/* ============================================================
   Study Sprint Tracker — Design System
   Dark-mode-first, glassmorphism, category-colored
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Backgrounds */
  --bg-body: #09090b;
  --bg-surface: #131316;
  --bg-card: #18181b;
  --bg-card-hover: #1f1f23;
  --bg-elevated: #27272a;
  --bg-input: #1c1c20;

  /* Borders */
  --border-default: #27272a;
  --border-subtle: #1f1f23;
  --border-hover: #3f3f46;

  /* Text */
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --text-disabled: #52525b;

  /* Category Colors */
  --cat-dsa: #3b82f6;
  --cat-dsa-light: #60a5fa;
  --cat-dsa-bg: rgba(59, 130, 246, 0.08);
  --cat-dsa-border: rgba(59, 130, 246, 0.2);
  --cat-backend: #f97316;
  --cat-backend-light: #fb923c;
  --cat-backend-bg: rgba(249, 115, 22, 0.08);
  --cat-backend-border: rgba(249, 115, 22, 0.2);
  --cat-english: #22c55e;
  --cat-english-light: #4ade80;
  --cat-english-bg: rgba(34, 197, 94, 0.08);
  --cat-english-border: rgba(34, 197, 94, 0.2);
  --cat-review: #a855f7;
  --cat-review-light: #c084fc;
  --cat-review-bg: rgba(168, 85, 247, 0.08);
  --cat-review-border: rgba(168, 85, 247, 0.2);

  /* Status */
  --status-done: #22c55e;
  --status-done-bg: rgba(34, 197, 94, 0.1);
  --status-skipped: #71717a;
  --status-skipped-bg: rgba(113, 113, 122, 0.1);
  --status-pending: #3f3f46;

  /* Accent / CTA */
  --accent: #6366f1;
  --accent-light: #818cf8;
  --accent-bg: rgba(99, 102, 241, 0.1);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', monospace;

  /* Spacing scale */
  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.25rem;
  --sp-6: 1.5rem;
  --sp-8: 2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;

  /* Radii */
  --r-sm: 0.375rem;
  --r-md: 0.5rem;
  --r-lg: 0.75rem;
  --r-xl: 1rem;
  --r-2xl: 1.25rem;
  --r-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
  --shadow-glow-dsa: 0 0 24px rgba(59,130,246,0.12);
  --shadow-glow-backend: 0 0 24px rgba(249,115,22,0.12);
  --shadow-glow-english: 0 0 24px rgba(34,197,94,0.12);
  --shadow-glow-review: 0 0 24px rgba(168,85,247,0.12);

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --t-fast: 150ms var(--ease-out);
  --t-normal: 250ms var(--ease-out);
  --t-slow: 400ms var(--ease-out);
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Subtle background pattern */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99,102,241,0.08), transparent),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(59,130,246,0.05), transparent);
  pointer-events: none;
  z-index: 0;
}

a { color: var(--accent-light); text-decoration: none; transition: color var(--t-fast); }
a:hover { color: var(--cat-dsa-light); }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-default); border-radius: var(--r-full); }
::-webkit-scrollbar-thumb:hover { background: var(--border-hover); }

/* ---------- Layout ---------- */
#app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9,9,11,0.82);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  padding: var(--sp-3) var(--sp-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 0;
}

.header-logo {
  width: 32px;
  height: 32px;
  border-radius: var(--r-md);
  object-fit: cover;
}

.header-brand h1 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  white-space: nowrap;
  background: linear-gradient(135deg, #fff 0%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-brand .subtitle {
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ---------- Navigation ---------- */
#main-nav {
  display: flex;
  gap: var(--sp-1);
  background: var(--bg-surface);
  padding: 3px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border-subtle);
}

.nav-btn {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  padding: var(--sp-2) var(--sp-4);
  border: none;
  border-radius: var(--r-md);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--t-fast);
  white-space: nowrap;
  position: relative;
}

.nav-btn:hover {
  color: var(--text-secondary);
  background: var(--bg-card);
}

.nav-btn.active {
  color: var(--text-primary);
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
}

.nav-btn .badge {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 8px;
  height: 8px;
  border-radius: var(--r-full);
  background: #ef4444;
}

/* ---------- Main Content ---------- */
#app-main {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: var(--sp-6);
}

