@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,300;0,14..32,400;0,14..32,500;0,14..32,600;1,14..32,400&display=swap');

/* ─── TOKENS ─────────────────────────────────────────────────── */
:root {
  --bg:           #F4F3F0;
  --surface:      #FEFEFE;
  --surface-alt:  #F0EFF0;
  --border:       #E3E1DC;
  --border-hover: #C5C3BC;

  --ink:          #111111;
  --ink-2:        #55555A;
  --ink-3:        #9A9A9F;

  --ok:     #15803D;
  --ok-bg:  #DCFCE7;
  --warn:   #92400E;
  --warn-bg:#FEF3C7;
  --danger:        #B91C1C;
  --danger-bg:     #FEE2E2;
  --danger-border: #FECACA;

  --n1: #D4D4D8;
  --n2: #A1A1AA;
  --n3: #52525B;
  --n4: #18181B;

  --radius-sm: 6px;
  --radius:    10px;
  --radius-lg: 14px;
  --radius-xl: 20px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
  --shadow:    0 1px 3px rgba(0,0,0,.08), 0 4px 12px rgba(0,0,0,.05);
  --shadow-lg: 0 4px 6px rgba(0,0,0,.07), 0 16px 32px rgba(0,0,0,.08);

  --ease: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --fast: 150ms;
  --mid:  250ms;
  --slow: 400ms;
}

/* ─── RESET ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}
button { font-family: inherit; cursor: pointer; }
input  { font-family: inherit; }

/* ─── LAYOUT ─────────────────────────────────────────────────── */
.app-shell {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
}

/* ─── TOPBAR ─────────────────────────────────────────────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(247, 246, 243, .85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.topbar-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-size: .9rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -.01em;
}

.brand-badge {
  background: var(--ink);
  color: #fff;
  font-size: .6rem;
  font-weight: 700;
  padding: .15rem .4rem;
  border-radius: 3px;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: .4rem;
  font-size: .8rem;
  color: var(--ink-3);
}
.breadcrumb a {
  color: var(--ink-2);
  text-decoration: none;
  cursor: pointer;
}
.breadcrumb a:hover { color: var(--ink); }
.breadcrumb span { color: var(--ink-3); }

/* ─── BUTTONS ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .45rem .9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--ink);
  font-size: .82rem;
  font-weight: 500;
  line-height: 1;
  transition: background var(--fast) var(--ease),
              border-color var(--fast) var(--ease),
              box-shadow var(--fast) var(--ease),
              transform var(--fast) var(--ease);
  white-space: nowrap;
  user-select: none;
}
.btn:hover {
  background: var(--surface-alt);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-sm);
}
.btn:active { transform: scale(.97); }

.btn-primary {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
}
.btn-primary:hover {
  background: #2d2d2d;
  border-color: #2d2d2d;
}

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--ink-2);
}
.btn-ghost:hover {
  background: var(--surface-alt);
  border-color: var(--border);
  color: var(--ink);
}

.btn-danger {
  background: transparent;
  border-color: transparent;
  color: var(--ink-3);
}
.btn-danger:hover {
  background: var(--danger-bg);
  border-color: var(--danger-border);
  color: var(--danger);
}

.btn-icon {
  padding: .45rem;
  width: 32px;
  height: 32px;
  justify-content: center;
}

/* ─── PAGE CONTAINER ─────────────────────────────────────────── */
.page {
  max-width: 1080px;
  margin: 0 auto;
  padding: 2.5rem 2rem 5rem;
}

/* ─── DASHBOARD ──────────────────────────────────────────────── */
.page-header {
  margin-bottom: 2rem;
}
.page-title {
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--ink);
}
.page-subtitle {
  font-size: .82rem;
  color: var(--ink-3);
  margin-top: .2rem;
}

/* Deck Grid */
.deck-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1rem;
}

.deck-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.4rem;
  cursor: pointer;
  transition: border-color var(--fast) var(--ease),
              box-shadow var(--mid) var(--ease),
              transform var(--mid) var(--ease);
  position: relative;
  overflow: hidden;
}
.deck-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--ink);
  opacity: 0;
  transition: opacity var(--fast) var(--ease);
}
.deck-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow);
  transform: translateY(-1px);
}
.deck-card:active { transform: translateY(0); }

.deck-card-name {
  font-size: .95rem;
  font-weight: 600;
  letter-spacing: -.01em;
  margin-bottom: .3rem;
}
.deck-card-meta {
  font-size: .75rem;
  color: var(--ink-3);
  margin-bottom: 1.2rem;
}

