/* =========================================================
   Chemistry Platform — optimized stylesheet
   - Mobile-first, low-end Android friendly
   - Reduced blur/glow, content-visibility for cards
   ========================================================= */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent}
:root{
  --teal:#00e5cc;--teal-glow:rgba(0,229,204,0.28);--teal-dim:rgba(0,229,204,0.10);
  --gold:#f9c74f;--red:#ff4757;--blue:#4dabf7;--green:#25d366;
  --bg:#060d14;--bg2:#0b1724;--bg3:#111f2e;--card:#0e1d2a;--card2:#142330;
  --border:rgba(0,229,204,0.16);--text:#e8f4f8;--muted:#6b8fa8;
  --radius-sm:10px;--radius:14px;--radius-lg:18px;
  --shadow-sm:0 4px 12px rgba(0,0,0,0.20);
  --shadow:0 6px 20px rgba(0,0,0,0.25);
}
html{scroll-behavior:smooth;background:var(--bg)}
body{font-family:'Cairo',system-ui,sans-serif;background:var(--bg);color:var(--text);min-height:100vh;overflow-x:hidden;-webkit-text-size-adjust:100%;text-size-adjust:100%}

/* helpers */
.c-teal{color:var(--teal)}.c-gold{color:var(--gold)}.c-red{color:var(--red)}.c-green{color:var(--green)}
.is-hidden{display:none !important}
[hidden]{display:none !important}
.num-input{direction:ltr;text-align:center;font-family:inherit}
.mono-input{font-family:ui-monospace,monospace;letter-spacing:3px;text-align:center;direction:ltr}

/* ===== SPLASH ===== */
.splash{position:fixed;inset:0;background:var(--bg);z-index:9999;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:18px;transition:opacity .35s ease}
.splash.hide{opacity:0;pointer-events:none}
.splash-logo{width:64px;height:64px;border-radius:18px;background:linear-gradient(135deg,var(--teal),#009688);display:flex;align-items:center;justify-content:center;font-size:1.7rem;box-shadow:0 0 26px var(--teal-glow)}
.splash-spin{width:34px;height:34px;border:3px solid var(--teal-dim);border-top-color:var(--teal);border-radius:50%;animation:spin .9s linear infinite}
.splash-text{color:var(--muted);font-size:.85rem;font-weight:700}
@keyframes spin{to{transform:rotate(360deg)}}

/* ===== BG (lightweight) ===== */
.bg-canvas{position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden}
.grid-lines{position:absolute;inset:0;background-image:linear-gradient(rgba(0,229,204,0.025) 1px,transparent 1px),linear-gradient(90deg,rgba(0,229,204,0.025) 1px,transparent 1px);background-size:60px 60px}
.orb{position:absolute;border-radius:50%;filter:blur(70px);opacity:.10;will-change:transform}
.orb1{width:380px;height:380px;background:var(--teal);top:-160px;right:-90px}
.orb2{width:280px;height:280px;background:#4040c0;bottom:-100px;left:-70px}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none !important;transition:none !important}
}
@media (max-width:480px){
  /* Drop second orb on small mobiles for perf */
  .orb2{display:none}
  .grid-lines{background-size:80px 80px}
}

/* ===== HEADER ===== */
.site-header{position:relative;z-index:10;padding:18px 16px 14px;background:linear-gradient(180deg,rgba(0,229,204,0.06),transparent);border-bottom:1px solid var(--border)}
.header-inner{max-width:580px;margin:0 auto;display:flex;align-items:center;justify-content:center}
.header-brand{display:flex;align-items:center;gap:10px}
.logo-icon{width:44px;height:44px;background:linear-gradient(135deg,var(--teal),#009688);border-radius:13px;display:flex;align-items:center;justify-content:center;font-size:1.25rem;box-shadow:0 0 18px var(--teal-glow);flex-shrink:0}
.header-titles h1{font-size:1.05rem;font-weight:900;color:#fff;line-height:1.2}
.header-titles .sub{color:var(--teal);font-size:.65rem;letter-spacing:1.5px;font-weight:700}

