/* ============================================================
   CALCULATOR — style.css (PHASE 2: FRESH LOOK)
   Premium calculator with an ultra-smooth, floating deck aesthetic.
   ============================================================ */

/* ── Calculator Card ── */
.calc-card {
  max-width: 420px;
  margin: 0 auto;
}

/* ── Display Screen ── */
.calc-screen {
  width: 100%;
  padding: 1.5rem 1.25rem;
  font-size: 2.25rem;
  font-family: "Poppins", system-ui, monospace;
  font-weight: 700;
  text-align: right;
  background: var(--bg-input);
  border: 2px solid var(--border-color);
  border-radius: 1.25rem;
  color: var(--text-primary);
  outline: none;
  margin-bottom: 1.5rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow:
    inset 0 2px 4px rgba(0, 0, 0, 0.05),
    0 4px 6px -1px rgba(0, 0, 0, 0.02);
}

.calc-screen:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-glow);
  transform: translateY(-1px);
}

.calc-screen::placeholder {
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: normal;
}

/* ── Keypad Grid ── */
.calc-keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.calc-keys-sci {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
}

/* ── Base Button ── */
.calc-btn {
  width: 100%;
  aspect-ratio: 1;
  max-width: 80px;
  max-height: 80px;
  margin: 0 auto;
  border: 1px solid var(--border-color);
  border-radius: 1.25rem; /* Squircle feel */
  font-family: "Poppins", sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  position: relative;
  overflow: hidden;
}

.calc-btn:active {
  transform: scale(0.9);
}

/* ── Number Keys ── */
.calc-num {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.calc-num:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* ── Operator Keys ── */
.calc-operate {
  background: var(--bg-input);
  color: var(--accent);
  box-shadow: var(--shadow-sm);
}

.calc-operate:hover {
  background: var(--accent-glow);
  color: var(--accent-hover);
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* ── Equals Button ── */
.calc-equals {
  background: var(--accent-gradient);
  color: white;
  border: none;
  box-shadow: 0 8px 20px -4px var(--accent-glow);
  font-size: 1.5rem;
}

.calc-equals:hover {
  background: var(--accent-gradient-hover);
  box-shadow: 0 12px 28px -4px var(--accent-glow);
  transform: translateY(-4px) scale(1.05);
}

.calc-equals::after {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.3),
    transparent
  );
  transition: 0.6s;
}

.calc-equals:hover::after {
  left: 100%;
}

/* ── Light theme specific refinements ── */
[data-theme="light"] .calc-num {
  background: white;
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .calc-keys {
    gap: 10px;
  }

  .calc-keys-sci {
    grid-template-columns: repeat(4, 1fr);
  }

  .calc-btn {
    border-radius: 1rem;
    font-size: 1.125rem;
  }

  .calc-screen {
    font-size: 1.75rem;
    padding: 1.25rem 1rem;
  }
}

/* History Feature */
.calc-history {
  max-height: 150px;
  overflow-y: auto;
  border-top: 1px solid var(--border-color);
  margin-top: 1rem;
  padding-top: 0.5rem;
  font-family: monospace;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.calc-history-item {
  display: flex;
  justify-content: space-between;
  padding: 0.25rem 0;
}

/* ── Toggle Switch UI ── */
.toggle-container {
  display: inline-flex;
  background-color: var(--bg-card);
  padding: 0.35rem;
  border-radius: 1.5rem;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.05);
  border: 1px solid var(--border-color);
  height: 3.5rem;
}
.toggle-btn {
  height: 100%;
  padding: 0 2rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 1.15rem;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  cursor: pointer;
}
.toggle-btn.active {
  background-color: var(--accent);
  color: white;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}
.toggle-btn:not(.active):hover {
  color: var(--text-primary);
}