/* ============================================================
   WATTSUP — 3lite Education
   Design System v1.0 | "Lab Terminal" Aesthetic
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Space+Mono:ital,wght@0,400;0,700;1,400&family=DM+Sans:opsz,wght@9..40,300;9..40,400;9..40,500;9..40,600;9..40,700;9..40,800&display=swap');

/* 1. ROOT VARIABLES */
:root {
  --bg:             #080a0f;
  --bg-raised:      #0d1017;
  --bg-surface:     #121620;
  --bg-elevated:    #171d2a;
  --bg-hover:       #1e2535;
  --border:         rgba(255,255,255,0.07);
  --border-mid:     rgba(255,255,255,0.12);
  --border-strong:  rgba(255,255,255,0.22);
  --text-primary:   #e8edf5;
  --text-secondary: #6b7a99;
  --text-muted:     #3d4a63;
  --cyan:    #00e5cc;
  --blue:    #3b82f6;
  --green:   #22d3a1;
  --orange:  #f59e0b;
  --red:     #ef4444;
  --purple:  #a855f7;
  --glow-cyan:   0 0 20px rgba(0,229,204,0.3), 0 0 60px rgba(0,229,204,0.1);
  --glass:         rgba(13,16,23,0.88);
  --grad-brand:    linear-gradient(135deg, #00e5cc, #3b82f6);
  --font-ui:   'DM Sans', sans-serif;
  --font-mono: 'Space Mono', monospace;
  --r-sm:  8px; --r-md: 14px; --r-lg: 20px; --r-xl: 28px; --r-2xl: 36px;
  --ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}
body.light-mode {
  --bg:#f0f2f7; --bg-raised:#f7f8fc; --bg-surface:#ffffff; --bg-elevated:#ffffff; --bg-hover:#eef0f7;
  --border:rgba(0,0,0,0.07); --border-mid:rgba(0,0,0,0.11); --border-strong:rgba(0,0,0,0.2);
  --text-primary:#111827; --text-secondary:#6b7280; --text-muted:#9ca3af;
  --cyan:#009e8e; --blue:#2563eb; --green:#059669; --orange:#d97706; --red:#dc2626; --purple:#7c3aed;
  --glow-cyan:none; --glass:rgba(255,255,255,0.92); --grad-brand:linear-gradient(135deg,#009e8e,#2563eb);
}

/* 2. RESET */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{-webkit-text-size-adjust:100%;}
body{
  font-family:var(--font-ui);font-size:15px;line-height:1.5;
  color:var(--text-primary);background:var(--bg);overflow-x:hidden;min-height:100vh;
  -webkit-font-smoothing:antialiased;
  transition:background .4s var(--ease-smooth),color .4s var(--ease-smooth);
}
img,svg{display:block;}
button{font-family:var(--font-ui);cursor:pointer;border:none;background:none;}
input,textarea,select{-webkit-user-select:text;user-select:text;}

/* 3. BACKGROUND */
.fluid-bg{position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden;}
.fluid-bg::before{
  content:'';position:absolute;inset:0;
  background-image:linear-gradient(rgba(0,229,204,.018) 1px,transparent 1px),linear-gradient(90deg,rgba(0,229,204,.018) 1px,transparent 1px);
  background-size:56px 56px;
  mask-image:radial-gradient(ellipse 90% 80% at 50% 0%,black 20%,transparent 100%);
  animation:grid-drift 50s linear infinite;
}
body.light-mode .fluid-bg::before{
  background-image:linear-gradient(rgba(0,0,0,.018) 1px,transparent 1px),linear-gradient(90deg,rgba(0,0,0,.018) 1px,transparent 1px);
  opacity:.6;
}
@keyframes grid-drift{0%{transform:translateY(0)}100%{transform:translateY(56px)}}

