/* ==========================================================================
   CSS DESIGN SYSTEM & STYLING FOR "老机复活" (Old Machine Revival)
   Fresh, Clean, Glassmorphism, Micro-interactions, Responsive
   ========================================================================== */

/* --- CSS Custom Variables (Default Light Theme) --- */
:root {
    --primary: #2e7d32;            /* Fresh Forest Green */
    --primary-light: #ebf5ec;      /* Soft Light Green background */
    --primary-medium: #a5d6a7;     /* Medium Soft Green for borders/accents */
    --primary-hover: #1b5e20;      /* Dark Green for hover states */
    
    --accent: #f57c00;             /* Eco Amber/Warm Orange */
    --accent-light: #fff3e0;
    
    --bg-base: #f7f9f6;            /* Warm Leaf-infused off-white base */
    --bg-card: #ffffff;            /* Pure white cards */
    --bg-header: rgba(255, 255, 255, 0.85); /* Glassmorphism header */
    
    --text-main: #2c3e50;          /* Deep Slate Blue-Gray */
    --text-muted: #546e7a;         /* Soft Gray for secondary content */
    --text-light: #90a4ae;         /* Light Gray for metadata */
    
    --border: rgba(46, 125, 50, 0.09); /* Leafy subtle borders */
    --border-strong: #cfd8dc;
    
    --shadow-sm: 0 4px 12px rgba(46, 125, 50, 0.03);
    --shadow-md: 0 10px 30px rgba(46, 125, 50, 0.06);
    --shadow-lg: 0 20px 48px rgba(46, 125, 50, 0.1);
    
    --font-sans: 'Nunito', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    
    --header-height: 80px;
    --max-width: 1200px;
}

/* --- Dark Theme Variables Override --- */
[data-theme="dark"] {
    --primary: #81c784;            /* Soft Sage Green */
    --primary-light: #1b261d;      /* Dark Greenish Black background */
    --primary-medium: #388e3c;
    --primary-hover: #a5d6a7;
    
    --accent: #ffb74d;             /* Lighter Warm Orange */
    --accent-light: #2e210b;
    
    --bg-base: #111612;            /* Deep Forest Night */
    --bg-card: #18201a;            /* Dark Slate Green Card */
    --bg-header: rgba(24, 32, 26, 0.85);
    
    --text-main: #edf4ec;          /* Bright Soft Greenish White */
    --text-muted: #b0bec5;         /* Soft Blue-Gray */
    --text-light: #78909c;
    
    --border: rgba(129, 199, 132, 0.12);
    --border-strong: #37474f;
    
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.4);
}

/* ==========================================================================
   1. GLOBAL STYLES & RESET
   ========================================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-base);
    color: var(--text-main);
    font-family: var(--font-sans);
    line-height: 1.7;
    overflow-x: hidden;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

img, svg {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

ul {
    list-style: none;
}

button, input, textarea, select {
    font-family: inherit;
    font-size: 1rem;
    color: inherit;
    background: none;
    border: none;
    outline: none;
}

button {
    cursor: pointer;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
    width: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-base);
}
::-webkit-scrollbar-thumb {
    background: var(--primary-medium);
    border-radius: 5px;
    border: 2px solid var(--bg-base);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* ==========================================================================
   2. REUSABLE COMPONENTS & UTILITIES
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 700;
    font-size: 0.95rem;
    gap: 0.5rem;
    transition: all var(--transition-fast);
}

.btn-primary {
    background-color: var(--primary);
    color: #ffffff !important;
    box-shadow: 0 4px 14px rgba(46, 125, 50, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(46, 125, 50, 0.4);
}

.btn-secondary {
    background-color: var(--primary-light);
    color: var(--primary) !important;
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background-color: var(--primary-medium);
    color: var(--primary-hover) !important;
    transform: translateY(-2px);
}

.btn-block {
    display: flex;
    width: 100%;
}

.icon {
    width: 20px;
    height: 20px;
}

.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 4rem 1.5rem;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 3rem;
    position: relative;
    letter-spacing: -0.5px;
}

.section-title.text-center::after {
    content: '';
    display: block;
    width: 50px;
    height: 4px;
    background: var(--primary);
    margin: 10px auto 0;
    border-radius: 2px;
}

.sub-section-title {
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.text-center {
    text-align: center;
}

