:root {
  --blue: #0493CE; --blue-d: #0071A0; --blue-l: #E4F3FA;
  --green: #9CCB3B; --green-d: #5D8A12; --green-l: #EEF6D8;
  --rust: #C02B0A; --rust-l: #FBEAE6; --amber: #B26A00; --amber-l: #FFF3DD;
  --ink: #0D0D0D; --grey-3: #333333; --grey-4: #666666; --grey-5: #7D7D7D;
  --paper: #F4F4F4; --white: #FFFFFF; --rule: #DDDDDD; --rule-s: #EAEAEA;
  --shadow: 0 1px 3px rgba(0,0,0,.08);
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { background: var(--paper); color: var(--grey-3); font-family: "IBM Plex Sans", -apple-system, sans-serif; font-size: 15px; line-height: 1.5; }
.app { max-width: 900px; margin: 0 auto; padding: 0 20px 90px; }
[hidden] { display: none !important; }

/* top bar */
.topbar { background: var(--blue); color: #fff; padding: 16px 20px; display: flex; align-items: center; gap: 14px; position: sticky; top: 0; z-index: 20; box-shadow: 0 2px 8px rgba(0,0,0,.1); }
.topbar .badge { width: 38px; height: 38px; border-radius: 50%; border: 2px solid rgba(255,255,255,.85); display: flex; align-items: center; justify-content: center; font-family: "Archivo", sans-serif; font-weight: 700; font-size: 14px; flex-shrink: 0; }
.topbar .tt { font-family: "Archivo", sans-serif; font-weight: 600; font-size: 17px; flex: 1; min-width: 0; }
.topbar .tt small { display: block; font-family: "IBM Plex Mono", monospace; font-size: 10.5px; letter-spacing: .08em; text-transform: uppercase; color: rgba(255,255,255,.75); font-weight: 400; margin-top: 2px; }
.topbar .back { background: none; border: none; color: #fff; font-size: 26px; cursor: pointer; padding: 0 6px; line-height: 1; }
.topbar .rv { font-family: "IBM Plex Mono", monospace; font-size: 10px; letter-spacing: .1em; text-transform: uppercase; background: #fff; color: var(--blue-d); padding: 4px 9px; border-radius: 4px; font-weight: 500; }

/* home */
.homehead { padding: 26px 0 6px; }
.homehead h1 { font-family: "Archivo", sans-serif; font-weight: 700; font-size: 28px; margin: 0 0 8px; letter-spacing: -.02em; }
.homehead p { color: var(--grey-4); margin: 0; max-width: 62ch; }
.card { background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 18px 20px; margin: 18px 0; box-shadow: var(--shadow); }
.card .q { font-weight: 600; color: var(--ink); margin-bottom: 12px; font-size: 15.5px; }
.card .opts { display: flex; gap: 10px; flex-wrap: wrap; }
.pill { font-family: inherit; font-size: 14px; font-weight: 500; padding: 9px 20px; border-radius: 30px; border: 2px solid var(--rule); background: var(--white); color: var(--grey-4); cursor: pointer; }
.pill.sel { border-color: var(--blue); color: var(--blue-d); background: var(--blue-l); }
.profile { display: grid; grid-template-columns: 1fr 1fr 1fr auto; gap: 10px; align-items: end; }
.profile label, .field label { display: block; font-size: 12px; font-weight: 500; color: var(--grey-4); margin-bottom: 4px; }
input[type=text], input[type=email], textarea, select { width: 100%; padding: 10px 12px; border: 1px solid var(--rule); border-radius: 7px; font-size: 14.5px; font-family: inherit; background: #fff; color: var(--grey-3); }
textarea { min-height: 84px; resize: vertical; }
.profile-saved { display: flex; justify-content: space-between; align-items: center; gap: 12px; font-size: 14px; }
.profile-saved b { color: var(--ink); }
.linkbtn { background: none; border: none; color: var(--blue-d); cursor: pointer; font-size: 13px; text-decoration: underline; padding: 0; font-family: inherit; }
.overallwrap { margin: 4px 0 24px; }
.overallrow { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 6px; }
.overallrow span:first-child { font-family: "IBM Plex Mono", monospace; font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase; color: var(--grey-5); }
.overallrow span:last-child { font-family: "IBM Plex Mono", monospace; font-size: 12px; color: var(--grey-4); }
.bar { height: 6px; background: var(--rule-s); border-radius: 3px; overflow: hidden; }
.bar > div { height: 100%; background: var(--green); border-radius: 3px; transition: width .3s; }
.modgrid { display: flex; flex-direction: column; gap: 10px; margin-top: 6px; }
.modtile { display: flex; align-items: center; gap: 16px; background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 15px 18px; box-shadow: var(--shadow); cursor: pointer; text-align: left; width: 100%; font-family: inherit; color: inherit; }
.modtile .mnum { width: 42px; height: 42px; border-radius: 8px; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-family: "IBM Plex Mono", monospace; font-size: 15px; font-weight: 500; background: var(--blue-l); color: var(--blue-d); }
.modtile.complete .mnum { background: var(--green); color: #fff; }
.modtile.skipped { opacity: .6; }
.modtile .mbody { flex: 1; min-width: 0; }
.modtile .mtitle { font-weight: 600; color: var(--ink); font-size: 15.5px; margin-bottom: 2px; }
.modtile .msub { font-size: 12.5px; color: var(--grey-5); }
.modtile .mtag { font-family: "IBM Plex Mono", monospace; font-size: 9.5px; letter-spacing: .07em; text-transform: uppercase; color: var(--blue-d); border: 1px solid var(--blue); border-radius: 3px; padding: 2px 7px; white-space: nowrap; flex-shrink: 0; }
.modtile .chev { color: var(--grey-5); font-size: 20px; flex-shrink: 0; }
.rvsummary { margin: 4px 0 18px; padding: 12px 16px; background: var(--amber-l); border-radius: 8px; font-size: 13.5px; color: var(--grey-3); }

