:root {
  --bg: #f0f0f0;
  --container: #ffffff;
  --text: #333;
  --border: #ddd;
  --accent: #707070;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
  --input-bg: #f9f9f9;
  --button: #7f619b;
  --button-text: #fff;
}

html.dark {
  --bg: #111;
  --container: #222;
  --text: #eee;
  --border: #333;
  --accent: #707070;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
  --input-bg: #252525;
  --button: #7f619b;
  --button-text: #fff;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  font-size: 14px;
  background-color: var(--bg);
  color: var(--text);
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  min-height: 100vh;
  line-height: 1.4;
}

.container {
  background: var(--container);
  border: 1px solid var(--border);
  border-radius: 15px;
  width: 95%;
  max-width: 600px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-top: 20px;
}

.theme-toggle {
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
  font-size: 13pt;
  margin-left: auto;
  padding: 0;
  opacity: 0.6;
  transition: opacity 0.2s;
}

.theme-toggle:hover {
  opacity: 1;
}

h1 {
  font-size: 14px;
  margin: 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

h2,
h3 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  color: var(--accent);
}

.box {
  padding: 15px;
  background: var(--input-bg);
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 13px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

input[type="datetime-local"],
textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--container);
  color: var(--text);
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s;
}

input[type="datetime-local"]:focus,
textarea:focus {
  border-color: var(--accent);
}

input[type="submit"] {
  flex: 1;
  padding: 8px 5px;
  border-radius: 10px;
  border: none;
  font-weight: bold;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 13px;
  transition: all 0.2s;
  background: var(--button);
  color: var(--button-text);
}

input[type="submit"]:active {
  transform: scale(0.98);
}

.timer {
  font-size: 28px;
  font-weight: bold;
  font-variant-numeric: tabular-nums;
}

textarea {
  resize: none;
  font-family: monospace;
  font-size: 12px;
  line-height: 1.6;
  background: var(--bg);
}

#footer {
  padding: 10px 15px;
  display: flex;
  justify-content: space-between;
  width: 100%;
  max-width: 400px;
  margin: 20px auto;
  background: var(--container);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 11px;
}

a {
  text-decoration: none;
  color: inherit;
}

@media (max-width: 768px) {
  .container {
    margin-top: 10px;
    padding: 20px;
  }
}