/* Excel.Flo – gemeinsames Design-System für Übersicht & Übungen */

:root {
  --excel-green: #107C41;
  --excel-green-dark: #0B5C30;
  --excel-green-tint: #E9F6EE;
  --grid-gray: #D7DCE1;
  --header-gray: #F2F4F6;
  --error-red: #D92D20;
  --success-green: #15803D;

  --text-primary: #1F2A24;
  --text-muted: #5B6B63;
  --border-color: #E1E5E2;
  --surface: #FFFFFF;
  --page-bg: #F7F9F8;

  --font-heading: "Space Grotesk", sans-serif;
  --font-body: "Inter", sans-serif;
  --font-mono: "JetBrains Mono", monospace;
  --font-excel: "Aptos Narrow", Aptos, Calibri, "Segoe UI", Arial, sans-serif;
  --font-excel-ui: "Segoe UI", "Segoe UI Variable", system-ui, -apple-system, Arial, sans-serif;

  --radius: 10px;
  --shadow-card: 0 1px 2px rgba(16, 124, 65, 0.06), 0 4px 14px rgba(16, 124, 65, 0.06);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-body);
  background-color: var(--page-bg);
  background-image: url("img/bg-green.webp");
  background-size: cover;
  background-position: center top;
  background-repeat: no-repeat;
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  margin: 0;
  color: var(--text-primary);
}

/* ---------- Kopfbereich ---------- */

.site-header {
  background: linear-gradient(135deg, var(--excel-green) 0%, var(--excel-green-dark) 100%);
  color: #fff;
  padding: 1.1rem 1.5rem;
}

.site-header__inner {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: #fff;
}

.brand__icon {
  width: 26px;
  height: 32px;
  display: block;
  flex-shrink: 0;
}

.brand__icon img,
.brand__icon svg {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}

.brand__wordmark {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

.brand__wordmark .dot {
  opacity: 0.75;
}

.site-header__back {
  font-family: var(--font-body);
  font-size: 0.9rem;
  text-decoration: none;
  color: #fff;
  opacity: 0.9;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  transition: background 0.15s ease;
}

.site-header__back:hover {
  background: rgba(255, 255, 255, 0.24);
}

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

main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 2.25rem 1.5rem 4rem;
}

.page-intro {
  margin-bottom: 2rem;
}

.page-intro h1 {
  font-size: 1.75rem;
  margin-bottom: 0.5rem;
}

.page-intro p {
  color: var(--text-muted);
  max-width: 620px;
}

/* ---------- Übersichts-Karten ---------- */

.exercise-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.1rem;
}

.exercise-card {
  background: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-card);
  transition: transform 0.12s ease, box-shadow 0.12s ease, border-color 0.12s ease;
}

.exercise-card:hover {
  transform: translateY(-2px);
  border-color: var(--excel-green);
  box-shadow: 0 6px 20px rgba(16, 124, 65, 0.14);
}

.exercise-card__badges {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  text-transform: uppercase;
}

.badge--category {
  background: var(--excel-green-tint);
  color: var(--excel-green-dark);
}

.exercise-card h3 {
  font-size: 1.05rem;
}

.exercise-card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
  flex-grow: 1;
}

.exercise-card__cta {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.88rem;
  color: var(--excel-green);
}

.exercise-grid__empty {
  color: var(--text-muted);
  font-style: italic;
}

.badge--done {
  background: #E9F6EE;
  color: var(--success-green);
}

.badge--level {
  background: var(--header-gray);
  color: var(--text-muted);
}

.exercise-card.is-done {
  border-color: #BFE8CE;
}

/* ---------- Level-Tabs & Stufen-Banner ---------- */

.level-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 1.25rem;
}

.level-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.level-tab {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1rem;
  border-radius: 999px;
  border: 1.5px solid var(--border-color);
  background: var(--surface);
  color: var(--text-muted);
  cursor: pointer;
  transition: border-color 0.12s ease, color 0.12s ease, background 0.12s ease;
}

.level-tab:hover {
  border-color: var(--excel-green);
  color: var(--excel-green-dark);
}

.level-tab.is-active {
  background: var(--excel-green);
  border-color: var(--excel-green);
  color: #fff;
}

.level-tab__count {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  opacity: 0.85;
}

.level-reset__btn {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.8rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  border: 1.5px solid var(--border-color);
  background: var(--surface);
  color: var(--text-muted);
  cursor: pointer;
  transition: border-color 0.12s ease, color 0.12s ease, background 0.12s ease;
}

.level-reset__btn:hover {
  border-color: var(--error-red);
  color: var(--error-red);
  background: #FDF2F1;
}

.stage-banner {
  display: none;
  margin-bottom: 1.25rem;
}

.stage-banner.is-visible {
  display: block;
}

.stage-banner p {
  margin: 0;
  background: var(--excel-green-tint);
  border: 1px solid #CFEBDB;
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  color: var(--excel-green-dark);
  font-weight: 600;
}