.view { display: none; }
.view.active { display: block; animation: fadeIn 0.3s var(--ease-out); }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---------- Day Selector ---------- */
#day-selector {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-4);
  margin-bottom: var(--sp-6);
  padding: var(--sp-3) 0;
}

#day-selector .day-nav-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-default);
  border-radius: var(--r-md);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1rem;
  transition: all var(--t-fast);
}

#day-selector .day-nav-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  color: var(--text-primary);
}

#day-selector .day-nav-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

#day-label {
  font-size: 1rem;
  font-weight: 600;
  min-width: 160px;
  text-align: center;
}

#day-label .day-num {
  font-size: 1.8rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent-light), var(--cat-dsa-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#day-label .day-date {
  display: block;
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 2px;
}

/* ---------- Session Cards ---------- */
.session-card {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  border-radius: var(--r-xl);
  padding: var(--sp-5);
  margin-bottom: var(--sp-3);
  cursor: pointer;
  transition: all var(--t-normal);
  position: relative;
  overflow: hidden;
}

.session-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  border-radius: var(--r-full);
}

.session-card[data-category="DSA"]::before { background: var(--cat-dsa); }
.session-card[data-category="Backend"]::before { background: var(--cat-backend); }
.session-card[data-category="English"]::before { background: var(--cat-english); }
.session-card[data-category="Review"]::before { background: var(--cat-review); }

.session-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.session-card[data-category="DSA"]:hover { box-shadow: var(--shadow-glow-dsa); }
.session-card[data-category="Backend"]:hover { box-shadow: var(--shadow-glow-backend); }
.session-card[data-category="English"]:hover { box-shadow: var(--shadow-glow-english); }
.session-card[data-category="Review"]:hover { box-shadow: var(--shadow-glow-review); }

.session-card[data-status="done"] {
  opacity: 0.65;
  border-color: var(--cat-english-border);
}

.session-card[data-status="skipped"] {
  opacity: 0.4;
}

.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--sp-3);
  margin-bottom: var(--sp-2);
}

.card-header-left {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 0;
  flex: 1;
}

.card-title {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
}

.session-card[data-status="done"] .card-title {
  text-decoration: line-through;
  text-decoration-color: var(--status-done);
}

.session-card[data-status="skipped"] .card-title {
  text-decoration: line-through;
  text-decoration-color: var(--status-skipped);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  flex-wrap: wrap;
  margin-bottom: var(--sp-3);
}

.card-time {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

.card-time svg { width: 14px; height: 14px; opacity: 0.6; }

/* ---------- Category Badge ---------- */
.cat-badge {
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 10px;
  border-radius: var(--r-full);
  flex-shrink: 0;
}

.cat-badge[data-cat="DSA"] {
  color: var(--cat-dsa-light);
  background: var(--cat-dsa-bg);
  border: 1px solid var(--cat-dsa-border);
}
.cat-badge[data-cat="Backend"] {
  color: var(--cat-backend-light);
  background: var(--cat-backend-bg);
  border: 1px solid var(--cat-backend-border);
}
.cat-badge[data-cat="English"] {
  color: var(--cat-english-light);
  background: var(--cat-english-bg);
  border: 1px solid var(--cat-english-border);
}
.cat-badge[data-cat="Review"] {
  color: var(--cat-review-light);
  background: var(--cat-review-bg);
  border: 1px solid var(--cat-review-border);
}

/* ---------- Status Button ---------- */
.status-btn {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: var(--r-full);
  border: 2px solid var(--border-default);
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--t-fast);
  color: transparent;
  font-size: 0.85rem;
}

.status-btn:hover {
  border-color: var(--border-hover);
  background: var(--bg-elevated);
}

.status-btn[data-status="done"] {
  border-color: var(--status-done);
  background: var(--status-done);
  color: #fff;
  animation: statusPop 0.3s var(--ease-out);
}

.status-btn[data-status="skipped"] {
  border-color: var(--status-skipped);
  background: var(--status-skipped-bg);
  color: var(--status-skipped);
}

@keyframes statusPop {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.2); }
  100% { transform: scale(1); }
}

/* ---------- Card Expandable Body ---------- */
.card-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s var(--ease-out), opacity 0.3s var(--ease-out);
  opacity: 0;
}

.session-card.expanded .card-body {
  max-height: 600px;
  opacity: 1;
}

.card-body-inner {
  padding-top: var(--sp-3);
  border-top: 1px solid var(--border-subtle);
  margin-top: var(--sp-3);
}