.aurora-orb{position:absolute;border-radius:50%;pointer-events:none;}
.aurora-orb-1{
  width:780px;height:780px;
  background:radial-gradient(circle,rgba(0,229,204,.07) 0%,transparent 65%);
  top:-20%;left:-22%;filter:blur(55px);
  animation:aurora-1 22s ease-in-out infinite alternate;
}
.aurora-orb-2{
  width:650px;height:650px;
  background:radial-gradient(circle,rgba(59,130,246,.07) 0%,transparent 65%);
  bottom:0%;right:-18%;filter:blur(60px);
  animation:aurora-2 28s ease-in-out infinite alternate;
}
.aurora-orb-3{
  width:420px;height:420px;
  background:radial-gradient(circle,rgba(168,85,247,.055) 0%,transparent 65%);
  top:38%;left:52%;filter:blur(50px);
  animation:aurora-3 34s ease-in-out infinite alternate;
}
body.light-mode .aurora-orb-1{background:radial-gradient(circle,rgba(0,158,142,.06) 0%,transparent 65%);}
body.light-mode .aurora-orb-2{background:radial-gradient(circle,rgba(37,99,235,.05) 0%,transparent 65%);}
body.light-mode .aurora-orb-3{background:radial-gradient(circle,rgba(124,58,237,.04) 0%,transparent 65%);}
@keyframes aurora-1{0%{transform:translate(0,0) scale(1)}100%{transform:translate(70px,55px) scale(1.14)}}
@keyframes aurora-2{0%{transform:translate(0,0) scale(1)}100%{transform:translate(-55px,-70px) scale(1.1)}}
@keyframes aurora-3{0%{transform:translate(0,0) scale(1)}100%{transform:translate(35px,-45px) scale(.88)}}

/* 4. LAYOUT */
.app-container{position:relative;z-index:1;width:100%;max-width:700px;margin:0 auto;padding:0 16px 56px;}

/* 5. HEADER */
.app-header{display:flex;justify-content:space-between;align-items:center;padding:20px 0 0;margin-bottom:24px;}
.brand-block{display:flex;flex-direction:column;gap:2px;}
.brand-name{font-family:var(--font-mono);font-size:13px;font-weight:700;letter-spacing:.15em;text-transform:uppercase;background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;}
.brand-sub{font-size:11px;font-weight:500;letter-spacing:.06em;color:var(--text-muted);text-transform:uppercase;}
.header-controls{display:flex;align-items:center;gap:12px;}

/* Toggle pill */
.toggle-group{display:flex;align-items:center;gap:7px;}
.toggle-pill{position:relative;width:44px;height:24px;flex-shrink:0;}
.toggle-pill input{opacity:0;width:0;height:0;position:absolute;}
.toggle-track{position:absolute;inset:0;background:var(--bg-elevated);border:1px solid var(--border-mid);border-radius:100px;cursor:pointer;transition:all .3s var(--ease-smooth);}
.toggle-track::before{content:'';position:absolute;top:3px;left:3px;width:16px;height:16px;border-radius:50%;background:var(--text-muted);transition:all .3s var(--ease-spring);}
.toggle-pill input:checked+.toggle-track{background:rgba(0,229,204,.15);border-color:rgba(0,229,204,.4);}
.toggle-pill input:checked+.toggle-track::before{transform:translateX(20px);background:var(--cyan);box-shadow:0 0 8px rgba(0,229,204,.6);}
.toggle-icon{font-size:15px;line-height:1;}

/* 6. TAB BAR */
.tab-bar-wrap{position:sticky;top:0;z-index:200;padding:8px 0 4px;margin:0 -16px;padding-left:16px;padding-right:16px;background:var(--bg);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);}
body.light-mode .tab-bar-wrap{background:rgba(240,242,247,.92);}
.tab-bar{display:flex;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-xl);padding:5px;gap:3px;}
.tab-btn{flex:1;text-align:center;padding:10px 6px;font-size:13px;font-weight:600;color:var(--text-secondary);border-radius:var(--r-lg);cursor:pointer;transition:all .2s var(--ease-smooth);white-space:nowrap;line-height:1.2;}
.tab-btn:hover:not(.active){color:var(--text-primary);background:var(--bg-hover);}
.tab-btn.active{background:linear-gradient(135deg,rgba(0,229,204,.12),rgba(59,130,246,.07));color:var(--cyan);box-shadow:0 1px 8px rgba(0,0,0,.3),0 0 0 1px rgba(0,229,204,.2),0 0 24px rgba(0,229,204,.07);}
body.light-mode .tab-btn.active{background:rgba(0,158,142,.08);box-shadow:0 1px 6px rgba(0,0,0,.08),0 0 0 1px rgba(0,158,142,.2);}
.tab-panel{display:none;animation:fade-up .35s var(--ease-smooth) both;}
.tab-panel.active{display:block;}

