/* ==========================================================================
   MyTube — Core Design System
   Fonts: Sora (display) / Inter (body) / JetBrains Mono (data & timers)
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;500;600;700;800&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root{
  --bg-primary:#09090b;
  --bg-secondary:#111114;
  --bg-card:#17171c;
  --bg-card-hover:#1c1c22;
  --bg-elevated:#1e1e24;

  --text-primary:#ffffff;
  --text-secondary:#a1a1aa;
  --text-tertiary:#6c6c77;

  --accent:#ff3b30;
  --accent-hover:#ff5148;
  --accent-soft:rgba(255,59,48,.12);
  --accent-soft-strong:rgba(255,59,48,.2);

  --success:#22c55e;
  --success-soft:rgba(34,197,94,.14);
  --warning:#f5a524;

  --border:rgba(255,255,255,.08);
  --border-strong:rgba(255,255,255,.16);

  --font-display:'Sora',sans-serif;
  --font-body:'Inter',sans-serif;
  --font-mono:'JetBrains Mono',monospace;

  --radius-sm:10px;
  --radius-md:16px;
  --radius-lg:22px;
  --radius-full:999px;

  --shadow-sm:0 2px 10px rgba(0,0,0,.25);
  --shadow-md:0 10px 30px rgba(0,0,0,.35);
  --shadow-glow:0 0 0 1px rgba(255,59,48,.15),0 8px 24px rgba(255,59,48,.18);

  --ease:cubic-bezier(.4,0,.2,1);
  --sidebar-w:236px;
  --bottomnav-h:66px;
}

[data-theme="light"]{
  --bg-primary:#f7f7f8;
  --bg-secondary:#ffffff;
  --bg-card:#ffffff;
  --bg-card-hover:#f1f1f4;
  --bg-elevated:#ffffff;
  --text-primary:#0d0d10;
  --text-secondary:#55555f;
  --text-tertiary:#8a8a94;
  --border:rgba(0,0,0,.08);
  --border-strong:rgba(0,0,0,.14);
  --shadow-sm:0 2px 10px rgba(0,0,0,.06);
  --shadow-md:0 10px 30px rgba(0,0,0,.08);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body{
  background:var(--bg-primary);
  color:var(--text-primary);
  font-family:var(--font-body);
  line-height:1.5;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
  transition:background .25s var(--ease),color .25s var(--ease);
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
button,input,select{font-family:inherit;color:inherit;}
ul{list-style:none;}
h1,h2,h3,h4{font-family:var(--font-display);letter-spacing:-.02em;line-height:1.15;}

:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px;}

@media (prefers-reduced-motion:reduce){
  *{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important;scroll-behavior:auto !important;}
}

.container{max-width:1180px;margin:0 auto;padding:0 24px;}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--font-body);font-weight:600;font-size:.94rem;
  padding:13px 24px;border-radius:var(--radius-full);border:1px solid transparent;
  cursor:pointer;transition:transform .18s var(--ease),background .18s var(--ease),box-shadow .18s var(--ease),border-color .18s var(--ease);
  white-space:nowrap;
}
.btn:active{transform:scale(.97);}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 6px 20px rgba(255,59,48,.28);}
.btn-primary:hover{background:var(--accent-hover);box-shadow:0 8px 26px rgba(255,59,48,.36);}
.btn-secondary{background:var(--bg-card);color:var(--text-primary);border-color:var(--border-strong);}
.btn-secondary:hover{background:var(--bg-card-hover);border-color:var(--accent);}
.btn-ghost{background:transparent;color:var(--text-secondary);}
.btn-ghost:hover{color:var(--text-primary);background:var(--bg-card);}
.btn-block{width:100%;}
.btn-sm{padding:9px 16px;font-size:.85rem;}
.btn-icon{width:42px;height:42px;padding:0;border-radius:var(--radius-full);background:var(--bg-card);border:1px solid var(--border);}
.btn-icon:hover{background:var(--bg-card-hover);}
.btn:disabled{opacity:.45;cursor:not-allowed;}

