:root {
  --bg-top: #1a1a1c;
  --bg-bottom: #0d0d0e;
  --surface: #2a2a2d;
  --surface-active: #3a3a3e;
  --border: #45454a;
  --text: #f2f2f2;
  --text-muted: #9a9a9e;
  --accent: #cfcfd4;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  background: radial-gradient(circle at 50% 0%, var(--bg-top), var(--bg-bottom) 70%);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-tap-highlight-color: transparent;
  overscroll-behavior: none;
}

.app {
  width: 100%;
  max-width: 480px;
  padding: 32px 20px calc(24px + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
}

.app__header {
  text-align: center;
}

.app__title {
  margin: 0;
  font-size: clamp(2.2rem, 8vw, 3rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text);
}

.app__subtitle {
  margin: 4px 0 0;
  font-size: 0.95rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.pad {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.btn {
  width: 100%;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 16px;
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  user-select: none;
  transition: transform 80ms ease, background-color 120ms ease, box-shadow 120ms ease;
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.03);
}

.btn__icon {
  font-size: 1.3rem;
  opacity: 0.85;
}

.btn:hover {
  background: var(--surface-active);
}

.btn:active,
.btn.is-active {
  background: var(--surface-active);
  transform: scale(0.97);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.03);
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.app__footer {
  color: var(--text-muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (min-width: 560px) {
  .pad {
    flex-direction: row;
  }

  .btn {
    min-height: 120px;
    flex-direction: column;
  }
}