/* Base Colors & CSS Variables */
:root {
    /* Light Theme */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --border-color: #e2e8f0;
    --nav-bg: rgba(255, 255, 255, 0.8);
    --card-bg: rgba(255, 255, 255, 0.7);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --code-bg: #1e1e1e;
    --code-text: #f8fafc;
    --glass-border: rgba(255, 255, 255, 0.5);
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #60a5fa;
    --accent-hover: #93c5fd;
    --border-color: #334155;
    --nav-bg: rgba(15, 23, 42, 0.8);
    --card-bg: rgba(30, 41, 59, 0.7);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --code-bg: #0d1117;
    --code-text: #e2e8f0;
    --glass-border: rgba(255, 255, 255, 0.05);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Background Gradients */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
                radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.15), transparent 25%);
    z-index: -1;
    pointer-events: none;
}

[data-theme="dark"] body::before {
    background: radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.1), transparent 25%),
                radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.1), transparent 25%);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 0.5em;
    color: var(--text-primary);
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--accent-hover);
}

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo:hover {
    color: var(--text-primary);
}

.title {
    background: linear-gradient(135deg, var(--accent-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.theme-toggle {
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.hidden {
    display: none;
}

/* Layout Container */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
    flex: 1;
    width: 100%;
}

/* Views */
.view {
    display: none;
    animation: fadeIn 0.4s ease forwards;
}

.section-active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 0 3rem;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 2.5rem;
    letter-spacing: -0.025em;
    margin-bottom: 1rem;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Notes Grid */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.note-card {
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.note-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), #8b5cf6);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.note-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-color);
}

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

.note-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.note-path {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-family: 'Fira Code', monospace;
    opacity: 0.8;
}

/* Note Detail View */
.note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.back-button, .edit-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

.back-button:hover, .edit-button:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
    background-color: var(--bg-primary);
}

.glass-panel {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

/* Loading Spinner */
.loader {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 0;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(59, 130, 246, 0.2);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s ease-in-out infinite;
    margin-bottom: 1rem;
}

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

/* Markdown Content Styling */
.markdown-body {
    font-size: 1rem;
    color: var(--text-primary);
}

.markdown-body h1, .markdown-body h2 {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
    margin-top: 2em;
}

.markdown-body h1 { margin-top: 0; font-size: 2em; }
.markdown-body h2 { font-size: 1.5em; }
.markdown-body h3 { font-size: 1.25em; margin-top: 1.5em; }

.markdown-body p, .markdown-body ul, .markdown-body ol {
    margin-bottom: 1em;
}

.markdown-body ul, .markdown-body ol {
    padding-left: 2em;
}

.markdown-body li {
    margin-bottom: 0.25em;
}

/* Callouts / Blockquotes */
.markdown-body blockquote {
    padding: 0.5rem 1rem;
    margin: 1.5rem 0;
    color: var(--text-secondary);
    border-left: 4px solid var(--accent-color);
    background-color: rgba(59, 130, 246, 0.05);
    border-radius: 0 8px 8px 0;
}

/* Tables */
.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
}

.markdown-body th, .markdown-body td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

.markdown-body th {
    background-color: var(--bg-primary);
    font-weight: 600;
}

.markdown-body tr:nth-child(2n) {
    background-color: var(--bg-primary);
}

/* Code Blocks */
.markdown-body code {
    font-family: 'Fira Code', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.875em;
    background-color: rgba(136, 136, 136, 0.15);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    color: var(--accent-color);
}

.markdown-body pre {
    margin: 1.5em 0;
    border-radius: 8px;
    background-color: var(--code-bg);
    padding: 1rem;
    overflow-x: auto;
    border: 1px solid var(--border-color);
    position: relative;
}

.markdown-body pre:hover .copy-btn {
    opacity: 1;
}

.copy-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    padding: 0.4rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 6px;
    color: var(--code-text);
    cursor: pointer;
    opacity: 0;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.copy-btn.copied {
    background: rgba(16, 185, 129, 0.2);
    border-color: rgba(16, 185, 129, 0.5);
    color: #10b981;
    opacity: 1;
}

[data-theme="light"] .copy-btn {
    background: rgba(0, 0, 0, 0.05);
    border-color: rgba(0, 0, 0, 0.1);
    color: var(--text-secondary);
}

[data-theme="light"] .copy-btn:hover {
    background: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .copy-btn.copied {
    background: rgba(16, 185, 129, 0.1);
    border-color: rgba(16, 185, 129, 0.3);
    color: #059669;
}

.markdown-body pre code {
    background-color: transparent;
    padding: 0;
    font-size: 0.9em;
    line-height: 1.45;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .glass-panel {
        padding: 1.5rem;
    }
}

/* TOC Sidebar Layout */
.note-container {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.markdown-body {
    flex: 1;
    min-width: 0;
}

.toc-sidebar {
    width: 250px;
    position: sticky;
    top: 5rem;
    max-height: calc(100vh - 8rem);
    overflow-y: auto;
    flex-shrink: 0;
}

.toc-title {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

#toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

#toc-list li {
    margin-bottom: 0.5rem;
}

#toc-list a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    display: block;
    transition: color 0.2s;
    line-height: 1.4;
}

#toc-list a:hover {
    color: var(--accent-color);
}

.toc-h1 { padding-left: 0; font-weight: 500; }
.toc-h2 { padding-left: 0.5rem; }
.toc-h3 { padding-left: 1.5rem; }
.toc-h4 { padding-left: 2.5rem; }

@media (max-width: 1024px) {
    .note-container {
        flex-direction: column;
    }

    .toc-sidebar {
        width: 100%;
        position: static;
        max-height: none;
        margin-top: 1.5rem;
        order: -1;
    }
}