/*
Theme Name: Nàng Ther
Theme URI: https://ngocanhblog.com/
Author: Antigravity
Description: A minimalist, typography-first WordPress theme optimized for Core Web Vitals, SEO, Googlebot, AdSense & Tracking. Zero-framework, semantic HTML, and accessibility-ready.
Version: 1.2.1
Text Domain: aether
*/

:root {
    /* Colors - Light Theme (Default) */
    --bg-color: #fafafa;
    --text-main: #1a1a1a;
    --text-muted: #555555;
    --primary-color: #0056b3;
    --border-color: #e5e5e5;
    --progress-color: var(--primary-color);
    --card-bg: #ffffff;
    --ad-bg: #f5f5f5;
    
    /* Fluid Typography using clamp() */
    --base-font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem); /* 16px to 18px */
    --h1-size: clamp(2rem, 1.8rem + 1vw, 2.5rem);
    --h2-size: clamp(1.5rem, 1.4rem + 0.5vw, 2rem);
    
    /* Fluid Spacing using clamp() */
    --spacing-sm: clamp(0.5rem, 0.4rem + 0.5vw, 0.75rem);
    --spacing-md: clamp(1rem, 0.8rem + 1vw, 1.5rem);
    --spacing-lg: clamp(1.5rem, 1.2rem + 1.5vw, 2.5rem);
    --spacing-xl: clamp(2.5rem, 2rem + 2.5vw, 4rem);
    
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-serif: ui-serif, Georgia, Cambria, "Times New Roman", Times, serif;
    --container-width: 1000px;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-color: #121212;
    --text-main: #e0e0e0;
    --text-muted: #a0a0a0;
    --primary-color: #66b2ff;
    --border-color: #333333;
    --card-bg: #1e1e1e;
    --ad-bg: #181818;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg-color: #121212;
        --text-main: #e0e0e0;
        --text-muted: #a0a0a0;
        --primary-color: #66b2ff;
        --border-color: #333333;
        --card-bg: #1e1e1e;
        --ad-bg: #181818;
    }
}

/* Document Reset & Base */
*, *::before, *::after { box-sizing: border-box; }

html {
    scroll-behavior: smooth;
}

body { 
    margin: 0; 
    padding: 0; 
    font-family: var(--font-sans); 
    background: var(--bg-color); 
    color: var(--text-main); 
    line-height: 1.6; 
    font-size: var(--base-font-size); 
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Lock body scrolling when mobile menu is active */
body.is-menu-open {
    overflow: hidden !important;
}

h1, h2, h3, h4, h5, h6 { 
    font-family: var(--font-serif); 
    margin-top: 0; 
    line-height: 1.25; 
    font-weight: 700; 
    color: var(--text-main); 
    transition: color 0.3s ease;
}

h1 { font-size: var(--h1-size); }
h2 { font-size: var(--h2-size); }
h3 { font-size: calc(var(--base-font-size) * 1.3); }

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

/* Micro-interaction: Animated underline for content links */
.post-content a:not(.post-thumbnail a):not(.button) {
    background-image: linear-gradient(var(--primary-color), var(--primary-color));
    background-position: 0% 100%;
    background-repeat: no-repeat;
    background-size: 0% 2px;
    transition: background-size 0.3s ease;
}

.post-content a:not(.post-thumbnail a):not(.button):hover, 
.post-content a:not(.post-thumbnail a):not(.button):focus { 
    background-size: 100% 2px;
    color: var(--primary-color); 
}

[data-theme="dark"] .post-content a:not(.post-thumbnail a):not(.button):hover { 
    color: #99ccff; 
}

/* Images & Media: Zero layout shift */
img { 
    max-width: 100%; 
    height: auto; 
    display: block; 
    border-radius: 4px;
}

/* Reading Progress Bar */
#reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--progress-color);
    transform-origin: 0 50%;
    transform: scaleX(0);
    z-index: 9999;
    pointer-events: none;
}

/* Modern CSS Scroll-driven Animation for reading progress (Zero JS runtime on modern browsers) */
@supports (animation-timeline: scroll()) {
    #reading-progress {
        transform: none !important;
        animation: aether-reading-progress linear;
        animation-timeline: scroll();
    }
    @keyframes aether-reading-progress {
        from { transform: scaleX(0); }
        to { transform: scaleX(1); }
    }
}

/* Layout */
.site-container { 
    max-width: var(--container-width); 
    margin: 0 auto; 
    padding: 0 var(--spacing-md); 
}

.site-header { 
    padding: var(--spacing-lg) 0; 
    border-bottom: 1px solid var(--border-color); 
    margin-bottom: var(--spacing-lg); 
    display: flex; 
    flex-wrap: wrap;
    justify-content: space-between; 
    align-items: center; 
    transition: border-color 0.3s ease;
}

.site-title { 
    margin: 0; 
    font-family: var(--font-sans); 
    font-weight: 700;
}

