/* -------------------------------------
   1. Base Button — shared foundation
------------------------------------- */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  padding: 0.75rem 1.4rem;
  border-radius: var(--radius);

  font-size: var(--size-md);
  font-weight: 500;
  line-height: 1;

  cursor: pointer;
  border: none;
  background: none;

  transition: background var(--transition-fast),
              color var(--transition-fast),
              box-shadow var(--transition-fast),
              border-color var(--transition-fast),
              transform var(--transition-fast);
}

/* -------------------------------------
   2. Primary Button (filled)
------------------------------------- */
.button.button-primary {
  background: var(--accent);
  border: var(--border-thickness-bold) solid var(--accent);
  border-radius: var(--radius-round);
  color: #000;
  box-shadow: var(--shadow-accent-strong);
  text-transform: uppercase;
  font-weight: 600;
  padding: 1rem 2rem;
}

.button.button-primary:hover {
  background: #35c8f7;
  border: var(--border-thickness-bold) solid #35c8f7;
  box-shadow: 0 0 18px rgba(91, 224, 255, 0.8);
}

/* ------------------------------------
   3. Secondary Button (outlined)
------------------------------------ */
.button.button-secondary {
  background: transparent;
  border: var(--border-thickness-bold) solid var(--fg);
  border-radius: var(--radius-round);

  color: var(--fg);
}

.button.button-secondary:hover {
  border-color: var(--hover-bg);
  color: var(--fg);
}

@media (max-width: 768px) {
  .button.button-secondary {
    width: 100%;
    text-align: center;
    padding: 0.75rem 1rem;
    font-size: 1rem;
  }
}

/* -------------------------------------
   4. Tertiary Button (minimal link)
------------------------------------ */
.button.button-tertiary {
  background: none;
  border: none;
  padding: 0 6px;

  font: inherit;
  color: var(--fg);
  text-decoration: underline;
  text-decoration-thickness: 3px;
  text-underline-offset: 4px;
}

.button.button-tertiary:hover {
  color: var(--fg);
}

/* -------------------------------------
   5. Icon Button (circular, minimal)
------------------------------------- */
.button.button-icon {
  padding: 0.5rem;
  border-radius: var(--radius-round);
  background: transparent;
  border: var(--border-thickness-bold) solid var(--fg);
  width: 42px;
  height: 42px;
  line-height: 0;
}

.button.button-icon .material-icons {
  font-size: 1.35rem;
  color: var(--fg);
}

.button.button-icon:hover {
  border-color: var(--hover-bg);
  color: var(--fg);
  
  transform: scale(1.05);
}

.button.button-icon:active {
  transform: scale(0.95);
}