/* EdgeFX Formation ICT — Ultra Premium Dark Theme V3 */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#030507;--bg-panel:rgba(6,10,18,0.99);--bg-card:rgba(10,16,28,0.96);
  --bg-hover:rgba(14,22,38,0.97);--bg-active:rgba(17,27,46,0.98);
  --border:rgba(79,138,255,0.1);--border2:rgba(194,208,228,0.14);--border-gold:rgba(245,166,35,0.2);
  --accent:#4f8aff;--accent-l:#7c5cf7;--accent-g:rgba(79,138,255,0.12);
  --silver:#c2d0e8;--silver2:#8a9bba;--silver3:#3e5270;
  --gold:#f5a623;--gold2:#e09020;--gold-g:rgba(245,166,35,0.1);
  --green:#00d97e;--red:#ff5c5c;--cyan:#00d9ff;
  --t1:#edf2fb;--t2:#8a9fbe;--t3:#3a5070;
  --r-sm:6px;--r-md:10px;--r-lg:16px;--r-xl:20px;
  --sh:0 12px 48px rgba(0,0,0,.8);--sh-sm:0 4px 16px rgba(0,0,0,.6);
  --glow:0 0 24px rgba(79,138,255,0.2);--glow-gold:0 0 20px rgba(245,166,35,0.18);
  --font:'Inter','Segoe UI',system-ui,sans-serif;
  --sidebar-w:272px;
  --header-h:54px;
}
html{font-size:15px;scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--t1);height:100dvh;overflow:hidden;display:flex;flex-direction:column;line-height:1.6}
::-webkit-scrollbar{width:4px;height:4px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:rgba(79,138,255,0.15);border-radius:2px}
::-webkit-scrollbar-thumb:hover{background:var(--accent)}

/* ── HEADER ──────────────────────────────────────────────── */
#app-header{
  display:flex;align-items:center;gap:10px;padding:0 16px;height:var(--header-h);
  background:rgba(3,5,10,0.97);
  border-bottom:1px solid rgba(79,138,255,0.15);
  box-shadow:0 1px 0 rgba(245,166,35,0.04),0 4px 32px rgba(0,0,0,0.7);
  flex-shrink:0;z-index:200;
  backdrop-filter:blur(24px) saturate(1.8);-webkit-backdrop-filter:blur(24px) saturate(1.8);
  position:relative;
}
/* gold shimmer line on header */
#app-header::after{
  content:'';position:absolute;bottom:-1px;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent 0%,rgba(245,166,35,0.3) 30%,rgba(79,138,255,0.4) 60%,transparent 100%);
}
.logo-wrap{display:flex;align-items:center;gap:9px;text-decoration:none;transition:filter .25s}
.logo-wrap:hover{filter:drop-shadow(0 0 12px rgba(79,138,255,0.5))}
.logo-icon{display:none}
.logo-text{
  font-size:.85rem;font-weight:800;letter-spacing:-.2px;white-space:nowrap;
  background:linear-gradient(135deg,var(--silver) 0%,var(--accent) 60%,var(--gold) 100%);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;
}
.logo-sub{font-size:.62rem;color:var(--silver3);letter-spacing:.02em}
.header-sep{width:1px;height:26px;background:linear-gradient(180deg,transparent,rgba(79,138,255,0.2),transparent);flex-shrink:0}
#header-prog{flex:1;max-width:260px;display:flex;align-items:center;gap:8px}
.prog-track{flex:1;height:3px;background:rgba(79,138,255,0.08);border-radius:2px;overflow:hidden}
.prog-fill{
  height:100%;
  background:linear-gradient(90deg,var(--accent),var(--accent-l),var(--gold));
  border-radius:2px;transition:width .6s cubic-bezier(.4,0,.2,1);width:0%;
  box-shadow:0 0 10px rgba(79,138,255,0.4);
}
.prog-label{font-size:.66rem;color:var(--t3);white-space:nowrap;font-variant-numeric:tabular-nums}
.header-right{margin-left:auto;display:flex;align-items:center;gap:6px}
#menu-toggle{
  display:none;background:none;border:1px solid rgba(79,138,255,0.2);
  color:var(--silver2);width:34px;height:34px;border-radius:var(--r-sm);
  cursor:pointer;font-size:1rem;align-items:center;justify-content:center;
  transition:all .2s;
}
#menu-toggle:hover{border-color:var(--accent);color:var(--t1);background:rgba(79,138,255,0.08)}
#voice-indicator{width:7px;height:7px;border-radius:50%;background:var(--t3);transition:all .3s;flex-shrink:0}
#voice-indicator.active{background:var(--gold);box-shadow:0 0 8px var(--gold);animation:pdot 1s infinite}
@keyframes pdot{0%,100%{opacity:1;transform:scale(1)}50%{opacity:.6;transform:scale(1.6)}}
#voice-toggle-btn{
  padding:4px 11px;font-size:.72rem;
  background:rgba(10,16,28,0.9);border:1px solid rgba(79,138,255,0.18);
  color:var(--t1);border-radius:20px;cursor:pointer;transition:all .2s;white-space:nowrap;
}
#voice-toggle-btn:hover{border-color:var(--accent);color:var(--accent)}
#voice-toggle-btn.muted{opacity:.4}
#voice-panel-btn{
  padding:4px 9px;font-size:.72rem;
  background:rgba(10,16,28,0.9);border:1px solid rgba(79,138,255,0.14);
  color:var(--t2);border-radius:var(--r-sm);cursor:pointer;transition:all .2s;
}
#voice-panel-btn:hover{border-color:var(--gold);color:var(--gold)}