.card-section {
  margin-bottom: var(--sp-4);
}

.card-section-label {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--sp-1);
}

.card-section-content {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card-section-content a {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  color: var(--accent-light);
  word-break: break-all;
}

.card-link-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-primary);
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--r-md);
  cursor: pointer;
  transition: all var(--t-fast);
  text-decoration: none;
}

.card-link-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
}

.card-link-btn svg { width: 16px; height: 16px; }

/* ---------- Calendar / List View ---------- */
.calendar-day-group {
  margin-bottom: var(--sp-8);
}

.day-group-header {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-4);
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--border-subtle);
}

.day-group-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  min-width: 48px;
}

.day-group-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.day-group-progress {
  margin-left: auto;
  font-size: 0.75rem;
  font-weight: 600;
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--r-full);
  background: var(--bg-elevated);
  color: var(--text-secondary);
}

.day-group-progress.complete {
  background: var(--status-done-bg);
  color: var(--status-done);
}

/* ---------- Dashboard ---------- */
.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--sp-4);
  margin-bottom: var(--sp-8);
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  border-radius: var(--r-xl);
  padding: var(--sp-5);
  text-align: center;
  transition: all var(--t-normal);
}

.stat-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-value {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--sp-1);
}

.stat-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.stat-card.overall .stat-value {
  background: linear-gradient(135deg, var(--accent-light), var(--cat-dsa-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-card.streak .stat-value { color: var(--cat-english); }
.stat-card.backlog .stat-value { color: #ef4444; }

/* Progress Bar */
.progress-bar-container {
  margin-bottom: var(--sp-6);
}

.progress-bar-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--sp-2);
  font-size: 0.8rem;
}

.progress-bar-label .label { color: var(--text-secondary); font-weight: 500; }
.progress-bar-label .value { color: var(--text-muted); font-variant-numeric: tabular-nums; }

.progress-bar-track {
  height: 8px;
  background: var(--bg-elevated);
  border-radius: var(--r-full);
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  border-radius: var(--r-full);
  transition: width 0.6s var(--ease-out);
  position: relative;
}

.progress-bar-fill::after {
  content: '';
  position: absolute;
  right: 0;
  top: 0;
  width: 30px;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2));
  border-radius: var(--r-full);
}

.progress-bar-fill.dsa { background: linear-gradient(90deg, var(--cat-dsa), var(--cat-dsa-light)); }
.progress-bar-fill.backend { background: linear-gradient(90deg, var(--cat-backend), var(--cat-backend-light)); }
.progress-bar-fill.english { background: linear-gradient(90deg, var(--cat-english), var(--cat-english-light)); }
.progress-bar-fill.review { background: linear-gradient(90deg, var(--cat-review), var(--cat-review-light)); }
.progress-bar-fill.overall { background: linear-gradient(90deg, var(--accent), var(--accent-light)); }

/* ---------- Backlog ---------- */
.backlog-header {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-6);
}

.backlog-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
}

.backlog-count {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: var(--r-full);
  background: rgba(239,68,68,0.1);
  color: #ef4444;
  border: 1px solid rgba(239,68,68,0.2);
}

.backlog-empty {
  text-align: center;
  padding: var(--sp-16) var(--sp-8);
  color: var(--text-muted);
}

.backlog-empty-icon {
  font-size: 3rem;
  margin-bottom: var(--sp-4);
  opacity: 0.5;
}

/* ---------- Settings ---------- */
.settings-section {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  border-radius: var(--r-xl);
  padding: var(--sp-6);
  margin-bottom: var(--sp-4);
}

.settings-section h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: var(--sp-4);
}

.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.setting-row:last-child { border-bottom: none; }

.setting-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.setting-desc {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Toggle Switch */
.toggle {
  position: relative;
  width: 44px;
  height: 24px;
  flex-shrink: 0;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-track {
  position: absolute;
  inset: 0;
  background: var(--bg-elevated);
  border-radius: var(--r-full);
  border: 1px solid var(--border-default);
  cursor: pointer;
  transition: all var(--t-fast);
}

.toggle-track::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  background: var(--text-secondary);
  border-radius: var(--r-full);
  transition: all var(--t-fast);
}

.toggle input:checked + .toggle-track {
  background: var(--accent);
  border-color: var(--accent);
}

.toggle input:checked + .toggle-track::after {
  transform: translateX(20px);
  background: #fff;
}

