/* Blue Blocks & Icons Design */
:root {
    /* Palette: Dark Blue & Light Blue */
    --sidebar-bg: #1E3A8A;
    /* Dark Navy Blue */
    --sidebar-text: #BFDBFE;
    /* Light Blue Text */
    --sidebar-active: #FFFFFF;
    --sidebar-active-bg: rgba(255, 255, 255, 0.15);

    --bg-color: #EFF6FF;
    /* Very Light Blue Background */
    --card-bg: #FFFFFF;

    --primary-text: #172554;
    /* Deep Blue-Black */
    --secondary-text: #334155;
    /* Slate */

    --accent-color: #2563EB;
    /* Bright Royal Blue */
    --border-color: #DBEAFE;
    /* Blue-ish Border */

    --sidebar-width: 280px;
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;

    /* Stronger Shadows for Blocks */
    --shadow-block: 0 4px 6px -1px rgba(30, 58, 138, 0.1), 0 2px 4px -1px rgba(30, 58, 138, 0.06);
    --shadow-header: 0 2px 4px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: var(--font-main);
    color: var(--secondary-text);
    background-color: var(--bg-color);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

/* --- Blue Sidebar --- */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    color: var(--sidebar-text);
    height: 100vh;
    position: fixed;
    top: 0;
    left: 0;
    overflow-y: auto;
    z-index: 100;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
}

.sidebar-header {
    padding: 1.5rem;
    background-color: rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-brand {
    font-size: 1.2rem;
    font-weight: 800;
    color: white;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-links {
    list-style: none;
    padding: 1rem 0;
}

.nav-group-title {
    padding: 1.5rem 1.5rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #93C5FD;
    /* Lighter Blue */
    letter-spacing: 0.05em;
}

.nav-item a {
    display: block;
    padding: 0.75rem 1.5rem;
    color: var(--sidebar-text);
    text-decoration: none;
    font-size: 0.95rem;
    transition: all 0.2s;
    border-left: 4px solid transparent;
}

.nav-item a:hover {
    color: white;
    background-color: rgba(255, 255, 255, 0.05);
}

.nav-item a.active {
    color: white;
    background-color: var(--sidebar-active-bg);
    border-left-color: #60A5FA;
    /* Active Bright Blue Border */
    font-weight: 600;
}

/* --- Search Input --- */
#searchInput {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background-color: rgba(0, 0, 0, 0.2);
    color: white;
    font-family: var(--font-main);
    font-size: 0.9rem;
    outline: none;
    transition: all 0.2s;
    margin-top: 1rem;
}

#searchInput:focus {
    border-color: #60A5FA;
    background-color: rgba(0, 0, 0, 0.3);
}

#searchInput::placeholder {
    color: #93C5FD;
}

/* --- Main Content --- */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 3rem 4rem;
    max-width: 1400px;
}

.page-header {
    text-align: center;
    margin-bottom: 4rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.page-header h1 {
    font-size: 3rem;
    color: var(--primary-text);
    font-weight: 800;
    margin-bottom: 1rem;
}

/* --- Block Styling --- */
div[id^="part"] {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 0;
    /* Reset padding for header separation */
    margin-bottom: 3rem;
    box-shadow: var(--shadow-block);
    border: 1px solid var(--border-color);
    overflow: hidden;
    /* For header radius */
}

/* Block Header */
div[id^="part"]>h2 {
    background-color: #F8FAFC;
    /* Very Light Gray/Blue */
    color: var(--primary-text);
    font-size: 1.5rem;
    margin: 0;
    padding: 1.5rem 2.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 12px;
}

div[id^="part"]>h2 i {
    color: var(--accent-color);
    font-size: 1.2em;
    /* Bigger Icon */
}

/* Block Content */
section {
    padding: 2rem 2.5rem;
    border-bottom: 1px solid #F1F5F9;
}

section:last-child {
    border-bottom: none;
}

section h2 {
    font-size: 1.4rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

/* --- Components --- */
.deep-dive {
    background: linear-gradient(135deg, #1e3a8a 0%, #0f172a 100%);
    color: white;
    border-radius: 12px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.deep-dive h3 {
    color: #38bdf8;
    /* Light blue accent */
    margin-top: 0;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.deep-dive ul {
    list-style: none;
    /* remove default bullets */
    padding-left: 0;
}

.deep-dive li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.8rem;
}

.deep-dive li::before {
    content: "➢";
    position: absolute;
    left: 0;
    color: #38bdf8;
}

.callout {
    background-color: #EFF6FF;
    border-left: 5px solid var(--accent-color);
    border-radius: 6px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.callout h4 {
    color: var(--primary-text);
}

.stat-box {
    background: linear-gradient(135deg, var(--sidebar-bg), var(--accent-color));
    color: white;
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    text-align: center;
    box-shadow: var(--shadow-block);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: #93C5FD;
    display: block;
}

table {
    width: 100%;
    margin: 1.5rem 0;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

th {
    background-color: #DBEAFE;
    /* Light Blue Header */
    color: var(--primary-text);
    font-weight: 700;
    padding: 1rem;
    text-align: left;
}

td {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    background: white;
}

/* Mobile Header */
.mobile-header {
    display: none;
    background-color: var(--sidebar-bg);
    color: white;
    padding: 1rem 1.5rem;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 99;
    box-shadow: var(--shadow-header);
}

.menu-toggle {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Responsive */
@media (max-width: 1024px) {
    .main-content {
        padding: 2rem;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        padding: 1rem;
    }

    .mobile-header {
        display: flex;
    }

    div[id^="part"]>h2 {
        padding: 1.2rem 1.5rem;
        font-size: 1.2rem;
    }

    section {
        padding: 1.5rem;
    }

    .overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 90;
    }

    .overlay.active {
        display: block;
    }
}