:root {
    --bg-primary: #0A0A0A;
    --bg-secondary: #111111;
    --bg-tertiary: #1D1D1D;
    --text-primary: #F3F4F6;
    --text-secondary: #9CA3AF;
    --border-color: rgba(255, 255, 255, 0.1);
    --accent-1: #4f46e5;
    --accent-2: #a855f7;
    --accent-3: #ec4899;
    --glow-color: rgba(79, 70, 229, 0.25);
}

html[data-theme='light'] {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-tertiary: #F3F4F6;
    --text-primary: #1F2937;
    --text-secondary: #4B5563;
    --border-color: rgba(0, 0, 0, 0.1);
    --glow-color: rgba(79, 70, 229, 0.15);
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background: radial-gradient(ellipse at bottom, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, opacity 0.3s ease;
}

header {
    background-color: color-mix(in srgb, var(--bg-secondary) 70%, transparent);
    border-color: var(--border-color);
}
.header-title, .nav-link {
    color: var(--text-primary);
}
.nav-link:hover {
    color: var(--accent-1);
}
.theme-toggle-button:hover {
    background-color: var(--bg-tertiary);
}

.hero-section {
    background-color: var(--bg-secondary);
}
.bg-grid {
    background-image: linear-gradient(var(--border-color) 1px, transparent 1px), linear-gradient(to right, var(--border-color) 1px, var(--bg-secondary) 1px);
    background-size: 2rem 2rem;
    opacity: 0.5;
    mask-image: linear-gradient(to bottom, white 5%, transparent 90%);
    animation: pan-grid 30s linear infinite;
}

@keyframes pan-grid {
  0% { background-position: 0 0; }
  100% { background-position: 2rem 2rem; }
}

.main-title {
    color: var(--text-primary);
}
.main-subtitle {
    color: var(--text-secondary);
}
.secondary-button {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.section-title {
    color: var(--text-primary);
    position: relative;
    padding-bottom: 0.75rem;
    display: inline-block;
}
.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(to right, var(--accent-1), var(--accent-2));
    border-radius: 2px;
    transition: width 0.3s ease;
}
.section-title:hover::after {
    width: 80px;
}

.glass-card {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}
.glass-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 0 40px var(--glow-color);
    border-color: var(--accent-1);
}
.card-title {
    color: var(--text-primary);
}
.card-text {
    color: var(--text-secondary);
}
.feature-icon {
    background: linear-gradient(to bottom right, var(--accent-1), var(--accent-2));
}

.commands-section {
    background-color: var(--bg-secondary);
}
.command-desc {
    color: var(--text-secondary);
}
.code-block {
    background-color: var(--bg-primary);
    padding: 0.75rem;
    border-radius: 0.375rem;
}

.faq-item {
    overflow: hidden;
}
.faq-item summary {
    list-style: none;
}
.faq-item summary::-webkit-details-marker {
    display: none;
}
.faq-item[open] > summary svg {
    transform: rotate(180deg);
}
.faq-content {
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.25, 0.1, 0.25, 1.0);
    max-height: 0;
}
.faq-item[open] > .faq-content {
    max-height: 500px;
}
.faq-content p {
    color: var(--text-secondary);
}


footer {
    background-color: var(--bg-secondary);
    border-color: var(--border-color);
}
.footer-text {
    color: var(--text-secondary);
}
.footer-link {
    color: var(--text-secondary);
}
.footer-link:hover {
    color: var(--accent-1);
}

#to-top-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    opacity: 0;
    transform: translateY(20px);
    visibility: hidden;
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
}
#to-top-button.active {
    opacity: 1;
    transform: translateY(0);
    visibility: visible;
}

#devtools-warning {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.9);
    color: white;
    justify-content: center;
    align-items: center;
    text-align: center;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.devtools-warning-box {
    background-color: var(--bg-tertiary);
}

.gradient-text {
    background: linear-gradient(to right, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-size: 200% auto;
    animation: text-gradient-animation 5s ease-in-out infinite;
}

@keyframes text-gradient-animation {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}