/* ITSL Tutor — mobile-first dark theme. No external assets except local KaTeX. */

:root {
  color-scheme: dark;
  --bg: #0b0f14;
  --card: #111820;
  --card-2: #0d141c;
  --card-3: #151e28;
  --border: #1f2a37;
  --border-strong: #2b3949;
  --text: #e6edf3;
  --muted: #94a3b8;
  --faint: #64748b;
  --accent: #6ea8fe;
  --accent-strong: #8ab8ff;
  --accent-soft: rgba(110, 168, 254, 0.14);
  --success: #34d399;
  --success-soft: rgba(52, 211, 153, 0.13);
  --warn: #fbbf24;
  --warn-soft: rgba(251, 191, 36, 0.13);
  --danger: #f87171;
  --danger-soft: rgba(248, 113, 113, 0.13);
  --radius: 16px;
  --radius-sm: 12px;
  --tap: 44px;
  --nav-h: 64px;
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-top: env(safe-area-inset-top, 0px);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.26);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 16px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  background: var(--bg);
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(700px 320px at 50% -140px, rgba(110, 168, 254, 0.13), transparent 72%),
    var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.55;
  overflow-x: hidden;
  overflow-x: clip;
  -webkit-tap-highlight-color: transparent;
}

body.modal-open {
  overflow: hidden;
}

button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: 0;
  background: none;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

a {
  color: var(--accent);
}

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

svg {
  display: block;
  flex: none;
}

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

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.muted {
  color: var(--muted);
}

.small {
  font-size: 0.8125rem;
  line-height: 1.45;
}

.mono {
  font-family: var(--mono);
}

.accent {
  color: var(--accent);
}

.success {
  color: var(--success);
}

.warn {
  color: var(--warn);
}

.danger {
  color: var(--danger);
}

.app-shell {
  position: relative;
  width: 100%;
  max-width: 520px;
  min-height: 100vh;
  margin: 0 auto;
  padding-bottom: calc(var(--nav-h) + var(--safe-bottom) + 18px);
}

/* ---------- Sticky top bar ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  padding-top: var(--safe-top);
  background: rgba(11, 15, 20, 0.9);
  border-bottom: 1px solid rgba(31, 42, 55, 0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.topbar-inner {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 62px;
  max-width: 520px;
  margin: 0 auto;
  padding: 8px 16px;
}

.topbar-text {
  min-width: 0;
  flex: 1;
}

.eyebrow {
  color: var(--muted);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.top-title {
  color: var(--text);
  font-size: 1.375rem;
  font-weight: 750;
  letter-spacing: -0.02em;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.top-meta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex: none;
  padding: 5px 9px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--card-2);
  color: var(--muted);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.offline-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 3px var(--success-soft);
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--tap);
  height: var(--tap);
  min-width: var(--tap);
  border-radius: 12px;
  color: var(--text);
  border: 1px solid transparent;
}

.icon-btn:hover {
  background: var(--card-3);
}

.back-btn {
  margin-left: -8px;
  color: var(--accent);
}

/* ---------- Layout ---------- */

.view {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
  outline: none;
}

.view-inner {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 16px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  min-width: 0;
}

.stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.spacer {
  flex: 1;
}

.section {
  display: flex;
  flex-direction: column;
  gap: 9px;
  min-width: 0;
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 2px 2px 0;
}

.section-title {
  color: var(--text);
  font-size: 0.8125rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-note {
  color: var(--faint);
  font-size: 0.75rem;
}

/* ---------- Today ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding: 18px;
  background:
    radial-gradient(320px 150px at 100% 0%, rgba(110, 168, 254, 0.17), transparent 70%),
    linear-gradient(180deg, #131d29, var(--card));
  border-color: #253449;
}

.hero .eyebrow {
  color: var(--accent);
}

.hero-main {
  display: flex;
  align-items: baseline;
  gap: 9px;
  margin: 2px 0 2px;
}

.hero-days {
  font-size: 3.5rem;
  line-height: 1;
  font-weight: 800;
  letter-spacing: -0.05em;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.hero-unit {
  color: var(--muted);
  font-size: 1rem;
  font-weight: 650;
}