/* lesson nav */
.steprow { display: flex; gap: 6px; overflow-x: auto; padding: 16px 0 6px; scrollbar-width: thin; }
.stepchip { flex-shrink: 0; min-width: 34px; height: 34px; padding: 0 4px; border-radius: 17px; display: flex; align-items: center; justify-content: center; font-family: "IBM Plex Mono", monospace; font-size: 12px; border: 2px solid var(--rule); color: var(--grey-5); background: var(--white); cursor: pointer; position: relative; }
.stepchip.current { border-color: var(--blue); color: var(--blue-d); background: var(--blue-l); font-weight: 600; }
.stepchip.done { border-color: var(--green); background: var(--green); color: #fff; }
.stepchip .rvdot { position: absolute; top: -3px; right: -3px; width: 11px; height: 11px; border-radius: 50%; border: 2px solid var(--paper); }
.rvdot.ok { background: var(--green-d); } .rvdot.chg { background: var(--rust); }
.lessonhead { margin: 16px 0 4px; }
.lessonhead .eyebrow { font-family: "IBM Plex Mono", monospace; font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--blue); margin-bottom: 6px; }
.lessonhead h2 { font-family: "Archivo", sans-serif; font-weight: 600; font-size: 24px; margin: 0; letter-spacing: -.015em; }
.videowrap { margin: 16px 0; border-radius: 10px; overflow: hidden; background: #000; box-shadow: var(--shadow); position: relative; }
.videowrap video { width: 100%; display: block; }
.videowrap .ytbox { position: relative; padding-top: 56.25%; }
.videowrap .ytbox iframe, .videowrap .ytbox #ytplayer { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.previewtag { position: absolute; top: 10px; left: 10px; z-index: 2; font-family: "IBM Plex Mono", monospace; font-size: 10px; letter-spacing: .1em; text-transform: uppercase; background: rgba(0,0,0,.65); color: #fff; padding: 4px 9px; border-radius: 4px; pointer-events: none; }
.navrow { display: flex; justify-content: space-between; gap: 12px; margin-top: 20px; }
.btn { font-family: inherit; font-size: 14.5px; font-weight: 600; padding: 11px 22px; border-radius: 8px; border: none; cursor: pointer; }
.btn.primary { background: var(--blue); color: #fff; }
.btn.primary:disabled { background: var(--rule-s); color: var(--grey-5); cursor: not-allowed; }
.btn.ghost { background: var(--white); border: 1px solid var(--rule); color: var(--grey-4); }
.btn.green { background: var(--green-d); color: #fff; }
.btn.small { padding: 8px 16px; font-size: 13.5px; }
.hint { font-size: 12.5px; color: var(--grey-5); margin-top: 10px; }

