:root{--navy:#0a3264;--navy2:#104e89;--blue:#1768ad;--green:#18804f;--gold:#b67b16;--red:#a43b3b;--ink:#23313d;--muted:#687b8d;--line:#d8e3ee;--bg:#f4f7fa;--white:#fff}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);font-family:"Segoe UI",Tahoma,Arial,sans-serif;color:var(--ink);direction:rtl}
a{text-decoration:none;color:inherit}.topbar{min-height:66px;background:linear-gradient(90deg,#082a55,#0f4d88);color:#fff;display:flex;align-items:center;justify-content:space-between;padding:10px 22px;box-shadow:0 3px 14px #0002;position:sticky;top:0;z-index:30}
.brand{font-size:20px;font-weight:800}.actions{display:flex;gap:8px;flex-wrap:wrap}.actions a,.actions button{color:#fff;background:#ffffff0d;border:1px solid #ffffff55;border-radius:9px;padding:8px 12px;font:inherit}
.pagewrap{max-width:1450px;margin:auto;padding:20px;display:grid;grid-template-columns:310px minmax(0,1fr);gap:20px}
.sidebar{background:#fff;border:1px solid var(--line);border-radius:16px;padding:15px;align-self:start;position:sticky;top:88px;box-shadow:0 4px 15px rgba(10,45,80,.05)}
.sidebar h2{font-size:20px;color:var(--navy);margin:3px 5px 14px}.navitem{display:grid;grid-template-columns:42px 1fr;gap:9px;align-items:center;padding:10px 11px;margin:6px 0;border-radius:10px;border:1px solid #e1e8ef;color:#455869}
.navitem:hover{background:#f4f8fc}.navitem.active{background:linear-gradient(90deg,#0c5bae,#0a3f80);color:#fff;border-color:#0c5bae;font-weight:800}.navicon{width:37px;height:37px;border-radius:9px;background:#edf5fb;color:var(--blue);display:grid;place-items:center;font-weight:900}.active .navicon{background:#ffffff17;color:#fff}
.main{min-width:0}.content{background:#fff;border:1px solid var(--line);border-radius:18px;padding:27px;box-shadow:0 4px 15px rgba(10,45,80,.05)}
.hero{border-radius:18px;background:linear-gradient(135deg,#edf6fc,#f8fbfd);border:1px solid #d6e6ef;padding:25px;display:grid;grid-template-columns:1fr 180px;gap:20px;align-items:center}
.hero h1{margin:0;color:var(--navy);font-size:35px}.hero p{margin:8px 0 0;color:var(--muted);line-height:1.9;font-size:17px}.baseorb{width:145px;height:145px;border-radius:50%;background:#0d315a;color:#fff;display:grid;place-items:center;text-align:center;margin:auto;box-shadow:0 15px 28px #0a326422}.baseorb b{font-size:42px;display:block}.baseorb small{opacity:.8}
.title{margin:26px 0 13px;color:var(--navy);font-size:24px;font-weight:900;display:flex;align-items:center;gap:10px}.title:after{content:"";height:2px;background:#dce6ef;flex:1}
.info-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.info{border:1px solid var(--line);border-radius:14px;padding:17px;background:#fff}.info h3{margin:0 0 7px;color:var(--navy2);font-size:18px}.info p{margin:0;color:#526779;line-height:1.8}
.digits{direction:ltr;font-family:Consolas,monospace;font-size:18px;background:#f5f8fb;border:1px solid #e2eaf1;border-radius:10px;padding:12px;text-align:center;word-spacing:8px}
.note{background:#f3faf6;border-right:4px solid var(--green);padding:15px 17px;border-radius:11px;line-height:1.9;color:#40574a}
.warn{background:#fff8ef;border-right-color:var(--gold);color:#665126}.example-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:15px}.example{border:1px solid var(--line);border-radius:14px;padding:18px;background:#fff}.example h3{margin:0 0 8px;color:var(--navy2);font-size:19px}.example p{margin:0 0 8px;line-height:1.8;color:#536779}.math{direction:ltr;text-align:left;font-family:Consolas,"Courier New",monospace;font-size:16px;white-space:pre-line;background:#f7fafc;border:1px dashed #bfd0df;border-radius:10px;padding:12px 14px;line-height:1.8}
.map{width:100%;border-collapse:collapse;font-size:15px}.map th,.map td{border:1px solid #dbe5ee;padding:9px;text-align:center}.map th{background:#edf5fb;color:var(--navy)}
.op-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.op-card{border:1px solid var(--line);border-radius:14px;padding:17px}.op-card h3{margin:0 0 8px;color:var(--navy2)}
.footerbar{margin-top:24px;padding-top:18px;border-top:1px solid var(--line);display:flex;justify-content:space-between;align-items:center}.footerbar a{background:var(--navy);color:#fff;padding:9px 15px;border-radius:9px}
.system-cards{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.system-card{border:1px solid var(--line);border-radius:16px;padding:20px;background:#fff;text-align:center;transition:.15s}.system-card:hover{transform:translateY(-2px);box-shadow:0 8px 20px #0a326414}.system-card .big{font-size:35px;font-weight:900;color:var(--navy)}.system-card h3{color:var(--navy2);margin:7px 0}.system-card p{color:var(--muted);line-height:1.7;font-size:14px}.open{display:inline-block;margin-top:8px;background:var(--navy);color:#fff;padding:8px 12px;border-radius:9px;font-weight:800}
@media(max-width:1050px){.info-grid{grid-template-columns:1fr 1fr}.system-cards{grid-template-columns:1fr 1fr}.hero{grid-template-columns:1fr}.example-grid,.op-grid{grid-template-columns:1fr}}
@media(max-width:850px){.pagewrap{grid-template-columns:1fr}.sidebar{position:static}.info-grid,.system-cards{grid-template-columns:1fr}}
@media print{.topbar,.sidebar,.footerbar{display:none!important}.pagewrap{display:block;padding:0}.content{border:0;box-shadow:none}.example,.info,.op-card{break-inside:avoid}}

