:root {
  --nav-height: 2.5rem;
  --hu-blue-primary: #00376c;
  --hu-blue-secondary: #d7dde1;
  --hu-blue-hover: #99c2ff;
  --hu-margin: 0.4rem;
  --hu-padding: 0.4rem;
  --hu-padding2: 0.8rem;
  --hu-gap: 0.6rem;
  --hu-gap2: 0.3rem;
  --hu-panel-width: 400px;
  --hu-sparrow: "Sparrow 13:";
}

/* ===== GLOBAL ===== */
* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  height: 100%;
  font-family: system-ui, sans-serif;
  overflow: hidden; /* verhindert doppeltes Scrollen */
  scrollbar-gutter: stable;
}

button {
    background-color: white;
    color: black;
    border: none;
    padding: 5px 10px;
    font-size: 1.2rem;
    cursor: pointer;
}

textarea {
  font-family: system-ui, sans-serif;
  font-size: 1rem;
}

input[type="text"] {
  font-family: system-ui, sans-serif;
  font-size: 1rem;
  width: 100%;
}

details details {
    margin-left: 0.25rem;
}

details div {
    margin-left: 1.25rem;
}

.tree summary,
.tree div {
    color: #0000ee;
    cursor: pointer;
    text-decoration: underline;
}

.tree summary::marker {
    color: black;
}

.spinner {
  width: 20vmin;
  height: 20vmin;
  border-width: 5vmin;
  border-style: solid;
  border-color: var(--hu-blue-secondary);
  border-top-color: var(--hu-blue-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: var(--hu-margin) auto;
}

.spinner-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.3); /* optional: dunkler Hintergrund */
  z-index: 9999;
}

.spinner-overlay[hidden] {
  display: none !important;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

#master {
  position: absolute;
  inset: 0;
  
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;

  background-color: var(--hu-blue-primary);
}

/* ===== NAVIGATION ===== */
#nav {
  grid-row: 1;

  display: flex;
  gap: var(--hu-gap);
  align-items: center;
  padding: var(--hu-padding);

  background: var(--hu-blue-primary);
}

#nav a {
  display: inline-block;
  padding: var(--hu-padding);
  background: white;
  border: 1px solid #ccc;
  text-decoration: none;
  color: black;
}

#nav a:hover {
  background: var(--hu-blue-hover);
}

#panel-container {
  grid-row: 2;

  display: grid;
  grid-template-columns: repeat(4, var(--hu-panel-width));
  grid-template-rows: 1fr auto;
  min-height: 0;
  height: 100%;
  column-gap: var(--hu-gap);

  overflow-x: auto;
  overflow-y: hidden;
}

#p1 {
  grid-column: 1; 
  grid-row: 1;

  display: grid; 
  grid-template-rows: 8fr 2fr; 
  gap: var(--hu-gap);
  
  height: 100%;
  min-height: 0;
}

#chatOutput {
  padding: var(--hu-padding);
  min-height: 0;           
  overflow-y: auto;

  background-color: var(--hu-blue-secondary);
}

#chatInput {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-rows: 1fr auto;
  gap: 10px;
  height: 100%;
}

#chatInput > textarea {
  width: 100%;
  height: 100%;
  min-height: 0;
  overflow-y: auto;
  padding: var(--hu-padding);
  resize: none;
}

#chatButton {
  display: flex;
  flex-direction: column;
  gap: 8px;   /* Abstand zwischen den Buttons */
}

#chatBar {
  grid-column: 1;
  grid-row: 2;
}
 
#p2 {
  grid-column: 2;
  grid-row: 1;

  display: grid; 
  grid-template-rows:  minmax(0, 2fr) minmax(0, 3fr) minmax(0, 2fr); 
  gap: var(--hu-gap);
  
  height: 100%;
  min-height: 0;
   min-width: 0;
}

#help {
  overflow-y: auto;    
  min-height: 0;
  height: 100%;  
  background-color: var(--hu-blue-secondary);
  padding: var(--hu-padding);
}

#exerciseselect {
  background-color: white;  
  display: flex;
  flex-direction: column;
  padding: var(--hu-padding);
  min-height: 0;
  height: 100%;
}