/* ── VOICE PANEL ──────────────────────────────────────────── */
#voice-panel{
  position:absolute;top:calc(var(--header-h) + 4px);right:12px;width:268px;
  background:linear-gradient(160deg,rgba(8,13,22,0.99),rgba(10,16,28,0.98));
  border:1px solid rgba(79,138,255,0.2);border-radius:var(--r-xl);
  padding:16px;z-index:300;display:none;
  box-shadow:var(--sh),0 0 0 1px rgba(245,166,35,0.04);
  backdrop-filter:blur(20px);
}
#voice-panel::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;border-radius:var(--r-xl) var(--r-xl) 0 0;
  background:linear-gradient(90deg,transparent,rgba(245,166,35,0.25),transparent)}
#voice-panel.open{display:block}
.vp-title{font-size:.72rem;font-weight:700;color:var(--gold);text-transform:uppercase;letter-spacing:.1em;margin-bottom:12px;display:flex;align-items:center;gap:6px}
.vp-row{display:flex;align-items:center;gap:8px;margin-bottom:10px;font-size:.78rem;color:var(--t2)}
.vp-row label{min-width:50px;font-weight:500}
.vp-row input[type=range]{flex:1;accent-color:var(--gold)}
.voice-gender-btns{display:flex;gap:6px;margin-bottom:10px}
.voice-gender-btn{
  flex:1;padding:7px;font-size:.75rem;
  background:rgba(10,16,28,0.9);border:1px solid rgba(79,138,255,0.15);
  color:var(--t2);border-radius:var(--r-sm);cursor:pointer;transition:all .2s;text-align:center;
}
.voice-gender-btn.active{
  background:linear-gradient(135deg,rgba(245,166,35,0.12),rgba(79,138,255,0.1));
  border-color:var(--gold);color:var(--gold);font-weight:700;
}
#voice-select{
  width:100%;background:rgba(10,16,28,0.9);
  border:1px solid rgba(79,138,255,0.15);color:var(--t1);
  padding:6px 8px;border-radius:var(--r-sm);font-size:.75rem;margin-top:6px;
}

/* ── LAYOUT ──────────────────────────────────────────────── */
#app-body{display:flex;flex:1;overflow:hidden;position:relative}

