:root {
  --bg: #0e1014;
  --panel: #1a1e27;
  --muted: #999;
  --accent: #3b79ff;
  --success: #2ecc71;
  --danger: #e74c3c;
  --btn-bg: #2a2f3a;
  --btn-hover: #3b79ff;
  --btn-text: #fff;
  --card: #181c24;
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  font-family: 'Segoe UI', sans-serif;
  color: #eee;
  font-size: 15px;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

h1, h2, h3 {
  color: #fff;
  margin-bottom: 15px;
}

p, li {
  line-height: 1.6;
}

input[type="number"] {
  width: 100%;
  padding: 10px;
  margin-top: 4px;
  background-color: var(--panel);
  color: #fff;
  border: 1px solid #333;
  border-radius: 8px;
  font-size: 14px;
}

label {
  display: block;
  margin-top: 20px;
  color: #ccc;
}

button {
  padding: 10px 16px;
  border: none;
  background-color: var(--btn-bg);
  color: var(--btn-text);
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s;
  margin-right: 10px;
  font-size: 14px;
}

button:hover {
  background-color: var(--btn-hover);
}

.form-actions {
  margin-top: 20px;
}

#results {
  background-color: var(--panel);
  border: 1px solid #333;
  border-radius: 10px;
  padding: 20px;
  margin-top: 30px;
}

#results strong {
  display: inline-block;
  width: 160px;
  color: #fff;
}

#chartSection {
  background-color: var(--panel);
  padding: 20px;
  margin-top: 30px;
  border-radius: 10px;
}

#tipsSection {
  background-color: var(--panel);
  padding: 20px;
  margin-top: 30px;
  border-radius: 10px;
}

#smartTips li {
  margin-bottom: 8px;
}

.topbar {
  background-color: var(--card);
  padding: 10px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.topbar .btn {
  background-color: var(--btn-bg);
  padding: 6px 14px;
  border-radius: 8px;
  color: #fff;
  text-decoration: none;
  font-size: 13px;
  margin-right: 10px;
  transition: background 0.2s;
}

.topbar .btn:hover {
  background-color: var(--btn-hover);
}

@media (max-width: 600px) {
  .container {
    padding: 15px;
  }

  input[type="number"] {
    font-size: 13px;
  }

  button {
    font-size: 13px;
    padding: 8px 12px;
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
  }

  .topbar .btn {
    margin-bottom: 6px;
  }
}

.btn {
  background-color: var(--accent);
  color: white;
  text-decoration: none;
  padding: 8px 16px;
  font-size: 14px;
  border-radius: 10px;
  margin-right: 10px;
  display: inline-block;
  transition: background-color 0.2s ease-in-out;
}

.btn:hover {
  background-color: #2a66db;
  color: white;
}

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

.btn.small {
  padding: 6px 12px;
  font-size: 13px;
}

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

.btn.ghost {
  background-color: transparent;
  border: 1px solid var(--muted);
  color: var(--muted);
}

.btn.ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.buttons button,
.form-actions button,
button,
.btn {
  background-color: var(--accent);
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: 10px;
  font-size: 14px;
  cursor: pointer;
  margin-right: 10px;
  transition: background-color 0.2s ease-in-out;
}

.buttons button:hover,
.form-actions button:hover,
button:hover,
.btn:hover {
  background-color: #2a66db;
  color: white;
}

.topbar {
  display: flex;
  justify-content: flex-start;
  margin: 20px 0;
  padding: 0 20px;
}

.topbar nav a.btn {
  background-color: #3b79ff;
  color: white;
  text-decoration: none;
  padding: 8px 16px;
  font-size: 14px;
  border-radius: 10px;
  margin-right: 10px;
  display: inline-block;
  transition: background-color 0.2s ease-in-out;
}

.topbar nav a.btn:hover {
  background-color: #2a66db;
  color: white;
}