/* storyboard fallback + transcript */
.storyboard { background: var(--white); border: 1px dashed var(--rule); border-radius: 10px; padding: 18px 20px; margin: 16px 0; }
.storyboard h3 { margin: 0 0 4px; font-family: "Archivo", sans-serif; font-size: 16px; }
.storyboard p.sub { margin: 0 0 12px; color: var(--grey-5); font-size: 13px; }
.seg { display: grid; grid-template-columns: 44px 1fr; gap: 10px; padding: 9px 0; border-top: 1px solid var(--rule-s); font-size: 14px; }
.seg .sid { font-family: "IBM Plex Mono", monospace; font-size: 11px; color: var(--rust); padding-top: 2px; }
details.tx { margin: 10px 0 0; background: var(--white); border: 1px solid var(--rule-s); border-radius: 8px; padding: 0 16px; }
details.tx summary { cursor: pointer; padding: 12px 0; font-weight: 600; color: var(--blue-d); font-size: 14px; }
details.tx .seg:first-of-type { border-top: 1px solid var(--rule-s); }

/* page lessons */
.items { list-style: none; margin: 14px 0; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.items > li { display: grid; grid-template-columns: auto 1fr; gap: 14px; align-items: start; background: var(--white); border: 1px solid var(--rule-s); border-radius: 8px; padding: 14px 16px; box-shadow: var(--shadow); }
.items .ico { width: 28px; height: 28px; border-radius: 6px; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-family: "IBM Plex Mono", monospace; font-size: 12px; font-weight: 500; background: rgba(4,147,206,.1); color: var(--blue-d); }
.items li.red .ico { background: rgba(192,43,10,.1); color: var(--rust); }
.items b { display: block; color: var(--ink); font-weight: 600; font-size: 14px; margin-bottom: 2px; }
.items span.d { font-size: 13px; color: var(--grey-4); line-height: 1.45; }
.hotstub { margin-top: 20px; padding: 16px 18px; background: var(--rule-s); border-radius: 8px; font-size: 13px; color: var(--grey-5); text-align: center; }
.section { background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 18px 20px; margin: 14px 0; box-shadow: var(--shadow); }
.section h3 { font-family: "Archivo", sans-serif; font-size: 17px; margin: 0 0 10px; color: var(--blue-d); }
.section table { width: 100%; border-collapse: collapse; font-size: 14px; }
.section td { padding: 8px 6px; border-bottom: 1px solid var(--rule-s); vertical-align: top; }
.section td:last-child { text-align: right; font-family: "IBM Plex Mono", monospace; color: var(--green-d); white-space: nowrap; padding-left: 14px; }
.section tr:last-child td { border-bottom: none; }
.section ul { margin: 0; padding-left: 20px; } .section li { margin-bottom: 6px; font-size: 14px; }
.section .note { margin: 10px 0 0; font-size: 13px; color: var(--grey-4); }

