;padding:14px 0;border-top:1px solid #1a2330}
.post:first-child{border-top:0}
.avatar{flex:none;width:36px;height:36px;border-radius:50%;background:#1e2836;display:grid;place-items:center;font-weight:700;color:#9fadbe;font-size:14px;overflow:hidden}
.avatar img{width:100%;height:100%;object-fit:cover}
.post-body{flex:1;min-width:0}
.post-meta{font-size:12.5px;color:var(--muted)}
.post-meta b{color:var(--ink);font-size:13.5px;margin-right:6px}
.post-text{white-space:pre-wrap;word-break:break-word;margin:2px 0 6px}
.reacts{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.react{border:1px solid var(--line);background:#182231;border-radius:999px;padding:1px 9px;font-size:13px;line-height:1.8}
.react.mine{border-color:var(--accent);background:var(--accent-soft)}
.picker{display:flex;gap:2px;background:#182231;border:1px solid var(--line);border-radius:999px;padding:2px 6px;box-shadow:var(--shadow)}
.picker button{border:0;background:none;font-size:17px;padding:2px 4px;border-radius:6px}
.picker button:hover{background:#243043}
.replies{margin-top:8px;padding-left:14px;border-left:2px solid #1e2836}
.replies .post{padding:10px 0}
.replies .avatar{width:28px;height:28px;font-size:12px}
.composer{position:sticky;bottom:0;background:var(--bg);padding:12px 0 4px}
@media (max-width:860px){.composer{bottom:62px}}

/* table */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:var(--card)}
table{border-collapse:collapse;width:100%;font-size:13.5px}
th,td{padding:10px 12px;border-bottom:1px solid #1a2330;text-align:left;white-space:nowrap}
th{font-size:12px;color:var(--muted);font-weight:600;background:#0e151d}
tr:last-child td{border-bottom:0}

/* login */
.auth{min-height:100vh;display:grid;place-items:center;padding:24px 16px;background:radial-gradient(1100px 480px at 80% -10%,rgba(10,186,181,.20) 0,transparent 60%),var(--bg)}
.auth .card{width:100%;max-width:400px;padding:28px}
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.6);display:grid;place-items:center;padding:16px;z-index:50}
.modal{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px;width:100%;max-width:520px;max-height:90vh;overflow:auto}
.empty{text-align:center;color:var(--muted);padding:36px 12px}
.spin{display:inline-block;width:18px;height:18px;border:2px solid #243043;border-top-color:var(--accent);border-radius:50%;animation:s .7s linear infinite}
@keyframes s{to{transform:rotate(360deg)}}

/* tags */
.tagchip{display:inline-flex;align-items:center;gap:4px;font-size:12px;font-weight:700;padding:2px 10px;border-radius:999px;border:1px solid transparent;cursor:pointer;background:#1b2534;color:var(--ink-2)}
.tagchip.gray{background:#1b2534;color:#aebac9}
.tagchip.orange{background:#33200f;color:#ffb184}
.tagchip.blue{background:#14233d;color:#8db4ff}
.tagchip.green{background:#0e2a22;color:#6ee7b7}
.tagchip.red{background:#331617;color:#ff9b95}
.tagchip.purple{background:#241a3d;color:#c7a5ff}
.tagchip.off{background:transparent;border-color:var(--line);color:var(--muted)}
.tagchip.sel{outline:2px solid var(--accent);outline-offset:1px}
.tagrow{display:flex;gap:6px;flex-wrap:wrap;align-items:center}