.hero-figure{width:100%;max-width:250px;height:auto;margin:auto;display:block}
.visual-block{margin:16px 0 22px;background:#f8fbfd;border:1px solid #d7e5ef;border-radius:16px;padding:14px;text-align:center}
.visual-block img{width:min(100%,700px);height:auto;display:block;margin:auto}
.video-card{margin:15px 0;background:#f5faf7;border:1px solid #cfe5d7;border-right:5px solid var(--green);border-radius:14px;padding:14px;display:grid;grid-template-columns:95px 1fr;gap:15px;align-items:center}
.video-card img{width:90px;height:90px;background:#fff;border:5px solid #fff;border-radius:10px}
.video-card h4{margin:0 0 5px;color:var(--navy);font-size:18px}.video-card p{margin:0 0 8px;color:#5d6e66;line-height:1.7}.video-card a{display:inline-block;background:var(--green);color:#fff;padding:7px 12px;border-radius:8px;font-weight:800}
@media(max-width:650px){.video-card{grid-template-columns:1fr;text-align:center}.video-card img{margin:auto}}

.printlink{margin-top:18px;padding:14px;border:1px solid var(--line);border-radius:12px;background:#fbfcfd;display:flex;gap:12px;align-items:center;color:var(--navy);font-weight:700}
.logic-values{display:grid;grid-template-columns:1fr 1fr;gap:15px}
.logic-value{border:1px solid var(--line);border-radius:15px;padding:20px;text-align:center}
.logic-value b{display:block;font-size:45px}.logic-value.true{background:#f3faf6;color:var(--green)}.logic-value.false{background:#fff5f5;color:var(--red)}
.logic-value span{color:var(--muted)}
.logic-ops{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.logic-op{border:1px solid var(--line);border-radius:15px;padding:18px;text-align:center;background:#fff}
.logic-op .symbol{font-size:42px;font-weight:900;color:var(--navy)}
.logic-op h3{color:var(--navy2);margin:6px 0}.logic-op p{line-height:1.8;color:var(--muted)}
.truth-table{width:100%;border-collapse:collapse}.truth-table th,.truth-table td{border:1px solid #dbe5ee;padding:11px;text-align:center;font-size:17px}
.truth-table th{background:#edf5fb;color:var(--navy)}.truth-table .t{background:#f3faf6;color:var(--green);font-weight:900}.truth-table .f{background:#fff5f5;color:var(--red);font-weight:900}
.exercise-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.exercise{border:1px solid var(--line);border-radius:14px;padding:17px;background:#fff}.exercise h3{margin:0 0 8px;color:var(--navy2)}.exercise li{line-height:1.95}
.discuss-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.discuss-card{border:1px solid var(--line);border-radius:15px;padding:17px;background:#fff}.dicon{width:48px;height:48px;border-radius:13px;background:#edf5fb;color:var(--blue);display:grid;place-items:center;font-size:26px;margin-bottom:9px}.discuss-card h3{color:var(--navy2);margin:0 0 7px}.discuss-card p{color:#536779;line-height:1.85}
.hero-logic{width:100%;max-width:230px;margin:auto;display:block}
@media(max-width:1050px){.logic-ops,.discuss-grid{grid-template-columns:1fr 1fr}}
@media(max-width:850px){.logic-ops,.discuss-grid,.exercise-grid,.logic-values{grid-template-columns:1fr}}

.practice-table{width:100%;border-collapse:collapse;margin-top:12px}
.practice-table th,.practice-table td{border:1px solid #dbe5ee;padding:11px;text-align:center}
.practice-table th{background:#edf5fb;color:var(--navy)}
.blank-cell{height:38px;background:#fff}
.exercise-note{margin-top:10px;color:#647786;font-size:14px;line-height:1.8}