.max-width-600 {
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Page transitions */
.page-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    z-index: 9999;
    transition: width 0.2s ease;
}

.page-view {
    display: none;
    opacity: 0;
    transform: translateY(15px);
    transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.page-view.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================================================
   3. HEADER & NAVIGATION (Glassmorphism & Mobile Menu)
   ========================================================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--bg-header);
    backdrop-filter: blur(16px) saturate(140%);
    -webkit-backdrop-filter: blur(16px) saturate(140%);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.header-container {
    max-width: var(--max-width);
    height: 100%;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-main);
}

.logo:hover .logo-svg {
    transform: rotate(5deg) scale(1.05);
    color: var(--primary);
}

.logo-svg {
    width: 44px;
    height: 44px;
    color: var(--text-muted);
    transition: transform var(--transition-normal), color var(--transition-normal);
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.brand-title {
    font-size: 1.3rem;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: 0.5px;
}

.brand-subtitle {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--text-muted);
}

/* Navigation Menu */
.desktop-nav ul {
    display: flex;
    gap: 1.5rem;
}

.nav-item {
    font-weight: 700;
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-item:hover, .nav-item.active {
    color: var(--primary);
    background-color: var(--primary-light);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Theme Toggle Button */
.theme-toggle-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--primary-light);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
    transform: rotate(15deg) scale(1.08);
    background-color: var(--primary-medium);
    color: var(--primary-hover);
}

.calc-shortcut-btn {
    background-color: var(--accent-light);
    color: var(--accent);
    font-weight: 700;
    font-size: 0.9rem;
    padding: 0.55rem 1.1rem;
    border-radius: var(--radius-md);
    border: 1px solid rgba(245, 124, 0, 0.15);
    transition: all var(--transition-fast);
}

.calc-shortcut-btn:hover {
    background-color: var(--accent);
    color: #ffffff;
    box-shadow: 0 4px 10px rgba(245, 124, 0, 0.2);
}

/* Mobile Nav Toggle Button */
.mobile-nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 20px;
    z-index: 1001;
}

.mobile-nav-toggle span {
    display: block;
    height: 3px;
    width: 100%;
    background-color: var(--text-main);
    border-radius: 2px;
    transition: all var(--transition-normal);
}

.mobile-nav-toggle.open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-nav-toggle.open span:nth-child(2) {
    opacity: 0;
}

.mobile-nav-toggle.open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Mobile Drawer Nav */
.mobile-nav-drawer {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1.5rem;
    z-index: 999;
    box-shadow: var(--shadow-lg);
    animation: slideDown 0.3s ease-out;
}

.mobile-nav-drawer ul {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.mobile-nav-item {
    display: block;
    padding: 0.8rem 1.2rem;
    font-weight: 700;
    border-radius: var(--radius-md);
    color: var(--text-main);
}

.mobile-nav-item:hover, .mobile-nav-item.active {
    background-color: var(--primary-light);
    color: var(--primary);
}

@keyframes slideDown {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* ==========================================================================
   4. HOME HERO SECTION & ARTWORK
   ========================================================================== */
.main-content {
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height) - 150px);
}

.hero-section {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 3rem;
    align-items: center;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 5rem 1.5rem;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.hero-badge {
    background-color: var(--primary-light);
    color: var(--primary);
    padding: 0.5rem 1.1rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    letter-spacing: 0.5px;
    border: 1px solid var(--border);
}

.hero-title {
    font-size: 3.5rem;
    line-height: 1.15;
    font-weight: 900;
    color: var(--text-main);
    margin-bottom: 1.5rem;
    letter-spacing: -1.5px;
}

.hero-desc {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    line-height: 1.75;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

/* Retro Machine Artwork (CSS/SVG Graphic) */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.retro-machine-artwork {
    position: relative;
    width: 320px;
    height: 320px;
    background: radial-gradient(circle, var(--primary-light) 0%, rgba(247,249,246,0) 70%);
    display: flex;
    justify-content: center;
    align-items: center;
}

.monitor-wrapper {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    filter: drop-shadow(0 15px 30px rgba(46,125,50,0.15));
}