.icon{width:20px;height:20px;stroke:currentColor;flex-shrink:0;}

/* ---------- App Shell ---------- */
.app-shell{display:flex;min-height:100vh;}

.sidebar{
  width:var(--sidebar-w);flex-shrink:0;background:var(--bg-secondary);
  border-right:1px solid var(--border);padding:26px 18px;
  display:flex;flex-direction:column;position:sticky;top:0;height:100vh;
}
.sidebar-logo{display:flex;align-items:center;gap:10px;padding:6px 10px 30px;font-family:var(--font-display);font-weight:700;font-size:1.15rem;}
.sidebar-logo img{width:32px;height:32px;}
.sidebar-nav{display:flex;flex-direction:column;gap:4px;flex:1;}
.nav-item{
  display:flex;align-items:center;gap:12px;padding:12px 14px;border-radius:var(--radius-sm);
  color:var(--text-secondary);font-weight:500;font-size:.93rem;transition:background .16s var(--ease),color .16s var(--ease);position:relative;
}
.nav-item:hover{background:var(--bg-card);color:var(--text-primary);}
.nav-item.active{background:var(--accent-soft);color:var(--text-primary);}
.nav-item.active::before{content:'';position:absolute;left:-18px;top:50%;transform:translateY(-50%);width:3px;height:18px;background:var(--accent);border-radius:var(--radius-full);}
.sidebar-divider{height:1px;background:var(--border);margin:14px 4px;}

.main-content{flex:1;min-width:0;padding:34px 40px 100px;}
.page-header{margin-bottom:28px;}
.page-header h1{font-size:1.7rem;font-weight:700;}
.page-header p{color:var(--text-secondary);margin-top:6px;font-size:.96rem;}

/* ---------- Bottom Nav (mobile) ---------- */
.bottom-nav{
  display:none;position:fixed;bottom:0;left:0;right:0;z-index:60;
  background:rgba(17,17,20,.85);backdrop-filter:blur(18px) saturate(160%);
  border-top:1px solid var(--border);padding:8px 6px calc(env(safe-area-inset-bottom) + 6px);
  justify-content:space-around;
}
[data-theme="light"] .bottom-nav{background:rgba(255,255,255,.85);}
.bottom-nav .nav-item{flex-direction:column;gap:3px;font-size:.68rem;padding:6px 10px;flex:1;text-align:center;border-radius:12px;}
.bottom-nav .nav-item.active::before{display:none;}
.bottom-nav .nav-item.active{color:var(--accent);background:transparent;}
.bottom-nav .icon{width:22px;height:22px;margin:0 auto;}

/* ---------- Cards ---------- */
.card{
  background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-md);
  padding:20px;transition:border-color .2s var(--ease),transform .2s var(--ease),background .2s var(--ease);
}
.card:hover{border-color:var(--border-strong);}

/* ---------- Progress bar ---------- */
.progress-track{height:7px;border-radius:var(--radius-full);background:var(--border);overflow:hidden;}
.progress-fill{height:100%;border-radius:var(--radius-full);background:linear-gradient(90deg,var(--accent),#ff8a70);transition:width .5s var(--ease);}
.progress-fill.success{background:linear-gradient(90deg,#22c55e,#5be08a);}

/* ---------- Forms ---------- */
.field{margin-bottom:18px;}
.field label{display:block;font-size:.85rem;font-weight:600;color:var(--text-secondary);margin-bottom:8px;}
.input,.select{
  width:100%;background:var(--bg-secondary);border:1px solid var(--border-strong);border-radius:var(--radius-sm);
  padding:13px 16px;font-size:.95rem;color:var(--text-primary);transition:border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.input:focus,.select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft);}
.input::placeholder{color:var(--text-tertiary);}

/* ---------- Selection rows (add-content / channel) ---------- */
.add-content-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-bottom:10px;}
.add-card{padding:32px;}
.add-card .add-icon{width:52px;height:52px;border-radius:14px;background:var(--accent-soft);display:flex;align-items:center;justify-content:center;font-size:1.4rem;margin-bottom:18px;}
.add-card h2{font-size:1.15rem;font-weight:700;margin-bottom:8px;}
.add-card p{color:var(--text-secondary);font-size:.9rem;margin-bottom:20px;line-height:1.55;}
.add-card form{display:flex;flex-direction:column;gap:12px;}

