/* public/css/sat-learn.css — gold-standard two-column study layout + SAT exam tools
   (Desmos calculator dock + formula sheet). Pairs with sat-study.css. */

/* Two-column shell (sticky sidebar + content), matching the Physics/Chemistry standard.
   Whole shell centers on ultra-wide screens; content fills its column (fluid) with
   comfortable padding so there are no large uneven blanks. */
.sat-shell{display:grid;grid-template-columns:288px minmax(0,1fr);background:#fff;min-height:calc(100vh - var(--nav-h,64px));max-width:1680px;margin-inline:auto}
.sat-main{width:100%;min-width:0;padding:1.4rem clamp(1.25rem,3.2vw,3rem) 4.5rem;font-family:var(--font-sans,'DM Sans',system-ui,sans-serif)}
@media(max-width:980px){.sat-shell{grid-template-columns:1fr}.sat-shell .study-sidebar{display:none}.sat-main{padding:1.2rem 1.1rem 4rem}}

/* Breadcrumb */
.sat-crumb{font-size:.8rem;color:#78716c;margin-bottom:1rem}
.sat-crumb a{color:#78716c;text-decoration:none}
.sat-crumb a:hover{color:var(--ch-color,#1d4ed8)}
.sat-crumb .sep{margin:0 .4rem;opacity:.5}

/* Topic tabs */
.sat-tabs{display:flex;flex-wrap:wrap;gap:.5rem;padding:.1rem 0 1rem;margin-bottom:1.3rem;border-bottom:1px solid #ece8e0}
.sat-tab{display:inline-flex;align-items:center;gap:.45rem;font-size:.84rem;font-weight:600;color:#57534e;text-decoration:none;background:#f5f4f1;border:1px solid #e7e5e4;border-radius:999px;padding:.45rem .95rem;transition:all .15s}
.sat-tab:hover{border-color:var(--ch-color,#1d4ed8);color:var(--ch-color,#1d4ed8)}
.sat-tab.active{background:var(--ch-color,#1d4ed8);color:#fff;border-color:transparent}
.sat-tab .tn{font-weight:800;opacity:.7}
.sat-tab.active .tn{opacity:1}

/* Header */
.sat-head{margin-bottom:1.4rem}
.sat-head .kicker{font-size:.74rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--ch-color,#1d4ed8);margin-bottom:.4rem}
.sat-head h1{font-family:var(--font-serif,'Fraunces',Georgia,serif);font-size:clamp(1.7rem,3.6vw,2.4rem);font-weight:700;color:#1c1917;line-height:1.12;margin:0}

/* Concept / notes box */
.sat-concept{font-size:1.02rem;line-height:1.75;color:#3f3c38;background:#fbfaf7;border:1px solid #ece8e0;border-left:4px solid var(--ch-color,#1d4ed8);border-radius:12px;padding:1.1rem 1.3rem;margin-bottom:1.2rem;max-width:1100px}

/* Diagram / graph figure */
.sat-figure{margin:0 0 1.4rem;max-width:760px}
.sat-figure .diagram-stack{display:flex;flex-direction:column;gap:14px}
.sat-figure svg{display:block;width:100%;height:auto;background:#fff;border:1px solid #ece8e0;border-radius:12px;padding:10px 8px;box-shadow:0 1px 3px rgba(28,25,23,.05)}