.hero-date {
  color: var(--text);
  font-size: 0.9375rem;
  font-weight: 600;
}

.hero-sub {
  color: var(--muted);
  font-size: 0.8125rem;
  margin-top: 3px;
}

.hero-foot {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  padding-top: 11px;
  border-top: 1px solid rgba(43, 57, 73, 0.7);
  color: var(--muted);
  font-size: 0.8125rem;
}

.today-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.goal-card {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 16px;
}

.ring-wrap {
  position: relative;
  width: 82px;
  height: 82px;
  flex: none;
}

.ring {
  width: 82px;
  height: 82px;
  transform: rotate(-90deg);
}

.ring-track {
  fill: none;
  stroke: #1c2734;
  stroke-width: 8;
}

.ring-fill {
  fill: none;
  stroke: var(--accent);
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dashoffset 240ms ease;
}

.ring-center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  line-height: 1.05;
}

.ring-count {
  font-size: 1.375rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}

.ring-of {
  color: var(--muted);
  font-size: 0.6875rem;
  font-weight: 650;
}

.goal-text {
  min-width: 0;
}

.goal-title {
  font-size: 1rem;
  font-weight: 700;
}

.goal-copy {
  color: var(--muted);
  font-size: 0.8125rem;
  margin-top: 3px;
}

.metric {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 13px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--card);
  min-width: 0;
}

.metric-label {
  color: var(--muted);
  font-size: 0.71875rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.metric-value {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 1.625rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.metric-unit {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0;
}

.cta {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  min-height: 76px;
  padding: 14px 16px;
  border-radius: var(--radius);
  border: 1px solid rgba(110, 168, 254, 0.4);
  background:
    linear-gradient(180deg, rgba(110, 168, 254, 0.17), rgba(110, 168, 254, 0.08)),
    var(--card);
  color: var(--text);
  text-align: left;
  transition: transform 120ms ease, border-color 120ms ease;
}

.cta:active {
  transform: scale(0.99);
}

.cta-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: none;
  width: 46px;
  height: 46px;
  border-radius: 13px;
  background: var(--accent);
  color: #07111f;
  font-size: 1.375rem;
  font-weight: 800;
}

.cta-text {
  flex: 1;
  min-width: 0;
}

.cta-title {
  display: block;
  font-size: 1.0625rem;
  font-weight: 750;
  letter-spacing: -0.01em;
}

.cta-sub {
  display: block;
  color: var(--muted);
  font-size: 0.8125rem;
  margin-top: 2px;
}

.cta-chev {
  color: var(--accent);
  font-size: 1.5rem;
  line-height: 1;
}

.topic-list,
.due-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.topic-row {
  display: flex;
  flex-direction: column;
  gap: 7px;
  width: 100%;
  min-height: var(--tap);
  padding: 11px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--card-2);
  text-align: left;
}

.topic-row:hover {
  border-color: var(--border-strong);
}

.topic-row-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.topic-name {
  font-size: 0.9375rem;
  font-weight: 650;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.topic-acc {
  flex: none;
  color: var(--muted);
  font-size: 0.8125rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.due-item {
  display: flex;
  align-items: center;
  gap: 11px;
  width: 100%;
  min-height: 58px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--card-2);
  text-align: left;
}

.due-item:hover {
  border-color: var(--border-strong);
}

.due-main {
  flex: 1;
  min-width: 0;
}

.due-name {
  display: block;
  font-size: 0.9375rem;
  font-weight: 650;
  line-height: 1.35;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.due-meta {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
  margin-top: 2px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.due-badge {
  flex: none;
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.6875rem;
  font-weight: 750;
  white-space: nowrap;
}

/* ---------- Badges / pills ---------- */

.pill,
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  border-radius: 999px;
  font-size: 0.6875rem;
  font-weight: 750;
  letter-spacing: 0.02em;
  line-height: 1;
  white-space: nowrap;
}

