/* =========================================================
   StudyAtlas — design tokens
   ========================================================= */
:root{
  --bg:#F6F3EC;
  --bg-alt:#FFFFFF;
  --surface:#FFFFFF;
  --surface-2:#FBF9F2;
  --ink:#21243D; 
  --ink-soft:#63637D;
  --ink-faint:#9694A8;
  --border:#E7E2D3;
  --accent:#5B5FEF;
  --accent-soft:#EDEDFF;
  --accent-ink:#FFFFFF;
  --coral:#FF6B5B;
  --coral-soft:#FFEBE8;
  --green:#28A66C;
  --green-soft:#E4F7ED;
  --amber:#DB9A15;
  --amber-soft:#FCF1D8;
  --shadow:0 10px 30px rgba(33,36,61,0.08);
  --shadow-sm:0 3px 10px rgba(33,36,61,0.06);
  --radius-lg:20px;
  --radius-md:14px;
  --radius-sm:9px;
  --font-display:'Fraunces', serif;
  --font-body:'Inter', sans-serif;
  --font-mono:'JetBrains Mono', monospace;
  --sidebar-w:236px;
}

[data-theme="dark"]{
  --bg:#12142A;
  --bg-alt:#181B36;
  --surface:#1B1E3B;
  --surface-2:#232748;
  --ink:#EEEDFB;
  --ink-soft:#A6A4CC;
  --ink-faint:#726F9B;
  --border:#31356090;
  --accent:#8A8DFF;
  --accent-soft:#26295A;
  --accent-ink:#12142A;
  --coral:#FF8B7B;
  --coral-soft:#3A2340;
  --green:#4FDB94;
  --green-soft:#173B32;
  --amber:#F5C453;
  --amber-soft:#3A311A;
  --shadow:0 10px 30px rgba(0,0,0,0.45);
  --shadow-sm:0 4px 14px rgba(0,0,0,0.35);
}

/* subject tag palette — used identically in both themes */
:root, [data-theme="dark"]{
  --tag-0:#5B5FEF; --tag-1:#FF6B5B; --tag-2:#28A66C; --tag-3:#DB9A15;
  --tag-4:#EC4899; --tag-5:#06B6D4; --tag-6:#8B5CF6; --tag-7:#F97316;
}

/* =========================================================
   Reset
   ========================================================= */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{-webkit-text-size-adjust:100%;}
body{
  font-family:var(--font-body);
  background:var(--bg);
  color:var(--ink);
  min-height:100vh;
  transition:background .25s ease,color .25s ease;
}
ul{list-style:none;}
button,input,select,textarea{font:inherit;color:inherit;}
button{cursor:pointer;background:none;border:none;}
a{color:inherit;}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:6px;}

/* =========================================================
   App shell
   ========================================================= */
.app{
  display:grid;
  grid-template-columns:var(--sidebar-w) 1fr;
  min-height:100vh;
}

/* ---- Sidebar ---- */
.sidebar{
  background:var(--surface);
  border-right:1px solid var(--border);
  display:flex;
  flex-direction:column;
  padding:26px 18px;
  position:sticky;
  top:0;
  height:100vh;
}
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  padding:0 8px 26px;
  font-family:var(--font-display);
  font-size:1.35rem;
  font-weight:700;
}
.brand-mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:34px;height:34px;
  border-radius:10px;
  background:var(--accent);
  color:var(--accent-ink);
  font-size:1.1rem;
}
.brand-name em{font-style:italic;color:var(--accent);}

.nav{display:flex;flex-direction:column;gap:4px;flex:1;}
.nav-item{
  display:flex;align-items:center;gap:12px;
  padding:11px 14px;
  border-radius:var(--radius-sm);
  font-weight:600;
  font-size:.95rem;
  color:var(--ink-soft);
  text-align:left;
  transition:background .15s ease,color .15s ease;
}
.nav-item .nav-ico{font-size:1.05rem;}
.nav-item:hover{background:var(--surface-2);color:var(--ink);}
.nav-item.active{background:var(--accent-soft);color:var(--accent);}

