/* =========================================
   CENTRAL THEME REGISTRY
   Add new themes as [data-theme="name"]
========================================= */

:root,
[data-theme="dark"] {
    /* 1. Core Layout Colors */
    --bg-color: #050810;
    --card-bg: rgba(15, 20, 30, 0.5);
    --card-border: rgba(255, 255, 255, 0.15);
    --nav-bg: rgba(5, 8, 16, 0.8);
    --nav-bg-mobile: rgba(5, 8, 16, 0.95);

    /* 2. Typography */
    --text-main: #f8fafc;
    --text-muted: #94a3b8;

    /* 3. Accents */
    --accent-cyan: #00f2fe;
    --accent-violet: #9b51e0;

    /* 4. Canvas Variables (Read by JS) */
    --canvas-dot-rgb: 255, 255, 255;
    --canvas-line-rgb: 0, 242, 254;
    --canvas-line-opacity: 0.15;

    /* 5. Subtle elements for inner cards/accordions */
    --surface-bg: rgba(255, 255, 255, 0.02);
    --border-light: rgba(255, 255, 255, 0.06);

    /* 6. Extended Color Ramps */
    --primary-50: rgba(0, 242, 254, 0.03);
    --primary-100: rgba(0, 242, 254, 0.08);
    --primary-200: rgba(0, 242, 254, 0.15);
    --primary-300: rgba(0, 242, 254, 0.25);
    --primary-400: rgba(0, 242, 254, 0.4);
    --primary-500: #00f2fe;
    --primary-600: #00c2d4;

    --secondary-50: rgba(155, 81, 224, 0.03);
    --secondary-100: rgba(155, 81, 224, 0.08);
    --secondary-200: rgba(155, 81, 224, 0.15);
    --secondary-300: rgba(155, 81, 224, 0.25);
    --secondary-500: #9b51e0;

    --accent-success: #00e676;
    --accent-warning: #ff9100;
    --accent-error: #ff5252;

    --neutral-50: rgba(255, 255, 255, 0.02);
    --neutral-100: rgba(255, 255, 255, 0.05);
    --neutral-200: rgba(255, 255, 255, 0.08);
    --neutral-300: rgba(255, 255, 255, 0.12);
    --neutral-400: rgba(255, 255, 255, 0.2);

    /* 7. Gradient Definitions */
    --gradient-primary: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
    --gradient-secondary: linear-gradient(135deg, #9b51e0 0%, #6d28d9 100%);
    --gradient-mesh: radial-gradient(ellipse at top left, rgba(0, 242, 254, 0.08), transparent 50%),
                     radial-gradient(ellipse at bottom right, rgba(155, 81, 224, 0.06), transparent 50%);

    /* 8. Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.15);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.35);
    --shadow-glow: 0 0 30px rgba(0, 242, 254, 0.12);
    --shadow-glow-violet: 0 0 30px rgba(155, 81, 224, 0.12);
}

[data-theme="light"] {
    /* 1. Core Layout Colors */
    --bg-color: #f4f7f9;
    --card-bg: rgba(255, 255, 255, 0.85);
    --card-border: rgba(0, 0, 0, 0.15);
    --nav-bg: rgba(244, 247, 249, 0.9);
    --nav-bg-mobile: rgba(244, 247, 249, 0.98);

    /* 2. Typography */
    --text-main: #111827;
    --text-muted: #4b5563;

    /* 3. Accents */
    --accent-cyan: #0284c7;
    --accent-violet: #6d28d9;

    /* 4. Canvas Variables (Read by JS) */
    --canvas-dot-rgb: 17, 24, 39;
    --canvas-line-rgb: 2, 132, 199;
    --canvas-line-opacity: 0.25;

    /* 5. Subtle elements */
    --surface-bg: rgba(0, 0, 0, 0.03);
    --border-light: rgba(0, 0, 0, 0.1);

    /* 6. Extended Color Ramps */
    --primary-50: rgba(2, 132, 199, 0.03);
    --primary-100: rgba(2, 132, 199, 0.08);
    --primary-200: rgba(2, 132, 199, 0.15);
    --primary-300: rgba(2, 132, 199, 0.25);
    --primary-400: rgba(2, 132, 199, 0.4);
    --primary-500: #0284c7;
    --primary-600: #0369a1;

    --secondary-50: rgba(109, 40, 217, 0.03);
    --secondary-100: rgba(109, 40, 217, 0.08);
    --secondary-200: rgba(109, 40, 217, 0.15);
    --secondary-300: rgba(109, 40, 217, 0.25);
    --secondary-500: #6d28d9;

    --accent-success: #16a34a;
    --accent-warning: #ea580c;
    --accent-error: #dc2626;

    --neutral-50: rgba(0, 0, 0, 0.02);
    --neutral-100: rgba(0, 0, 0, 0.04);
    --neutral-200: rgba(0, 0, 0, 0.06);
    --neutral-300: rgba(0, 0, 0, 0.1);
    --neutral-400: rgba(0, 0, 0, 0.15);

