/* ===== HEADER SECTION ===== */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 24px;
  background: var(--header-bg);
  color: var(--header-text);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

header h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0;
  margin-right: auto;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #38E8C6 0%, #82A0FF 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  position: relative;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  background: var(--btn-bg);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.theme-toggle-btn:hover {
  background: var(--accent-muted);
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-2px) rotate(8deg);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.toggle-icon-wrapper {
  position: relative;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.sun-icon, .moon-icon {
  position: absolute;
  width: 20px;
  height: 20px;
  top: 0;
  left: 0;
  transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
}

/* Glass effect for all header buttons */
.controls .btn-icon {
    border-radius: 50% !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: visible !important;
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    transition: all 0.3s ease;
}

.light-theme .controls .btn-icon {
    background: rgba(0, 0, 0, 0.03);
}

.controls .btn-icon:hover {
    transform: translateY(-2px) scale(1.05);
}

/* Colored Button Overrides */
#run-btn {
    background: linear-gradient(135deg, #00d2ff 0%, #3a7bd5 100%) !important;
    color: white !important;
    border: 1px solid rgba(0, 210, 255, 0.4) !important;
}

#run-btn:hover {
    box-shadow: 0 0 15px rgba(0, 210, 255, 0.5) !important;
    transform: translateY(-2px) scale(1.1) !important;
}

#copy-btn {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%) !important;
    color: white !important;
    border: 1px solid rgba(56, 239, 125, 0.4) !important;
}

#copy-btn:hover {
    box-shadow: 0 0 15px rgba(56, 239, 125, 0.5) !important;
    transform: translateY(-2px) scale(1.1) !important;
}

#header-clear-btn {
    background: linear-gradient(135deg, #ff4b2b 0%, #ff416c 100%) !important;
    color: white !important;
    border: 1px solid rgba(255, 75, 43, 0.4) !important;
}

#header-clear-btn:hover {
    box-shadow: 0 0 15px rgba(245, 87, 108, 0.5) !important;
    transform: translateY(-2px) scale(1.1) !important;
}

.sun-icon, .moon-icon {
  position: absolute;
  width: 20px;
  height: 20px;
  transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
}

/* Default state = Dark Mode (No light-theme class) */
.sun-icon {
  opacity: 0;
  transform: scale(0) rotate(90deg);
}

.moon-icon {
  opacity: 1;
  transform: scale(1) rotate(0);
}

/* Light Mode state (Body has light-theme class) */
.light-theme .sun-icon {
  opacity: 1;
  transform: scale(1) rotate(0);
}

.light-theme .moon-icon {
  opacity: 0;
  transform: scale(0) rotate(-90deg);
}

/* Visual separator */
.btn-separator {
    width: 1px;
    height: 24px;
    background: var(--border);
    margin: 0 8px;
    opacity: 0.5;
}

.light-theme .btn-separator {
    background: #cbd5e1;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 16px;
        text-align: center;
        padding: 16px;
    }

    .controls {
        justify-content: center;
        width: 100%;
    }
}