.selection-panel{margin-top:30px;padding:28px;}
.selection-panel h2{font-size:1.15rem;font-weight:700;margin-bottom:4px;}
.selection-panel .panel-sub{color:var(--text-secondary);font-size:.88rem;margin-bottom:22px;}
.select-group{margin-bottom:20px;}
.select-group h4{font-size:.78rem;text-transform:uppercase;letter-spacing:.06em;color:var(--text-tertiary);margin-bottom:10px;}
.select-row{
  display:flex;align-items:center;gap:12px;padding:12px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);
  margin-bottom:8px;cursor:pointer;font-size:.9rem;font-weight:500;transition:border-color .15s var(--ease),background .15s var(--ease);
}
.select-row:hover{border-color:var(--border-strong);background:var(--bg-card-hover);}
.select-row input[type="checkbox"]{width:18px;height:18px;accent-color:var(--accent);flex-shrink:0;}
.select-row .select-count{margin-left:auto;color:var(--text-tertiary);font-size:.78rem;font-weight:400;}
.selection-actions{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;margin-top:20px;padding-top:20px;border-top:1px solid var(--border);}
.selection-actions-left{display:flex;gap:10px;}
.selected-count-label{color:var(--text-secondary);font-size:.88rem;}
.selected-count-label b{color:var(--text-primary);font-family:var(--font-mono);}

/* ---------- Toast ---------- */
.toast-stack{position:fixed;top:20px;right:20px;z-index:200;display:flex;flex-direction:column;gap:10px;}
.toast{
  display:flex;align-items:center;gap:10px;background:var(--bg-elevated);border:1px solid var(--border-strong);
  padding:14px 18px;border-radius:var(--radius-sm);box-shadow:var(--shadow-md);font-size:.88rem;font-weight:500;
  min-width:230px;animation:toastIn .3s var(--ease);
}
.toast.success{border-left:3px solid var(--success);}
.toast.warning{border-left:3px solid var(--warning);}
.toast.leaving{animation:toastOut .25s var(--ease) forwards;}
@keyframes toastIn{from{opacity:0;transform:translateX(30px);}to{opacity:1;transform:translateX(0);}}
@keyframes toastOut{to{opacity:0;transform:translateX(30px);}}

/* ---------- Badges / pills ---------- */
.pill{display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border-radius:var(--radius-full);font-size:.76rem;font-weight:600;background:var(--bg-card);border:1px solid var(--border);color:var(--text-secondary);}
.pill.accent{background:var(--accent-soft);color:var(--accent-hover);border-color:transparent;}

/* ---------- Tabs ---------- */
.tabs{display:flex;gap:6px;background:var(--bg-card);padding:5px;border-radius:var(--radius-full);width:fit-content;border:1px solid var(--border);}
.tab{padding:9px 20px;border-radius:var(--radius-full);font-size:.87rem;font-weight:600;color:var(--text-secondary);cursor:pointer;transition:all .18s var(--ease);}
.tab.active{background:var(--accent);color:#fff;}

/* ---------- Settings ---------- */
.settings-section{margin-bottom:26px;padding:26px 28px;}
.settings-section h2{font-size:1.05rem;font-weight:700;margin-bottom:18px;}
.settings-row{display:flex;align-items:center;justify-content:space-between;padding:14px 0;border-bottom:1px solid var(--border);gap:16px;}
.settings-row:last-child{border-bottom:none;}
.settings-row-label{font-size:.92rem;font-weight:500;}
.settings-row-sub{color:var(--text-tertiary);font-size:.78rem;margin-top:2px;}
.settings-row .select,.settings-row .input{width:auto;min-width:150px;}

.toggle-switch{position:relative;display:inline-block;width:44px;height:26px;flex-shrink:0;}
.toggle-switch input{opacity:0;width:0;height:0;}
.toggle-slider{position:absolute;inset:0;background:var(--border-strong);border-radius:var(--radius-full);cursor:pointer;transition:background .2s var(--ease);}
.toggle-slider::before{content:'';position:absolute;left:3px;top:3px;width:20px;height:20px;background:#fff;border-radius:50%;transition:transform .2s var(--ease);}
.toggle-switch input:checked + .toggle-slider{background:var(--accent);}
.toggle-switch input:checked + .toggle-slider::before{transform:translateX(18px);}

.theme-switcher{display:flex;gap:8px;background:var(--bg-secondary);padding:4px;border-radius:var(--radius-full);border:1px solid var(--border);}
.theme-option{padding:8px 16px;border-radius:var(--radius-full);font-size:.82rem;font-weight:600;color:var(--text-secondary);cursor:pointer;}
.theme-option.active{background:var(--accent);color:#fff;}