/* 7. PANELS */
.panel{background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--r-xl);padding:24px;margin-top:16px;position:relative;overflow:hidden;transition:border-color .35s,background .4s,box-shadow .35s;}
.panel::before{content:'';position:absolute;top:0;left:15%;right:15%;height:1px;background:linear-gradient(90deg,transparent,rgba(255,255,255,.1),transparent);}
.panel:hover{border-color:rgba(0,229,204,.14);box-shadow:0 0 0 1px rgba(0,229,204,.05),0 12px 40px rgba(0,0,0,.28),inset 0 1px 0 rgba(255,255,255,.035);}
body.light-mode .panel:hover{border-color:rgba(0,158,142,.18);box-shadow:0 4px 24px rgba(0,0,0,.08);}
.panel-first{margin-top:0;}

/* 8. TYPOGRAPHY */
.section-eyebrow{font-family:var(--font-mono);font-size:10px;font-weight:700;letter-spacing:.2em;text-transform:uppercase;background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:6px;}
.section-title{font-size:22px;font-weight:800;letter-spacing:-.5px;color:var(--text-primary);line-height:1.2;}
.section-desc{font-size:13px;color:var(--text-secondary);line-height:1.6;margin-top:4px;}
.mt-2{margin-top:8px}.mt-3{margin-top:12px}.mt-4{margin-top:16px}.mt-5{margin-top:20px}

/* App icon */
.app-icon{width:68px;height:68px;border-radius:18px;background:linear-gradient(145deg,#141c2e,#0d1117);border:1px solid rgba(0,229,204,.18);box-shadow:0 0 0 1px rgba(0,229,204,.07),0 16px 40px rgba(0,0,0,.5),inset 0 1px 0 rgba(255,255,255,.05);display:flex;align-items:center;justify-content:center;margin:0 auto 16px;position:relative;overflow:hidden;}
.app-icon::after{content:'';position:absolute;top:-30%;left:-10%;width:120%;height:60%;background:linear-gradient(to bottom,rgba(0,229,204,.07),transparent);transform:rotate(-8deg);}
.app-icon svg{z-index:1;filter:drop-shadow(0 0 8px rgba(0,229,204,.5));}
body.light-mode .app-icon{background:linear-gradient(145deg,#dde3f0,#edf0f8);border-color:rgba(0,158,142,.2);box-shadow:0 8px 24px rgba(0,0,0,.08),inset 0 1px 0 rgba(255,255,255,.9);}

/* 9. INPUTS */
.input-field{width:100%;height:48px;padding:0 14px;background:var(--bg-raised);border:1px solid var(--border-mid);border-radius:var(--r-md);font-family:var(--font-mono);font-size:14px;color:var(--text-primary);outline:none;transition:all .2s var(--ease-smooth);-webkit-appearance:none;appearance:none;}
.input-field::placeholder{color:var(--text-muted);font-family:var(--font-ui);font-size:13px;}
.input-field:focus{border-color:rgba(0,229,204,.6);background:var(--bg-surface);box-shadow:0 0 0 3px rgba(0,229,204,.08),0 0 16px rgba(0,229,204,.12);}
.input-label{font-family:var(--font-mono);font-size:10px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--text-muted);margin-bottom:6px;display:block;}
.input-wrap{display:flex;flex-direction:column;}

/* 10. BUTTONS */
.btn{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;height:48px;padding:0 20px;border-radius:var(--r-md);font-family:var(--font-ui);font-size:15px;font-weight:700;cursor:pointer;border:none;outline:none;transition:all .2s var(--ease-spring);position:relative;overflow:hidden;}
.btn:active{transform:scale(.97);}
.btn-cyan{background:var(--grad-brand);color:#030608;box-shadow:0 4px 20px rgba(0,229,204,.25),0 1px 0 rgba(255,255,255,.15) inset;overflow:hidden;}
.btn-cyan::before{content:'';position:absolute;top:0;left:-80%;width:55%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.22),transparent);transform:skewX(-18deg);pointer-events:none;}
.btn-cyan:hover{box-shadow:0 6px 32px rgba(0,229,204,.45),0 1px 0 rgba(255,255,255,.15) inset;transform:translateY(-1px);}
.btn-cyan:hover::before{animation:btn-shimmer .52s ease-in-out;}
@keyframes btn-shimmer{0%{left:-80%}100%{left:140%}}
.btn-ghost{background:transparent;border:1px solid var(--border-mid);color:var(--text-secondary);}
.btn-ghost:hover{border-color:var(--border-strong);color:var(--text-primary);}
body.light-mode .btn-cyan{color:#fff;}