/* ===== PROFILE BAR ===== */
.profile-section{position:relative;z-index:10;animation:fadeUp .35s ease both}
.profile-wrap{max-width:580px;margin:0 auto;padding:12px 16px 4px}
.profile-card{
  background:linear-gradient(135deg,rgba(0,229,204,0.08),rgba(249,199,79,0.04));
  border:1px solid var(--border);
  border-radius:18px;padding:12px;
  display:flex;flex-direction:column;gap:10px;
  box-shadow:var(--shadow-sm)
}
.profile-top{display:flex;align-items:center;gap:12px}
.profile-av{
  width:48px;height:48px;min-width:48px;border-radius:14px;
  background:linear-gradient(135deg,var(--teal),#009688);
  display:flex;align-items:center;justify-content:center;
  font-weight:900;color:var(--bg);font-size:1.15rem;
  box-shadow:0 0 14px var(--teal-glow)
}
.profile-meta{flex:1;min-width:0}
.profile-name{display:flex;align-items:center;gap:6px;font-size:1rem;font-weight:800;color:#fff;line-height:1.25}
.profile-name-text{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:100%}
.verified{color:var(--teal);font-size:.78rem;flex-shrink:0}
.profile-sub{margin-top:3px;font-size:.72rem;color:var(--muted);font-weight:600;display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.profile-sub .chip{display:inline-flex;align-items:center;gap:5px;background:var(--teal-dim);color:var(--teal);padding:2px 9px;border-radius:20px;font-size:.68rem;font-weight:700;border:1px solid rgba(0,229,204,0.18)}
.profile-sub .dot{width:3px;height:3px;border-radius:50%;background:var(--muted);opacity:.6}
.profile-phone{direction:ltr;font-weight:700}
.profile-logout{
  width:36px;height:36px;border-radius:11px;flex-shrink:0;
  border:1px solid rgba(255,71,87,0.25);background:rgba(255,71,87,0.08);
  color:var(--red);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:.9rem;transition:transform .15s,background .15s
}
.profile-logout:active{transform:scale(.94)}

.profile-bottom{display:flex;align-items:center;justify-content:space-between;gap:10px;background:rgba(6,13,20,0.4);border:1px solid rgba(249,199,79,0.18);border-radius:13px;padding:9px 11px}
.balance-block{display:flex;align-items:center;gap:10px;min-width:0}
.balance-ico{width:32px;height:32px;border-radius:10px;background:linear-gradient(135deg,rgba(249,199,79,0.18),rgba(249,199,79,0.05));border:1px solid rgba(249,199,79,0.25);display:flex;align-items:center;justify-content:center;color:var(--gold);font-size:.82rem;flex-shrink:0}
.balance-label{font-size:.68rem;color:var(--muted);font-weight:700;line-height:1.1}
.balance-amount{font-size:1.05rem;font-weight:900;color:var(--gold);line-height:1.2;margin-top:2px}
.profile-actions{display:flex;align-items:center;gap:6px}
.btn-ghost{width:34px;height:34px;border-radius:10px;border:1px solid var(--border);background:transparent;color:var(--muted);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:.85rem;transition:color .15s,background .15s}
.btn-ghost:active{transform:scale(.94)}
.recharge-btn{display:flex;align-items:center;gap:6px;padding:8px 13px;border:1px solid rgba(249,199,79,0.35);background:linear-gradient(135deg,rgba(249,199,79,0.16),rgba(249,199,79,0.05));border-radius:10px;color:var(--gold);font-family:inherit;font-size:.78rem;font-weight:800;cursor:pointer;white-space:nowrap;transition:transform .15s}
.recharge-btn:active{transform:scale(.96)}

/* ===== CONTAINER + SCREENS ===== */
.container{max-width:580px;margin:0 auto;padding:24px 16px;position:relative;z-index:10}
.screen{display:none}
.screen.active{display:block}
.sec-hdr{text-align:center;margin-bottom:24px;animation:fadeUp .35s ease both}
.sec-hdr h2{font-size:1.3rem;font-weight:800;color:#fff}
.sec-hdr p{color:var(--muted);font-size:.85rem;margin-top:5px}
.divider{width:48px;height:3px;margin:10px auto 0;background:linear-gradient(90deg,var(--teal),var(--gold));border-radius:10px}
@keyframes fadeUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}

/* ===== TABS ===== */
.tabs{display:flex;gap:6px;background:var(--bg3);border-radius:13px;padding:5px;margin-bottom:18px;position:relative;border:1px solid var(--border)}
.tab{flex:1;padding:10px;border:none;background:transparent;color:var(--muted);font-family:inherit;font-size:.82rem;font-weight:700;cursor:pointer;border-radius:9px;transition:color .25s;position:relative;z-index:2;display:flex;align-items:center;justify-content:center;gap:5px}
.tab.active{color:var(--bg)}
.tab-indicator{position:absolute;top:5px;bottom:5px;background:linear-gradient(135deg,var(--teal),#00b39e);border-radius:9px;transition:right .35s cubic-bezier(.34,1.56,.64,1),width .35s cubic-bezier(.34,1.56,.64,1);z-index:1;box-shadow:0 4px 12px var(--teal-glow)}
.admin-tabs{flex-wrap:wrap}
.admin-tabs .tab{flex:1 1 30%;font-size:.76rem;padding:9px 6px}

