/* Layout specific to the tutorial. Palette and controls come from the shared SI / PneuLab styles. */
*{box-sizing:border-box}
body{margin:0;background:var(--bg-color);color:var(--text-color);font-family:var(--font-family);line-height:1.5}
main{max-width:1420px;margin:0 auto;padding:0 16px 34px}
a{color:var(--primary-color);text-underline-offset:3px}
.mob-header{padding:20px 12px 24px;text-align:center}
.mob-header h1{margin:6px 0 8px;color:var(--primary-color);font-size:clamp(1.55rem,4vw,2.25rem)}
.mob-header p{max-width:980px;margin:0 auto;color:var(--muted)}
.mob-eyebrow{color:var(--muted);font-weight:700;letter-spacing:.05em}
.mob-layout{display:grid;grid-template-columns:300px minmax(0,1fr);gap:18px;align-items:start}
.mob-navigation{position:sticky;top:14px;background:var(--panel-bg);border:1px solid var(--panel-border);border-radius:16px;box-shadow:var(--shadow-soft);padding:16px}
.mob-navigation h2{font-size:1.05rem;margin:0 0 12px}
.mob-navigation p{font-size:.88rem;color:var(--muted);margin-bottom:0}
#steps{display:grid;gap:8px}
button,select,input{font:inherit}
button{cursor:pointer;background:var(--panel-bg);border:1px solid var(--panel-border);padding:10px 13px;border-radius:10px;color:var(--text-color);min-height:42px}
#steps button{display:grid;grid-template-columns:30px minmax(0,1fr);align-items:center;gap:9px;text-align:left;padding:9px;font-weight:700}
.mob-step-number{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:#eef5f9;color:var(--primary-color)}
#steps button[aria-current=step]{background:#eef6ff;border:2px solid var(--primary-color);color:var(--navy)}
button:disabled{opacity:.45;cursor:not-allowed}
.mob-content{min-width:0}
.grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:16px}
.card{background:var(--panel-bg);border:1px solid var(--panel-border);border-radius:16px;padding:20px;margin-bottom:18px}
h2{margin-top:0;font-size:1.3rem}h3{font-size:1.05rem}
p,li{line-height:1.65}
.hint{background:#f1f7ff;padding:12px;border-left:4px solid var(--primary-color);border-radius:9px;color:var(--muted)}
.moves{display:flex;flex-wrap:wrap;gap:8px}
.feedback{min-height:64px;padding-top:16px;font-weight:600}
svg{display:block;width:100%;height:auto}
.schemax-trace{display:block;width:100%;height:360px;border:1px solid var(--panel-border);border-radius:12px;background:var(--panel-bg)}
.schemax-graph{height:275px}
.velocity-lab{padding:16px;background:#f7fbff;border:1px solid var(--panel-border);border-radius:12px;margin-bottom:20px}
.velocity-lab input[type=range]{display:block;width:100%;margin-top:8px}
.matrix-scroll{overflow-x:auto;margin:16px 0}
.matrix-table{font-family:Consolas,monospace;min-width:420px;text-align:center}
.matrix-table td,.matrix-table th{text-align:center;padding:10px}
.matrix-table caption{text-align:left;font-family:var(--font-family);color:var(--muted);padding-bottom:8px}
.matrix-nonzero{font-weight:800;color:var(--primary-color)}
.matrix-highlight{background:#fff1df}
.coefficient-grid{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:8px}
.coefficient-grid label{text-align:center}.coefficient-grid input{width:100%;min-width:0;text-align:center}
label{display:block;margin:12px 0;font-weight:600}
input{width:80px;padding:8px;border:1px solid var(--panel-border);border-radius:10px}
select{max-width:100%;padding:10px;border:1px solid var(--panel-border)}
table{width:100%;border-collapse:collapse}td,th{text-align:left;padding:10px;border-bottom:1px solid var(--panel-border)}
.equations{font-family:Consolas,monospace;line-height:1.9;background:#f7fbff;border:1px solid var(--panel-border);border-radius:12px;padding:16px;white-space:pre-wrap;overflow-wrap:anywhere}
.footer{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:8px 0}
small{color:var(--muted)}
@media(max-width:900px){.mob-layout{grid-template-columns:1fr}.mob-navigation{position:static;padding:10px}.mob-navigation h2,.mob-navigation p{display:none}#steps{display:flex;overflow-x:auto;gap:6px;padding-bottom:4px}#steps button{flex:0 0 auto;white-space:nowrap}.grid{grid-template-columns:1fr}}
@media(max-width:560px){main{padding:0 12px 24px}.mob-header{padding:16px 0 20px}.card{padding:16px}.footer{font-size:.85rem}.footer button{padding:9px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto}}
@media print{.mob-navigation,.footer,.moves{display:none}.mob-layout,.grid{display:block}.card{box-shadow:none;break-inside:avoid}}