/* ── SIDEBAR ─────────────────────────────────────────────── */
#sidebar{
  width:var(--sidebar-w);
  background:linear-gradient(180deg,rgba(4,7,14,0.99),rgba(3,5,10,0.99));
  border-right:1px solid rgba(79,138,255,0.1);
  display:flex;flex-direction:column;flex-shrink:0;overflow:hidden;
  transition:transform .28s cubic-bezier(.4,0,.2,1);
}
/* sidebar top shimmer */
#sidebar::before{
  content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(245,166,35,0.15),transparent);
  z-index:1;
}
.sidebar-search{padding:10px 12px;border-bottom:1px solid rgba(79,138,255,0.08);position:relative}
.sidebar-search input{
  width:100%;background:rgba(10,16,28,0.9);
  border:1px solid rgba(79,138,255,0.14);border-radius:var(--r-sm);
  padding:7px 8px 7px 28px;color:var(--t1);font-size:.78rem;outline:none;transition:all .2s;
}
.sidebar-search input:focus{border-color:var(--accent);box-shadow:0 0 0 2px rgba(79,138,255,0.08)}
.search-icon{position:absolute;left:20px;top:50%;transform:translateY(-50%);font-size:.72rem;color:var(--t3);pointer-events:none}
#module-list{flex:1;overflow-y:auto;padding:4px 0}
.module-item{cursor:pointer;user-select:none}
.module-header{display:flex;align-items:center;gap:8px;padding:9px 12px;transition:background .15s}
.module-header:hover{background:rgba(79,138,255,0.05)}
.module-item.active>.module-header,.module-item.open>.module-header{background:rgba(79,138,255,0.07)}
.module-icon{width:28px;height:28px;border-radius:var(--r-sm);display:flex;align-items:center;justify-content:center;font-size:13px;flex-shrink:0}
.module-meta{flex:1;min-width:0}
.module-title{font-size:.78rem;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--t1)}
.module-duration{font-size:.65rem;color:var(--t3)}
.module-chevron{font-size:.6rem;color:var(--t3);transition:transform .22s;flex-shrink:0}
.module-item.open .module-chevron{transform:rotate(90deg)}
.mod-prog-mini{height:2px;background:rgba(79,138,255,0.08);margin:0 12px 2px;border-radius:1px;overflow:hidden}
.mod-prog-fill{height:100%;border-radius:1px;transition:width .4s;background:linear-gradient(90deg,var(--accent),var(--gold))}
.lesson-list{display:none;background:rgba(2,4,9,0.5);border-top:1px solid rgba(79,138,255,0.06)}
.module-item.open .lesson-list{display:block}
.lesson-item{
  display:flex;align-items:center;gap:8px;
  padding:7px 12px 7px 20px;cursor:pointer;
  transition:all .15s;font-size:.76rem;color:var(--t2);
  border-left:2px solid transparent;
}
.lesson-item:hover{background:rgba(79,138,255,0.06);color:var(--t1)}
.lesson-item.active{
  background:linear-gradient(90deg,rgba(79,138,255,0.1),transparent);
  color:var(--accent);border-left-color:var(--accent);
}
.lesson-item.completed{color:var(--green)}
.lesson-item.completed .lesson-check{background:var(--green);border-color:var(--green);color:#000}
.lesson-item.active .lesson-check{border-color:var(--accent)}
.lesson-check{width:16px;height:16px;border-radius:50%;border:1.5px solid rgba(79,138,255,0.2);display:flex;align-items:center;justify-content:center;font-size:8px;flex-shrink:0;transition:all .2s}
.lesson-item-title{flex:1;line-height:1.3}

/* ── SIDEBAR OVERLAY (mobile) ─────────────────────────────── */
#sidebar-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,0.72);z-index:149;backdrop-filter:blur(2px)}

/* ── MAIN ─────────────────────────────────────────────────── */
#main-content{flex:1;display:flex;flex-direction:column;overflow:hidden;background:var(--bg);min-width:0}