/* ── Tutorial / how-to lessons (Ch34-36) ── */
.sat-tut-h{font-family:var(--font-serif,'Fraunces',Georgia,serif);font-size:1.3rem;font-weight:700;color:#1c1917;margin:1.7rem 0 .6rem;max-width:820px}
.sat-tut-p{font-size:1.04rem;line-height:1.75;color:#3f3c38;margin:0 0 1rem;max-width:820px}
.sat-tut-p code{background:#f1ede6;border:1px solid #e7e2d8;border-radius:5px;padding:.05rem .35rem;font-size:.92em;color:#1d4ed8}
.sat-tut-tip{display:flex;gap:12px;align-items:flex-start;max-width:820px;background:#fffaf0;border:1px solid #fde9c8;border-left:4px solid #f59e0b;border-radius:12px;padding:1rem 1.2rem;margin:0 0 1.3rem;color:#5b4a2e;line-height:1.65}
.sat-tut-tip__i{font-size:1.2rem;flex:none}
.sat-tut-fig{max-width:680px}
.sat-tut-fig figcaption{font-size:.88rem;color:#78716c;text-align:center;margin-top:.4rem}
.sat-tut-steps{counter-reset:tut;list-style:none;padding:0;margin:0 0 1.4rem;max-width:820px;display:flex;flex-direction:column;gap:10px}
.sat-tut-steps li{position:relative;background:#fbfaf7;border:1px solid #ece8e0;border-radius:12px;padding:.85rem 1rem .85rem 3.1rem}
.sat-tut-steps li::before{counter-increment:tut;content:counter(tut);position:absolute;left:.85rem;top:.85rem;width:26px;height:26px;border-radius:50%;background:var(--ch-color,#1d4ed8);color:#fff;display:grid;place-items:center;font-weight:700;font-size:.85rem}
.sat-tut-do{display:block;color:#1c1917;font-weight:600}
.sat-tut-do code{background:#eef4ff;border:1px solid #d6e2ff;border-radius:5px;padding:.05rem .4rem;color:#1d4ed8;font-weight:700}
.sat-tut-see{display:block;color:#57534e;font-size:.93rem;margin-top:.25rem}
.sat-tut-see::before{content:"→ ";color:#16a34a;font-weight:700}
.sat-tut-demo{max-width:820px;border:1px solid #d6e2ff;border-radius:14px;padding:1.1rem 1.2rem;margin:0 0 1.6rem;background:#f7faff}
.sat-tut-demo__head{font-weight:700;color:#1c2434;margin-bottom:.5rem;display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.sat-tut-demo__badge{background:#1d4ed8;color:#fff;font-size:.7rem;font-weight:700;letter-spacing:.04em;text-transform:uppercase;padding:.2rem .55rem;border-radius:999px}
.sat-tut-demo__list{margin:.2rem 0 .9rem;padding-left:1.1rem;color:#3f3c38;line-height:1.7}
.sat-tut-demo__list code{background:#eef4ff;border:1px solid #d6e2ff;border-radius:5px;padding:.05rem .4rem;color:#1d4ed8;font-weight:700}
.sat-tut-calc{background:#fff;border:1px solid #e2e8f0;border-radius:12px;overflow:hidden;min-height:430px}
.sat-tut-calc .sc-canvaswrap{min-height:300px}

/* Section heading inside content */
.sat-h2{font-family:var(--font-serif,'Fraunces',Georgia,serif);font-size:1.3rem;font-weight:700;color:#1c1917;margin:2rem 0 .8rem;display:flex;align-items:center;gap:.5rem}

/* Exam tools dock (fixed, top-right under navbar) */
.sat-dock{position:fixed;top:calc(var(--nav-h,64px) + 14px);right:18px;z-index:50;display:flex;flex-direction:column;gap:8px}
.sat-dock__btn{display:inline-flex;align-items:center;gap:7px;font-family:var(--font-sans,'DM Sans',sans-serif);font-size:.82rem;font-weight:700;background:#fff;color:#1c1917;border:1px solid #e2ddd2;border-radius:10px;padding:9px 13px;cursor:pointer;box-shadow:0 4px 14px rgba(10,22,40,.10);transition:all .15s}
.sat-dock__btn span{font-size:1rem}
.sat-dock__btn:hover{border-color:var(--saffron,#ff7a18);transform:translateY(-1px)}
.sat-dock__btn--primary{background:var(--saffron,#ff7a18);color:#fff;border-color:transparent}
.sat-dock__btn--primary:hover{background:var(--saffron-d,#e85d04)}
@media(max-width:600px){.sat-dock{flex-direction:row;top:auto;bottom:14px;right:14px}.sat-dock__btn span{margin:0}.sat-dock__btn{padding:9px 11px}}

