:root {
  --primary: #007BFF;
  --secondary: #e63946;
  --background: #121212;
  --text: #f0f0f0;
  --card: #1f1f1f;
}

body.light {
  --background: #ffffff;
  --text: #121212;
  --card: #f5f5f5;
}

body {
  background: var(--background);
  color: var(--text);
  margin: 0;
  font-family: monospace;
  transition: background 0.5s ease, color 0.5s ease;
}

.hidden {
  display: none;
}

/* INTRO */
.intro {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: black;
  color: cyan;
  font-size: 2rem;
  font-weight: bold;
  z-index: 10;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
}

.slide-up {
  animation: slideUp 1s forwards;
}

@keyframes slideUp {
  0% { transform: translateY(0); opacity: 1; }
  100% { transform: translateY(-100%); opacity: 0; }
}

/* APP */
.app {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  opacity: 0;
  pointer-events: none;
  transition: opacity 1s ease;
}

.app.show {
  opacity: 1;
  pointer-events: all;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
}

header h1 {
  color: var(--primary);
}

.toolbar button {
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
}

#clock {
  font-size: 0.9rem;
  margin-left: 1rem;
}

main {
  max-width: 600px;
  margin: 2rem auto;
  background: var(--card);
  border-radius: 10px;
  padding: 1rem;
  box-shadow: 0 0 10px rgba(0,0,0,0.5);
}

form {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 1rem;
}

form input, form select {
  padding: 0.5rem;
  border-radius: 5px;
  border: 1px solid var(--primary);
  background: var(--background);
  color: var(--text);
}

form button {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 0.5rem;
  border-radius: 5px;
  cursor: pointer;
}

form button:hover {
  background: var(--secondary);
}

ul {
  list-style: none;
  padding: 0;
}

li {
  background: rgba(0, 123, 255, 0.1);
  margin-top: 0.5rem;
  padding: 0.5rem;
  border-radius: 5px;
  display: flex;
  justify-content: space-between;
}

#view-summary {
  margin-top: 1rem;
  background: var(--secondary);
  color: white;
  border: none;
  padding: 0.5rem;
  border-radius: 5px;
  cursor: pointer;
}

#view-summary:hover {
  background: darkred;
}

/* summary page */
.summary-page {
  background: var(--background);
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.summary-container {
  text-align: center;
}

#total-amount {
  font-size: 3rem;
  margin-top: 1rem;
  animation: roll 1s forwards;
}

@keyframes roll {
  0% { transform: translateY(-50px); opacity: 0; }
  100% { transform: translateY(0); opacity: 1; }
}