:root {
  --bg: #0a0a0f;         
  --card: #151521;        
  --accent: #7b5fff;      
  --accent-hover: #9a7fff;
  --text: #ffffff;        
  --text-muted: #bbb;
  --border: #2b2b40;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Roboto, sans-serif;
}

body {
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
 
}

.app {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  width: 100%;
  max-width: 1200px;
  margin-top: 60px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 4px 14px rgba(0,0,0,0.5);
}

h2, h3, h4 {
  color: var(--accent);
}

.mini {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.muted {
  opacity: 0.7;
}

.display {
  background: #0f0f18;
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 12px;
  border: 1px solid var(--border);
}

.expr {
  font-size: 1.2rem;
  color: var(--text-muted);
}

.result {
  font-size: 1.8rem;
  font-weight: bold;
  color: var(--accent);
  margin-top: 6px;
}

button {
  cursor: pointer;
  border: none;
  border-radius: 8px;
  padding: 10px 14px;
  background: var(--border);
  color: var(--text);
  font-size: 1rem;
  transition: background 0.2s, transform 0.1s;
}

button:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
}

button:active {
  transform: translateY(0);
}

.theme-btn {
  background: var(--accent);
  color: #fff;
}

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

.keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 12px;
}

.key {
  background: #1e1e2e;
  font-size: 1.1rem;
  font-weight: bold;
}

.key.op {
  background: var(--accent);
  color: #fff;
}

.key#equals {
  background: #00c853; 
  color: #fff;
}

.history {
  margin-top: 10px;
  max-height: 150px;
  overflow-y: auto;
}

.history-item {
  background: #1e1e2e;
  padding: 6px 8px;
  border-radius: 6px;
  margin-bottom: 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modules-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.module {
  padding: 8px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, border 0.2s;
}

.module:hover {
  background: #1e1e2e;
}

.module.active {
  border: 1px solid var(--accent);
  background: #221a35;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.85);
  display: flex;
  justify-content: center;
  align-items: center;
}

.modal {
  width: 90%;
  max-width: 500px;
  padding: 20px;
}

.modes {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 12px;
}

.mode {
  padding: 12px;
  background: #1e1e2e;
  border-radius: 8px;
  border: 1px dashed var(--border);
  cursor: pointer;
  transition: background 0.2s, border 0.2s;
}

.mode:hover {
  background: var(--accent);
  border: 1px solid var(--accent);
}

::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 3px;
}
::-webkit-scrollbar-track {
  background: #0f0f18;
}

input, select {
  background: #1a1a1a; 
  color: #fff;
  border: 2px solid #6b46c1; 
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 14px;
  outline: none;
}

input:focus, select:focus {
  border-color: #9f7aea; 
  box-shadow: 0 0 8px rgba(159, 122, 234, 0.6);
}

.creditos {
  margin-top: 20px;
  text-align: center;
  color: #bbb;
}

.creditos summary {
  cursor: pointer;
  color: #9f7aea;
  font-weight: bold;
}

.creditos .links {
  margin-top: 10px;
  display: flex;
  justify-content: center;
  gap: 15px;
}

.creditos img {
  width: 28px;
  height: 28px;
  filter: invert(80%);
  transition: transform 0.2s ease;
}

.creditos img:hover {
  transform: scale(1.2);
}

.creditos {
  margin-top: 20px;
  text-align: center;
  color: #bbb;
}

.creditos summary {
  cursor: pointer;
  color: #d6d6d6;
  font-weight: bold;
}

.creditos .links {
  margin-top: 10px;
  display: flex;
  justify-content: center;
  gap: 15px;
}

.creditos img {
  width: 28px;
  height: 28px;
  filter: invert(80%);
  transition: transform 0.2s ease;
}

.creditos img:hover {
  transform: scale(1.2);
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.app {
  flex: 1;
}

footer.creditos {
  width: 100%;
  display: flex;
  justify-content: center; 
  align-items: center;     
  padding: 14px 20px;
  box-sizing: border-box;
  color: #bdbdbd;
  background: transparent; 
}

footer.creditos details {
  display: inline-block; 
  text-align: left;      
  padding: 8px 12px;
  border-radius: 8px;
  background: rgba(255,255,255,0.02);
}


footer.creditos details summary {
  cursor: pointer;
  font-weight: 600;
  color: #e6e6ff;
  list-style: none; 
}