:root {
    --bg-color: #111827;
    --text-color: #e5e7eb;
    --panel-bg-color: rgba(17, 24, 39, 0.8);
    --panel-border-color: rgba(255, 255, 255, 0.1);
    --text-muted-color: #9ca3af;
}

body.light-mode {
    --bg-color: #f3f4f6;
    --text-color: #1f2937;
    --panel-bg-color: rgba(255, 255, 255, 0.7);
    --panel-border-color: rgba(0, 0, 0, 0.1);
    --text-muted-color: #4b5563;
}

/* PERBAIKAN BUG: Mencegah halaman bergeser secara horizontal */
html, body {
    overflow-x: hidden;
    width: 100%;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}
.panel {
    background-color: var(--panel-bg-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--panel-border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}
h1, h2, h3 {
    color: var(--text-color);
}
p, span {
     color: var(--text-muted-color);
}
strong {
     color: var(--text-color);
}
.btn {
    background-color: #3b82f6;
    color: white;
    padding: 8px 16px;
    border-radius: 8px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.1s ease, opacity 0.3s ease;
    text-align: center;
}
.btn:hover:not(:disabled) {
    background-color: #2563eb;
}
.btn:active:not(:disabled) {
    transform: scale(0.95);
}
.btn-secondary {
    background-color: #4b5563;
}
.btn-secondary:hover:not(:disabled) {
    background-color: #374151;
}
 .btn-danger {
    background-color: #ef4444;
}
.btn-danger:hover:not(:disabled) {
    background-color: #dc2626;
}
.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}
.stability-stabil { color: #22c55e; }
.stability-tidak-stabil { color: #f97316; }
body.light-mode .stability-stabil { color: #16a34a; }
body.light-mode .stability-tidak-stabil { color: #ea580c; }

/* Gaya baru untuk panel yang bisa disembunyikan ke samping */
#info-panel, #lattice-info-panel, #lattice-controls-panel {
    transition: transform 0.5s ease-in-out;
}

#info-panel.collapsed-side-right, #lattice-info-panel.collapsed-side-right {
    transform: translateX(calc(100% + 2rem));
}

#lattice-controls-panel.collapsed-side-left {
    transform: translateX(calc(-100% - 2rem));
}

/* Gaya baru untuk tombol ikon di sisi layar */
.icon-btn {
    background-color: rgba(75, 85, 99, 0.3); /* abu-abu semi-transparan */
    color: var(--text-color);
    border: 1px solid var(--panel-border-color);
    border-radius: 9999px; /* circular */
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s ease;
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
}
.icon-btn:hover {
    background-color: rgba(107, 114, 128, 0.5);
}
body.light-mode .icon-btn {
    background-color: rgba(229, 231, 235, 0.4);
}
body.light-mode .icon-btn:hover {
    background-color: rgba(209, 213, 219, 0.6);
}

/* Gaya untuk tombol ikon yang aktif */
.icon-btn.active {
    background-color: rgba(99, 102, 241, 0.6); /* Indigo, semi-transparan */
}
body.light-mode .icon-btn.active {
    background-color: rgba(99, 102, 241, 0.4); 
}

/* Gaya untuk Modal */
.modal {
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
}
.modal-container {
     background-color: var(--panel-bg-color);
     border: 1px solid var(--panel-border-color);
}

/* Kategori Warna Unsur */
.cat-alkali-metal { background-color: #ef4444; }
.cat-alkaline-earth-metal { background-color: #f97316; }
.cat-lanthanide { background-color: #a3e635; }
.cat-actinide { background-color: #4ade80; }
.cat-transition-metal { background-color: #22d3ee; }
.cat-post-transition-metal { background-color: #60a5fa; }
.cat-metalloid { background-color: #818cf8; }
.cat-nonmetal { background-color: #c084fc; }
.cat-halogen { background-color: #f472b6; }
.cat-noble-gas { background-color: #fb7185; }

#footer-text {
    color: var(--text-muted-color);
    transition: color 0.3s ease;
}

/* Gaya untuk slider */
.slider-container {
    transition: opacity 0.3s ease, transform 0.3s ease;
}
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    background: rgba(107, 114, 128, 0.5);
    border-radius: 5px;
    outline: none;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: #e5e7eb;
    cursor: pointer;
    border-radius: 50%;
}
body.light-mode input[type="range"] {
     background: rgba(156, 163, 175, 0.5);
}
body.light-mode input[type="range"]::-webkit-slider-thumb {
    background: #374151;
}

/* Gaya untuk kontrol kisi */
#lattice-controls {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

#lattice-controls label, #lattice-display-controls label {
    display: flex;
    align-items: center;
    cursor: pointer;
}

#lattice-controls select {
    background-color: rgba(75, 85, 99, 0.3);
    border: 1px solid var(--panel-border-color);
    border-radius: 0.375rem;
    padding: 0.25rem 0.5rem;
    color: var(--text-color);
}

body.light-mode #lattice-controls select {
    background-color: rgba(229, 231, 235, 0.4);
}

input[type="radio"] {
    -webkit-appearance: none;
    appearance: none;
    background-color: transparent;
    margin: 0;
    font: inherit;
    color: var(--text-muted-color);
    width: 1.15em;
    height: 1.15em;
    border: 0.15em solid currentColor;
    border-radius: 50%;
    transform: translateY(-0.075em);
    display: grid;
    place-content: center;
}
input[type="radio"]::before {
    content: "";
    width: 0.65em;
    height: 0.65em;
    border-radius: 50%;
    transform: scale(0);
    transition: 120ms transform ease-in-out;
    box-shadow: inset 1em 1em #3b82f6;
}
input[type="radio"]:checked::before {
    transform: scale(1);
}