/* ---------- Übungs-Seite ---------- */

.exercise-header {
  margin-bottom: 1.75rem;
}

.exercise-header__badges {
  display: flex;
  gap: 0.4rem;
  margin-bottom: 0.75rem;
}

.exercise-header h1 {
  font-size: 1.6rem;
  margin-bottom: 0.6rem;
}

.exercise-task {
  background: var(--excel-green-tint);
  border: 1px solid #CFEBDB;
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 1.75rem;
}

.exercise-task__intro {
  margin: 0 0 0.5rem;
  color: var(--text-primary);
}

.exercise-task__steps {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-primary);
}

.exercise-task__steps li {
  margin-bottom: 0.3rem;
}

.exercise-task__steps li:last-child {
  margin-bottom: 0;
}

/* ---------- Tabellen-Grid ---------- */

.sheet-wrap {
  position: relative;
  border: 1px solid #D4D4D4;
  border-radius: 10px;
  background: var(--surface);
  margin-bottom: 1.5rem;
}

/* overflow clippt die Tabelle an den abgerundeten unteren Ecken */
.sheet-scroll {
  overflow-x: auto;
  border-radius: 0 0 9px 9px;
}

/* Funktions-QuickInfo wie in Excel: weiß, feiner grauer Rahmen, aktuelles Argument fett */
.formula-hint {
  display: none;
  position: absolute;
  z-index: 10;
  background: #FFFFFF;
  color: #262626;
  border: 1px solid #C8C8C8;
  font-family: var(--font-excel-ui);
  font-size: 12px;
  padding: 3px 7px;
  border-radius: 2px;
  white-space: nowrap;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.14);
}

.formula-hint.is-visible {
  display: block;
}

.formula-hint .tok-func {
  color: #0F6CBD;
  font-weight: 400;
  text-decoration: underline;
}

.formula-hint .is-active {
  color: inherit;
  font-weight: 700;
  text-decoration: none;
}

/* Spaltenbreiten setzt engine.js: Datenspalten nach Inhalt, leere Spalten füllen die volle Breite */
table.sheet {
  border-collapse: collapse;
  table-layout: fixed;
  width: 100%;
  font-family: var(--font-excel);
  font-size: 15px; /* = CELL_FONT_SIZE in engine.js */
  color: #1F1F1F;
}

table.sheet th,
table.sheet td {
  border: 1px solid #E1E1E1;
  padding: 4px 8px;
  height: 28px;
  text-align: left;
  white-space: nowrap;
}

/* Spalten- und Zeilenköpfe wie in Excel 365: hellgrau, Segoe UI, aktive Kopfzelle mit grüner Kante */
table.sheet thead th,
table.sheet .row-head {
  background: #F5F5F5;
  border-color: #D4D4D4;
  color: #444;
  font-family: var(--font-excel-ui);
  font-size: 13px;
  font-weight: 400;
  text-align: center;
  transition: background 0.1s ease, color 0.1s ease;
}

table.sheet thead th {
  position: sticky;
  top: 0;
}

table.sheet .row-head {
  width: 34px;
  min-width: 34px;
  padding: 3px 4px;
}

table.sheet thead th.is-active {
  background: #E1E1E1;
  color: #0E6B37;
  box-shadow: inset 0 -2px 0 var(--excel-green);
}

table.sheet .row-head.is-active {
  background: #E1E1E1;
  color: #0E6B37;
  box-shadow: inset -2px 0 0 var(--excel-green);
}

/* Das kleine graue Dreieck in der linken oberen Ecke ("Alles auswählen") */
table.sheet thead th.row-head::after {
  content: "";
  position: absolute;
  right: 3px;
  bottom: 3px;
  border-style: solid;
  border-width: 0 0 8px 8px;
  border-color: transparent transparent #BDBDBD transparent;
}

td.cell--header {
  font-weight: 700;
}

table.sheet td.cell--num {
  text-align: right;
}

td.cell--empty {
  background: var(--surface);
}

td[data-ref] {
  cursor: cell;
  position: relative;
}

td.is-selected {
  outline: 2px solid var(--excel-green);
  outline-offset: -2px;
  z-index: 2;
}

td.is-range-selected {
  background: rgba(16, 124, 65, 0.12);
  outline: 1px solid rgba(16, 124, 65, 0.35);
  outline-offset: -1px;
  z-index: 1;
}

td.is-fill-preview {
  outline: 2px dashed var(--excel-green);
  outline-offset: -2px;
  z-index: 1;
}

td.cell--input {
  background: #FFFBEA;
}

.cell-editable {
  min-height: 1.2em;
  white-space: pre;
  outline: none;
  font-family: inherit;
  font-size: inherit;
  color: #1F1F1F;
}