.pill {
  height: 24px;
  padding: 0 9px;
  border: 1px solid var(--border-strong);
  color: var(--muted);
  background: var(--card-2);
}

.pill.lecture {
  color: var(--accent);
  border-color: rgba(110, 168, 254, 0.35);
  background: var(--accent-soft);
}

.pill.topic {
  max-width: 190px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: inline-block;
  line-height: 22px;
}

.badge {
  height: 22px;
  padding: 0 8px;
  background: #172130;
  color: var(--muted);
  border: 1px solid var(--border-strong);
}

.badge.bloom {
  color: var(--bloom, var(--accent));
  border-color: var(--border-strong);
  border-color: color-mix(in srgb, var(--bloom, var(--accent)) 36%, transparent);
  background: rgba(148, 163, 184, 0.1);
  background: color-mix(in srgb, var(--bloom, var(--accent)) 13%, transparent);
}

.bloom.l1 { --bloom: #94a3b8; }
.bloom.l2 { --bloom: #6ea8fe; }
.bloom.l3 { --bloom: #34d399; }
.bloom.l4 { --bloom: #c084fc; }
.bloom.l5 { --bloom: #fbbf24; }
.bloom.l6 { --bloom: #f472b6; }

.badge.status-full {
  color: var(--success);
  border-color: rgba(52, 211, 153, 0.35);
  background: var(--success-soft);
}

.badge.status-outline {
  color: var(--warn);
  border-color: rgba(251, 191, 36, 0.35);
  background: var(--warn-soft);
}

/* ---------- Library ---------- */

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 14px;
  color: var(--faint);
  pointer-events: none;
}

.search-input {
  width: 100%;
  min-height: 50px;
  padding: 0 14px 0 42px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  color: var(--text);
  font-size: 1rem;
  -webkit-appearance: none;
  appearance: none;
}

.search-input::placeholder {
  color: var(--faint);
}

.search-input:focus {
  border-color: var(--accent);
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.filter-groups {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.chip-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.chip-group-label {
  color: var(--faint);
  font-size: 0.6875rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-left: 2px;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  min-height: var(--tap);
  padding: 0 13px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--card);
  color: var(--muted);
  font-size: 0.8125rem;
  font-weight: 650;
  transition: border-color 120ms ease, color 120ms ease, background 120ms ease;
}

.chip:hover {
  border-color: var(--border-strong);
}

.chip.active,
.chip[aria-pressed="true"] {
  border-color: rgba(110, 168, 254, 0.55);
  background: var(--accent-soft);
  color: var(--accent);
}

.result-count {
  color: var(--muted);
  font-size: 0.8125rem;
  padding: 0 2px;
}

.lib-list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.lib-card {
  display: block;
  width: 100%;
  padding: 13px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--card);
  color: var(--text);
  text-align: left;
  min-height: 76px;
  transition: border-color 120ms ease, transform 120ms ease;
}

.lib-card:hover {
  border-color: var(--border-strong);
}

.lib-card:active {
  transform: scale(0.995);
}

.lib-top {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 7px;
}

.lib-name {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.005em;
  overflow-wrap: break-word;
}

.lib-meta {
  display: block;
  color: var(--muted);
  font-size: 0.8125rem;
  margin-top: 4px;
  overflow-wrap: break-word;
}

/* ---------- Detail ---------- */

.detail-head {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.detail-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.detail-title {
  font-size: 1.3125rem;
  font-weight: 780;
  letter-spacing: -0.02em;
  line-height: 1.3;
  overflow-wrap: break-word;
}

.detail-sub {
  color: var(--muted);
  font-size: 0.875rem;
  overflow-wrap: anywhere;
}

.formula-block {
  overflow: hidden;
  padding: 12px 10px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #0a1016;
}

.detail-section {
  padding: 15px 16px;
}

.detail-section .section-title {
  margin-bottom: 9px;
  display: block;
}

.section-body {
  color: #cfdae6;
  font-size: 0.9375rem;
  overflow-wrap: break-word;
}

.section-body p + p {
  margin-top: 8px;
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.step {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 12px;
  border-left: 2px solid #223143;
  min-width: 0;
}

