:root {
  color-scheme: dark;
  --bg: #0f141d;
  --panel: #171d29;
  --panel-2: #202838;
  --text: #f3f6fb;
  --muted: #9ca7ba;
  --primary: #335cba;
  --gray: #6b707f;
  --green: #1f8c48;
  --red: #bd3030;
  --radius: 16px;
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.24);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
}

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

button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: var(--radius);
  background: var(--primary);
  color: var(--text);
  font-weight: 700;
  min-height: 46px;
  padding: 0 16px;
  cursor: pointer;
  transition: transform 0.12s ease, opacity 0.12s ease, filter 0.12s ease;
}

.material-symbols-rounded {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: "Material Symbols Rounded";
  font-size: 24px;
  font-style: normal;
  font-weight: normal;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  white-space: nowrap;
  direction: ltr;
  font-feature-settings: "liga";
  font-variation-settings: "FILL" 0, "wght" 500, "GRAD" 0, "opsz" 24;
  -webkit-font-smoothing: antialiased;
}

button:active {
  transform: scale(0.98);
}

button:disabled {
  cursor: default;
  opacity: 0.55;
  transform: none;
}

.app-shell {
  width: min(860px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: max(12px, env(safe-area-inset-top)) 12px max(16px, env(safe-area-inset-bottom));
}

.view {
  display: flex;
  min-height: calc(100vh - 28px);
  flex-direction: column;
  gap: 12px;
}

.practice-view {
  height: calc(100vh - 28px);
  max-height: calc(100vh - 28px);
  overflow: hidden;
}

.login-view {
  display: grid;
  min-height: calc(100vh - 28px);
  place-items: center;
  padding: 20px 0;
}

.login-card {
  display: grid;
  width: min(420px, 100%);
  gap: 14px;
  border-radius: 20px;
  background: var(--panel);
  box-shadow: var(--shadow);
  padding: 20px;
}

.login-card h1 {
  margin: 0 0 4px;
  text-align: center;
  font-size: 24px;
}

.login-card label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-weight: 700;
}

.warning-text {
  margin: 0;
  border-radius: 14px;
  background: rgba(189, 48, 48, 0.18);
  color: #ffd4d4;
  padding: 12px;
}

.header {
  position: relative;
  min-height: 40px;
  flex: 0 0 auto;
}

.header h1 {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  padding: 0 116px;
  text-align: center;
  font-size: 18px;
  line-height: 1.2;
  pointer-events: none;
}

.header .left,
.header .right {
  position: absolute;
  top: 0;
  height: 40px;
  min-height: 40px;
  padding: 0 12px;
  z-index: 1;
}

.header .left {
  left: 0;
}

.header .right {
  right: 0;
}

.icon-btn {
  width: 44px;
  padding: 0;
}

.icon-action {
  min-height: 54px;
}

.icon-action .material-symbols-rounded {
  font-size: 28px;
}

.scroll {
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}

.home-scroll,
.content-scroll {
  flex: 1 1 auto;
}

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

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.stat {
  min-height: 72px;
  border-radius: var(--radius);
  background: var(--panel);
  padding: 12px;
  text-align: center;
}

.stat.green {
  background: rgba(31, 140, 72, 0.82);
}

.stat.red {
  background: rgba(189, 48, 48, 0.82);
}

.stat.gray {
  background: #2a303d;
}

.stat .label {
  display: block;
  color: rgba(255, 255, 255, 0.78);
  font-size: 13px;
}

.stat .value {
  display: block;
  margin-top: 6px;
  font-size: 26px;
  font-weight: 800;
}

.half-button {
  align-self: center;
  position: relative;
  width: min(82%, 440px);
  min-width: 240px;
  min-height: 70px;
  overflow: hidden;
  font-size: 17px;
}

.half-button.due-ready {
  box-shadow: inset -28px 0 42px rgba(255, 255, 255, 0.12);
}

.half-button.due-ready::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 60, 60, 0.3) 12%,
    rgba(255, 180, 60, 0.32) 25%,
    rgba(255, 245, 80, 0.3) 38%,
    rgba(70, 220, 120, 0.32) 52%,
    rgba(60, 170, 255, 0.32) 67%,
    rgba(145, 90, 255, 0.3) 82%,
    transparent 100%
  );
  transform: translateX(-115%);
  animation: rainbow-inset 2.2s linear infinite;
  mix-blend-mode: screen;
}

.section-title {
  margin: 8px 0 0;
  font-size: 18px;
}

.category-list,
.card-list {
  display: grid;
  gap: 10px;
}

.category-row-wrap {
  display: grid;
  grid-template-columns: 1fr 48px;
  gap: 10px;
}

.category-row,
.card-row {
  width: 100%;
  min-height: 58px;
  padding: 10px 12px;
  justify-content: flex-start;
  text-align: left;
  white-space: normal;
}

.card-row {
  min-height: 0;
  padding: 9px 12px;
  flex-direction: column;
  align-items: flex-start;
}

.category-row strong,
.card-row strong {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-row small {
  display: block;
  margin-top: 4px;
  color: inherit;
  opacity: 0.78;
}