/* ===== AUTH FORMS ===== */
.auth-form{animation:fadeUp .35s ease both}
.card{background:linear-gradient(180deg,var(--card),var(--card2));border:1px solid var(--border);border-radius:18px;padding:22px 18px;margin-bottom:14px;box-shadow:var(--shadow)}
.field{margin-bottom:13px}
.field label{display:flex;align-items:center;gap:6px;font-size:.74rem;color:var(--muted);font-weight:700;margin-bottom:6px}
.field input,.field select{width:100%;padding:12px 14px;background:var(--bg3);border:1px solid var(--border);border-radius:11px;color:var(--text);font-family:inherit;font-size:.92rem;transition:border-color .2s,box-shadow .2s}
.field input:focus,.field select:focus{outline:none;border-color:var(--teal);box-shadow:0 0 0 3px var(--teal-dim);background:var(--bg2)}
.field input::placeholder{color:var(--muted);opacity:.5}
.field input.error{border-color:var(--red);box-shadow:0 0 0 3px rgba(255,71,87,0.15);animation:shake .35s}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}
.field-hint{font-size:.7rem;color:var(--muted);margin-top:5px;display:flex;align-items:center;gap:5px;min-height:14px}
.field-hint.ok{color:var(--teal)}.field-hint.bad{color:var(--red)}

.pw-wrap{position:relative}
.pw-wrap input{padding-left:42px !important}
.pw-toggle{position:absolute;left:8px;top:50%;transform:translateY(-50%);width:30px;height:30px;border:none;background:transparent;color:var(--muted);cursor:pointer;border-radius:8px;display:flex;align-items:center;justify-content:center;transition:color .15s}
.pw-toggle:active{transform:translateY(-50%) scale(.9)}

/* ===== BUTTONS ===== */
.btn-primary{width:100%;padding:13px;border:none;border-radius:13px;background:linear-gradient(135deg,var(--teal),#009688);color:var(--bg);font-family:inherit;font-size:.98rem;font-weight:800;cursor:pointer;transition:transform .15s,box-shadow .2s;box-shadow:0 4px 14px var(--teal-glow);display:flex;align-items:center;justify-content:center;gap:8px;position:relative}
.btn-primary:active{transform:scale(.98)}
.btn-primary:disabled{opacity:.65;cursor:not-allowed}
.btn-primary.loading{pointer-events:none}
.btn-primary.loading .btn-label{opacity:0}
.btn-primary .spinner{position:absolute;width:20px;height:20px;border:3px solid rgba(6,13,20,0.2);border-top-color:var(--bg);border-radius:50%;animation:spin .8s linear infinite;opacity:0}
.btn-primary.loading .spinner{opacity:1}
.btn-gold{background:linear-gradient(135deg,var(--gold),#e67e22) !important;color:#1a0a00 !important}
.btn-red{background:linear-gradient(135deg,#ff6b7a,#c0392b) !important;color:#fff !important}
.btn-teal{padding:9px 14px;border:none;border-radius:9px;background:linear-gradient(135deg,var(--teal),#009688);color:var(--bg);font-family:inherit;font-weight:800;font-size:.82rem;cursor:pointer;white-space:nowrap;display:flex;align-items:center;gap:5px;transition:transform .15s}
.btn-teal:active{transform:scale(.96)}
.btn-secondary{width:100%;padding:11px;border:1px solid var(--border);border-radius:12px;background:transparent;color:var(--muted);font-family:inherit;font-size:.88rem;font-weight:700;cursor:pointer;transition:background .2s,color .2s;margin-top:8px}
.btn-secondary:active{transform:scale(.98)}
.btn-danger{padding:8px 14px;border:1px solid rgba(255,71,87,0.3);border-radius:10px;background:rgba(255,71,87,0.08);color:var(--red);font-family:inherit;font-size:.8rem;font-weight:700;cursor:pointer;transition:background .15s}
.btn-danger:active{transform:scale(.96)}
.link-btn{width:100%;padding:9px;border:1px solid rgba(0,229,204,0.2);border-radius:11px;background:transparent;color:var(--muted);font-family:inherit;font-size:.78rem;font-weight:700;cursor:pointer;margin-top:10px}