.step-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  flex: none;
  border-radius: 50%;
  background: #1a2634;
  color: var(--accent);
  font-size: 0.6875rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}

.step-why {
  color: #cfdae6;
  font-size: 0.9rem;
}

.bloom-note {
  display: block;
  padding: 8px 10px;
  border-radius: 9px;
  background: var(--card-2);
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.8125rem;
}

.bloom-note strong {
  color: var(--text);
  font-weight: 700;
}

.step-src {
  color: var(--faint);
  font-size: 0.75rem;
}

.example-prompt {
  color: var(--text);
  font-size: 0.9375rem;
  font-weight: 550;
}

.answer-box {
  margin-top: 10px;
  padding: 11px 12px;
  border: 1px solid rgba(52, 211, 153, 0.3);
  border-radius: 10px;
  background: var(--success-soft);
}

.answer-label {
  display: block;
  color: var(--success);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.answer-text {
  color: #d7f5e8;
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.5;
  overflow-wrap: break-word;
}

.traps {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.traps li {
  position: relative;
  padding-left: 24px;
  color: #d6dee8;
  font-size: 0.9rem;
}

.traps li::before {
  content: "!";
  position: absolute;
  left: 0;
  top: 1px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  background: var(--warn-soft);
  color: var(--warn);
  font-size: 0.6875rem;
  font-weight: 800;
}

.sources {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.source-row {
  display: grid;
  grid-template-columns: 62px 1fr;
  gap: 10px;
  align-items: baseline;
  font-size: 0.875rem;
}

.source-key {
  color: var(--faint);
  font-size: 0.71875rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.source-val {
  color: #cfdae6;
  overflow-wrap: break-word;
}

.prereq-list {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.prereq-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  max-width: 100%;
  min-height: var(--tap);
  padding: 0 13px;
  border: 1px solid rgba(110, 168, 254, 0.3);
  border-radius: 11px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 700;
  font-family: var(--mono);
  overflow-wrap: anywhere;
}

.prereq-btn.missing {
  border-color: rgba(251, 191, 36, 0.35);
  background: var(--warn-soft);
  color: var(--warn);
}

.prereq-btn .missing-tag {
  font-family: var(--font);
  font-size: 0.625rem;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ---------- Drill ---------- */

.drill-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mode-switch {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card-2);
}

.mode-btn {
  min-height: var(--tap);
  padding: 0 8px;
  border-radius: 10px;
  color: var(--muted);
  font-size: 0.875rem;
  font-weight: 700;
  transition: background 120ms ease, color 120ms ease;
}

.mode-btn:hover {
  color: var(--text);
}

.mode-btn[aria-pressed="true"] {
  background: var(--accent);
  color: #07111f;
}

.drill-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.8125rem;
}

.timer-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  background: var(--card-2);
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 650;
  font-variant-numeric: tabular-nums;
}

.timer-chip .timer-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.timer-chip.paused .timer-dot {
  background: var(--muted);
}

.progress-chip {
  margin-left: auto;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.drill-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 17px 16px;
  min-height: 180px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(180deg, #121a24, var(--card));
  box-shadow: var(--shadow);
  min-width: 0;
}

.mode-label {
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--accent);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.drill-name {
  font-size: 1.25rem;
  font-weight: 780;
  letter-spacing: -0.02em;
  line-height: 1.3;
  overflow-wrap: break-word;
}

.drill-statement {
  color: #cbd6e2;
  font-size: 0.9375rem;
  overflow-wrap: break-word;
}

.hidden-note {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  padding: 11px 12px;
  border: 1px dashed var(--border-strong);
  border-radius: 11px;
  color: var(--muted);
  background: rgba(13, 20, 28, 0.65);
  font-size: 0.875rem;
}

.hidden-note .lock {
  color: var(--accent);
  font-size: 1rem;
  line-height: 1.2;
}

.drill-actions {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  align-items: stretch;
}

.reveal-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.checklist {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 12px;
  border: 1px solid rgba(52, 211, 153, 0.26);
  border-radius: 11px;
  background: var(--success-soft);
}

