:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-secondary: #64748b;
  --color-bg: #f1f5f9;
  --color-card: #ffffff;
  --color-text: #1e293b;
  --radius: 12px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: #fff;
  text-align: center;
  padding: 48px 16px;
}

.site-title {
  font-size: 2rem;
  letter-spacing: 0.05em;
}

.site-subtitle {
  margin-top: 8px;
  opacity: 0.85;
}

.container {
  flex: 1;
  width: min(720px, 92%);
  margin: 32px auto;
  display: grid;
  gap: 24px;
}

.card {
  background: var(--color-card);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.08);
}

.card h2 {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.counter {
  font-size: 3rem;
  font-weight: 700;
  text-align: center;
  color: var(--color-primary);
  margin: 16px 0;
}

.button-row,
.form-row {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 12px;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 10px 24px;
  font-size: 1rem;
  cursor: pointer;
  transition: opacity 0.2s ease, transform 0.1s ease;
}

.btn:hover {
  opacity: 0.9;
}

.btn:active {
  transform: scale(0.97);
}

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

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

.text-input {
  flex: 1;
  min-width: 200px;
  padding: 10px 14px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 1rem;
}

.text-input:focus {
  outline: 2px solid var(--color-primary);
  border-color: transparent;
}

.greeting {
  text-align: center;
  margin-top: 16px;
  font-weight: 600;
  color: var(--color-primary-dark);
  min-height: 1.7em;
}

.site-footer {
  text-align: center;
  padding: 24px 16px;
  color: var(--color-secondary);
  font-size: 0.875rem;
}