:root {
  --bg: #0b0f17;
  --card: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.12);
  --text: rgba(255, 255, 255, 0.95);
  --muted: rgba(255, 255, 255, 0.65);
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.45);

  --green: rgba(90, 255, 170, 0.22);
  --green-border: rgba(90, 255, 170, 0.35);

  --yellow: rgba(255, 200, 90, 0.22);
  --red: rgba(255, 90, 90, 0.22);
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  background:
    radial-gradient(1000px 500px at 15% 10%, rgba(98, 0, 255, .25), transparent 60%),
    radial-gradient(900px 500px at 85% 20%, rgba(0, 255, 210, .18), transparent 60%),
    radial-gradient(900px 700px at 50% 90%, rgba(255, 190, 0, .12), transparent 60%),
    var(--bg);
  color: var(--text);
  display: grid;
  place-items: center;
  padding: 24px;
}

/* CARD */
.container {
  width: min(420px, 100%);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 26px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
  text-align: center;
}

/* TÍTULO */
.container h1 {
  margin: 0 0 14px;
  font-size: 1.6em;
  letter-spacing: -0.02em;
}

/* RELÓGIO */
.relogio {
  margin: 20px 0 26px;
  font-size: 3.4em;
  font-weight: 700;
  letter-spacing: 4px;

  padding: 24px 16px;
  border-radius: 18px;

  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--border);

  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.03);
}

/* BOTÕES */
.container p:last-of-type {
  display: flex;
  gap: 12px;
}

button {
  flex: 1;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.25);
  color: var(--text);

  padding: 12px;
  border-radius: 14px;
  font-size: 1em;
  font-weight: 600;

  cursor: pointer;
  transition: transform 0.06s ease, background 0.2s ease, border-color 0.2s ease;
}

button:hover {
  background: rgba(0, 0, 0, 0.35);
}

button:active {
  transform: translateY(1px);
}

/* CORES DOS BOTÕES */
.iniciar {
  background: var(--green);
  border-color: var(--green-border);
}

.pausar {
  background: var(--yellow);
}

.zerar {
  background: var(--red);
}