/* ================================
   BASE LAYOUT (DESKTOP)
=================================== */

body {
  font-family: sans-serif;
  background: #111;
  color: #fff;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 900px;
  margin: auto;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-align: center;
}

/* ================================
   BUTTONS
=================================== */

button {
  background: #007bff;
  color: white;
  border: none;
  padding: 1rem 2rem;
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.3s;
  font-size: 1rem;
}

button:hover {
  background: #0056b3;
}

button:disabled {
  background: #444;
  cursor: not-allowed;
  position: relative;
}

button:disabled::after {
  content: " 🔒";
  position: absolute;
  right: 1rem;
}

/* ================================
   INPUTS
=================================== */

input {
  padding: 0.75rem;
  border-radius: 5px;
  border: none;
  font-size: 1rem;
}

input[readonly] {
  background-color: #222;
  color: #ccc;
  border: 1px solid #444;
}

/* ================================
   TEXT ELEMENTS
=================================== */

.error {
  color: red;
  margin-top: 1rem;
}

.note {
  font-size: 0.9rem;
  color: #ccc;
  margin-top: 0.5rem;
}

.link {
  color: #0af;
  cursor: pointer;
  text-decoration: underline;
  font-size: 0.9rem;
  text-align: center;
}

.footer {
  margin-top: 3rem;
  font-size: 0.9rem;
  color: #aaa;
  text-align: center;
}

/* ================================
   INDEX PAGE CONTAINER
=================================== */

.container {
  max-width: 400px;
  width: 100%;
  background: #222;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 0 20px rgba(0,0,0,0.5);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.mode-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.mode-buttons button {
  padding: 0.5rem 1rem;
  font-size: 1rem;
}

.form {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form h2 {
  text-align: center;
  margin-bottom: 0.5rem;
}

.form input {
  width: 100%;
  background: #333;
  color: #fff;
  border: 1px solid #555;
}

.form button {
  background: #28a745;
}

.form button:hover {
  background: #218838;
}

/* ============================================================
   📱 MOBILE OPTIMIZATION — PHONES (max-width: 700px)
=============================================================== */

@media (max-width: 700px) {

  body {
    padding: 1.5rem;
  }

  h1 {
    font-size: 2rem;
  }

  /* Buttons full width */
  button {
    width: 100%;
    padding: 1rem;
    font-size: 1.05rem;
  }

  /* Inputs larger for touch */
  input {
    width: 100%;
    padding: 0.9rem;
    font-size: 1rem;
  }

  /* Container expands */
  .container {
    padding: 1.5rem;
    width: 100%;
    max-width: 100%;
    border-radius: 10px;
  }

  /* Mode buttons stack if needed */
  .mode-buttons {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .mode-buttons button {
    flex: 1;
    min-width: 120px;
    padding: 0.75rem;
  }

  .form button {
    width: 100%;
    padding: 1rem;
  }

  .footer {
    font-size: 0.85rem;
  }
}

/* ============================================================
   📲 SMALL PHONES — VERY NARROW (max-width: 450px)
=============================================================== */

@media (max-width: 450px) {

  h1 {
    font-size: 1.7rem;
  }

  .container {
    padding: 1.25rem;
  }

  button {
    font-size: 1rem;
    padding: 0.9rem;
  }

  input {
    font-size: 0.95rem;
    padding: 0.8rem;
  }

  .note,
  .link,
  .footer {
    font-size: 0.85rem;
  }
}