.sidebar-foot{display:flex;flex-direction:column;gap:14px;padding-top:16px;border-top:1px solid var(--border);}
.theme-toggle{
  display:flex;align-items:center;gap:8px;
  padding:10px 14px;
  border-radius:var(--radius-sm);
  background:var(--surface-2);
  font-weight:600;
  font-size:.88rem;
  justify-content:center;
}
.tagline{font-family:var(--font-display);font-style:italic;color:var(--ink-faint);font-size:.85rem;text-align:center;}

/* =========================================================
   Main column
   ========================================================= */
.main{padding:26px 34px 60px;max-width:1100px;width:100%;}

.topbar{
  display:flex;align-items:center;gap:16px;
  margin-bottom:26px;
}
.menu-btn{display:none;font-size:1.3rem;}
.topbar-title h1{
  font-family:var(--font-display);
  font-size:1.6rem;font-weight:700;
}
.topbar-title p{color:var(--ink-faint);font-size:.85rem;font-family:var(--font-mono);margin-top:2px;}
.add-btn{
  margin-left:auto;
  background:var(--accent);
  color:var(--accent-ink);
  padding:11px 18px;
  border-radius:999px;
  font-weight:700;
  font-size:.9rem;
  box-shadow:var(--shadow-sm);
  transition:transform .12s ease,opacity .12s ease;
}
.add-btn:hover{opacity:.92;transform:translateY(-1px);}
.add-btn:active{transform:scale(.97);}

/* =========================================================
   Views
   ========================================================= */
.view{display:none;animation:viewIn .3s ease;}
.view.active{display:block;}
@keyframes viewIn{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:translateY(0);}}

/* ---- Dashboard greet strip ---- */
.greet-strip{
  display:flex;align-items:center;justify-content:space-between;
  background:linear-gradient(135deg,var(--accent) 0%,#8285FF 100%);
  color:#fff;
  border-radius:var(--radius-lg);
  padding:24px 28px;
  margin-bottom:20px;
  box-shadow:var(--shadow);
  flex-wrap:wrap;gap:14px;
}
.eyebrow{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;opacity:.85;}
.greet-strip h2{font-family:var(--font-display);font-size:1.5rem;font-weight:600;margin-top:4px;max-width:420px;}
.streak-chip{
  display:flex;align-items:center;gap:10px;
  background:rgba(255,255,255,.16);
  padding:10px 18px;
  border-radius:999px;
  backdrop-filter:blur(4px);
}
.streak-chip .flame{font-size:1.4rem;}
.streak-chip strong{display:block;font-size:1.2rem;font-family:var(--font-mono);line-height:1;}
.streak-chip small{font-size:.7rem;opacity:.85;}

/* ---- Stat grid ---- */
.stat-grid{
  display:grid;grid-template-columns:repeat(4,1fr);gap:14px;
  margin-bottom:20px;
}
.stat-card{
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:var(--radius-md);
  padding:16px 18px;
  box-shadow:var(--shadow-sm);
}
.stat-label{font-size:.78rem;color:var(--ink-faint);font-weight:600;}
.stat-value{font-family:var(--font-mono);font-size:1.9rem;font-weight:600;margin-top:6px;}
.stat-value.warn{color:var(--coral);}

/* ---- Two-column dash area ---- */
.dash-columns{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:18px;}
.card{
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:var(--radius-lg);
  padding:22px;
  box-shadow:var(--shadow-sm);
}
.card h3{font-family:var(--font-display);font-size:1.1rem;margin-bottom:14px;}
.card h3 small{display:block;font-family:var(--font-body);font-size:.72rem;color:var(--ink-faint);font-weight:500;margin-top:2px;}

/* ---- Focus ring ---- */
.ring-wrap{position:relative;width:140px;height:140px;margin:0 auto 14px;}
.ring-svg{width:140px;height:140px;transform:rotate(-90deg);}
.ring-track{fill:none;stroke:var(--surface-2);stroke-width:12;}
.ring-progress{
  fill:none;stroke:var(--accent);stroke-width:12;stroke-linecap:round;
  stroke-dasharray:377;stroke-dashoffset:377;
  transition:stroke-dashoffset .6s cubic-bezier(.65,0,.35,1);
}
.ring-center{
  position:absolute;inset:0;display:flex;flex-direction:column;
  align-items:center;justify-content:center;
}
.ring-center span{font-family:var(--font-mono);font-size:1.5rem;font-weight:700;}
.ring-center small{color:var(--ink-faint);font-size:.72rem;}