/* ── WELCOME ─────────────────────────────────────────────── */
#welcome-screen{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:32px 20px;text-align:center;overflow-y:auto}
.welcome-logo{font-size:2.5rem;margin-bottom:16px}
.welcome-title{
  font-size:clamp(1.3rem,4vw,2rem);font-weight:800;margin-bottom:8px;
  background:linear-gradient(135deg,var(--silver) 0%,var(--accent-l) 40%,var(--gold) 100%);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;
}
.welcome-sub{color:var(--t2);font-size:.88rem;margin-bottom:24px;max-width:500px;line-height:1.7}
.welcome-stats{display:flex;gap:24px;margin-bottom:28px;flex-wrap:wrap;justify-content:center}
.w-stat{display:flex;flex-direction:column;align-items:center;gap:3px}
.w-stat-num{font-size:1.6rem;font-weight:800;background:linear-gradient(135deg,var(--accent-l),var(--gold));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;}
.w-stat-label{font-size:.65rem;color:var(--t3);text-transform:uppercase;letter-spacing:.06em}
.welcome-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(120px,1fr));gap:10px;max-width:700px;width:100%}
.welcome-card{
  background:linear-gradient(145deg,rgba(10,16,28,0.96),rgba(8,13,22,0.94));
  border:1px solid rgba(79,138,255,0.12);border-radius:var(--r-lg);
  padding:14px 10px;cursor:pointer;transition:all .22s;text-align:center;
  position:relative;overflow:hidden;
}
.welcome-card::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(245,166,35,0.2),transparent);opacity:0;transition:opacity .22s}
.welcome-card:hover{border-color:rgba(245,166,35,0.3);transform:translateY(-2px);box-shadow:0 8px 24px rgba(0,0,0,0.5),var(--glow-gold)}
.welcome-card:hover::before{opacity:1}
.wc-icon{font-size:1.4rem;margin-bottom:6px}
.wc-title{font-size:.68rem;font-weight:600;color:var(--t2);line-height:1.3}
.wc-prog{font-size:.62rem;color:var(--t3);margin-top:3px}
.btn-start{
  padding:11px 28px;
  background:linear-gradient(135deg,var(--accent),var(--accent-l));
  border:none;color:#fff;border-radius:var(--r-xl);
  font-size:.88rem;font-weight:700;cursor:pointer;margin-top:8px;
  transition:all .22s;box-shadow:0 4px 16px rgba(79,138,255,0.3);
}
.btn-start:hover{transform:translateY(-2px);box-shadow:0 8px 28px rgba(79,138,255,0.4)}

/* ── LESSON VIEW ─────────────────────────────────────────── */
#lesson-view{flex:1;display:none;flex-direction:column;overflow:hidden}
.lesson-topbar{
  display:flex;align-items:center;gap:10px;padding:10px 16px;
  background:rgba(5,8,16,0.98);border-bottom:1px solid rgba(79,138,255,0.1);
  flex-shrink:0;flex-wrap:wrap;gap:8px;
}
.lesson-breadcrumb{font-size:.7rem;color:var(--t3);display:flex;align-items:center;gap:5px;flex-wrap:wrap}
.lesson-breadcrumb span{color:var(--t2)}
.lesson-title-h{font-size:.9rem;font-weight:700;color:var(--t1);margin-top:1px}
.lesson-nav{margin-left:auto;display:flex;gap:6px;flex-shrink:0}
.nav-btn{
  padding:6px 13px;font-size:.73rem;
  background:rgba(10,16,28,0.9);border:1px solid rgba(79,138,255,0.16);
  color:var(--t1);border-radius:var(--r-sm);cursor:pointer;transition:all .2s;white-space:nowrap;
}
.nav-btn:hover:not(:disabled){border-color:var(--accent);background:rgba(79,138,255,0.08)}
.nav-btn:disabled{opacity:.25;cursor:default}
.nav-btn.primary{
  background:linear-gradient(135deg,var(--gold),var(--gold2));
  border-color:var(--gold);color:#000;font-weight:700;
  box-shadow:0 2px 12px rgba(245,166,35,0.25);
}
.nav-btn.primary:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 4px 18px rgba(245,166,35,0.35)}
#lesson-scroll{flex:1;overflow-y:auto;padding:28px 24px;max-width:860px;width:100%;margin:0 auto}

/* ── CONTENT TYPOGRAPHY ──────────────────────────────────── */
#lesson-content-area h3{
  font-size:1.05rem;font-weight:700;color:var(--t1);
  margin:24px 0 11px;padding-bottom:6px;
  border-bottom:1px solid rgba(79,138,255,0.1);
}
#lesson-content-area h3:first-child{margin-top:0}
#lesson-content-area p{color:var(--t2);margin-bottom:13px;line-height:1.78;font-size:.88rem}
#lesson-content-area strong{color:var(--t1)}
#lesson-content-area ul,#lesson-content-area ol{padding-left:18px;margin-bottom:13px}
#lesson-content-area li{color:var(--t2);margin-bottom:6px;line-height:1.65;font-size:.86rem}
#lesson-content-area table{font-size:.8rem}