.checklist-title {
  color: var(--success);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.checklist li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  color: #d7e5df;
  font-size: 0.875rem;
}

.checklist li::before {
  content: "";
  flex: none;
  width: 14px;
  height: 14px;
  margin-top: 3px;
  border: 1.5px solid var(--success);
  border-radius: 3px;
}

.grade-panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.grade-title {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.grade-row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}

.grade-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  min-height: 60px;
  padding: 6px 2px;
  border: 1px solid var(--border-strong);
  border-color: color-mix(in srgb, var(--g, var(--accent)) 40%, var(--border));
  border-radius: 11px;
  background: var(--card-2);
  color: var(--g, var(--text));
  transition: background 120ms ease, transform 120ms ease;
}

.grade-btn:hover {
  background: color-mix(in srgb, var(--g, var(--accent)) 13%, var(--card-2));
}

.grade-btn:active {
  transform: scale(0.97);
}

.grade-num {
  font-size: 1.125rem;
  font-weight: 800;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.grade-label {
  color: var(--muted);
  font-size: 0.625rem;
  font-weight: 650;
  line-height: 1.2;
}

.grade-0,
.grade-1 { --g: #f87171; }
.grade-2 { --g: #fbbf24; }
.grade-3 { --g: #34d399; }
.grade-4 { --g: #6ea8fe; }

.session-summary {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 26px 18px;
  text-align: center;
}

.summary-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: var(--success-soft);
  color: var(--success);
  font-size: 1.5rem;
  font-weight: 800;
}

.summary-title {
  font-size: 1.25rem;
  font-weight: 780;
}

.summary-score {
  color: var(--accent);
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

.summary-copy {
  color: var(--muted);
  font-size: 0.875rem;
  max-width: 34ch;
}

.summary-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  width: 100%;
  margin-top: 8px;
}

/* ---------- Stats ---------- */

.stat-hero {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.stat-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 14px;
}

.stat-block {
  min-width: 0;
}

.stat-label {
  color: var(--muted);
  font-size: 0.6875rem;
  font-weight: 750;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.stat-value {
  font-size: 2.125rem;
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.15;
  font-variant-numeric: tabular-nums;
}

.stat-value.smaller {
  font-size: 1.5rem;
}

.stat-sub {
  color: var(--muted);
  font-size: 0.75rem;
  line-height: 1.4;
}

.projected-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 10px;
}

.score-line {
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.score-big {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.score-unit {
  color: var(--muted);
  font-size: 0.875rem;
  font-weight: 650;
}

.range-chip {
  flex: none;
  padding: 5px 9px;
  border: 1px solid rgba(110, 168, 254, 0.3);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.71875rem;
  font-weight: 750;
  white-space: nowrap;
}

.range-track {
  position: relative;
  height: 8px;
  margin-top: 12px;
  border-radius: 999px;
  background: #0a1016;
  border: 1px solid var(--border);
}

.range-band {
  position: absolute;
  top: 0;
  bottom: 0;
  border-radius: 999px;
  background: rgba(110, 168, 254, 0.25);
}

.range-marker {
  position: absolute;
  top: 50%;
  width: 12px;
  height: 12px;
  margin-left: -6px;
  transform: translateY(-50%);
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid #0b0f14;
  box-shadow: 0 0 0 2px rgba(110, 168, 254, 0.4);
}

.range-labels {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-top: 7px;
  color: var(--faint);
  font-size: 0.6875rem;
  font-variant-numeric: tabular-nums;
}

.bar-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.bar-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.bar-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.bar-label {
  display: flex;
  align-items: center;
  gap: 7px;
  min-width: 0;
  font-size: 0.875rem;
  font-weight: 650;
  overflow-wrap: break-word;
}

.bar-value {
  flex: none;
  color: var(--muted);
  font-size: 0.8125rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.bar-track {
  height: 8px;
  border-radius: 999px;
  background: #0a1016;
  border: 1px solid var(--border);
  overflow: hidden;
}