/* 11. SEGMENTED CONTROL */
.seg-control{display:flex;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-md);padding:4px;gap:2px;margin-bottom:14px;}
.seg-btn{flex:1;text-align:center;padding:8px 6px;font-size:12px;font-weight:600;color:var(--text-secondary);border-radius:var(--r-sm);cursor:pointer;transition:all .2s var(--ease-smooth);white-space:nowrap;line-height:1.2;}
.seg-btn:hover:not(.active){color:var(--text-primary);background:var(--bg-hover);}
.seg-btn.active{background:var(--bg-elevated);color:var(--cyan);box-shadow:0 1px 6px rgba(0,0,0,.25),0 0 0 1px var(--border-mid);}

/* 12. RESULT CHIPS */
.results-bar{display:flex;gap:8px;margin-top:14px;flex-wrap:wrap;}
.result-chip{flex:1;min-width:70px;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-lg);padding:13px 14px;text-align:center;transition:border-color .2s,box-shadow .2s;}
.result-chip.highlight{border-color:rgba(0,229,204,.28);background:linear-gradient(145deg,rgba(0,229,204,.06),rgba(59,130,246,.03));box-shadow:0 0 0 1px rgba(0,229,204,.06),0 4px 20px rgba(0,229,204,.05);}
.result-chip-val{font-family:var(--font-mono);font-size:20px;font-weight:700;background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;line-height:1.1;}
.result-chip-label{font-family:var(--font-mono);font-size:9px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--text-muted);margin-top:5px;}

/* 13. TOAST */
#toast-container{position:fixed;top:-80px;left:50%;transform:translateX(-50%);z-index:9999;display:flex;align-items:center;gap:8px;padding:11px 20px;background:var(--bg-elevated);border:1px solid var(--border-mid);border-radius:100px;font-size:14px;font-weight:600;color:var(--text-primary);white-space:nowrap;box-shadow:0 8px 32px rgba(0,0,0,.4);transition:top .45s var(--ease-spring);}
#toast-container.show{top:20px;}
#toast-container.toast-error{border-color:rgba(239,68,68,.4);color:var(--red);}
#toast-container.toast-success{border-color:rgba(34,211,161,.4);color:var(--green);}
#toast-container.toast-info{border-color:rgba(0,229,204,.3);color:var(--cyan);}

/* 14. LOADING */
.loading-spin{width:16px;height:16px;border:2px solid rgba(0,229,204,.25);border-top-color:var(--cyan);border-radius:50%;animation:spin .6s linear infinite;flex-shrink:0;}
.loading-row{display:flex;align-items:center;gap:10px;}

/* 15. ANIMATIONS */
@keyframes fade-up{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:translateY(0)}}
@keyframes shake{0%,100%{transform:translateX(0)}20%{transform:translateX(-6px)}40%{transform:translateX(6px)}60%{transform:translateX(-4px)}80%{transform:translateX(4px)}}
@keyframes spin{to{transform:rotate(360deg)}}

/* 16. YIELD BAR */
.yield-bar-bg{height:8px;background:var(--bg-raised);border-radius:100px;margin-top:10px;overflow:hidden;border:1px solid var(--border);}
.yield-bar-fill{height:100%;background:var(--grad-brand);border-radius:100px;transition:width .6s var(--ease-spring);width:0%;}
.info-row{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:var(--text-muted);margin-top:4px;}

/* 17. TABLE */
.mw-table{width:100%;border-collapse:collapse;font-family:var(--font-mono);font-size:12px;}
.mw-table th{padding:6px 8px;border-bottom:1px solid var(--border-mid);color:var(--text-muted);font-weight:700;text-align:left;font-size:10px;letter-spacing:.1em;text-transform:uppercase;}
.mw-table td{padding:7px 8px;border-bottom:1px solid var(--border);color:var(--text-secondary);}
.mw-table td:first-child{color:var(--text-primary);font-weight:700;}
.mw-table tr:last-child td{border-bottom:none;}