/* ── CONTENT COMPONENTS ──────────────────────────────────── */
.info-box{
  background:linear-gradient(135deg,rgba(30,26,64,0.9),rgba(26,26,40,0.9));
  border:1px solid rgba(79,138,255,0.25);border-left:3px solid var(--accent);
  border-radius:var(--r-lg);padding:13px 16px;margin:16px 0;
  font-size:.84rem;color:var(--t1);line-height:1.65;
}
.warning-box{
  background:linear-gradient(135deg,rgba(42,26,10,0.9),rgba(30,24,12,0.9));
  border:1px solid rgba(245,166,35,0.25);border-left:3px solid var(--gold);
  border-radius:var(--r-lg);padding:13px 16px;margin:16px 0;
  font-size:.84rem;color:var(--t1);line-height:1.65;
}
.key-point{
  display:flex;align-items:flex-start;gap:10px;
  background:linear-gradient(135deg,rgba(10,16,28,0.95),rgba(8,13,22,0.95));
  border:1px solid rgba(79,138,255,0.14);border-radius:var(--r-lg);
  padding:13px 16px;margin:16px 0;font-size:.84rem;color:var(--t2);line-height:1.65;
  position:relative;overflow:hidden;
}
.key-point::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(245,166,35,0.15),transparent)}
.kp-icon{font-size:1.1rem;flex-shrink:0;margin-top:1px}
.compare-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}
.compare-card{
  background:linear-gradient(145deg,rgba(10,16,28,0.95),rgba(8,13,22,0.93));
  border:1px solid rgba(79,138,255,0.12);border-radius:var(--r-lg);padding:14px;font-size:.8rem;
}
.compare-card.green{border-top:2px solid var(--green)}
.compare-card.red{border-top:2px solid var(--red)}
.compare-card h4{font-size:.82rem;margin-bottom:8px;color:var(--t1);font-weight:700}
.compare-card ul{padding-left:15px}
.compare-card li{color:var(--t2);margin-bottom:4px;font-size:.78rem}
.concept-visual{display:flex;align-items:stretch;gap:10px;margin:16px 0;flex-wrap:wrap}
.cv-item{
  display:flex;align-items:flex-start;gap:9px;
  background:linear-gradient(145deg,rgba(10,16,28,0.95),rgba(8,13,22,0.93));
  border:1px solid rgba(79,138,255,0.12);border-radius:var(--r-lg);
  padding:11px;flex:1;min-width:140px;
}
.cv-icon{font-size:1.3rem;flex-shrink:0}
.cv-text{font-size:.76rem;color:var(--t2);line-height:1.5}
.cv-text strong{color:var(--t1);display:block;margin-bottom:2px}
.cv-arrow{color:var(--gold);font-size:1.1rem;flex-shrink:0;align-self:center}
.step-list{margin:16px 0}
.step-item{display:flex;align-items:flex-start;gap:11px;margin-bottom:12px}
.step-num{
  width:26px;height:26px;border-radius:50%;
  background:linear-gradient(135deg,var(--accent),var(--accent-l));
  color:#fff;font-size:.72rem;font-weight:700;
  display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:1px;
  box-shadow:0 2px 8px rgba(79,138,255,0.3);
}
.step-content{flex:1}
.step-content strong{color:var(--t1);font-size:.85rem}
.step-content p{color:var(--t2);font-size:.8rem;margin:3px 0 0}
.chart-container{
  background:linear-gradient(145deg,rgba(10,16,28,0.95),rgba(8,13,22,0.93));
  border:1px solid rgba(79,138,255,0.12);border-radius:var(--r-lg);
  padding:16px;margin:16px 0;overflow-x:auto;
}
.chart-container svg{display:block}
.def-box{
  background:linear-gradient(145deg,rgba(10,16,28,0.95),rgba(8,13,22,0.93));
  border:1px solid rgba(79,138,255,0.12);border-radius:var(--r-lg);
  padding:13px 16px;margin:11px 0;
}
.def-term{font-weight:700;color:var(--gold);font-size:.84rem;margin-bottom:3px}
.def-desc{color:var(--t2);font-size:.8rem;line-height:1.65}

