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

body {
    font-family: 'Inter', sans-serif;
    background: #f9f9f9;
    color: #222;
    display: flex;
    flex-direction: column;   /* Organiza en columna */
    min-height: 100vh;        /* Altura completa */
}

/* La tarjeta centrada */
.container {
    background: white;
    padding: 2rem;
    width: 350px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    text-align: center;
    margin: auto; /* la mantiene centrada */
}

/* Avatar */
.avatar {
    margin: 0 auto 1rem auto;
    background: #2078f4;
    color: white;
    font-weight: 700;
    width: 70px;
    height: 70px;
    border-radius: 50%;
    font-size: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

h1 {
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.subtitle {
    font-size: 0.9rem;
    color: #555;
    margin-bottom: 1.5rem;
}

#timer {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #2078f4;
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.btn {
    background-color: #2078f4;
    border: none;
    color: white;
    font-weight: 700;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s ease;
    font-size: 0.9rem;
}

.btn:hover {
    background-color: #155bb5;
}

#modeText {
    font-weight: 600;
    margin-bottom: 1rem;
}

.phrase {
    font-style: italic;
    color: #444;
    min-height: 2rem;
    margin-bottom: 1.5rem;
}

.focus-btn {
    background-color: #555;
}

/* --- Estilo del botón 'Volver al inicio' --- */
.btn-volver {
  display: inline-block;
  text-align: center;
  padding: 10px 20px;
  background-color: #007bff;
  color: white;
  text-decoration: none;
  border-radius: 20px;
  font-size: 16px;
  font-weight: bold;
  transition: background-color 0.3s;
  margin: 20px auto; /* centrado horizontal */
}

.btn-volver:hover {
  background-color: #0056b3;
}