.site-title a { 
    color: var(--text-main); 
    text-decoration: none; 
}

.site-description {
    margin: 0.25rem 0 0 0;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.site-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.site-nav ul { 
    list-style: none; 
    margin: 0; 
    padding: 0; 
    display: flex; 
    gap: var(--spacing-md); 
}

/* Mobile Navigation Backdrop Overlay */
.site-nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(2px);
    z-index: 990;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

body.is-menu-open .site-nav-overlay {
    opacity: 1;
    pointer-events: auto;
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.2s ease, color 0.3s ease;
}

.theme-toggle:hover {
    background-color: rgba(0,0,0,0.05);
}
[data-theme="dark"] .theme-toggle:hover {
    background-color: rgba(255,255,255,0.1);
}

.site-main { 
    min-height: 60vh; 
    transition: opacity 0.2s ease-in-out;
}

.site-footer { 
    margin-top: var(--spacing-xl); 
    padding: var(--spacing-lg) 0; 
    border-top: 1px solid var(--border-color); 
    text-align: center; 
    color: var(--text-muted); 
    font-size: 0.9em;
}

.site-footer a {
    color: var(--text-main);
    text-decoration: underline;
}

/* ==========================================================================
   Breadcrumbs Navigation (SEO & UX)
   ========================================================================== */
.site-breadcrumbs {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
    padding: 0.25rem 0;
}

.site-breadcrumbs a {
    color: var(--text-muted);
}

.site-breadcrumbs a:hover {
    color: var(--primary-color);
}

.site-breadcrumbs .sep {
    margin: 0 0.4rem;
    opacity: 0.6;
}

.site-breadcrumbs .current {
    color: var(--text-main);
    font-weight: 500;
}

/* ==========================================================================
   Core Web Vitals & Google AdSense CLS Protection
   Pre-reserves container dimensions to eliminate Layout Shift entirely
   ========================================================================== */
.aether-ad-slot {
    display: block;
    margin: var(--spacing-lg) auto;
    text-align: center;
    background: var(--ad-bg);
    border: 1px dashed var(--border-color);
    border-radius: 6px;
    padding: 0.5rem;
    min-height: 280px; /* Standard Medium Rectangle (300x250) + label */
    contain: layout;
    overflow: hidden;
    position: relative;
}

.aether-ad-slot .ad-label {
    font-size: 0.7rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
    opacity: 0.8;
}

.aether-ad-slot .ad-container-inner {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 250px;
    width: 100%;
}

.aether-ad-slot ins.adsbygoogle {
    display: block !important;
    width: 100% !important;
    min-width: 250px;
    margin: 0 auto;
}

.aether-ad-placeholder {
    border-style: dotted;
    background: rgba(0, 0, 0, 0.02);
}

.aether-ad-header,
.aether-ad-footer {
    min-height: 110px; /* Leaderboard (728x90) + label */
}

.aether-ad-header .ad-container-inner,
.aether-ad-footer .ad-container-inner {
    min-height: 90px;
}

/* ==========================================================================
   Article & Typography Components
   ========================================================================== */
.post-list { 
    display: flex; 
    flex-direction: column; 
    gap: var(--spacing-xl); 
}

.post-item { 
    display: flex; 
    flex-direction: column; 
    gap: var(--spacing-md); 
}

.post-thumbnail-link { 
    display: block; 
    overflow: hidden; 
    border-radius: 8px; 
    background: rgba(0,0,0,0.03); 
    position: relative;
    aspect-ratio: 16 / 10;
}

[data-theme="dark"] .post-thumbnail-link { background: rgba(255,255,255,0.05); }

.post-thumbnail {
    margin: 0;
    width: 100%;
    height: 100%;
}

.post-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
    border-radius: 8px;
}

.post-item:hover .post-thumbnail img {
    transform: scale(1.02);
}

.post-category {
    font-size: 0.8em;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.post-category a {
    color: var(--primary-color);
}

.post-title { 
    margin-bottom: var(--spacing-sm); 
}

.post-title a { 
    color: var(--text-main); 
    text-decoration: none; 
}

.post-title a:hover { 
    color: var(--primary-color); 
}

.post-meta { 
    color: var(--text-muted); 
    font-size: 0.85em; 
    margin-bottom: var(--spacing-sm); 
}

.post-content { 
    margin-top: var(--spacing-lg); 
}

.post-content p { 
    margin-bottom: 1.5em; 
}

.post-content blockquote {
    border-left: 3px solid var(--primary-color);
    margin: var(--spacing-lg) 0;
    padding-left: 1.5em;
    font-style: italic;
    color: var(--text-muted);
}

.post-content pre {
    background: #2d2d2d;
    color: #f8f8f2;
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    font-size: 0.9em;
}

/* Entry Footer */
.entry-footer {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    font-size: 0.9em;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.entry-footer .footer-label {
    font-weight: 600;
    color: var(--text-main);
    margin-right: 0.25rem;
}