/* ── QUIZ ─────────────────────────────────────────────────── */
#quiz-section{
  background:linear-gradient(145deg,rgba(10,16,28,0.97),rgba(8,13,22,0.95));
  border:1px solid rgba(79,138,255,0.15);border-radius:var(--r-xl);
  padding:22px;margin-top:26px;margin-bottom:16px;
  position:relative;overflow:hidden;
}
#quiz-section::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(245,166,35,0.3),rgba(79,138,255,0.3),transparent)}
.quiz-title{font-size:.7rem;font-weight:800;text-transform:uppercase;letter-spacing:.1em;
  color:var(--gold);margin-bottom:14px;display:flex;align-items:center;gap:6px}
.quiz-question{font-size:.92rem;font-weight:600;color:var(--t1);margin-bottom:16px;line-height:1.55}
.quiz-options{display:flex;flex-direction:column;gap:8px}
.quiz-option{
  display:flex;align-items:center;gap:10px;padding:11px 14px;
  background:rgba(8,13,22,0.8);border:1.5px solid rgba(79,138,255,0.12);
  border-radius:var(--r-lg);cursor:pointer;transition:all .2s;
  font-size:.83rem;color:var(--t2);
}
.quiz-option:hover:not(.answered){border-color:rgba(79,138,255,0.4);background:rgba(79,138,255,0.06);color:var(--t1)}
.quiz-option.selected{border-color:var(--accent);background:rgba(79,138,255,0.1);color:var(--accent)}
.quiz-option.correct{border-color:var(--green);background:rgba(0,217,126,0.08);color:var(--green)}
.quiz-option.wrong{border-color:var(--red);background:rgba(255,92,92,0.07);color:var(--red)}
.option-letter{
  width:24px;height:24px;border-radius:50%;border:1.5px solid currentColor;
  display:flex;align-items:center;justify-content:center;
  font-size:.7rem;font-weight:700;flex-shrink:0;
}
.quiz-submit-btn{
  margin-top:14px;padding:9px 20px;
  background:linear-gradient(135deg,var(--gold),var(--gold2));
  border:none;color:#000;border-radius:var(--r-lg);
  font-size:.82rem;font-weight:700;cursor:pointer;transition:all .22s;
  box-shadow:0 2px 12px rgba(245,166,35,0.25);
}
.quiz-submit-btn:hover{transform:translateY(-1px);box-shadow:0 4px 18px rgba(245,166,35,0.35)}
.quiz-submit-btn:disabled{opacity:.35;cursor:default;transform:none}
.quiz-explanation{
  display:none;margin-top:13px;padding:12px 15px;
  background:rgba(8,13,22,0.8);border:1px solid rgba(79,138,255,0.12);
  border-radius:var(--r-lg);font-size:.8rem;color:var(--t2);line-height:1.65;
}
.quiz-explanation.show{display:block}

/* ── EXERCISE ─────────────────────────────────────────────── */
.exercise-block{
  background:linear-gradient(145deg,rgba(16,20,42,0.95),rgba(12,16,34,0.95));
  border:1px solid rgba(79,138,255,0.2);border-radius:var(--r-xl);
  padding:20px;margin:20px 0;position:relative;overflow:hidden;
}
.exercise-block::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(79,138,255,0.4),transparent)}
.ex-badge{
  display:inline-flex;align-items:center;gap:5px;
  background:rgba(79,138,255,0.1);border:1px solid rgba(79,138,255,0.25);
  border-radius:12px;padding:3px 10px;font-size:.68rem;font-weight:700;
  color:var(--accent);margin-bottom:10px;
}
.ex-title{font-size:.9rem;font-weight:700;color:var(--t1);margin-bottom:8px}
.ex-instructions{font-size:.83rem;color:var(--t2);line-height:1.72;margin-bottom:10px}
.ex-tips{font-size:.78rem;color:var(--t3);border-left:2px solid var(--gold);padding-left:10px;margin-top:8px;line-height:1.65}
.ex-tips::before{content:'💡 ';color:var(--gold)}