.monitor-frame {
    width: 200px;
    height: 160px;
    background-color: #d1c7bd;   /* Retro beige computer color */
    border: 8px solid #beada1;
    border-radius: 20px;
    padding: 10px;
    box-shadow: inset 0 -6px 0 rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.1);
    display: flex;
    justify-content: center;
    align-items: center;
}

[data-theme="dark"] .monitor-frame {
    background-color: #4a4744;
    border-color: #3b3937;
}

.monitor-screen {
    width: 100%;
    height: 100%;
    background-color: #1e1e1e;   /* Terminal Black */
    border-radius: 8px;
    padding: 8px;
    overflow: hidden;
    position: relative;
    border: 3px solid #ac9b8e;
    box-shadow: inset 0 2px 8px rgba(0,0,0,0.8);
}

[data-theme="dark"] .monitor-screen {
    border-color: #2b2a28;
}

.screen-glow {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(76, 175, 80, 0.15) 0%, rgba(0,0,0,0) 80%);
    pointer-events: none;
    z-index: 3;
}

.terminal-text {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.7rem;
    color: #4af626; /* Neo Green */
    line-height: 1.4;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.terminal-text p {
    white-space: nowrap;
    overflow: hidden;
}

.blink-cursor::after {
    content: '_';
    animation: cursorBlink 1s step-end infinite;
}

@keyframes cursorBlink {
    50% { opacity: 0; }
}

.monitor-neck {
    width: 40px;
    height: 25px;
    background-color: #beada1;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}
[data-theme="dark"] .monitor-neck {
    background-color: #3b3937;
}

.monitor-base {
    width: 110px;
    height: 15px;
    background-color: #beada1;
    border-radius: 8px 8px 0 0;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1), inset 0 3px 0 rgba(255,255,255,0.2);
}
[data-theme="dark"] .monitor-base {
    background-color: #3b3937;
}

/* Floating Retro Elements */
.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
}

.floating-item {
    position: absolute;
    padding: 0.4rem 0.8rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.3rem;
    animation: floatUpDown 4s ease-in-out infinite;
}

.item-ram { top: 15%; left: 5%; animation-delay: 0.5s; color: var(--accent); }
.item-ssd { top: 75%; left: 8%; animation-delay: 1.5s; color: #2196f3; }
.item-tux { top: 20%; right: 5%; animation-delay: 0s; color: #ffeb3b; }
.item-leaf { top: 70%; right: 8%; animation-delay: 2.2s; color: var(--primary); }

@keyframes floatUpDown {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

/* Features Grid section */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-medium);
}

.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.bg-green-light { background-color: var(--primary-light); color: var(--primary); }
.bg-orange-light { background-color: var(--accent-light); color: var(--accent); }
.bg-blue-light { background-color: #e3f2fd; color: #1e88e5; }
[data-theme="dark"] .bg-blue-light { background-color: #152938; color: #64b5f6; }

.feature-icon .icon-svg {
    width: 30px;
    height: 30px;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ==========================================================================
   5. HOME CONTENT LAYOUT: BLOG STREAM + SIDEBAR
   ========================================================================== */
.home-layout {
    display: grid;
    grid-template-columns: 1.3fr 0.7fr;
    gap: 3rem;
    padding-top: 2rem;
}

.column-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0.75rem;
}

.column-header h2 {
    margin-bottom: 0;
}

.link-more {
    font-weight: 700;
    font-size: 0.95rem;
}

/* Posts List (Simple layout for Home) */
.posts-list-simple {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.post-card-simple {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 1.75rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.post-card-simple:hover {
    transform: scale(1.01) translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-medium);
}

.post-card-simple::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background-color: var(--primary);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.post-card-simple:hover::before {
    opacity: 1;
}

.card-meta-row {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
    font-size: 0.85rem;
}

.card-tag {
    background-color: var(--primary-light);
    color: var(--primary);
    font-weight: 700;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
}

.card-date {
    color: var(--text-light);
}

.post-card-simple h3 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.post-card-simple h3 a {
    color: var(--text-main);
}

.post-card-simple h3 a:hover {
    color: var(--primary);
}

.post-card-simple p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 1.25rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-bottom-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-light);
}

.card-readmore {
    font-weight: 700;
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.card-stats {
    display: flex;
    gap: 1rem;
}

.card-stat-item {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* Sidebar Widgets */
.sidebar-column {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.widget-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.widget-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--primary);
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.75rem;
}