.bar-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #4b8ff0, var(--accent-strong));
  min-width: 0;
  transition: width 260ms ease;
}

.bar-fill.weak {
  background: linear-gradient(90deg, #d97706, var(--warn));
}

.bar-fill.empty {
  background: #243242;
}

.bar-sub {
  color: var(--faint);
  font-size: 0.71875rem;
}

.activity {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  height: 78px;
  padding-top: 4px;
}

.act-day {
  display: flex;
  flex: 1;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  gap: 5px;
  min-width: 0;
  height: 100%;
}

.act-bar {
  width: 100%;
  min-height: 4px;
  border-radius: 4px 4px 2px 2px;
  background: #223143;
}

.act-bar.has {
  background: linear-gradient(180deg, var(--accent), #3f74bd);
}

.act-bar.today {
  outline: 1px solid rgba(110, 168, 254, 0.55);
  outline-offset: 1px;
}

.act-label {
  color: var(--faint);
  font-size: 0.59375rem;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.activity-cap {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-top: 8px;
  color: var(--faint);
  font-size: 0.71875rem;
}

.data-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.data-actions .full {
  grid-column: 1 / -1;
}

.storage-note {
  color: var(--faint);
  font-size: 0.71875rem;
  margin-top: 8px;
  overflow-wrap: anywhere;
}

/* ---------- Settings ---------- */

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-label {
  color: var(--text);
  font-size: 0.875rem;
  font-weight: 650;
}

.field-hint {
  color: var(--faint);
  font-size: 0.75rem;
  line-height: 1.4;
}

.input {
  width: 100%;
  min-height: 48px;
  padding: 0 13px;
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  background: #0b1118;
  color: var(--text);
  font-size: 1rem;
  -webkit-appearance: none;
  appearance: none;
}

.input:focus {
  border-color: var(--accent);
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.input[type="date"] {
  min-height: 48px;
}

.about-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.about-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8125rem;
}

.about-row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.about-key {
  color: var(--muted);
  flex: none;
}

.about-val {
  color: var(--text);
  text-align: right;
  overflow-wrap: anywhere;
}

.about-copy {
  color: var(--muted);
  font-size: 0.8125rem;
  overflow-wrap: break-word;
}

.about-copy code {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--card-2);
  padding: 1px 4px;
  border-radius: 4px;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: var(--tap);
  padding: 0 15px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-size: 0.9375rem;
  font-weight: 700;
  text-align: center;
  transition: background 120ms ease, border-color 120ms ease, transform 120ms ease;
}

.btn:active {
  transform: scale(0.985);
}

.btn.primary {
  background: var(--accent);
  color: #07111f;
  border-color: var(--accent);
}

.btn.primary:hover {
  background: var(--accent-strong);
}

.btn.secondary {
  background: var(--card-2);
  color: var(--text);
  border-color: var(--border-strong);
}

.btn.secondary:hover {
  border-color: var(--accent);
}

.btn.ghost {
  background: transparent;
  color: var(--muted);
  border-color: var(--border);
}

.btn.ghost:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.btn.danger {
  background: var(--danger-soft);
  color: var(--danger);
  border-color: rgba(248, 113, 113, 0.4);
}

.btn.danger:hover {
  background: rgba(248, 113, 113, 0.2);
}

.btn.wide {
  width: 100%;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

/* ---------- Empty states ---------- */

.empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  padding: 34px 20px;
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius);
  background: rgba(17, 24, 32, 0.55);
  text-align: center;
}

.empty-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--card-3);
  color: var(--accent);
  font-size: 1.25rem;
  font-weight: 800;
}

.empty-title {
  font-size: 1rem;
  font-weight: 700;
}

.empty-text {
  color: var(--muted);
  font-size: 0.8125rem;
  max-width: 38ch;
}

.empty .btn {
  margin-top: 8px;
}

/* ---------- Math / KaTeX ---------- */

.math {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-x: contain;
  padding: 2px 0;
  font-size: 1rem;
}