/* Formula sheet modal */
.sat-modal{position:fixed;inset:0;z-index:120;display:flex;align-items:center;justify-content:center;padding:20px}
.sat-modal[hidden]{display:none}
.sat-modal__overlay{position:absolute;inset:0;background:rgba(10,22,40,.55)}
.sat-modal__panel{position:relative;background:#fff;border-radius:16px;max-width:560px;width:100%;max-height:86vh;display:flex;flex-direction:column;box-shadow:0 24px 60px rgba(10,22,40,.3)}
.sat-modal__head{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid #ece8e0}
.sat-modal__head h3{font-family:var(--font-serif,'Fraunces',serif);font-size:1.15rem;font-weight:700;color:#1c1917;margin:0}
.sat-modal__x{background:none;border:none;font-size:1.6rem;line-height:1;color:#78716c;cursor:pointer;padding:0 4px}
.sat-modal__x:hover{color:#1c1917}
.sat-modal__body{overflow-y:auto;padding:16px 20px 22px}
.sat-fs-tag{font-size:.68rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--saffron-d,#e85d04);background:var(--saffron-light,#fff2e8);border-radius:50px;padding:4px 11px;display:inline-block;margin:10px 0 6px}
.sat-fs-sec{margin-bottom:6px}
.sat-fs-sec h4{font-size:.92rem;font-weight:700;color:#1c1917;margin:12px 0 4px}
.sat-fs-tbl{width:100%;border-collapse:collapse;font-size:.88rem}
.sat-fs-tbl th{text-align:left;font-weight:600;color:#57534e;padding:5px 10px 5px 0;vertical-align:top;width:46%}
.sat-fs-tbl td{padding:5px 0;color:#1c1917;font-family:var(--font-mono,'DM Mono',monospace);font-weight:500}

/* Native graphing calculator panel (draggable, toggleable) */
.sat-calc{position:fixed;right:18px;bottom:18px;z-index:110;width:min(560px,94vw);height:min(640px,88vh);background:#fff;border:1px solid #d6d3cc;border-radius:14px;box-shadow:0 24px 60px rgba(10,22,40,.32);display:flex;flex-direction:column;overflow:hidden}
.sat-calc[hidden]{display:none}
.sat-calc__head{display:flex;align-items:center;justify-content:space-between;padding:9px 13px;background:#0a1628;color:#fff;font-size:.82rem;font-weight:700;cursor:move;user-select:none}
.sat-calc__x{background:none;border:none;color:#fff;font-size:1.4rem;line-height:1;cursor:pointer;padding:0 4px}
.sat-calc__body{flex:1;min-height:0;display:flex}