.mini-list{display:flex;flex-direction:column;gap:8px;}
.mini-list li{
  display:flex;align-items:center;gap:10px;
  padding:9px 12px;
  background:var(--surface-2);
  border-radius:var(--radius-sm);
  font-size:.85rem;
}
.mini-list .tag-dot{width:8px;height:8px;border-radius:50%;flex-shrink:0;}
.mini-list .mini-due{margin-left:auto;font-family:var(--font-mono);font-size:.72rem;color:var(--ink-faint);}
.mini-list .mini-empty{color:var(--ink-faint);font-style:italic;background:none;padding:6px 0;}

/* ---- Heatmap (signature element) ---- */
.heatmap{
  display:grid;
  grid-auto-flow:column;
  grid-template-rows:repeat(7,1fr);
  gap:3px;
  overflow-x:auto;
  padding-bottom:6px;
}
.heatmap i{
  width:12px;height:12px;border-radius:3px;
  background:var(--surface-2);
  display:block;
}
.heatmap-lg i{width:14px;height:14px;}
.heatmap i.lv0{background:var(--surface-2);}
.heatmap i.lv1{background:color-mix(in srgb, var(--green) 25%, var(--surface-2));}
.heatmap i.lv2{background:color-mix(in srgb, var(--green) 50%, var(--surface-2));}
.heatmap i.lv3{background:color-mix(in srgb, var(--green) 75%, var(--surface-2));}
.heatmap i.lv4{background:var(--green);}
.heatmap-legend{display:flex;align-items:center;gap:5px;margin-top:8px;font-size:.7rem;color:var(--ink-faint);}
.heatmap-legend i{width:10px;height:10px;border-radius:3px;}
.heatmap-legend .lv0{background:var(--surface-2);}
.heatmap-legend .lv1{background:color-mix(in srgb, var(--green) 25%, var(--surface-2));}
.heatmap-legend .lv2{background:color-mix(in srgb, var(--green) 50%, var(--surface-2));}
.heatmap-legend .lv3{background:color-mix(in srgb, var(--green) 75%, var(--surface-2));}
.heatmap-legend .lv4{background:var(--green);}

/* =========================================================
   Toolbar / segmented control
   ========================================================= */
.toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:16px;flex-wrap:wrap;}
.seg{display:flex;background:var(--surface);border:1px solid var(--border);border-radius:999px;padding:4px;box-shadow:var(--shadow-sm);}
.seg-btn{padding:7px 16px;border-radius:999px;font-size:.85rem;font-weight:600;color:var(--ink-soft);}
.seg-btn.active{background:var(--accent);color:var(--accent-ink);}
.select{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius-sm);padding:9px 12px;font-size:.85rem;font-weight:600;
  box-shadow:var(--shadow-sm);
}

/* =========================================================
   Task list (index-card signature)
   ========================================================= */
.task-list{display:flex;flex-direction:column;gap:10px;}
.task-card{
  display:flex;align-items:flex-start;gap:14px;
  background:var(--surface);
  border:1px solid var(--border);
  border-left:5px solid var(--tag-0);
  border-radius:var(--radius-md);
  padding:14px 16px;
  box-shadow:var(--shadow-sm);
  transition:transform .12s ease,box-shadow .12s ease;
}
.task-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);}
.task-check{
  width:22px;height:22px;border-radius:50%;
  border:2px solid var(--border);
  flex-shrink:0;margin-top:2px;
  display:flex;align-items:center;justify-content:center;
  font-size:.7rem;color:transparent;
  transition:all .15s ease;
}
.task-check.checked{background:var(--green);border-color:var(--green);color:#fff;}
.task-body{flex:1;min-width:0;}
.task-title{font-weight:600;font-size:.95rem;word-break:break-word;}
.task-card.done .task-title{text-decoration:line-through;color:var(--ink-faint);}
.task-meta{display:flex;flex-wrap:wrap;gap:8px;margin-top:6px;align-items:center;}
.pill{
  font-size:.68rem;font-weight:700;letter-spacing:.02em;
  padding:3px 9px;border-radius:999px;
  font-family:var(--font-mono);
}
.pill.subject{background:var(--accent-soft);color:var(--accent);}
.pill.priority-low{background:var(--green-soft);color:var(--green);}
.pill.priority-medium{background:var(--amber-soft);color:var(--amber);}
.pill.priority-high{background:var(--coral-soft);color:var(--coral);}
.pill.due{background:var(--surface-2);color:var(--ink-soft);}
.pill.due.overdue{background:var(--coral-soft);color:var(--coral);}
.task-notes{margin-top:6px;font-size:.8rem;color:var(--ink-faint);}
.task-actions{display:flex;gap:6px;}
.icon-btn{
  width:30px;height:30px;border-radius:8px;
  display:flex;align-items:center;justify-content:center;
  background:var(--surface-2);font-size:.85rem;
}
.icon-btn:hover{background:var(--border);}