.math .katex-display {
  margin: 0.15em 0;
  text-align: left;
}

.math .katex-display > .katex {
  text-align: left;
  white-space: nowrap;
}

.math .katex {
  font-size: 1.05em;
}

.math-raw {
  display: block;
  padding: 10px 11px;
  border: 1px dashed rgba(251, 191, 36, 0.45);
  border-radius: 8px;
  background: rgba(251, 191, 36, 0.06);
  color: var(--warn);
  font-family: var(--mono);
  font-size: 0.8125rem;
  line-height: 1.5;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.math-missing {
  color: var(--faint);
  font-size: 0.8125rem;
  font-style: italic;
}

/* ---------- Bottom nav ---------- */

.bottom-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 40;
  background: rgba(13, 19, 26, 0.96);
  border-top: 1px solid var(--border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 -8px 24px rgba(0, 0, 0, 0.28);
}

.nav-inner {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 2px;
  max-width: 520px;
  margin: 0 auto;
  padding: 6px 8px calc(6px + var(--safe-bottom));
}

.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  min-height: 52px;
  padding: 4px 2px;
  border-radius: 11px;
  color: var(--faint);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  transition: color 120ms ease, background 120ms ease;
}

.nav-btn:hover {
  color: var(--muted);
  background: rgba(255, 255, 255, 0.03);
}

.nav-btn.active {
  color: var(--accent);
  background: var(--accent-soft);
}

.nav-btn svg {
  opacity: 0.9;
}

/* ---------- Toasts ---------- */

.toast-region {
  position: fixed;
  left: 50%;
  bottom: calc(var(--nav-h) + var(--safe-bottom) + 14px);
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  width: min(440px, calc(100vw - 28px));
  transform: translateX(-50%);
  pointer-events: none;
}

.toast {
  max-width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border-strong);
  border-radius: 11px;
  background: rgba(21, 30, 40, 0.98);
  color: var(--text);
  box-shadow: var(--shadow);
  font-size: 0.8125rem;
  font-weight: 600;
  text-align: center;
  overflow-wrap: break-word;
  animation: toast-in 160ms ease-out;
}

.toast.success {
  border-color: rgba(52, 211, 153, 0.45);
  color: #a7f3d0;
}

.toast.warn {
  border-color: rgba(251, 191, 36, 0.45);
  color: #fde68a;
}

@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- Modal ---------- */

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 12px;
  padding-bottom: calc(12px + var(--safe-bottom));
  background: rgba(3, 6, 10, 0.76);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.modal {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 480px;
  max-height: 86vh;
  border: 1px solid var(--border-strong);
  border-radius: 20px;
  background: var(--card);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.modal-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 15px 14px 12px 18px;
  border-bottom: 1px solid var(--border);
}

.modal-title {
  flex: 1;
  font-size: 1.0625rem;
  font-weight: 750;
  letter-spacing: -0.01em;
}

.modal-close {
  color: var(--muted);
}

.modal-body {
  padding: 15px 18px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.modal-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 12px 18px calc(14px + var(--safe-bottom));
  border-top: 1px solid var(--border);
}

.modal-actions .btn {
  flex: 1;
  min-width: 110px;
}

.modal-textarea {
  width: 100%;
  min-height: 170px;
  padding: 11px;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  background: #0a1016;
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.45;
  resize: vertical;
  overflow-wrap: anywhere;
}

.file-row {
  display: flex;
  align-items: center;
  gap: 9px;
  flex-wrap: wrap;
}

.modal-note {
  color: var(--muted);
  font-size: 0.8125rem;
}

.modal-note.danger {
  color: var(--danger);
}

/* ---------- Responsive / motion ---------- */

@media (min-width: 480px) {
  .modal-overlay {
    align-items: center;
  }

  .hero-days {
    font-size: 4rem;
  }
}

@media (max-width: 340px) {
  .stat-grid {
    grid-template-columns: 1fr;
  }

  .grade-label {
    font-size: 0.5625rem;
  }

  .today-grid {
    grid-template-columns: 1fr;
  }

  .goal-card {
    grid-column: auto;
  }

  .summary-actions,
  .data-actions {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}