/* --- calculator UI --- */
.satcalc{display:flex;flex-direction:column;width:100%;min-height:0;font-family:var(--font-sans,'DM Sans',system-ui,sans-serif);font-size:.85rem}
.sc-tabs{display:flex;border-bottom:1px solid #e7e5e4;flex:none}
.sc-tab{flex:1;background:#f7f6f3;border:none;border-bottom:2px solid transparent;padding:8px;font-weight:700;color:#6b7280;cursor:pointer;font-family:inherit}
.sc-tab.active{background:#fff;color:#0a1628;border-bottom-color:var(--saffron,#ff7a18)}
.sc-pane{flex:1;min-height:0;display:flex;flex-direction:column}
.sc-pane[hidden]{display:none}
.sc-graph{flex:1;min-height:0;display:flex;flex-direction:column}
.sc-exprs{flex:none;max-height:120px;overflow-y:auto;padding:6px 8px 0}
.sc-row{display:flex;align-items:center;gap:7px;margin-bottom:5px}
.sc-row.bad .sc-in{border-color:#dc2626;background:#fef2f2}
.sc-dot{width:11px;height:11px;border-radius:50%;flex:none}
.sc-in{flex:1;min-width:0;border:1px solid #d6d3cc;border-radius:7px;padding:6px 9px;font-family:var(--font-mono,'DM Mono',monospace);font-size:.85rem}
.sc-in:focus{outline:none;border-color:var(--saffron,#ff7a18)}
.sc-del{background:none;border:none;color:#9ca3af;font-size:1.1rem;cursor:pointer;line-height:1;padding:0 2px}
.sc-del:hover{color:#dc2626}
.sc-add{flex:none;margin:2px 8px 6px;align-self:flex-start;background:var(--saffron-light,#fff2e8);color:var(--saffron-d,#e85d04);border:1px solid var(--saffron-mid,#ffcba0);border-radius:7px;padding:5px 11px;font-weight:700;cursor:pointer;font-size:.78rem}
.sc-sliders{flex:none;padding:0 8px}
.sc-slider{display:flex;align-items:center;gap:8px;margin:3px 0}
.sc-slider label{font-size:.78rem;color:#374151;white-space:nowrap;min-width:64px}
.sc-slider input{flex:1}
.sc-canvaswrap{flex:1;min-height:240px;position:relative;border-top:1px solid #ece8e0;margin-top:4px}
.sc-canvas{position:absolute;inset:0;width:100%;height:100%;touch-action:none;cursor:crosshair;display:block}
.sc-toolbar{flex:none;display:flex;align-items:center;gap:6px;padding:5px 8px;border-top:1px solid #ece8e0;font-size:.76rem;color:#6b7280}
.sc-toolbar button{width:26px;height:26px;border:1px solid #d6d3cc;background:#fff;border-radius:6px;cursor:pointer;font-size:.95rem;line-height:1}
.sc-toolbar button:hover{border-color:var(--saffron,#ff7a18)}
.sc-key{display:flex;align-items:center;gap:4px;cursor:pointer}
.sc-readout{margin-left:auto;font-family:var(--font-mono,monospace);color:#0a1628}
.sc-table{flex:none;max-height:0;overflow:hidden}
.sc-table table{width:100%;border-collapse:collapse;font-size:.74rem;font-family:var(--font-mono,monospace)}
.sc-table th,.sc-table td{border:1px solid #ece8e0;padding:2px 8px;text-align:center}
/* scientific */
.sc-sci{flex:1;min-height:0;display:flex;flex-direction:column;padding:8px}
.sc-sci-out{flex:1;min-height:0;display:flex;flex-direction:column;border:1px solid #d6d3cc;border-radius:8px;overflow:hidden;margin-bottom:8px}
.sc-sci-hist{flex:1;overflow-y:auto;padding:8px;background:#fbfaf7}
.sc-hline{display:flex;justify-content:space-between;gap:10px;padding:4px 0;border-bottom:1px solid #f0eee9;font-family:var(--font-mono,monospace)}
.sc-hline .q{color:#6b7280}.sc-hline .a{color:#0a1628;font-weight:700}
.sc-sci-in{border:none;border-top:1px solid #d6d3cc;padding:10px;font-family:var(--font-mono,monospace);font-size:.95rem}
.sc-sci-in:focus{outline:none}
.sc-keypad{flex:none;display:grid;grid-template-columns:repeat(5,1fr);gap:5px}
.sc-keypad button{padding:9px 0;border:1px solid #d6d3cc;background:#fff;border-radius:7px;cursor:pointer;font-size:.85rem;font-family:var(--font-mono,monospace)}
.sc-keypad button:hover{background:#f5f4f1;border-color:var(--saffron,#ff7a18)}
.sc-keypad .sc-eq{background:var(--saffron,#ff7a18);color:#fff;border-color:transparent;font-weight:800}