.empty-state{
  text-align:center;color:var(--ink-faint);
  padding:40px 20px;font-family:var(--font-display);font-style:italic;font-size:1.05rem;
  display:none;
}
.empty-state.show{display:block;}

/* =========================================================
   Calendar
   ========================================================= */
.cal-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px;}
.cal-header h3{font-family:var(--font-display);font-size:1.2rem;}
.cal-nav{
  width:34px;height:34px;border-radius:50%;
  background:var(--surface);border:1px solid var(--border);
  font-size:1.1rem;box-shadow:var(--shadow-sm);
}
.cal-nav:hover{background:var(--accent-soft);color:var(--accent);}
.cal-weekdays{
  display:grid;grid-template-columns:repeat(7,1fr);
  text-align:center;font-size:.72rem;color:var(--ink-faint);
  font-weight:700;margin-bottom:6px;font-family:var(--font-mono);
}
.cal-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;margin-bottom:20px;}
.cal-day{
  aspect-ratio:1;border-radius:var(--radius-sm);
  background:var(--surface);border:1px solid var(--border);
  padding:6px 8px;font-size:.8rem;font-weight:600;
  display:flex;flex-direction:column;justify-content:space-between;
  cursor:pointer;transition:background .15s ease,transform .1s ease;
  position:relative;
}
.cal-day:hover{background:var(--surface-2);transform:translateY(-1px);}
.cal-day.outside{opacity:.35;}
.cal-day.today{border-color:var(--accent);box-shadow:0 0 0 2px var(--accent) inset;}
.cal-day.selected{background:var(--accent);color:var(--accent-ink);}
.cal-dots{display:flex;gap:3px;flex-wrap:wrap;}
.cal-dots span{width:5px;height:5px;border-radius:50%;background:var(--accent);}
.cal-day.selected .cal-dots span{background:var(--accent-ink);}

.day-detail h3{font-family:var(--font-mono);font-size:.95rem;}

/* =========================================================
   Deadlines
   ========================================================= */
.deadline-group{margin-bottom:22px;}
.deadline-group h4{
  font-family:var(--font-mono);font-size:.78rem;letter-spacing:.05em;text-transform:uppercase;
  color:var(--ink-faint);margin-bottom:10px;display:flex;align-items:center;gap:8px;
}
.deadline-group h4 .count{
  background:var(--surface-2);padding:1px 8px;border-radius:999px;color:var(--ink);
}
.deadline-group.overdue h4{color:var(--coral);}

/* =========================================================
   Progress
   ========================================================= */
.streak-stats{display:flex;justify-content:space-around;margin-top:16px;padding-top:16px;border-top:1px solid var(--border);}
.streak-stats div{text-align:center;}
.streak-stats strong{display:block;font-family:var(--font-mono);font-size:1.3rem;}
.streak-stats small{color:var(--ink-faint);font-size:.72rem;}

.subject-breakdown{display:flex;flex-direction:column;gap:14px;}
.subject-row .subject-row-head{display:flex;justify-content:space-between;font-size:.85rem;font-weight:600;margin-bottom:6px;}
.subject-row-head small{color:var(--ink-faint);font-weight:500;font-family:var(--font-mono);}
.bar-track{height:8px;background:var(--surface-2);border-radius:999px;overflow:hidden;}
.bar-fill{height:100%;border-radius:999px;transition:width .5s ease;}