/* ===== STAGE CARD ===== */
.stage-card{background:var(--card);border:1px solid var(--border);border-radius:18px;padding:20px 18px;margin-bottom:12px;cursor:pointer;display:flex;align-items:center;gap:14px;transition:transform .2s,border-color .2s;animation:fadeUp .4s ease both}
.stage-card:active{transform:scale(.98)}
.stage-icon{width:50px;height:50px;min-width:50px;background:linear-gradient(135deg,rgba(0,229,204,0.18),rgba(0,229,204,0.04));border:1px solid rgba(0,229,204,0.22);border-radius:14px;display:flex;align-items:center;justify-content:center;font-size:1.35rem}
.stage-info h3{font-size:1.02rem;font-weight:800;color:#fff}
.stage-info p{font-size:.74rem;color:var(--muted);margin-top:2px}

/* ===== SEARCH + FILTERS ===== */
.search-row{display:flex;flex-direction:column;gap:8px;margin-bottom:14px}
.search-input{position:relative;display:flex;align-items:center}
.search-input i{position:absolute;right:12px;color:var(--muted);font-size:.85rem}
.search-input input{width:100%;padding:11px 36px 11px 14px;background:var(--bg3);border:1px solid var(--border);border-radius:12px;color:var(--text);font-family:inherit;font-size:.88rem;transition:border-color .2s}
.search-input input:focus{outline:none;border-color:var(--teal)}
.filter-pills{display:flex;gap:6px;flex-wrap:wrap}
.pill{padding:7px 13px;border:1px solid var(--border);background:var(--card);color:var(--muted);border-radius:20px;font-family:inherit;font-size:.74rem;font-weight:700;cursor:pointer;transition:background .15s,color .15s}
.pill.active{background:var(--teal-dim);color:var(--teal);border-color:rgba(0,229,204,0.4)}

/* ===== SESSION CARDS ===== */
.session-card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:14px;margin-bottom:10px;position:relative;animation:fadeUp .35s ease both;content-visibility:auto;contain-intrinsic-size:auto 280px}
.session-card.unlocked{border-color:rgba(0,229,204,0.30)}
.sess-thumb{position:relative;width:100%;aspect-ratio:16/9;border-radius:11px;overflow:hidden;background:linear-gradient(135deg,rgba(0,229,204,0.06),rgba(249,199,79,0.03));border:1px solid var(--border);margin-bottom:10px}
.sess-thumb img{width:100%;height:100%;object-fit:cover;display:block;opacity:0;transition:opacity .3s}
.sess-thumb img.loaded{opacity:1}
.sess-thumb .play-ico{position:absolute;inset:auto 0 0 0;height:60%;display:flex;align-items:center;justify-content:center;background:linear-gradient(180deg,transparent,rgba(0,0,0,0.55));color:#fff;font-size:1.5rem;pointer-events:none}
.sess-thumb .lock-ico{position:absolute;top:8px;right:8px;background:rgba(6,13,20,0.7);border:1px solid var(--border);color:var(--muted);width:28px;height:28px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-size:.74rem}
.sess-thumb .num-pill{position:absolute;top:8px;left:8px;background:rgba(0,229,204,0.92);color:var(--bg);font-weight:900;font-size:.74rem;padding:3px 9px;border-radius:8px}
.sess-thumb.placeholder{display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:1.6rem}
.sess-progress{position:absolute;left:0;right:0;bottom:0;height:3px;background:rgba(255,255,255,0.1)}
.sess-progress .bar{height:100%;background:linear-gradient(90deg,var(--teal),var(--gold));transition:width .25s}

.sess-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px;gap:8px}
.sess-head-left{display:flex;align-items:center;gap:9px;min-width:0}
.sess-num{background:var(--bg2);border:1px solid var(--border);color:var(--teal);font-weight:800;font-size:.85rem;width:32px;height:32px;border-radius:10px;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.sess-title{font-weight:700;font-size:.9rem;color:#fff;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.status-badge{display:flex;align-items:center;gap:4px;padding:3px 9px;border-radius:20px;font-size:.68rem;font-weight:700;flex-shrink:0}
.status-locked{background:rgba(107,143,168,0.10);color:var(--muted);border:1px solid rgba(107,143,168,0.18)}
.status-unlocked{background:rgba(0,229,204,0.10);color:var(--teal);border:1px solid rgba(0,229,204,0.25)}