/* ── MODULE COMPLETE ─────────────────────────────────────── */
.mod-complete{
  background:linear-gradient(145deg,rgba(0,80,50,0.12),rgba(0,60,40,0.08));
  border:1px solid rgba(0,217,126,0.25);border-radius:var(--r-xl);
  padding:22px;margin:20px 0;text-align:center;position:relative;overflow:hidden;
}
.mod-complete::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(0,217,126,0.4),transparent)}
.mod-complete .mc-icon{font-size:2.2rem;margin-bottom:8px}
.mod-complete .mc-title{font-size:1rem;font-weight:800;color:var(--green);margin-bottom:5px}
.mod-complete .mc-sub{font-size:.82rem;color:var(--t2)}

/* ── TOAST ────────────────────────────────────────────────── */
#toast-container{position:fixed;bottom:16px;right:16px;z-index:9999;display:flex;flex-direction:column;gap:7px;pointer-events:none}
.toast{
  background:linear-gradient(145deg,rgba(10,16,28,0.98),rgba(8,13,22,0.97));
  border:1px solid rgba(79,138,255,0.18);border-left:3px solid var(--accent);
  border-radius:var(--r-lg);padding:10px 16px;font-size:.8rem;color:var(--t1);
  box-shadow:var(--sh);animation:ti .3s ease,to .3s ease 2.7s forwards;max-width:270px;
  backdrop-filter:blur(12px);
}
.toast.success{border-left-color:var(--green)}
.toast.error{border-left-color:var(--red)}
@keyframes ti{from{transform:translateX(110%);opacity:0}to{transform:translateX(0);opacity:1}}
@keyframes to{from{opacity:1}to{opacity:0;transform:translateX(110%)}}

/* ── SIDEBAR TOOLS LINK ──────────────────────────────────── */
.sidebar-tools-link{
  display:flex;align-items:center;gap:8px;margin:8px 10px 4px;
  padding:9px 14px;
  background:linear-gradient(135deg,rgba(245,166,35,0.07),rgba(79,138,255,0.07));
  border:1px solid rgba(245,166,35,0.18);border-radius:var(--r-md);
  font-size:.82rem;font-weight:600;color:var(--gold);text-decoration:none;
  transition:all .2s;
}
.sidebar-tools-link:hover{background:linear-gradient(135deg,rgba(245,166,35,0.14),rgba(79,138,255,0.1));border-color:var(--gold)}
.stl-badge{
  margin-left:auto;font-size:.62rem;font-weight:700;letter-spacing:.06em;
  background:linear-gradient(135deg,var(--gold),var(--gold2));color:#000;
  padding:2px 7px;border-radius:20px;
}

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media(max-width:768px){
  :root{--sidebar-w:82vw;--header-h:50px}
  #menu-toggle{display:flex}
  #sidebar{
    position:fixed;left:0;top:var(--header-h);
    height:calc(100dvh - var(--header-h));
    z-index:150;transform:translateX(-100%);
    box-shadow:8px 0 40px rgba(0,0,0,0.8);
  }
  #sidebar.open{transform:translateX(0)}
  #sidebar-overlay{display:block}
  #header-prog{display:none}
  #lesson-scroll{padding:16px 14px}
  .compare-grid{grid-template-columns:1fr}
  .concept-visual{flex-direction:column}
  .welcome-grid{grid-template-columns:repeat(2,1fr)}
  .lesson-topbar{padding:8px 12px}
  .lesson-nav .nav-btn{padding:5px 10px;font-size:.7rem}
}
@media(max-width:480px){
  #app-header{padding:0 10px;gap:6px}
  .logo-sub{display:none}
  .header-sep{display:none}
  .welcome-grid{grid-template-columns:repeat(2,1fr)}
  #voice-panel{right:0;left:0;border-radius:0 0 var(--r-xl) var(--r-xl);border-left:none;border-right:none}
  #lesson-scroll{padding:14px 12px}
}
@media(min-width:1200px){
  #lesson-scroll{padding:36px 44px}
  :root{--sidebar-w:290px}
}
.hidden{display:none!important}