/* 18. STEPPER */
.stepper{display:flex;align-items:center;gap:0;margin:16px 0 4px;}
.stepper-item{display:flex;align-items:center;gap:7px;flex-shrink:0;}
.stepper-circle{width:26px;height:26px;border-radius:50%;border:2px solid var(--border-mid);background:var(--bg-raised);display:flex;align-items:center;justify-content:center;font-family:var(--font-mono);font-size:11px;font-weight:700;color:var(--text-muted);transition:all .3s var(--ease-spring);flex-shrink:0;}
.stepper-label{font-family:var(--font-mono);font-size:10px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--text-muted);transition:color .3s;white-space:nowrap;}
.stepper-line{flex:1;height:1px;background:var(--border-mid);margin:0 8px;min-width:10px;transition:background .3s;}
.stepper-item.active .stepper-circle{border-color:var(--cyan);background:rgba(0,229,204,.12);color:var(--cyan);box-shadow:0 0 0 3px rgba(0,229,204,.12);}
.stepper-item.active .stepper-label{color:var(--cyan);}
.stepper-item.done .stepper-circle{border-color:var(--green);background:var(--green);color:#000;font-size:13px;}
.stepper-item.done .stepper-label{color:var(--green);}
.stepper-item.done + .stepper-line{background:var(--green);}

/* 19. STEP BLOCK */
.step-block{background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-lg);overflow:hidden;margin-top:14px;}
.step-items{padding:4px 16px 8px;display:flex;flex-direction:column;gap:0;}
.step-item{display:flex;align-items:baseline;gap:8px;font-family:var(--font-mono);font-size:12px;flex-wrap:wrap;padding:7px 0;border-bottom:1px solid rgba(255,255,255,.04);}
.step-item:last-child{border-bottom:none;}
.step-formula{color:var(--cyan);font-weight:700;flex-shrink:0;min-width:64px;}
.step-calc{color:var(--text-secondary);flex:1;line-height:1.6;}

/* 20. SPECIES GRID (branch cards) */
.species-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px;}
.species-card{background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-lg);padding:16px;position:relative;transition:border-color .25s,box-shadow .25s;}
.species-card:hover{border-color:var(--border-mid);}
.species-name{font-family:var(--font-mono);font-size:13px;font-weight:700;color:var(--text-primary);margin-bottom:8px;}
.value-row{display:flex;align-items:baseline;gap:5px;margin-bottom:2px;}
.value-num{font-family:var(--font-mono);font-size:19px;font-weight:700;color:var(--cyan);}
.value-unit{font-size:11px;color:var(--text-muted);}

/* 21. SLIDER */
.wu-slider{-webkit-appearance:none;appearance:none;width:100%;height:4px;border-radius:2px;background:var(--bg-elevated);border:1px solid var(--border-mid);outline:none;cursor:pointer;}
.wu-slider::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;border-radius:50%;background:var(--cyan);box-shadow:0 0 8px rgba(0,229,204,.5);cursor:pointer;transition:box-shadow .15s;}
.wu-slider::-webkit-slider-thumb:hover{box-shadow:0 0 14px rgba(0,229,204,.8);}
.wu-slider::-moz-range-thumb{width:18px;height:18px;border-radius:50%;background:var(--cyan);border:none;cursor:pointer;}
.slider-group{display:flex;flex-direction:column;gap:12px;margin-top:14px;}
.slider-row{display:flex;flex-direction:column;gap:6px;}
.slider-val-row{display:flex;align-items:center;gap:12px;}
.slider-val-row .wu-slider{flex:1;}
.slider-display{font-family:var(--font-mono);font-size:13px;font-weight:700;color:var(--cyan);min-width:64px;text-align:right;}

/* 22. FORMULA DISPLAY */
.formula-hero{text-align:center;margin:20px 0;}
.formula-main{font-family:var(--font-mono);font-size:36px;font-weight:700;background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;display:block;margin-bottom:10px;}
.formula-subs{display:flex;justify-content:center;gap:24px;font-family:var(--font-mono);font-size:14px;color:var(--text-secondary);}
.formula-trio{display:grid;grid-template-columns:1fr 1fr 1fr;gap:8px;margin-top:16px;}
.formula-card{background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-md);padding:14px 10px;text-align:center;}
.formula-card-eq{font-family:var(--font-mono);font-size:14px;font-weight:700;color:var(--cyan);display:block;margin-bottom:5px;}
.formula-card-desc{font-size:11px;color:var(--text-muted);display:block;}