.action-row{display:flex;gap:6px}
.action-btn{flex:1;padding:9px 4px;border:none;border-radius:10px;font-family:inherit;font-weight:700;font-size:.74rem;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:4px;transition:transform .15s}
.action-btn:active{transform:scale(.95)}
.btn-video{background:linear-gradient(135deg,#ff4757,#c0392b);color:#fff}
.btn-hw{background:linear-gradient(135deg,#4dabf7,#339af0);color:#fff}
.btn-test{background:linear-gradient(135deg,#f9c74f,#e67e22);color:#1a0a00}
.btn-quiz{background:linear-gradient(135deg,#a78bfa,#8b5cf6);color:#fff}
.btn-buy{background:linear-gradient(135deg,rgba(249,199,79,0.14),rgba(249,199,79,0.04));border:1px solid rgba(249,199,79,0.3);color:var(--gold);font-family:inherit;font-weight:700;font-size:.78rem;padding:9px 14px;border-radius:11px;cursor:pointer;display:flex;align-items:center;gap:6px;width:100%;justify-content:center;margin-top:8px}
.btn-buy:active{transform:scale(.97)}

/* ===== STATS ===== */
.stats-row{display:flex;gap:8px;margin-bottom:16px}
.stat{flex:1;background:var(--card);border:1px solid var(--border);border-radius:11px;padding:9px 6px;text-align:center}
.stat .val{font-size:1.15rem;font-weight:900;color:var(--teal)}
.stat .lbl{font-size:.64rem;color:var(--muted);margin-top:2px}

/* ===== CONTINUE WATCHING ===== */
.continue-row{display:flex;gap:10px;overflow-x:auto;padding-bottom:6px;margin-bottom:16px;scrollbar-width:none}
.continue-row::-webkit-scrollbar{display:none}
.continue-card{flex:0 0 200px;background:var(--card);border:1px solid var(--border);border-radius:13px;padding:10px;cursor:pointer}
.continue-card .thumb{width:100%;aspect-ratio:16/9;border-radius:9px;background:var(--bg3);margin-bottom:8px;position:relative;overflow:hidden}
.continue-card .thumb .bar{position:absolute;left:0;right:0;bottom:0;height:3px;background:rgba(255,255,255,0.1)}
.continue-card .thumb .bar i{display:block;height:100%;background:var(--teal)}
.continue-card .ttl{font-size:.78rem;font-weight:700;color:#fff;line-height:1.3}
.continue-card .meta{font-size:.66rem;color:var(--muted);margin-top:3px}

/* ===== BACK ===== */
.back-btn{display:flex;align-items:center;gap:8px;justify-content:center;width:100%;padding:12px;margin-top:14px;background:transparent;border:1px solid var(--border);border-radius:13px;color:var(--muted);font-family:inherit;font-size:.88rem;font-weight:700;cursor:pointer;transition:background .15s,color .15s}

/* ===== MODALS ===== */
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,0.72);display:none;align-items:center;justify-content:center;z-index:1000;padding:16px;animation:fadeIn .2s ease both}
.modal-bg.open{display:flex}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.modal-box{background:var(--bg2);border:1px solid rgba(0,229,204,0.22);border-radius:20px;padding:24px 20px;width:100%;max-width:360px;box-shadow:0 24px 50px rgba(0,0,0,0.45);animation:slideUp .25s cubic-bezier(.34,1.56,.64,1) both;position:relative;max-height:90vh;overflow-y:auto}
@keyframes slideUp{from{transform:translateY(30px) scale(.96);opacity:0}to{transform:none;opacity:1}}
.modal-icon{width:58px;height:58px;margin:0 auto 14px;background:var(--teal-dim);border:2px solid rgba(0,229,204,0.28);border-radius:18px;display:flex;align-items:center;justify-content:center;font-size:1.55rem}
.modal-title{text-align:center;font-size:1.15rem;font-weight:800;color:#fff;margin-bottom:4px}
.modal-sub{text-align:center;color:var(--muted);font-size:.8rem;margin-bottom:16px}
.modal-actions{display:flex;gap:8px;align-items:stretch}
.modal-actions .btn-primary{flex:2;margin:0}
.modal-actions .btn-danger{flex:1}
.modal-close{position:absolute;top:12px;left:12px;width:32px;height:32px;border:1px solid rgba(255,71,87,0.3);border-radius:10px;background:rgba(255,71,87,0.08);color:var(--red);font-size:.85rem;cursor:pointer;display:flex;align-items:center;justify-content:center}
.confirm-details{background:var(--bg3);border:1px solid rgba(249,199,79,0.15);border-radius:11px;padding:13px;margin-bottom:14px;font-size:.84rem;line-height:2}
.confirm-details .row{display:flex;justify-content:space-between}
.confirm-details .sep{height:1px;background:var(--border);margin:7px 0}