.widget-header h3 {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-main);
}

.widget-header .icon-svg {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.widget-intro {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

/* Profile Widget Specific */
.profile-widget {
    padding: 0;
    text-align: center;
}

.profile-avatar-bg {
    height: 90px;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-medium));
}

.profile-info {
    padding: 0 1.5rem 2rem;
    position: relative;
}

.profile-avatar-container {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 4px solid var(--bg-card);
    position: absolute;
    top: -40px;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

.profile-avatar {
    width: 100%;
    height: 100%;
}

.profile-info h3 {
    margin-top: 3rem;
    font-size: 1.2rem;
    font-weight: 800;
}

.profile-bio {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0.75rem 0 1.5rem;
    line-height: 1.6;
}

.profile-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    background-color: var(--primary-light);
    border-radius: var(--radius-md);
    padding: 0.75rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-num {
    font-weight: 800;
    font-size: 1.1rem;
    color: var(--primary);
}

.stat-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 700;
    text-transform: uppercase;
}

.border-left {
    border-left: 1px solid rgba(46, 125, 50, 0.15);
}

/* ==========================================================================
   6. CALCULATOR WIDGET STYLING
   ========================================================================== */
.calc-widget {
    border: 1px solid rgba(46, 125, 50, 0.2);
}

.calc-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    font-weight: 700;
}

.calc-val {
    color: var(--primary);
    background: var(--primary-light);
    padding: 0.1rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
}

/* Custom Sliders styling */
.calc-slider {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--primary-light);
    outline: none;
    transition: background 0.3s;
}

.calc-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.15);
    transition: transform 0.1s;
}

.calc-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--primary-hover);
}

/* Radio Group styling */
.radio-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

.radio-label {
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-strong);
    padding: 0.6rem 0.5rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 700;
    transition: all var(--transition-fast);
    background-color: var(--bg-card);
    text-align: center;
}

.radio-label input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.radio-label span {
    display: block;
}

.radio-label:has(input:checked) {
    background-color: var(--primary-light);
    border-color: var(--primary);
    color: var(--primary);
}

/* Result Box */
.calc-result-box {
    margin-top: 1.5rem;
    background-color: var(--primary-light);
    border: 1.5px dashed var(--primary);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    animation: fadeIn 0.4s ease-out;
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.result-badge {
    background-color: var(--primary);
    color: #ffffff;
    font-size: 0.75rem;
    font-weight: 800;
    padding: 0.2rem 0.6rem;
    border-radius: 50px;
}

.close-btn {
    font-size: 1.5rem;
    color: var(--text-muted);
    line-height: 1;
}

.close-btn:hover {
    color: var(--primary-hover);
}

.result-content {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    font-size: 0.85rem;
}

.result-item strong {
    color: var(--primary-hover);
    display: block;
    margin-bottom: 0.15rem;
}

.result-item p {
    color: var(--text-main);
    line-height: 1.5;
}

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

/* ==========================================================================
   7. BLOG LIST VIEW (Search & Filtering)
   ========================================================================== */
.view-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 2.5rem;
    gap: 2rem;
    flex-wrap: wrap;
}

.view-title {
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: -1px;
    line-height: 1.1;
    margin-bottom: 0.5rem;
}

.view-subtitle {
    color: var(--text-muted);
    font-size: 1.05rem;
}

.search-box {
    position: relative;
    width: 320px;
    max-width: 100%;
}

.search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--text-light);
    pointer-events: none;
}

.search-box input {
    width: 100%;
    background-color: var(--bg-card);
    border: 1.5px solid var(--border-strong);
    padding: 0.8rem 1rem 0.8rem 2.8rem;
    border-radius: 50px;
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.search-box input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(46, 125, 50, 0.15);
}

/* Category buttons */
.categories-bar {
    display: flex;
    gap: 0.75rem;
    overflow-x: auto;
    padding-bottom: 1rem;
    margin-bottom: 2.5rem;
    border-bottom: 1px solid var(--border);
    -webkit-overflow-scrolling: touch;
}

.category-btn {
    white-space: nowrap;
    padding: 0.5rem 1.25rem;
    font-weight: 700;
    border-radius: 50px;
    border: 1.5px solid var(--border-strong);
    background-color: var(--bg-card);
    transition: all var(--transition-fast);
    font-size: 0.9rem;
}