/* 23. INFO GRID */
.info-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:14px;}
.info-card{background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-md);padding:12px;display:flex;flex-direction:column;gap:4px;}
.info-card-icon{font-size:18px;}
.info-card-title{font-family:var(--font-mono);font-size:11px;font-weight:700;color:var(--text-primary);}
.info-card-desc{font-size:11px;color:var(--text-muted);}

/* 24. INPUT GRID */
.input-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;}
@media(max-width:480px){.input-grid{grid-template-columns:1fr;}}

/* 25. QUIZ */
.quiz-question{font-size:17px;font-weight:700;color:var(--text-primary);margin:12px 0 16px;line-height:1.4;}
.quiz-options{display:flex;flex-direction:column;gap:8px;}
.quiz-option{background:var(--bg-raised);border:1px solid var(--border-mid);border-radius:var(--r-md);padding:14px 16px;font-size:14px;color:var(--text-secondary);cursor:pointer;transition:all .18s var(--ease-smooth);text-align:left;font-family:var(--font-ui);position:relative;}
.quiz-option:hover:not(.selected):not(.correct):not(.wrong){border-color:var(--cyan);color:var(--text-primary);background:var(--bg-elevated);}
.quiz-option.correct{border-color:var(--green);background:rgba(34,211,161,.07);color:var(--green);}
.quiz-option.wrong{border-color:var(--red);background:rgba(239,68,68,.07);color:var(--red);}
.quiz-option.selected{border-color:var(--cyan);background:rgba(0,229,204,.06);color:var(--cyan);}
.quiz-badge{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-size:16px;}

/* 26. BUILDER */
.palette-btn{padding:8px 14px;background:var(--bg-raised);border:1px solid var(--border-mid);border-radius:var(--r-sm);font-size:12px;font-weight:600;color:var(--text-secondary);cursor:pointer;transition:all .15s;font-family:var(--font-ui);}
.palette-btn:hover{border-color:var(--cyan);color:var(--cyan);}
.palette-btn.active{border-color:var(--cyan);color:var(--cyan);background:rgba(0,229,204,.08);box-shadow:0 0 0 1px rgba(0,229,204,.15);}

/* 27. CIRCUIT SVG */
.circuit-svg-wrap{background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--r-md);padding:10px;}

/* 28. BOTTOM NAV */
.bottom-nav{display:none;}
@media(max-width:640px){
  .tab-bar-wrap{display:none;}
  .bottom-nav{
    display:flex;position:fixed;bottom:0;left:0;right:0;z-index:300;
    background:var(--glass);border-top:1px solid var(--border-mid);
    backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
    padding-bottom:env(safe-area-inset-bottom);
  }
  .app-container{padding-bottom:80px;}
}
.bottom-nav-item{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;padding:10px 4px 8px;cursor:pointer;color:var(--text-muted);transition:color .2s;-webkit-tap-highlight-color:transparent;}
.bottom-nav-item.active{color:var(--cyan);}
.bottom-nav-icon{font-size:20px;line-height:1;}
.bottom-nav-label{font-family:var(--font-mono);font-size:9px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;}

/* 29. LIGHT MODE */
body.light-mode .section-eyebrow,body.light-mode .brand-name{text-shadow:none;}
html.light-mode-pending body{--bg:#f0f2f7;--bg-raised:#f7f8fc;--bg-surface:#fff;--bg-elevated:#fff;--border:rgba(0,0,0,.07);--border-mid:rgba(0,0,0,.11);--text-primary:#111827;--text-secondary:#6b7280;--text-muted:#9ca3af;--cyan:#009e8e;--blue:#2563eb;--green:#059669;--orange:#d97706;--red:#dc2626;--glow-cyan:none;--grad-brand:linear-gradient(135deg,#009e8e,#2563eb);background:#f0f2f7;color:#111827;}

/* 30. RESPONSIVE */
@media(max-width:480px){
  .app-container{padding:0 12px 36px;}
  .panel{padding:16px;border-radius:var(--r-lg);}
  .section-title{font-size:19px;}
  .formula-trio{grid-template-columns:1fr;}
  .species-grid{grid-template-columns:1fr;}
  .results-bar{flex-direction:column;}
}
@media(min-width:900px){
  .app-container{max-width:860px;padding:0 32px 56px;}
  .panel{padding:32px 36px;border-radius:var(--r-2xl);}
  .section-title{font-size:28px;}
}