/* Mini level bars on deck card */
.deck-mini-levels {
  display: flex;
  gap: 4px;
  align-items: flex-end;
  height: 36px;
}
.deck-mini-bar-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: center;
  height: 100%;
  justify-content: flex-end;
}
.deck-mini-bar {
  width: 100%;
  border-radius: 2px;
  min-height: 3px;
  transition: height var(--slow) var(--ease);
}
.deck-mini-label {
  font-size: .6rem;
  color: var(--ink-3);
  font-weight: 500;
}
.deck-card-arrow {
  position: absolute;
  right: 1.4rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--ink-3);
  font-size: .9rem;
  transition: transform var(--fast) var(--ease), color var(--fast) var(--ease);
}
.deck-card:hover .deck-card-arrow {
  transform: translateY(-50%) translateX(3px);
  color: var(--ink);
}

/* ─── EMPTY STATE ────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 5rem 2rem;
  color: var(--ink-3);
}
.empty-state-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  display: block;
  opacity: .4;
}
.empty-state h3 {
  font-size: 1rem;
  font-weight: 500;
  color: var(--ink-2);
  margin-bottom: .4rem;
}
.empty-state p {
  font-size: .82rem;
  margin-bottom: 1.5rem;
}

/* ─── DECK VIEW ──────────────────────────────────────────────── */
.deck-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 2rem;
  gap: 1rem;
}
.deck-title-group { flex: 1; }
.deck-title {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -.025em;
  margin-bottom: .5rem;
}
.profile-pill {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .3rem .7rem;
  border-radius: 99px;
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .04em;
}
.profile-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}
.profile-ok     { background: var(--ok-bg);   color: var(--ok);   }
.profile-ok .profile-dot   { background: var(--ok);   }
.profile-warn   { background: var(--warn-bg); color: var(--warn); }
.profile-warn .profile-dot { background: var(--warn); }
.profile-danger { background: var(--danger-bg); color: var(--danger); }
.profile-danger .profile-dot { background: var(--danger); }

/* ─── LEVELS GRID ────────────────────────────────────────────── */
.levels-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.level-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.4rem 1.2rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: .6rem;
  transition: border-color var(--fast) var(--ease);
  position: relative;
  overflow: hidden;
}
.level-card.is-overflow {
  border-color: var(--danger-border);
  background: var(--danger-bg);
}

.level-card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.level-label {
  font-size: .65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--ink-3);
}
.level-interval-tag {
  font-size: .65rem;
  font-weight: 500;
  color: var(--ink-3);
  background: var(--surface-alt);
  padding: .15rem .45rem;
  border-radius: 99px;
  border: 1px solid var(--border);
}
.level-card.is-overflow .level-interval-tag {
  background: #fff;
  border-color: var(--danger-border);
}

.level-count {
  font-size: 2.8rem;
  font-weight: 300;
  letter-spacing: -.05em;
  color: var(--ink);
  line-height: 1;
}
.level-card.is-overflow .level-count { color: var(--danger); font-weight: 400; }

.level-unit {
  font-size: .7rem;
  color: var(--ink-3);
  margin-top: -.2rem;
}

/* Progress track */
.level-progress-track {
  width: 100%;
  height: 5px;
  background: var(--surface-alt);
  border-radius: 99px;
  overflow: hidden;
}
.level-card.is-overflow .level-progress-track {
  background: rgba(220, 38, 38, .15);
}
.level-progress-fill {
  height: 100%;
  border-radius: 99px;
  background: var(--ink);
  width: 0;
  transition: width 800ms var(--ease);
}
.level-card.is-overflow .level-progress-fill {
  background: var(--danger);
  width: 100% !important;
}

.level-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.level-limit-label {
  font-size: .68rem;
  color: var(--ink-3);
}
.overflow-badge {
  font-size: .6rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--danger);
  background: #fff;
  border: 1px solid var(--danger-border);
  padding: .15rem .45rem;
  border-radius: 3px;
  display: none;
}
.level-card.is-overflow .overflow-badge { display: block; }

/* ─── TWO-COLUMN LAYOUT ──────────────────────────────────────── */
.deck-body {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 1.5rem;
  align-items: start;
}

/* ─── SESSION PANEL ──────────────────────────────────────────── */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.panel-header {
  padding: 1.1rem 1.4rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: .5rem;
}
.panel-title {
  font-size: .82rem;
  font-weight: 600;
  color: var(--ink);
}
.panel-icon {
  font-size: .9rem;
}
.panel-body {
  padding: 1.4rem;
}

/* ─── SESSION FORM ───────────────────────────────────────────── */
.session-form { display: flex; flex-direction: column; gap: 1.2rem; }

.field-group { display: flex; flex-direction: column; gap: .4rem; }
.field-label {
  font-size: .72rem;
  font-weight: 600;
  color: var(--ink-2);
  text-transform: uppercase;
  letter-spacing: .04em;
}
.field-hint {
  font-size: .72rem;
  color: var(--ink-3);
  margin-top: .2rem;
}

