/* VOLC TOOLS: Professional Web Tool Styles */
:root {
    /* Brand Color Palette */
    --color-primary: #00C4CC;    /* Brand Teal */
    --color-secondary: #7D2AE8;  /* Brand Purple */
    --color-bg: #F4F7F6;         /* Light Gray BG */
    --color-surface: #FFFFFF;    /* Pure White Surface */
    --color-text-main: #0E1217;  /* Deep Charcoal */
    --color-text-muted: #5E6267; /* Muted Slate */
    --color-border: #E1E4E8;     /* Light Border */
    --color-hover: #F0F2F5;      /* Subtle Hover Gray */
    
    /* Spacing & Shapes */
    --sidebar-width: 280px;
    --radius-lg: 16px;
    --radius-md: 12px;
    --radius-sm: 8px;
    
    /* Shadows */
    --shadow-soft: 0 2px 12px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.08);
    
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Navigation */
.sidebar {
    width: var(--sidebar-width);
    background: var(--color-surface);
    border-right: 1px solid var(--color-border);
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;
    padding: 32px 16px;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    z-index: 100;
}

.sidebar-brand {
    padding: 0 12px 40px;
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.nav-group {
    margin-bottom: 8px;
}

.nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.nav-header:hover {
    background-color: var(--color-hover);
}

.nav-arrow {
    color: var(--color-text-muted);
    display: flex;
    align-items: center;
    transition: transform 0.3s ease;
    padding: 8px;
}

.nav-group.is-open .nav-arrow {
    transform: rotate(180deg);
    color: var(--color-primary);
}

.nav-list {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.3s ease-in-out;
}

.nav-group.is-open .nav-list {
    grid-template-rows: 1fr;
}

.nav-list-inner {
    overflow: hidden;
    min-height: 0;
    padding-left: 12px;
}

.nav-item {
    display: block;
    padding: 12px 16px;
    text-decoration: none;
    color: var(--color-text-main);
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    margin-bottom: 4px;
}

.nav-item:hover {
    background-color: var(--color-hover);
    color: var(--color-primary);
    transform: translateX(4px);
}

/* Main Area */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 60px 48px;
    min-height: 100vh;
}

/* Hero & Search */
.hero {
    margin-bottom: 50px;
    padding: 60px;
    background: linear-gradient(135deg, rgba(0, 196, 204, 0.1) 0%, rgba(125, 42, 232, 0.1) 100%);
    border-radius: var(--radius-lg);
}

/* Product Grid */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.tool-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: 24px;
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow-soft);
    transition: var(--transition);
    border: 1px solid transparent;
}

.tool-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
    border-color: var(--color-primary);
}

.tool-card img {
    width: 64px;
    height: 64px;
    margin-bottom: 20px;
    border-radius: var(--radius-md);
}

/* Responsive */
@media (max-width: 1024px) {
    .main-content { padding: 40px 24px; }
}

@media (max-width: 768px) {
    .sidebar { transform: translateX(-100%); transition: transform 0.3s; }
    .main-content { margin-left: 0; }
}