.code-input{width:100%;padding:13px;font-size:1.4rem;text-align:center;background:var(--bg3);border:2px solid rgba(0,229,204,0.2);border-radius:12px;color:var(--teal);font-family:ui-monospace,monospace;letter-spacing:5px;direction:ltr;transition:border-color .2s;margin-bottom:14px}
.code-input:focus{outline:none;border-color:var(--teal);box-shadow:0 0 0 3px var(--teal-dim)}

/* video modal */
.video-box{max-width:880px}
.video-title{font-size:.95rem;font-weight:800;color:#fff;margin:6px 36px 10px 0;text-align:center}
.video-frame{width:100%;aspect-ratio:16/9;background:#000;border-radius:12px;overflow:hidden;position:relative}
.video-frame iframe,.video-frame video{position:absolute;inset:0;width:100%;height:100%;border:none}

/* quiz modal */
.quiz-box{max-width:520px}
.quiz-header{margin-bottom:14px}
.quiz-title{font-size:1.05rem;font-weight:800;color:#fff;text-align:center;margin-bottom:8px}
.quiz-progress{height:6px;background:var(--bg3);border-radius:6px;overflow:hidden;margin-bottom:6px}
.quiz-progress-bar{height:100%;width:0%;background:linear-gradient(90deg,var(--teal),var(--gold));transition:width .3s}
.quiz-meta{font-size:.74rem;color:var(--muted);text-align:center}
.quiz-q{font-size:.95rem;font-weight:700;color:#fff;margin-bottom:14px;line-height:1.6}
.quiz-options{display:flex;flex-direction:column;gap:8px;margin-bottom:14px}
.quiz-opt{padding:12px 14px;background:var(--bg3);border:1px solid var(--border);border-radius:11px;cursor:pointer;font-family:inherit;font-size:.88rem;color:var(--text);text-align:right;transition:background .15s,border-color .15s,color .15s}
.quiz-opt:hover,.quiz-opt:active{background:var(--card2)}
.quiz-opt.selected{border-color:var(--teal);background:var(--teal-dim);color:var(--teal)}
.quiz-opt.correct{border-color:var(--teal);background:rgba(0,229,204,0.18);color:var(--teal)}
.quiz-opt.wrong{border-color:var(--red);background:rgba(255,71,87,0.15);color:var(--red)}
.quiz-result{text-align:center;padding:20px 0}
.quiz-result .score{font-size:2.2rem;font-weight:900;color:var(--teal);margin-bottom:6px}
.quiz-result .label{font-size:.85rem;color:var(--muted)}

/* tx modal */
.tx-box{max-width:480px}
.tx-list{display:flex;flex-direction:column;gap:8px;max-height:60vh;overflow-y:auto}
.tx-row{display:flex;align-items:center;gap:10px;padding:10px 12px;background:var(--bg3);border:1px solid var(--border);border-radius:11px}
.tx-row .ico{width:32px;height:32px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-size:.85rem;flex-shrink:0}
.tx-row .ico.pos{background:rgba(0,229,204,0.12);color:var(--teal)}
.tx-row .ico.neg{background:rgba(255,71,87,0.12);color:var(--red)}
.tx-row .ico.neu{background:var(--teal-dim);color:var(--muted)}
.tx-row .info{flex:1;min-width:0}
.tx-row .ttl{font-size:.85rem;font-weight:700;color:#fff}
.tx-row .meta{font-size:.68rem;color:var(--muted);margin-top:2px}
.tx-row .amt{font-size:.92rem;font-weight:800}
.tx-row .amt.pos{color:var(--teal)}
.tx-row .amt.neg{color:var(--red)}
.tx-empty{text-align:center;color:var(--muted);font-size:.85rem;padding:20px 0}