.category-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background-color: var(--primary-light);
}

.category-btn.active {
    background-color: var(--primary);
    color: #ffffff;
    border-color: var(--primary);
    box-shadow: 0 4px 10px rgba(46, 125, 50, 0.2);
}

/* Grid layout for all posts */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem;
}

.post-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    transition: all var(--transition-normal);
}

.post-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-medium);
}

.post-card-banner {
    height: 180px;
    background-size: cover;
    background-position: center;
    position: relative;
    display: flex;
    align-items: flex-end;
    padding: 1.25rem;
}

.card-banner-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(0deg, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0) 80%);
}

.post-card-banner .card-meta-row {
    position: relative;
    z-index: 2;
    margin-bottom: 0;
}

.post-card-banner .card-tag {
    background-color: var(--primary);
    color: #ffffff;
}

.post-card-banner .card-date {
    color: rgba(255,255,255,0.85);
}

.post-card-body {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.post-card-body h2 {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 0.75rem;
    line-height: 1.45;
}

.post-card-body h2 a {
    color: var(--text-main);
}

.post-card-body h2 a:hover {
    color: var(--primary);
}

.post-card-body p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-card-footer {
    margin-top: auto;
    border-top: 1px solid var(--border);
    padding-top: 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-light);
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px dashed var(--border-strong);
    max-width: 500px;
    margin: 2rem auto 0;
}

.empty-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.empty-state h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

/* ==========================================================================
   8. ARTICLE DETAIL VIEW (Readable typography)
   ========================================================================== */
.article-view-container {
    max-width: 800px;
    padding: 3rem 1.5rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    font-size: 0.95rem;
}

.back-link:hover {
    transform: translateX(-3px);
}

.article-detail {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    margin-bottom: 3rem;
}

.article-header {
    padding: 3rem 3rem 1.5rem;
    border-bottom: 1px solid var(--border);
}

.article-meta-top {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.article-category-badge {
    background-color: var(--primary-light);
    color: var(--primary);
    font-weight: 800;
    padding: 0.3rem 0.8rem;
    border-radius: 4px;
    font-size: 0.85rem;
}

.article-date {
    color: var(--text-light);
    font-size: 0.9rem;
}

.article-title-main {
    font-size: 2.25rem;
    font-weight: 900;
    line-height: 1.3;
    letter-spacing: -0.8px;
    color: var(--text-main);
    margin-bottom: 1.5rem;
}

.article-author-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.9rem;
}

.mini-avatar {
    width: 32px;
    height: 32px;
}

.author-name {
    font-weight: 700;
}

.read-time-badge {
    color: var(--text-light);
    margin-left: 0.5rem;
}

.article-banner {
    height: 280px;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.article-banner::before {
    content: '';
    position: absolute;
    top:0; left:0; right:0; bottom:0;
    background: rgba(0,0,0,0.45);
}

.banner-overlay-text {
    position: relative;
    z-index: 2;
    color: #ffffff;
    font-weight: 800;
    font-size: 1.75rem;
    letter-spacing: 2px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

/* Readable Markdown Body styling */
.markdown-body {
    padding: 3rem;
    font-size: 1.05rem;
    line-height: 1.8;
}

.markdown-body p {
    margin-bottom: 1.6rem;
}

.markdown-body h2 {
    font-size: 1.6rem;
    font-weight: 800;
    margin: 2.5rem 0 1.25rem;
    border-left: 5px solid var(--primary);
    padding-left: 0.75rem;
    line-height: 1.3;
}

.markdown-body h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin: 2rem 0 1rem;
}

.markdown-body ul, .markdown-body ol {
    margin-bottom: 1.6rem;
    padding-left: 1.5rem;
}

.markdown-body li {
    margin-bottom: 0.5rem;
}

.markdown-body blockquote {
    border-left: 4px solid var(--primary-medium);
    background-color: var(--primary-light);
    padding: 1rem 1.5rem;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin-bottom: 1.6rem;
    font-style: italic;
    color: var(--text-muted);
}

.markdown-body blockquote p:last-child {
    margin-bottom: 0;
}

.markdown-body strong {
    font-weight: 700;
    color: var(--primary-hover);
}

.markdown-body code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9em;
    background-color: var(--primary-light);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    color: var(--primary);
}