#exerciseselect b {
  flex: 0 0 auto;
}

#vanillatree {
  flex: 1;
  overflow-y: auto;           /* Scrollbalken nur IM Tab, falls der Text zu lang ist */
  min-height: 0;
  padding: var(--hu-padding);
  background-color: white;  
}

#exerciseHistory {
  padding: var(--hu-padding);
  background-color: var(--hu-blue-secondary);
  
  /* NEU: Macht den Verlauf zum Flex-Container, damit die Kinder (linkList) flexibel sind */
  display: flex;
  flex-direction: column;
  
  /* NEU: Verhindert, dass das Grid-Element durch großen Inhalt gesprengt wird */
  min-height: 0; 
  min-width: 0;
}

#linkList {
  flex: 1;
  overflow-y: auto;   /* Hier reicht das Scrollen völlig aus */
  min-height: 0;
  min-width: 0;
}

#recent {
  padding: var(--hu-padding);
  margin: 0;
  list-style: none; /* Optional: Schickere Listenoptik */
  min-width: 0;
}

#recent li {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#p3 {
  grid-column: 3;
  grid-row: 1;

  display: grid; 
  grid-template-rows: 1fr auto 1fr; 
  gap: var(--hu-gap);
  
  height: 100%;
  min-height: 0;
}

#calcOutput {
  background-color: var(--hu-blue-secondary);
  color: black;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
  font-size: 1.2rem;
}

#formOutput {
  background-color: var(--hu-blue-secondary);
  margin-top: var(--hu-padding2);
  padding: var(--hu-padding);
  overflow-y: auto;
  min-height: 0;
  color: black;
  min-height: 0;
}

#p4 {
  grid-column: 4;
  grid-row: 1;

  display: grid; 
  grid-template-rows: minmax(0, 1fr) minmax(0, 1fr); 
  gap: var(--hu-gap);
  
  height: 100%;
  min-height: 0;
}

#impressum {
  background-color: var(--hu-blue-secondary);
  padding: var(--hu-padding);
  overflow-y: auto;
  min-height: 0;
}

#datenschutzerklaerung {
  background-color: var(--hu-blue-secondary);
  padding: var(--hu-padding);
  overflow-y: auto;
  min-height: 0;
}

#exerciseBar {
  grid-column: 2;
  grid-row: 2;
}

#formInput {
  grid-column: 3;
  grid-row: 2;
}

#impressumInput {
  grid-column: 4;
  grid-row: 2;
}

/* Used in the introduction text */
#intro {
  display: grid; 
  grid-auto-flow: column; 
  grid-template-columns: 150px 1fr; 
  gap: var(--hu-gap);
}

#intro-img {
  width: 150px; 
  height: auto; 
  display: block;
}

#intro-col {
  display: flex; 
  flex-direction: column; 
  align-items: flex-start;
}

#intro-wrap {
  width: min(100%, 50ch); 
  display: table;
}

#intro-head {
  margin: 0 0 var(--hu-margin) 0;
  white-space: normal; 
  display: block; 
  font-family: sans-serif;
}

#intro-sparrow {
  width: 100%; 
  display: block; 
  height: auto;
}

.error-box {
    padding: var(--hu-padding);
    border-radius: 0.5rem;
    border: 0.125rem solid red;
    box-shadow: 0 0.125rem 1rem rgba(0, 0, 0, 0.3);
    font-family: sans-serif;
    text-align: center;
}

.error-box[open] {
    position: fixed;
    top: 50%;
    left: 50%;
    margin: 0;

    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--hu-gap);
}

.error-box p {
    margin: 0;
}

.error-box button {
    padding: var(--hu-padding)  var(--hu-padding2);
    cursor: pointer;
    border-radius: 0.125rem;
    border: 0.125rem solid #ccc;
    background-color: #f0f0f0;
}

#impressum {
  padding: var(--hu-padding);
  background-color: var(--hu-blue-secondary);
  height: 100%;
}

.button-bar {
  flex: 0 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
  padding-bottom: var(--hu-padding);
  padding-top: var(--hu-padding);
  column-gap: var(--hu-gap);
}

/*
#formInput, #impressumBar, #exerciseBar, #chatBar {
  margin-top: var(--hu-gap);
}
  */