/* recharge modal */
.recharge-box{max-width:420px;padding:0;overflow:hidden;border-color:rgba(249,199,79,0.3)}
.recharge-head{background:linear-gradient(135deg,rgba(249,199,79,0.16),rgba(249,199,79,0.04));padding:20px 22px 14px;border-bottom:1px solid rgba(249,199,79,0.15);text-align:center;position:relative}
.recharge-emoji{font-size:2rem;margin-bottom:5px}
.recharge-title{font-size:1.1rem;font-weight:900;color:#fff;margin-bottom:3px}
.recharge-sub{font-size:.76rem;color:rgba(249,199,79,0.85)}
.recharge-body{padding:16px 18px 20px;overflow-y:auto;max-height:70vh}
.steps{display:flex;flex-direction:column;gap:7px;margin-bottom:14px}
.step-row{display:flex;align-items:center;gap:10px;background:var(--bg3);border:1px solid rgba(249,199,79,0.1);border-radius:11px;padding:10px 13px;font-size:.8rem;color:var(--text)}
.step-grow{flex:1}
.step-num{width:26px;height:26px;min-width:26px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-size:.75rem;font-weight:900;background:rgba(0,229,204,0.10);border:1px solid rgba(0,229,204,0.22)}
.step-num.c-red{background:rgba(230,0,0,0.12);border-color:rgba(230,0,0,0.28)}
.step-num.c-gold{background:rgba(249,199,79,0.10);border-color:rgba(249,199,79,0.28)}
.step-num.c-green{background:rgba(37,211,102,0.10);border-color:rgba(37,211,102,0.28)}
.copy-btn{display:flex;align-items:center;gap:5px;padding:5px 10px;border:1px solid rgba(0,229,204,0.3);background:var(--teal-dim);color:var(--teal);border-radius:8px;font-family:inherit;font-size:.7rem;font-weight:800;cursor:pointer;white-space:nowrap}
.divider-row{display:flex;align-items:center;gap:10px;margin:12px 0}
.divider-row::before,.divider-row::after{content:'';flex:1;height:1px;background:var(--border)}
.divider-row span{font-size:.7rem;color:var(--muted);font-weight:700}
.recharge-form{background:var(--card);border:1px solid rgba(0,229,204,0.12);border-radius:13px;padding:13px;margin-bottom:12px}
.mini-label{display:block;font-size:.68rem;color:var(--muted);font-weight:700;margin-bottom:4px;margin-top:8px}
.mini-label:first-child{margin-top:0}
.mini-input{width:100%;padding:9px 11px;background:var(--bg2);border:1px solid var(--border);border-radius:9px;color:var(--text);font-family:inherit;font-size:.84rem;transition:border-color .15s}
.mini-input:focus{outline:none;border-color:var(--teal)}
.recipient{padding:9px 12px;background:rgba(249,199,79,0.05);border:1px solid rgba(249,199,79,0.18);border-radius:9px;font-size:.84rem;color:var(--gold);font-weight:700}
.amount-wrap{position:relative}
.amount-wrap .num-input{padding:10px 36px 10px 11px !important;color:var(--gold) !important;font-size:1rem !important;font-weight:800}
.amount-suffix{position:absolute;left:11px;top:50%;transform:translateY(-50%);font-size:.76rem;color:var(--muted);font-weight:700}
.price-hint{font-size:.66rem;color:var(--teal);background:var(--teal-dim);padding:2px 7px;border-radius:20px;margin-right:6px}
.wa-link{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;padding:12px;border-radius:12px;background:linear-gradient(135deg,#25d366,#128c7e);color:#fff;font-family:inherit;font-size:.92rem;font-weight:800;text-decoration:none;box-shadow:0 4px 14px rgba(37,211,102,0.22)}

/* admin */
.admin-fab{position:fixed;bottom:20px;left:18px;z-index:500;width:44px;height:44px;background:rgba(0,229,204,0.10);border:1px solid rgba(0,229,204,0.22);border-radius:13px;display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--muted);font-size:1.05rem;transition:background .15s,color .15s}
.admin-fab:active{transform:scale(.94)}
.admin-modal-box{background:var(--bg2);border:1px solid rgba(0,229,204,0.2);border-radius:22px;padding:20px 16px;width:100%;max-width:560px;max-height:90vh;overflow-y:auto;animation:slideUp .25s cubic-bezier(.34,1.56,.64,1) both}
.admin-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.admin-title{font-size:1rem;font-weight:800;color:#fff;display:flex;align-items:center;gap:6px}
.admin-prompt{text-align:center;color:var(--muted);font-size:.85rem;margin-bottom:14px}
.admin-lock{text-align:center;color:var(--red);font-size:.78rem;margin-top:10px}
.atab{animation:fadeUp .25s ease both}
.atab-toolbar{display:flex;flex-direction:column;gap:8px;margin-bottom:12px;font-size:.82rem;color:var(--muted)}
.search-mini{font-size:.82rem}
.student-row{background:var(--bg3);border:1px solid var(--border);border-radius:11px;padding:10px 12px;margin-bottom:8px;display:flex;align-items:center;gap:10px}
.student-row .avatar{width:34px;height:34px;border-radius:9px;background:linear-gradient(135deg,var(--teal),#009688);display:flex;align-items:center;justify-content:center;font-weight:900;color:var(--bg);font-size:.85rem;flex-shrink:0}
.student-row .info{flex:1;min-width:0}
.student-row .sname{font-size:.86rem;font-weight:700;color:#fff;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.student-row .smeta{font-size:.7rem;color:var(--muted);direction:ltr;text-align:right}
.student-bal{font-size:.86rem;font-weight:800;color:var(--gold);white-space:nowrap}
.row-actions{display:flex;gap:4px;flex-wrap:wrap;justify-content:flex-end}
.add-bal-btn{padding:5px 9px;border:none;border-radius:8px;font-family:inherit;font-size:.7rem;font-weight:700;cursor:pointer;white-space:nowrap}
.btn-sm-teal{background:linear-gradient(135deg,var(--teal),#009688);color:var(--bg);border:none}
.btn-sm-gold{background:rgba(249,199,79,0.10);color:var(--gold);border:1px solid rgba(249,199,79,0.3)}
.btn-sm-red{background:rgba(255,71,87,0.10);color:var(--red);border:1px solid rgba(255,71,87,0.3)}
.btn-sm-undo{background:rgba(77,171,247,0.10);color:var(--blue);border:1px solid rgba(77,171,247,0.3)}
.custom-charge{background:var(--bg3);border:1px solid rgba(0,229,204,0.15);border-radius:11px;padding:11px;margin-top:14px}
.custom-charge-row{display:flex;gap:6px;align-items:center}
.custom-charge-row .mini-input{flex:1}