    /* 7. Gradient Definitions */
    --gradient-primary: linear-gradient(135deg, #0284c7 0%, #0ea5e9 100%);
    --gradient-secondary: linear-gradient(135deg, #6d28d9 0%, #7c3aed 100%);
    --gradient-mesh: radial-gradient(ellipse at top left, rgba(2, 132, 199, 0.06), transparent 50%),
                     radial-gradient(ellipse at bottom right, rgba(109, 40, 217, 0.05), transparent 50%);

    /* 8. Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.15);
    --shadow-glow: 0 0 30px rgba(2, 132, 199, 0.1);
    --shadow-glow-violet: 0 0 30px rgba(109, 40, 217, 0.1);
}

/* ========================================= */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", sans-serif;
}

body {
    background-color: var(--bg-color);
    background-image: var(--gradient-mesh);
    color: var(--text-main);
    line-height: 1.7;
    min-height: 100vh;
    overflow-x: hidden;
    transition:
        background-color 0.4s ease,
        color 0.4s ease;
}

#network-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    pointer-events: none;
}

/* --- Global Navbar --- */
nav {
    padding: 1.5rem 2rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    z-index: 1000;
    position: sticky;
    top: 0;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--card-border);
    transition: padding 0.3s ease, box-shadow 0.3s ease;
}

.nav-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-main);
    letter-spacing: 1px;
    margin-right: auto;
    transition: text-shadow 0.3s ease;
}

.nav-brand:hover {
    text-shadow: 0 0 16px var(--primary-300);
}

#nav-links {
    order: 1;
}
#theme-toggle {
    order: 2;
}
.menu-toggle {
    order: 3;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: "";
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-main);
}

.menu-toggle {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-main);
    transition: transform 0.2s ease;
}

/* Mobile Navbar */
@media (max-width: 768px) {
    nav {
        padding: 0.8rem 1.2rem;
        gap: 1.2rem;
    }
    .menu-toggle {
        display: block;
    }
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--nav-bg-mobile);
        backdrop-filter: blur(12px);
        padding: 2rem;
        border-bottom: 1px solid var(--card-border);
        gap: 1.5rem;
        text-align: center;
        box-shadow: var(--shadow-md);
    }
    .nav-links.active {
        display: flex;
    }
}

/* --- Layout Containers --- */
.container {
    max-width: 1200px;
    margin: 3rem auto 6rem auto;
    padding: 0 2rem;
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.2rem;
        margin: 2rem auto 4rem auto;
    }
}

/* --- Base Glass Card --- */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 2.5rem;
    transition:
        transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
        border-color 0.3s ease,
        box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.glass-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary-300), transparent);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.glass-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-200);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.glass-card:hover::before {
    opacity: 1;
}

@media (max-width: 768px) {
    .glass-card {
        padding: 1.8rem;
        border-radius: 16px;
    }
}

/* --- Scroll Animations --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition:
        opacity 0.8s ease-out,
        transform 0.8s ease-out;
}
.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Global Markdown Formatting --- */
.markdown-content p {
    margin-bottom: 0.8rem;
    line-height: 1.6;
}
.markdown-content ul,
.markdown-content ol {
    margin-left: 1.5rem;
    margin-bottom: 0.8rem;
}
.markdown-content li {
    margin-bottom: 0.4rem;
}
.markdown-content strong {
    color: var(--text-main);
    font-weight: 600;
}
.markdown-content em {
    font-style: italic;
    color: var(--text-main);
}
.markdown-content a {
    color: var(--accent-cyan);
    text-decoration: none;
    border-bottom: 1px dotted var(--accent-cyan);
    transition: border-bottom 0.2s ease;
}
.markdown-content a:hover {
    border-bottom-style: solid;
}

/* --- Global Loading Screen --- */
.global-loader {
    position: fixed;
    inset: 0;
    background: var(--bg-color);
    z-index: 99999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition:
        opacity 0.5s ease,
        visibility 0.5s ease;
}

.global-loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-spinner {
    width: 60px;
    height: 60px;
    border: 3px solid var(--primary-100);
    border-radius: 50%;
    border-top-color: var(--accent-cyan);
    border-bottom-color: var(--accent-violet);
    animation: spin 1s cubic-bezier(0.68, -0.55, 0.265, 1.55) infinite;
}

.loader-text {
    margin-top: 1.5rem;
    color: var(--accent-cyan);
    font-size: 0.85rem;
    letter-spacing: 4px;
    text-transform: uppercase;
    font-weight: 600;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@keyframes pulse {
    0%,
    100% {
        opacity: 0.5;
    }
    50% {
        opacity: 1;
    }
}

/* --- Theme Toggle Button --- */
.theme-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.2rem;
    cursor: pointer;
    transition:
        color 0.3s ease,
        transform 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
.theme-btn:hover {
    color: var(--accent-cyan);
    transform: rotate(15deg);
}

/* --- Utility Animations --- */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes shimmer {
    0% {
        background-position: -200% center;
    }
    100% {
        background-position: 200% center;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-8px);
    }
}