/* ==== CSS Variables ==== */
:root {
  --background-color-light: #555;
  --background-color-mid: #444;
  --background-color-dark: #333;
  --shadow-small: 0 2px 4px rgba(0, 0, 0, 0.6);
  --shadow-large: 0 4px 16px rgba(0, 0, 0, 0.6);
  --font-family: Arial, sans-serif;
  --font-size-small: 10px;
  --font-size-standard: 12px;
  --font-size-large: 14px;
  --font-size-title: 32px;
  --text-color-light: white;
  --text-color-mid: whitesmoke;
  --text-color-dark: black;
}

/* ==== Global Reset ==== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ==== App Layout ==== */
body {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  background-color: var(--background-color-dark);
}

.app {
  width: 370px;
  height: 640px;
  position: relative;
  background-color: var(--background-color-light);
  font-family: var(--font-family);
  font-size: var(--font-size-standard);
  color: var(--text-color-light);
  border-radius: 10px;
  box-shadow: var(--shadow-large);
  padding: 10px;
  margin: 10px;
}

/* ==== Header ==== */
.header {
  width: 100%;
  height: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-evenly;
}

.header h1 {
  font-size: var(--font-size-title);
  text-shadow: var(--shadow-small);
  letter-spacing: 1px;
}

.header img {
  width: 180px;
  height: 120px;
  border: 1px solid black;
}

/* ==== Main ==== */
.main {
  width: 100%;
  height: 340px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-evenly;
}

.main a {
  color: var(--text-color-light);
  text-decoration: none;
}

.button {
  width: 130px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--background-color-mid);
  border: 1px solid black;
  border-radius: 5px;
  box-shadow: var(--shadow-small);
  cursor: pointer;
  font-size: var(--font-size-large);
  color: var(--text-color-light);
  font-weight: bold;
  text-shadow: var(--shadow-small);
  letter-spacing: 1px;
}

.button:hover {
  background-color: var(--background-color-light);
  color: chartreuse;
  border-color: chartreuse;
  transition: background 0.2s, color 0.2s, border 0.2s;
}

/* ==== Footer ==== */
.footer {
  width: 100%;
  height: 60px;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  font-size: var(--font-size-small);
  color: var(--text-color-mid);
}

.footer a {
  color: var(--text-color-mid);
  text-decoration: none;
}