/* Beim Tippen läuft eine lange Formel wie in Excel über die Nachbarzellen hinaus, statt die Spalte zu verbreitern */
.cell-editable[contenteditable="true"] {
  caret-color: var(--excel-green-dark);
  cursor: text;
  position: relative;
  z-index: 3;
  width: max-content;
  min-width: 100%;
  padding-right: 4px;
  background: #FFFBEA;
}

.is-copied {
  position: relative;
}

.is-copied::after {
  content: "";
  position: absolute;
  inset: 1px;
  border: 2px dashed var(--excel-green-dark);
  pointer-events: none;
  z-index: 4;
}

.tok-func {
  color: var(--excel-green-dark);
  font-weight: 700;
}

.tok-number {
  color: #b06000;
}

.fill-handle {
  display: none;
  position: absolute;
  right: -4px;
  bottom: -4px;
  width: 7px;
  height: 7px;
  background: var(--excel-green);
  border: 1px solid #fff;
  cursor: crosshair;
  z-index: 3;
}

td.cell--input.is-selected .fill-handle {
  display: block;
}

td.cell--input.is-correct {
  background: #F1FBF5;
}

td.cell--input.is-correct .cell-editable {
  color: var(--success-green);
}

td.cell--input.is-wrong {
  background: #FEF2F2;
}

td.cell--input.is-wrong .cell-editable {
  color: var(--error-red);
}

/* ---------- Namenfeld & Bearbeitungsleiste (Excel 365) ---------- */

.sheet-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px;
  background: #FFFFFF;
  border-bottom: 1px solid #E1E1E1;
  border-radius: 9px 9px 0 0;
  font-family: var(--font-excel-ui);
  font-size: 13px;
  color: #262626;
}

.sheet-toolbar__namebox,
.sheet-toolbar__functions,
.sheet-toolbar__formula {
  display: flex;
  align-items: center;
  height: 26px;
  border: 1px solid #D1D1D1;
  border-radius: 4px;
  background: #FFFFFF;
}

.sheet-toolbar__namebox {
  flex: 0 0 auto;
  justify-content: space-between;
  gap: 6px;
  width: 104px;
  padding: 0 6px 0 8px;
}

.sheet-toolbar__nameref {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sheet-toolbar__namebox svg,
.sheet-toolbar__fx svg {
  flex: 0 0 auto;
  color: #616161;
}

.sheet-toolbar__grip {
  display: flex;
  align-items: center;
  color: #8A8A8A;
}

.sheet-toolbar__functions {
  flex: 0 0 auto;
  gap: 2px;
  padding: 0 3px;
}

/* ✕ und ✓ sind wie in Excel ausgegraut, solange keine Eingabe läuft */
.sheet-toolbar__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 20px;
  padding: 0;
  border: none;
  border-radius: 3px;
  background: transparent;
  color: #B8B8B8;
  cursor: default;
}

.sheet-toolbar.is-editing .sheet-toolbar__icon {
  color: #424242;
  cursor: pointer;
}

.sheet-toolbar.is-editing .sheet-toolbar__icon:hover {
  background: #EBEBEB;
}

.sheet-toolbar__fx {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  height: 20px;
  padding: 0 4px 0 5px;
  color: #424242;
}

.sheet-toolbar__fx i {
  font-family: "Cambria Math", Cambria, "Times New Roman", serif;
  font-size: 15px;
  letter-spacing: -0.5px;
}

.sheet-toolbar__formula {
  flex: 1 1 auto;
  min-width: 0;
  padding: 0 8px;
  overflow: hidden;
}

.sheet-toolbar__content {
  width: 100%;
  font-family: var(--font-excel);
  font-size: 14px;
  color: #1F1F1F;
  white-space: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}

.sheet-toolbar__content::-webkit-scrollbar {
  display: none;
}

@media (max-width: 520px) {
  .sheet-toolbar__namebox {
    width: 70px;
  }

  .sheet-toolbar__grip {
    display: none;
  }
}

/* ---------- Aktionsleiste & Feedback ---------- */

.exercise-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.btn {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 8px;
  border: 1.5px solid transparent;
  padding: 0.6rem 1.1rem;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn--primary {
  background: var(--excel-green);
  color: #fff;
}

.btn--primary:hover {
  background: var(--excel-green-dark);
}

.btn--secondary {
  background: #fff;
  border-color: var(--grid-gray);
  color: var(--text-primary);
}

.btn--secondary:hover {
  border-color: var(--excel-green);
  color: var(--excel-green-dark);
}

.exercise-feedback {
  border-radius: var(--radius);
  padding: 0.8rem 1.1rem;
  font-size: 0.92rem;
  margin-bottom: 1.5rem;
  display: none;
}

.exercise-feedback.is-success {
  display: block;
  background: #F1FBF5;
  border: 1px solid #BFE8CE;
  color: var(--success-green);
}