/* =========================================================
   Modal
   ========================================================= */
.modal-overlay{
  position:fixed;inset:0;background:rgba(18,20,42,.5);
  display:none;align-items:center;justify-content:center;
  padding:20px;z-index:100;backdrop-filter:blur(2px);
}
.modal-overlay.open{display:flex;animation:fadeIn .2s ease;}
@keyframes fadeIn{from{opacity:0;}to{opacity:1;}}
.modal{
  background:var(--surface);
  border-radius:var(--radius-lg);
  padding:26px;
  width:100%;max-width:460px;
  box-shadow:var(--shadow);
  display:flex;flex-direction:column;gap:14px;
  max-height:90vh;overflow-y:auto;
  animation:modalIn .22s cubic-bezier(.2,.9,.3,1.2);
}
@keyframes modalIn{from{opacity:0;transform:translateY(10px) scale(.98);}to{opacity:1;transform:translateY(0) scale(1);}}
.modal-head{display:flex;align-items:center;justify-content:space-between;}
.modal-head h3{font-family:var(--font-display);font-size:1.25rem;}
.modal-close{font-size:1.1rem;width:30px;height:30px;border-radius:50%;background:var(--surface-2);}
.field{display:flex;flex-direction:column;gap:6px;font-size:.8rem;font-weight:600;color:var(--ink-soft);flex:1;}
.field input,.field select,.field textarea{
  background:var(--surface-2);
  border:1px solid var(--border);
  border-radius:var(--radius-sm);
  padding:10px 12px;font-size:.9rem;color:var(--ink);font-weight:500;
}
.field input:focus,.field select:focus,.field textarea:focus{border-color:var(--accent);}
.field-row{display:flex;gap:12px;}
.modal-actions{display:flex;align-items:center;gap:10px;margin-top:6px;}
.spacer{flex:1;}
.btn{padding:10px 18px;border-radius:999px;font-weight:700;font-size:.85rem;}
.btn.primary{background:var(--accent);color:var(--accent-ink);}
.btn.primary:hover{opacity:.92;}
.btn.ghost{background:var(--surface-2);color:var(--ink-soft);}
.btn.ghost:hover{background:var(--border);}

/* =========================================================
   Toast
   ========================================================= */
.toast{
  position:fixed;bottom:26px;left:50%;transform:translateX(-50%) translateY(20px);
  background:var(--ink);color:var(--bg);
  padding:12px 22px;border-radius:999px;font-size:.85rem;font-weight:600;
  opacity:0;pointer-events:none;transition:all .25s ease;z-index:200;
  box-shadow:var(--shadow);
}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}

/* =========================================================
   Bottom nav (mobile only)
   ========================================================= */
.bottom-nav{
  display:none;
  position:fixed;bottom:0;left:0;right:0;
  background:var(--surface);
  border-top:1px solid var(--border);
  padding:8px 10px calc(8px + env(safe-area-inset-bottom));
  justify-content:space-around;
  z-index:90;
  box-shadow:0 -6px 18px rgba(0,0,0,0.06);
}
.bn-item{
  width:44px;height:44px;border-radius:12px;
  display:flex;align-items:center;justify-content:center;
  font-size:1.2rem;color:var(--ink-faint);
}
.bn-item.active{background:var(--accent-soft);color:var(--accent);}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width:980px){
  .stat-grid{grid-template-columns:repeat(2,1fr);}
  .dash-columns{grid-template-columns:1fr;}
}

@media (max-width:760px){
  .app{grid-template-columns:1fr;}
  .sidebar{
    position:fixed;left:0;top:0;bottom:0;z-index:110;
    transform:translateX(-100%);
    transition:transform .25s ease;
    box-shadow:var(--shadow);
    width:240px;
  }
  .sidebar.open{transform:translateX(0);}
  .menu-btn{display:block;}
  .main{padding:18px 16px 90px;}
  .bottom-nav{display:flex;}
  .greet-strip{flex-direction:column;align-items:flex-start;}
  .field-row{flex-direction:column;}
  .topbar-title h1{font-size:1.3rem;}
}

@media (max-width:420px){
  .stat-grid{grid-template-columns:1fr 1fr;gap:10px;}
  .stat-value{font-size:1.5rem;}
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important;}
}