.cls-row{display:flex;flex-wrap:wrap;gap:5px;margin-bottom:12px}
.cls-btn{padding:7px 12px;border:1px solid var(--border);background:var(--card);color:var(--muted);border-radius:9px;font-family:inherit;font-size:.74rem;font-weight:700;cursor:pointer;transition:background .15s,color .15s}
.cls-btn.active{background:var(--teal-dim);color:var(--teal);border-color:rgba(0,229,204,0.4)}
.sess-editor{background:var(--bg3);border:1px solid var(--border);border-radius:12px;padding:12px;margin-bottom:8px}
.sess-editor-title{font-weight:800;color:#fff;font-size:.86rem;margin-bottom:8px;display:flex;justify-content:space-between;align-items:center}
.sess-editor-grid{display:grid;grid-template-columns:1fr 1fr;gap:7px}
.sess-editor-grid .full{grid-column:1/-1}

.upload-row{display:flex;align-items:center;gap:6px;margin-top:7px}
.upload-btn{padding:6px 11px;border:1px dashed var(--border);background:var(--bg2);color:var(--muted);border-radius:9px;font-family:inherit;font-size:.74rem;font-weight:700;cursor:pointer;display:flex;align-items:center;gap:5px}
.upload-progress{flex:1;height:5px;background:var(--bg2);border-radius:5px;overflow:hidden;display:none}
.upload-progress.show{display:block}
.upload-progress .bar{height:100%;width:0%;background:linear-gradient(90deg,var(--teal),var(--gold));transition:width .25s}

.settings-label{display:block;font-size:.74rem;font-weight:700;margin:12px 0 5px}
.settings-label:first-child{margin-top:0}

/* toast */
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(8px);padding:11px 20px;border-radius:24px;font-size:.84rem;font-weight:700;z-index:2000;opacity:0;transition:opacity .25s,transform .25s;pointer-events:none;white-space:nowrap;max-width:90vw;text-align:center}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.toast.ok{background:rgba(0,229,204,0.14);border:1px solid rgba(0,229,204,0.4);color:var(--teal)}
.toast.err{background:rgba(255,71,87,0.14);border:1px solid rgba(255,71,87,0.4);color:var(--red)}
.toast.info{background:rgba(249,199,79,0.14);border:1px solid rgba(249,199,79,0.36);color:var(--gold)}

/* skeletons */
@keyframes shimmer{0%{background-position:-380px 0}100%{background-position:380px 0}}
.skeleton{background:linear-gradient(90deg,var(--card) 0%,rgba(255,255,255,0.04) 50%,var(--card) 100%);background-size:760px 100%;animation:shimmer 1.3s linear infinite;border-radius:9px}
.sk-card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:14px;margin-bottom:10px}
.sk-thumb{width:100%;aspect-ratio:16/9;border-radius:11px;margin-bottom:10px}
.sk-line{height:11px;border-radius:6px;margin-bottom:7px}

/* scrollbars */
::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}

/* >=600 tweaks */
@media (min-width:600px){
  .search-row{flex-direction:row;align-items:center;justify-content:space-between}
  .search-input{flex:1;max-width:280px}
  .atab-toolbar{flex-direction:row;justify-content:space-between;align-items:center}
  .search-mini{max-width:240px}
}