/* ---------- Auth pages (login / register) ---------- */
.auth-shell{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;}
.auth-card{width:100%;max-width:400px;padding:38px 34px;}
.auth-logo{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:700;font-size:1.15rem;margin-bottom:26px;}
.auth-logo img{width:32px;height:32px;}
.auth-card h1{font-size:1.4rem;font-weight:800;margin-bottom:6px;}
.auth-sub{color:var(--text-secondary);font-size:.9rem;margin-bottom:26px;}
.auth-card form{display:flex;flex-direction:column;}
.auth-switch{text-align:center;margin-top:20px;color:var(--text-secondary);font-size:.87rem;}
.auth-switch a{color:var(--accent-hover);font-weight:600;}
.auth-error{display:none;background:rgba(255,59,48,.1);border:1px solid rgba(255,59,48,.3);color:#ff8a80;padding:10px 14px;border-radius:var(--radius-sm);font-size:.83rem;margin-bottom:16px;}
.auth-error.show{display:block;}

/* ---------- Card delete affordance ---------- */
.card-remove-btn{
  position:absolute;top:9px;right:9px;width:26px;height:26px;border-radius:50%;
  background:rgba(0,0,0,.55);color:#fff;border:none;font-size:.9rem;line-height:1;cursor:pointer;
  display:flex;align-items:center;justify-content:center;z-index:2;transition:background .15s var(--ease);
}
.card-remove-btn:hover{background:var(--accent);}
.content-card{position:relative;}

/* ---------- Empty state ---------- */
.empty-state{text-align:center;padding:60px 20px;color:var(--text-secondary);}
.empty-state h3{color:var(--text-primary);margin-bottom:8px;font-size:1.1rem;}

/* ==========================================================================
   Landing Page
   ========================================================================== */
.nav-landing{
  position:sticky;top:0;z-index:50;display:flex;align-items:center;justify-content:space-between;
  padding:18px 40px;background:rgba(9,9,11,.7);backdrop-filter:blur(16px);border-bottom:1px solid var(--border);
}
.nav-landing .brand{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:700;font-size:1.2rem;}
.nav-landing .brand img{width:32px;height:32px;}
.nav-landing-links{display:flex;gap:10px;}

.hero{padding:90px 40px 60px;max-width:1180px;margin:0 auto;display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center;}
.hero-eyebrow{display:inline-flex;align-items:center;gap:8px;color:var(--accent-hover);font-weight:600;font-size:.82rem;background:var(--accent-soft);padding:7px 14px;border-radius:var(--radius-full);margin-bottom:22px;}
.hero-eyebrow .dot{width:6px;height:6px;border-radius:50%;background:var(--accent);animation:pulse 2s infinite;}
@keyframes pulse{0%,100%{opacity:1;}50%{opacity:.35;}}
.hero h1{font-size:clamp(2.2rem,4.2vw,3.4rem);font-weight:800;margin-bottom:20px;}
.hero h1 span{color:var(--accent);}
.hero p.lead{color:var(--text-secondary);font-size:1.08rem;max-width:520px;margin-bottom:32px;line-height:1.65;}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;}

/* Study Mode mockup — signature element */
.mockup{
  background:var(--bg-card);border:1px solid var(--border-strong);border-radius:var(--radius-lg);
  padding:18px;box-shadow:var(--shadow-md);position:relative;animation:floatMockup 7s ease-in-out infinite;
}
@keyframes floatMockup{0%,100%{transform:translateY(0);}50%{transform:translateY(-10px);}}
.mockup-player{
  aspect-ratio:16/9;border-radius:var(--radius-md);background:linear-gradient(135deg,#1c1c22,#0f0f12);
  border:1px solid var(--border);display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden;margin-bottom:14px;
}
.mockup-player::before{content:'';position:absolute;inset:0;background:radial-gradient(circle at 30% 20%,rgba(255,59,48,.14),transparent 60%);}
.mockup-play{width:56px;height:56px;border-radius:50%;background:var(--accent);display:flex;align-items:center;justify-content:center;box-shadow:0 8px 24px rgba(255,59,48,.4);z-index:1;}
.mockup-play svg{width:22px;height:22px;fill:#fff;margin-left:3px;}
.mockup-scrub{position:absolute;bottom:12px;left:12px;right:12px;height:4px;background:rgba(255,255,255,.18);border-radius:var(--radius-full);}
.mockup-scrub::after{content:'';position:absolute;left:0;top:0;height:100%;width:42%;background:var(--accent);border-radius:var(--radius-full);}
.mockup-row{display:flex;gap:12px;align-items:center;}
.mockup-title{font-weight:600;font-size:.92rem;margin-bottom:10px;}
.mockup-ring{width:52px;height:52px;border-radius:50%;flex-shrink:0;background:conic-gradient(var(--accent) 0deg 235deg,var(--border) 235deg 360deg);display:flex;align-items:center;justify-content:center;}
.mockup-ring span{width:40px;height:40px;border-radius:50%;background:var(--bg-card);display:flex;align-items:center;justify-content:center;font-family:var(--font-mono);font-size:.62rem;font-weight:600;}
.mockup-list{flex:1;display:flex;flex-direction:column;gap:7px;}
.mockup-list-item{height:9px;border-radius:var(--radius-full);background:var(--border);}
.mockup-list-item:nth-child(1){width:100%;background:var(--accent-soft);}
.mockup-list-item:nth-child(2){width:82%;}
.mockup-list-item:nth-child(3){width:60%;}