/* quiz */
.modebar { display: flex; gap: 8px; margin: 14px 0 6px; }
.modebtn { flex: 1; text-align: left; font-family: inherit; background: var(--white); border: 2px solid var(--rule); border-radius: 10px; padding: 12px 14px; cursor: pointer; color: var(--grey-4); }
.modebtn b { display: block; color: var(--ink); font-size: 15px; }
.modebtn span { font-size: 12.5px; }
.modebtn.sel { border-color: var(--blue); background: var(--blue-l); }
.qcard { background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 18px 20px; margin-bottom: 14px; box-shadow: var(--shadow); border-left: 4px solid transparent; }
.qcard .qhead { display: flex; gap: 10px; align-items: baseline; margin-bottom: 8px; }
.qcard .qid { font-family: "IBM Plex Mono", monospace; font-size: 11px; color: var(--blue); }
.qcard .qtype { font-family: "IBM Plex Mono", monospace; font-size: 9.5px; letter-spacing: .07em; text-transform: uppercase; color: var(--grey-5); margin-left: auto; }
.qcard .stem { font-weight: 500; color: var(--ink); font-size: 15px; margin-bottom: 10px; line-height: 1.4; }
.qopt { display: flex; align-items: flex-start; gap: 10px; padding: 8px 10px; margin: 0 -10px; border-radius: 6px; font-size: 14px; cursor: pointer; }
.qopt input { margin-top: 3px; flex-shrink: 0; width: 17px; height: 17px; cursor: pointer; }
.qopt.good { background: var(--green-l); } .qopt.bad { background: var(--rust-l); } .qopt.missed { outline: 2px dashed var(--green-d); outline-offset: -2px; }
.qcard.right { border-left-color: var(--green-d); } .qcard.wrong { border-left-color: var(--rust); }
.whybox { margin-top: 12px; padding: 10px 14px; background: var(--paper); border-radius: 6px; font-size: 13px; color: var(--grey-4); line-height: 1.5; }
.verdict { font-weight: 600; margin-bottom: 4px; } .verdict.right { color: var(--green-d); } .verdict.wrong { color: var(--rust); }
.qgroup { font-family: "IBM Plex Mono", monospace; font-size: 11px; letter-spacing: .1em; text-transform: uppercase; color: var(--blue-d); margin: 22px 0 10px; }
.scorebar { position: sticky; bottom: 0; background: var(--white); border-top: 1px solid var(--rule); padding: 12px 20px; margin: 0 -20px; display: flex; justify-content: space-between; align-items: center; gap: 14px; z-index: 5; }
.scorebar .sc { font-family: "IBM Plex Mono", monospace; font-size: 13px; color: var(--grey-4); }
.scorebar .sc b { color: var(--ink); font-size: 15px; }
.resultbox { background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 22px; margin: 16px 0; text-align: center; box-shadow: var(--shadow); }
.resultbox .big { font-family: "Archivo", sans-serif; font-weight: 700; font-size: 40px; }
.resultbox.pass .big { color: var(--green-d); } .resultbox.fail .big { color: var(--rust); }

/* review panel */
.reviewpanel { margin-top: 26px; border: 2px solid var(--amber); background: var(--amber-l); border-radius: 10px; padding: 16px 18px; }
.reviewpanel h4 { margin: 0 0 4px; font-family: "Archivo", sans-serif; font-size: 15px; color: var(--amber); }
.reviewpanel p { margin: 0 0 10px; font-size: 13px; color: var(--grey-4); }
.reviewpanel .vrow { display: flex; gap: 8px; margin: 10px 0; }
.vbtn { font-family: inherit; font-size: 14px; font-weight: 600; padding: 9px 16px; border-radius: 8px; border: 2px solid var(--rule); background: #fff; color: var(--grey-4); cursor: pointer; }
.vbtn.sel.ok { border-color: var(--green-d); background: var(--green-l); color: var(--green-d); }
.vbtn.sel.chg { border-color: var(--rust); background: var(--rust-l); color: var(--rust); }
.reviewpanel .saved { font-size: 12.5px; color: var(--green-d); margin-top: 8px; }

/* completion */
.compform { background: var(--white); border: 1px solid var(--rule-s); border-radius: 10px; padding: 22px; margin: 16px 0; box-shadow: var(--shadow); }
.compform .field { margin-top: 14px; } .compform .field:first-child { margin-top: 0; }
.donebig { text-align: center; padding: 44px 20px; }
.donebig .check { width: 72px; height: 72px; border-radius: 50%; background: var(--green); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 36px; margin: 0 auto 18px; }
.donebig h2 { font-family: "Archivo", sans-serif; font-size: 24px; margin: 0 0 8px; }
.donebig p { color: var(--grey-4); margin: 0; }
.askbox { margin-top: 34px; padding-top: 18px; border-top: 1px solid var(--rule); }
.askbox summary { cursor: pointer; font-weight: 600; color: var(--blue-d); }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); background: var(--ink); color: #fff; padding: 11px 20px; border-radius: 8px; font-size: 14px; z-index: 50; box-shadow: 0 6px 20px rgba(0,0,0,.25); }
@media (max-width: 640px) { .profile { grid-template-columns: 1fr; } .app { padding: 0 14px 90px; } .modebar { flex-direction: column; } }