/* ---------- Buttons ---------- */
.btn {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  padding: var(--sp-2) var(--sp-5);
  border-radius: var(--r-md);
  border: 1px solid var(--border-default);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--t-fast);
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
}

.btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-light);
  border-color: var(--accent-light);
}

.btn-danger {
  color: #ef4444;
  border-color: rgba(239,68,68,0.3);
}

.btn-danger:hover {
  background: rgba(239,68,68,0.1);
}

.btn-group {
  display: flex;
  gap: var(--sp-2);
  flex-wrap: wrap;
}

/* ---------- Backlog Overlay on Day View ---------- */
.backlog-overlay {
  margin-top: var(--sp-6);
  padding-top: var(--sp-4);
  border-top: 2px dashed rgba(239,68,68,0.3);
}

.backlog-overlay-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: #ef4444;
  margin-bottom: var(--sp-3);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

/* ---------- Empty State ---------- */
.empty-state {
  text-align: center;
  padding: var(--sp-16) var(--sp-8);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: var(--sp-4);
  opacity: 0.3;
}

.empty-state-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--sp-2);
}

.empty-state-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  max-width: 300px;
  margin: 0 auto;
}

/* ---------- Loading Skeleton ---------- */
.skeleton {
  background: linear-gradient(90deg, var(--bg-card) 25%, var(--bg-card-hover) 50%, var(--bg-card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--r-md);
}

@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.skeleton-card {
  height: 80px;
  margin-bottom: var(--sp-3);
  border-radius: var(--r-xl);
}

/* ---------- Toast Notification ---------- */
.toast-container {
  position: fixed;
  bottom: var(--sp-6);
  right: var(--sp-6);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
}

.toast {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  border-radius: var(--r-lg);
  padding: var(--sp-3) var(--sp-5);
  font-size: 0.85rem;
  color: var(--text-secondary);
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.3s var(--ease-out);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

.toast.success { border-color: var(--cat-english-border); }
.toast.error   { border-color: rgba(239,68,68,0.3); }

@keyframes toastIn {
  from { opacity: 0; transform: translateY(16px) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(16px) scale(0.95); }
}

/* ---------- Mobile Menu Toggle ---------- */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--sp-2);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  #app-header {
    flex-wrap: wrap;
    padding: var(--sp-3) var(--sp-4);
  }

  .menu-toggle { display: block; }

  #main-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    order: 3;
  }

  #main-nav.open {
    display: flex;
  }

  #app-main {
    padding: var(--sp-4);
  }

  .dashboard-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stat-value {
    font-size: 2rem;
  }

  #day-label .day-num {
    font-size: 1.4rem;
  }
}

@media (max-width: 480px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .card-meta {
    flex-direction: column;
    align-items: flex-start;
  }

  .toast-container {
    left: var(--sp-4);
    right: var(--sp-4);
  }
}

/* ---------- Streak Calendar Mini ---------- */
.streak-grid {
  display: grid;
  grid-template-columns: repeat(15, 1fr);
  gap: 3px;
  margin-top: var(--sp-4);
}

.streak-cell {
  aspect-ratio: 1;
  border-radius: 3px;
  background: var(--bg-elevated);
  transition: all var(--t-fast);
}

.streak-cell.done { background: var(--status-done); }
.streak-cell.partial { background: rgba(34,197,94,0.3); }
.streak-cell.today { outline: 2px solid var(--accent-light); outline-offset: 1px; }

/* ---------- Utility ---------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

.text-center { text-align: center; }
.mt-4 { margin-top: var(--sp-4); }
.mt-6 { margin-top: var(--sp-6); }
.mb-4 { margin-bottom: var(--sp-4); }
.mb-6 { margin-bottom: var(--sp-6); }

/* ---------- Permission Banner ---------- */
.permission-banner {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(59, 130, 246, 0.15));
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--r-xl);
  padding: var(--sp-4) var(--sp-5);
  margin-bottom: var(--sp-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  animation: fadeIn 0.4s var(--ease-out);
}

.permission-banner-text {
  font-size: 0.85rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

/* ---------- Network Status Badge ---------- */
.network-badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: var(--r-full);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: rgba(34, 197, 94, 0.1);
  color: var(--status-done);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.network-badge.offline {
  background: rgba(249, 115, 22, 0.1);
  color: var(--cat-backend-light);
  border-color: rgba(249, 115, 22, 0.2);
}