.section-label{color:var(--accent-hover);font-weight:700;font-size:.78rem;letter-spacing:.08em;text-transform:uppercase;margin-bottom:10px;display:block;}
.section-head{text-align:center;max-width:560px;margin:0 auto 46px;}
.section-head h2{font-size:clamp(1.6rem,3vw,2.2rem);font-weight:800;}
.section-head p{color:var(--text-secondary);margin-top:12px;}

.features{padding:70px 40px;max-width:1180px;margin:0 auto;}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.feature-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);padding:30px 26px;transition:transform .25s var(--ease),border-color .25s var(--ease);}
.feature-card:hover{transform:translateY(-4px);border-color:var(--accent);}
.feature-icon{width:48px;height:48px;border-radius:14px;background:var(--accent-soft);display:flex;align-items:center;justify-content:center;font-size:1.3rem;margin-bottom:18px;}
.feature-card h3{font-size:1.08rem;font-weight:700;margin-bottom:8px;}
.feature-card p{color:var(--text-secondary);font-size:.92rem;line-height:1.6;}

.steps{padding:70px 40px;max-width:1180px;margin:0 auto;}
.step-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:0;position:relative;}
.step{padding:0 24px;position:relative;}
.step-num{font-family:var(--font-mono);font-size:.85rem;color:var(--accent);font-weight:700;margin-bottom:14px;}
.step h3{font-size:1.1rem;font-weight:700;margin-bottom:8px;}
.step p{color:var(--text-secondary);font-size:.92rem;}
.step:not(:last-child)::after{content:'';position:absolute;top:6px;right:-4px;width:40px;height:1px;background:var(--border-strong);}

.cta-section{padding:90px 40px;text-align:center;}
.cta-box{max-width:640px;margin:0 auto;background:linear-gradient(160deg,var(--bg-card),var(--bg-secondary));border:1px solid var(--border-strong);border-radius:var(--radius-lg);padding:60px 40px;position:relative;overflow:hidden;}
.cta-box::before{content:'';position:absolute;inset:0;background:radial-gradient(circle at 50% 0%,rgba(255,59,48,.16),transparent 60%);}
.cta-box h2{font-size:clamp(1.6rem,3.4vw,2.3rem);font-weight:800;margin-bottom:24px;position:relative;}
.cta-box .btn{position:relative;}

.landing-footer{padding:30px 40px;text-align:center;color:var(--text-tertiary);font-size:.83rem;border-top:1px solid var(--border);}

/* ---------- Responsive ---------- */
@media (max-width:980px){
  .hero{grid-template-columns:1fr;padding-top:50px;}
  .add-content-grid{grid-template-columns:1fr;}
  .feature-grid{grid-template-columns:1fr;}
  .step-grid{grid-template-columns:1fr;gap:28px;}
  .step:not(:last-child)::after{display:none;}
}

@media (max-width:860px){
  .sidebar{display:none;}
  .bottom-nav{display:flex;}
  .main-content{padding:22px 18px 100px;}
  .nav-landing{padding:16px 20px;}
  .hero,.features,.steps,.cta-section{padding-left:20px;padding-right:20px;}
  .nav-landing-links .btn-secondary{display:none;}
  .toast-stack{left:14px;right:14px;top:14px;}
  .toast{min-width:0;}
}