#velocityView .schemax-trace{height:415px}
#coaxialView{margin-top:14px}#coaxialView .schemax-trace{height:450px}
#coaxialOffset{display:block;width:100%;margin-top:8px}

.schemax-trace:not(.schemax-graph){height:580px}
#coaxialView .schemax-trace{height:560px}
.grid:has(.schemax-trace){grid-template-columns:1fr}
.mob-lesson-step{scroll-margin-top:16px;margin-bottom:38px}
.mob-stage-label{color:var(--primary-color);font-weight:800;border-top:1px solid var(--panel-border);padding-top:20px}
.mob-case{margin-top:24px;padding-top:12px;border-top:1px solid var(--panel-border)}
.schemax-trace,#velocityView .schemax-trace,#coaxialView .schemax-trace,.schemax-trace:not(.schemax-graph){height:790px}
@media(max-width:650px){.schemax-trace,#velocityView .schemax-trace,#coaxialView .schemax-trace,.schemax-trace:not(.schemax-graph){height:1050px}}

.mob-lesson-step[hidden]{display:none!important}
.schemax-observation>.moves{margin:10px 0}
.elimination-preview{background:#f1f7ff;border:1px solid var(--panel-border);border-left:4px solid var(--primary-color);border-radius:10px;padding:14px;margin:16px 0}
.elimination-preview p{margin:8px 0}
.matrix-table .elimination-target{background:#fff1df;outline:2px solid #e9a440;outline-offset:-2px}
.matrix-table td.elimination-coefficient{background:#dcecff;color:#164b85;box-shadow:inset 0 0 0 2px var(--blue);font-weight:900}
.matrix-table td.elimination-pivot{background:#ddf4e7;color:#17613c;box-shadow:inset 0 0 0 2px var(--green);font-weight:900}
.triangular-demo{background:#f7fbff;border:1px solid var(--panel-border);border-radius:12px;padding:16px;margin:18px 0}
.triangular-table{max-width:420px;margin:16px auto;border:2px solid var(--panel-border);font-family:Consolas,monospace}
.triangular-table td{text-align:center;border:2px solid white;padding:14px;font-size:1.15rem}
.triangle-diagonal{background:#dcecff;color:#164b85;font-weight:800}
.triangle-zero{background:#ddf4e7;color:#17613c;font-weight:800}
.triangle-upper{background:#edf0f4;color:var(--muted)}
.parameter-balance{margin:22px 0;padding:18px;border:1px solid var(--panel-border);border-radius:12px;background:#f7fbff}
.parameter-equations{display:grid;gap:12px}
.parameter-row{display:grid;grid-template-columns:100px minmax(0,1fr);gap:16px;align-items:center;padding:14px;background:var(--panel-bg);border:1px solid var(--panel-border);border-radius:12px}
.parameter-token{display:grid;place-items:center;min-height:64px;border-radius:10px;font-size:1.4rem;font-weight:800;font-family:Consolas,monospace}
.parameter-token.constrained{color:#a33232;background:#fff0f0;border:1px solid #efbaba}
.parameter-token.free{color:#17613c;background:#e9f8ef;border:2px solid var(--green)}
.parameter-row.free-parameter{border:2px solid var(--green)}
.parameter-row .equations{margin-top:8px;padding:10px;font-weight:700}
.parameter-row p{margin:8px 0 0;color:var(--muted)}
.parameter-summary{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-top:18px;padding:14px;border-radius:10px;background:#e9f8ef;color:#17613c}
@media(max-width:560px){.parameter-row{grid-template-columns:1fr}.parameter-token{min-height:48px}.parameter-balance{padding:12px}}

.matrix-table .rank-free-column{background:#fff1df;box-shadow:inset 0 0 0 2px #e9a440}

.graph-tutorial-frame{display:block;width:100%;height:420px;border:1px solid var(--panel-border);border-radius:12px;margin:16px 0}