/* ==========================================================================
   E-E-A-T Author Bio Box
   ========================================================================== */
.author-bio-box {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.author-bio-avatar img {
    border-radius: 50%;
    width: 70px;
    height: 70px;
    object-fit: cover;
}

.author-bio-info h3 {
    margin: 0 0 0.25rem 0;
    font-size: 1.1rem;
}

.author-bio-desc {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ==========================================================================
   Post Navigation (Internal Link Building)
   ========================================================================== */
.post-navigation {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md) 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.post-navigation .nav-links {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.post-navigation .nav-previous,
.post-navigation .nav-next {
    flex: 1 1 45%;
    display: flex;
    flex-direction: column;
}

.post-navigation .nav-next {
    text-align: right;
}

.post-navigation .nav-subtitle {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.post-navigation .nav-title a {
    font-weight: 600;
    color: var(--text-main);
}

/* ==========================================================================
   Table of Contents (With Collapsible Toggle & Sub-lists)
   ========================================================================== */
.table-of-contents {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 8px;
    margin: var(--spacing-lg) 0;
    transition: all 0.3s ease;
}

.toc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.toc-title {
    font-family: var(--font-sans);
    font-size: 1.05rem;
    font-weight: 700;
    margin: 0;
}

.toc-toggle {
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--primary-color);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-family: var(--font-sans);
    transition: background-color 0.2s ease;
}

.toc-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .toc-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.toc-list {
    list-style: decimal;
    margin: var(--spacing-sm) 0 0 0;
    padding-left: 1.25rem;
    transition: opacity 0.2s ease;
}

.table-of-contents.is-collapsed .toc-list {
    display: none;
}

.toc-list li {
    margin-bottom: 0.35rem;
    line-height: 1.45;
}

.toc-sublist {
    list-style: circle;
    margin-top: 0.3rem;
    margin-bottom: 0.3rem;
    padding-left: 1.25rem;
}

.toc-list a {
    color: var(--text-main);
}

.toc-list a:hover {
    color: var(--primary-color);
}

/* ==========================================================================
   Universal Comment Form & Discussion Styling (Desktop & Mobile)
   ========================================================================== */
.comments-area {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.comment-list {
    list-style: none;
    padding: 0;
    margin: var(--spacing-md) 0;
}

.custom-comment-box {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.comment-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
    display: flex;
    justify-content: space-between;
}

.comment-author .fn {
    color: var(--text-main);
}

.comment-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.comment-form label {
    display: block;
    margin-bottom: 0.3rem;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-main);
}

.comment-form input[type="text"],
.comment-form input[type="email"],
.comment-form input[type="url"],
.comment-form textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-main);
    font-family: inherit;
    font-size: 1rem;
    box-sizing: border-box;
    transition: border-color 0.2s ease;
}

.comment-form input[type="text"]:focus,
.comment-form input[type="email"]:focus,
.comment-form input[type="url"]:focus,
.comment-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.comment-form textarea {
    min-height: 120px;
    resize: vertical;
}

.submit-btn,
.comment-form .submit-btn {
    align-self: flex-start;
    background: var(--primary-color);
    color: #ffffff;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    font-family: inherit;
    font-size: 1rem;
    transition: opacity 0.2s ease, transform 0.1s ease;
}

.submit-btn:hover,
.comment-form .submit-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

/* ==========================================================================
   Accessibility & Mobile Responsive (@media strictly scoped)
   ========================================================================== */
.screen-reader-text {
    border: 0;
    clip: rect(1px, 1px, 1px, 1px);
    clip-path: inset(50%);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute !important;
    width: 1px;
    word-wrap: normal !important;
}

.screen-reader-text:focus {
    background-color: #f1f1f1;
    border-radius: 3px;
    box-shadow: 0 0 2px 2px rgba(0, 0, 0, 0.6);
    clip: auto !important;
    clip-path: none;
    color: #21759b;
    display: block;
    font-size: 0.875rem;
    font-weight: 700;
    height: auto;
    left: 5px;
    line-height: normal;
    padding: 15px 23px 14px;
    text-decoration: none;
    top: 5px;
    width: auto;
    z-index: 100000;
}

.mobile-menu-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-main);
    padding: 0.5rem;
    z-index: 1000;
}

@media (max-width: 640px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .site-nav-wrapper {
        display: none;
        position: fixed;
        top: 0;
        right: 0;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--card-bg);
        box-shadow: -5px 0 20px rgba(0, 0, 0, 0.15);
        z-index: 995;
        padding: var(--spacing-xl) var(--spacing-md);
        box-sizing: border-box;
        overflow-y: auto;
    }
    
    body.is-menu-open .site-nav-wrapper {
        display: block;
    }
    
    .site-nav ul {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .author-bio-box {
        flex-direction: column;
        text-align: center;
    }

    .table-of-contents {
        padding: var(--spacing-md);
    }
}