/* ---------- Filter Bar & Pills ---------- */
.filter-bar {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-4);
  overflow-x: auto;
  padding-bottom: 4px;
}

.filter-pill {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: var(--r-full);
  border: 1px solid var(--border-default);
  background: var(--bg-surface);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--t-fast);
  white-space: nowrap;
}

.filter-pill:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
}

.filter-pill.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 12px rgba(99, 102, 241, 0.3);
}

/* ---------- Floating Focus Timer Widget ---------- */
.focus-timer-bar {
  position: fixed;
  bottom: var(--sp-4);
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 32px);
  max-width: 600px;
  background: rgba(19, 19, 22, 0.95);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--border-hover);
  border-radius: var(--r-2xl);
  padding: var(--sp-3) var(--sp-5);
  box-shadow: var(--shadow-lg), 0 0 24px rgba(99, 102, 241, 0.2);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  animation: timerSlideUp 0.3s var(--ease-out);
}

@keyframes timerSlideUp {
  from { opacity: 0; transform: translate(-50%, 20px); }
  to   { opacity: 1; transform: translate(-50%, 0); }
}

.timer-left {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 0;
}

.timer-ring-wrapper {
  position: relative;
  width: 44px;
  height: 44px;
  flex-shrink: 0;
}

.timer-ring-wrapper svg {
  transform: rotate(-90deg);
  width: 44px;
  height: 44px;
}

.timer-ring-bg {
  stroke: var(--bg-elevated);
  stroke-width: 3.5;
  fill: none;
}

.timer-ring-progress {
  stroke: var(--accent-light);
  stroke-width: 3.5;
  stroke-linecap: round;
  fill: none;
  transition: stroke-dashoffset 1s linear;
}

.timer-digits {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.68rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text-primary);
}

.timer-meta {
  min-width: 0;
}

.timer-title {
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 200px;
}

.timer-status-text {
  font-size: 0.68rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.timer-actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-shrink: 0;
}

.timer-icon-btn {
  width: 34px;
  height: 34px;
  border-radius: var(--r-full);
  border: 1px solid var(--border-default);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  transition: all var(--t-fast);
}

.timer-icon-btn:hover {
  background: var(--bg-elevated);
  border-color: var(--border-hover);
}

.timer-icon-btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.timer-icon-btn.active {
  background: rgba(34, 197, 94, 0.2);
  border-color: var(--status-done);
  color: var(--status-done);
}

.focus-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  padding: 3px 10px;
  font-size: 0.72rem;
  font-weight: 600;
  border-radius: var(--r-md);
  border: 1px solid rgba(99, 102, 241, 0.3);
  background: rgba(99, 102, 241, 0.1);
  color: var(--accent-light);
  cursor: pointer;
  transition: all var(--t-fast);
}

.focus-btn:hover {
  background: rgba(99, 102, 241, 0.25);
  border-color: var(--accent-light);
}

/* ---------- Day Stat Meter ---------- */
.day-stat-meter {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-lg);
  padding: var(--sp-2) var(--sp-4);
  margin-bottom: var(--sp-4);
  font-size: 0.78rem;
}

.day-stat-track {
  flex: 1;
  height: 6px;
  background: var(--bg-elevated);
  border-radius: var(--r-full);
  overflow: hidden;
}

.day-stat-fill {
  height: 100%;
  border-radius: var(--r-full);
  background: linear-gradient(90deg, var(--accent), var(--status-done));
  transition: width 0.4s var(--ease-out);
}

/* ---------- Milestone Badges on Dashboard ---------- */
.milestone-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: var(--sp-3);
  margin-top: var(--sp-4);
}

.milestone-card {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  border-radius: var(--r-xl);
  padding: var(--sp-4) var(--sp-3);
  text-align: center;
  transition: all var(--t-normal);
  opacity: 0.45;
}

.milestone-card.unlocked {
  opacity: 1;
  border-color: rgba(234, 179, 8, 0.4);
  background: linear-gradient(135deg, rgba(234, 179, 8, 0.06), rgba(99, 102, 241, 0.06));
  box-shadow: 0 0 16px rgba(234, 179, 8, 0.1);
}

.milestone-icon {
  font-size: 1.8rem;
  margin-bottom: var(--sp-1);
}

.milestone-title {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-primary);
}

.milestone-desc {
  font-size: 0.65rem;
  color: var(--text-muted);
  margin-top: 2px;
}