.field-input-wrap {
  display: flex;
  align-items: center;
  gap: .5rem;
}

input[type="number"] {
  width: 100%;
  padding: .65rem .8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: .9rem;
  font-weight: 500;
  color: var(--ink);
  background: var(--surface);
  outline: none;
  transition: border-color var(--fast) var(--ease),
              box-shadow var(--fast) var(--ease);
  -moz-appearance: textfield;
}
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }
input[type="number"]:focus {
  border-color: var(--ink);
  box-shadow: 0 0 0 3px rgba(24,24,27,.08);
}

.flow-inputs {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: .4rem;
}
.flow-arrow {
  font-size: .7rem;
  color: var(--ink-3);
  font-weight: 600;
}
.flow-label {
  font-size: .65rem;
  color: var(--ink-3);
  text-align: center;
  display: block;
  margin-top: .3rem;
}

.divider {
  height: 1px;
  background: var(--border);
  margin: .2rem 0;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
}
.btn-submit {
  padding: .7rem 1.4rem;
  font-size: .85rem;
}

/* ─── HISTORY PANEL ──────────────────────────────────────────── */
.history-table {
  width: 100%;
  border-collapse: collapse;
}
.history-table th {
  text-align: left;
  font-size: .65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--ink-3);
  padding: .5rem .7rem;
  border-bottom: 1px solid var(--border);
}
.history-table td {
  padding: .75rem .7rem;
  font-size: .8rem;
  color: var(--ink-2);
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
.history-table tr:last-child td { border-bottom: none; }
.history-table tr:hover td { background: var(--surface-alt); }

.retention-chip {
  display: inline-block;
  padding: .15rem .45rem;
  border-radius: 4px;
  font-size: .72rem;
  font-weight: 600;
}
.ret-high  { background: var(--ok-bg);   color: var(--ok);   }
.ret-mid   { background: var(--warn-bg); color: var(--warn); }
.ret-low   { background: var(--danger-bg); color: var(--danger); }

.flow-cell {
  display: flex;
  flex-direction: column;
  gap: .1rem;
}
.flow-line {
  font-size: .72rem;
  color: var(--ink-3);
}
.flow-num {
  font-weight: 600;
  color: var(--ink);
}

.history-empty {
  padding: 2.5rem;
  text-align: center;
  color: var(--ink-3);
  font-size: .8rem;
}

/* ─── MODAL ──────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(247, 246, 243, .7);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--mid) var(--ease);
}
.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}
.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  padding: 2rem;
  width: min(420px, calc(100vw - 3rem));
  transform: translateY(12px) scale(.98);
  transition: transform var(--mid) var(--ease);
}
.modal-overlay.active .modal {
  transform: translateY(0) scale(1);
}
.modal-title {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -.01em;
  margin-bottom: 1.4rem;
}
.modal-field { margin-bottom: 1.4rem; }
.modal-label {
  display: block;
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--ink-2);
  margin-bottom: .5rem;
}
input[type="text"] {
  width: 100%;
  padding: .75rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: .95rem;
  font-weight: 500;
  outline: none;
  transition: border-color var(--fast) var(--ease), box-shadow var(--fast) var(--ease);
}
input[type="text"]:focus {
  border-color: var(--ink);
  box-shadow: 0 0 0 3px rgba(24,24,27,.08);
}
.modal-actions {
  display: flex;
  gap: .6rem;
  justify-content: flex-end;
}

/* ─── ANIMATIONS ─────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.fade-up {
  animation: fadeUp var(--slow) var(--ease) both;
}
.fade-in {
  animation: fadeIn var(--mid) var(--ease) both;
}

/* Staggered children */
.stagger > * { opacity: 0; }
.stagger.ready > *:nth-child(1) { animation: fadeUp var(--slow) 0ms   var(--ease) forwards; }
.stagger.ready > *:nth-child(2) { animation: fadeUp var(--slow) 60ms  var(--ease) forwards; }
.stagger.ready > *:nth-child(3) { animation: fadeUp var(--slow) 120ms var(--ease) forwards; }
.stagger.ready > *:nth-child(4) { animation: fadeUp var(--slow) 180ms var(--ease) forwards; }
.stagger.ready > *:nth-child(5) { animation: fadeUp var(--slow) 240ms var(--ease) forwards; }
.stagger.ready > *:nth-child(6) { animation: fadeUp var(--slow) 300ms var(--ease) forwards; }

/* ─── UTILITIES ──────────────────────────────────────────────── */
.hidden { display: none !important; }
.text-muted { color: var(--ink-3); font-size: .8rem; }

/* ─── RESPONSIVE ─────────────────────────────────────────────── */
@media (max-width: 840px) {
  .levels-grid { grid-template-columns: repeat(2, 1fr); }
  .deck-body   { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .page { padding: 1.5rem 1rem 4rem; }
  .topbar-inner { padding: 0 1rem; }
  .levels-grid { grid-template-columns: repeat(2, 1fr); }
}