.edit-btn {
  width: 48px;
  padding: 0;
}

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

.card-stage {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  gap: 12px;
}

.learn-card,
.editor-card {
  display: flex;
  flex: 1 1 auto;
  min-height: 330px;
  flex-direction: column;
  border-radius: var(--radius);
  padding: 14px;
}

.practice-card {
  min-height: 0;
  overflow: hidden;
}

.learn-meta {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  font-size: 13px;
  opacity: 0.82;
}

.learn-meta-left {
  display: grid;
  gap: 3px;
  text-align: left;
}

.card-text {
  display: flex;
  flex: 1 1 auto;
  min-height: 0;
  align-items: flex-start;
  justify-content: center;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  padding: 16px 8px;
  font-size: 21px;
  line-height: 1.35;
}

.rich-content {
  width: fit-content;
  max-width: min(100%, 680px);
  margin: auto;
  text-align: left;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  word-break: normal;
}

.completion-text .rich-content {
  text-align: center;
}

.rich-bullets {
  display: block;
  width: 100%;
  margin: 0.35em 0;
  padding-left: 1.25em;
  text-align: left;
  white-space: normal;
}

.rich-bullets li {
  margin: 0.25em 0;
  padding-left: 0.15em;
}

.practice-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.flip-action {
  grid-column: 1 / -1;
}

.red-btn {
  background: var(--red);
}

.green-btn {
  background: var(--green);
}

.gray-btn {
  background: var(--gray);
}

.form {
  display: grid;
  gap: 12px;
}

.form label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  border: 0;
  border-radius: 14px;
  background: var(--panel);
  color: var(--text);
  min-height: 44px;
  padding: 12px;
  outline: 1px solid transparent;
}

input:focus,
select:focus,
textarea:focus {
  outline-color: rgba(85, 126, 220, 0.8);
}

textarea {
  min-height: 128px;
  resize: vertical;
}

.toolbar {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 5px;
}

.toolbar button {
  min-height: 40px;
  padding: 0;
  background: var(--panel-2);
}

.toolbar .material-symbols-rounded {
  font-size: 22px;
}

.toolbar .font-size-small .material-symbols-rounded {
  font-size: 18px;
}

.toolbar .font-size-medium .material-symbols-rounded {
  font-size: 23px;
}

.toolbar .font-size-large .material-symbols-rounded {
  font-size: 29px;
}

.editor-card {
  min-height: 300px;
}

.preview-text {
  display: flex;
  min-height: 140px;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  line-height: 1.35;
}

.editor-textarea {
  margin-top: 12px;
  background: #151a24;
  color: var(--text);
}

.row {
  display: flex;
  gap: 10px;
}

.row > * {
  flex: 1 1 0;
}

.tier-row {
  display: grid;
  grid-template-columns: auto repeat(6, minmax(0, 1fr));
  align-items: center;
  gap: 6px;
}

.tier-row button {
  padding: 0;
}

.tier-row button.inactive {
  background: var(--gray);
}

.settings-card,
.color-preview {
  border-radius: var(--radius);
  background: var(--panel);
  padding: 12px;
}

.settings-card {
  display: grid;
  gap: 10px;
}

.compact-text {
  margin: 0;
}

.interval-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.interval-grid label {
  display: grid;
  grid-template-columns: 1fr;
  gap: 5px;
  border-radius: 14px;
  background: var(--panel-2);
  padding: 8px;
}

.interval-grid span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.interval-grid input {
  min-height: 38px;
  padding: 8px;
  text-align: center;
}

.interval-grid small {
  color: var(--muted);
  text-align: center;
  font-size: 11px;
}

.slider-row {
  display: grid;
  grid-template-columns: minmax(92px, 30%) minmax(0, 1fr);
  align-items: center;
  gap: 12px;
  padding-right: 10px;
}

input[type="range"] {
  min-height: 36px;
  padding: 0;
  cursor: grab;
  touch-action: pan-y;
  accent-color: var(--primary);
}

input[type="range"]:active {
  cursor: grabbing;
}

input[type="range"]:disabled {
  cursor: default;
  opacity: 0.45;
}

.disabled-control {
  opacity: 0.55;
}

.toggle-row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
  padding-right: 8px;
}

input[type="checkbox"] {
  width: 22px;
  min-height: 22px;
  padding: 0;
  accent-color: var(--primary);
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(0, 0, 0, 0.58);
}

.modal {
  width: min(440px, 100%);
  border-radius: 18px;
  background: #111722;
  box-shadow: var(--shadow);
  padding: 18px;
}

.modal h2 {
  margin: 0 0 12px;
  text-align: center;
  font-size: 19px;
}

.modal-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 16px;
}

.stacked-actions {
  grid-template-columns: 1fr;
}

.bottom-actions {
  display: flex;
  justify-content: center;
  flex: 0 0 auto;
}

@keyframes rainbow-inset {
  0% {
    transform: translateX(-115%);
  }
  100% {
    transform: translateX(115%);
  }
}

@media (max-width: 520px) {
  .app-shell {
    padding-left: 10px;
    padding-right: 10px;
  }

  .header h1 {
    padding: 0 86px;
  }

  .toolbar {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .interval-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .row {
    flex-direction: column;
  }
}