.exercise-feedback.is-error {
  display: block;
  background: #FEF2F2;
  border: 1px solid #F6C6C6;
  color: var(--error-red);
}

.exercise-feedback p {
  margin: 0;
}

.exercise-feedback p + p {
  margin-top: 0.6rem;
}

.exercise-feedback.is-success .exercise-feedback__explanation {
  color: var(--text-primary);
}

.exercise-feedback__next a {
  margin-top: 0.2rem;
}

.exercise-hints {
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background: var(--surface);
}

.exercise-hints summary {
  cursor: pointer;
  padding: 0.85rem 1.1rem;
  font-weight: 600;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  color: var(--excel-green-dark);
}

.exercise-hints ol {
  margin: 0;
  padding: 0 1.1rem 1rem 2rem;
  color: var(--text-primary);
}

.exercise-hints li {
  margin-bottom: 0.4rem;
}

.exercise-solution {
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  background: var(--header-gray);
  padding: 0.6rem 0.8rem;
  border-radius: 6px;
  display: none;
}

.exercise-solution.is-visible {
  display: block;
}

.exercise-hints__explanation {
  margin: 0.85rem 1.1rem 1rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.88rem;
}

.site-footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.82rem;
  padding: 2rem 1.5rem;
}

/* ---------- Erfolgs-Popup (beim richtigen Lösen einer Übung) ---------- */

.success-popup-overlay {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 30, 22, 0.4);
  border-radius: var(--radius);
  z-index: 9999;
  cursor: pointer;
  animation: success-fade-in 0.2s ease-out;
}

.success-popup {
  position: relative;
  background: var(--surface);
  border-radius: 18px;
  padding: 2.1rem 2.5rem 2rem;
  text-align: center;
  max-width: 320px;
  box-shadow: 0 24px 60px rgba(11, 92, 48, 0.28);
  cursor: default;
  animation: success-pop-in 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.success-popup__check-circle {
  stroke: var(--excel-green);
  stroke-width: 3;
  stroke-dasharray: 152;
  stroke-dashoffset: 152;
  animation: success-draw-circle 0.5s ease-out forwards;
}

.success-popup__check-mark {
  stroke: var(--excel-green);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 40;
  stroke-dashoffset: 40;
  animation: success-draw-check 0.35s 0.45s ease-out forwards;
}

.success-popup__title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0.9rem 0 0.3rem;
  color: var(--text-primary);
}

.success-popup__subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.success-popup__confetti {
  position: absolute;
  left: 50%;
  top: 38%;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  opacity: 0;
  animation: success-confetti 0.9s ease-out forwards;
}

@keyframes success-fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes success-pop-in {
  0% { transform: scale(0.6); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes success-draw-circle {
  to { stroke-dashoffset: 0; }
}

@keyframes success-draw-check {
  to { stroke-dashoffset: 0; }
}

@keyframes success-confetti {
  0% { transform: translate(0, 0) rotate(0deg); opacity: 1; }
  100% { transform: translate(var(--dx), var(--dy)) rotate(var(--rot)); opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .success-popup-overlay,
  .success-popup,
  .success-popup__check-circle,
  .success-popup__check-mark,
  .success-popup__confetti,
  .error-popup-overlay,
  .error-popup,
  .error-popup__icon-circle,
  .error-popup__icon-cross {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* ---------- Fehler-Popup (beim falschen Lösen einer Übung) — gleiche
   Mechanik/Animation wie das Erfolgs-Popup oben (dieselben Keyframes
   wiederverwendet), nur in Rot mit einem Kreuz statt Häkchen und ohne
   Konfetti; schließt sich per Klick statt automatisch, da der Text hier
   tatsächlich gelesen werden soll. ---------- */

.error-popup-overlay {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(40, 15, 15, 0.4);
  border-radius: var(--radius);
  z-index: 9999;
  cursor: pointer;
  animation: success-fade-in 0.2s ease-out;
}

.error-popup {
  position: relative;
  background: var(--surface);
  border-radius: 18px;
  padding: 2.1rem 2.5rem 2rem;
  text-align: center;
  max-width: 360px;
  box-shadow: 0 24px 60px rgba(146, 32, 32, 0.24);
  cursor: default;
  animation: success-pop-in 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.error-popup__icon-circle {
  stroke: var(--error-red);
  stroke-width: 3;
  stroke-dasharray: 152;
  stroke-dashoffset: 152;
  animation: success-draw-circle 0.5s ease-out forwards;
}

.error-popup__icon-cross {
  stroke: var(--error-red);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 52;
  stroke-dashoffset: 52;
  animation: success-draw-check 0.35s 0.45s ease-out forwards;
}

.error-popup__title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0.9rem 0 0.3rem;
  color: var(--text-primary);
}

.error-popup__subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}