.markdown-body hr {
    border: 0;
    height: 1px;
    background: var(--border);
    margin: 2.5rem 0;
}

.inline-link {
    font-weight: 700;
    text-decoration: underline;
}

/* Article Footer */
.article-footer {
    padding: 0 3rem 3rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding-top: 2rem;
}

.tag-badge {
    background-color: var(--bg-base);
    color: var(--text-muted);
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.3rem 0.8rem;
    border-radius: 50px;
    border: 1px solid var(--border-strong);
}

.article-actions-row {
    display: flex;
    gap: 1rem;
    border-top: 1px solid var(--border);
    padding-top: 1.5rem;
}

.action-btn-like, .action-btn-share {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.25rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
    border: 1.5px solid var(--border-strong);
}

.action-btn-like {
    background-color: var(--bg-card);
    color: var(--text-muted);
}

.action-btn-like:hover, .action-btn-like.liked {
    color: #e91e63;
    border-color: #ff80ab;
    background-color: #ffe4ec;
}

.action-btn-like.liked .heart-icon {
    fill: #e91e63;
}

.action-btn-share {
    background-color: var(--bg-card);
    color: var(--text-muted);
}

.action-btn-share:hover {
    color: var(--primary);
    border-color: var(--primary-medium);
    background-color: var(--primary-light);
}

/* ==========================================================================
   9. COMMENTS & GUESTBOOK WALL
   ========================================================================== */
.article-comments-section {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 3rem;
    box-shadow: var(--shadow-sm);
}

.comments-section-title {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.comments-badge {
    font-size: 0.85rem;
    background-color: var(--primary-light);
    color: var(--primary);
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
}

/* Common Comment Form style */
.comment-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-bottom: 3rem;
    background-color: var(--bg-base);
    padding: 2rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.form-row-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.comment-form .form-group input, .comment-form .form-group textarea {
    width: 100%;
    background-color: var(--bg-card);
    border: 1.5px solid var(--border-strong);
    border-radius: var(--radius-sm);
    padding: 0.8rem;
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.comment-form .form-group input:focus, .comment-form .form-group textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.1);
}

.comment-form label {
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    display: block;
}

/* Avatar Selector (Bubbles style) */
.avatar-selector {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    align-items: center;
}

.avatar-option {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    cursor: pointer;
    border: 3px solid transparent;
    transition: all var(--transition-fast);
    padding: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.avatar-option svg {
    width: 100%;
    height: 100%;
}

.avatar-option:hover {
    transform: scale(1.1);
}

.avatar-option.selected {
    border-color: var(--primary);
    background-color: var(--primary-light);
    transform: scale(1.1);
}

/* Comment Cards List */
.comments-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.comment-card {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding-bottom: 1.5rem;
    display: flex;
    gap: 1.25rem;
    animation: slideUp 0.3s ease-out;
}

.comment-card:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.comment-card-avatar {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
}

.comment-card-content {
    flex-grow: 1;
}

.comment-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.comment-nickname {
    font-weight: 800;
    color: var(--text-main);
}

.comment-date {
    font-size: 0.8rem;
    color: var(--text-light);
}

.comment-text-body {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-main);
    word-break: break-all;
}

/* GUESTBOOK VIEW LAYOUT */
.guestbook-layout {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 3rem;
    align-items: flex-start;
}

.guestbook-form-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: calc(var(--header-height) + 2rem);
}

.guestbook-form-card h3 {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
}

.guestbook-form-card .comment-form {
    background: transparent;
    padding: 0;
    border: none;
    margin-bottom: 0;
}

.guestbook-wall {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.wall-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0.75rem;
}

.wall-header h3 {
    font-size: 1.4rem;
    font-weight: 800;
}

.wall-count {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 700;
}

.guestbook-cards-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.25rem;
}

/* Message notes grid style for guestbook */
.guestbook-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    display: flex;
    gap: 1rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    position: relative;
    animation: slideUp 0.4s ease-out;
}

.guestbook-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-medium);
}

.guestbook-card-avatar {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
}

.guestbook-card-main {
    flex-grow: 1;
}

.guestbook-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.guestbook-card-name {
    font-weight: 800;
    font-size: 0.95rem;
}

.guestbook-card-date {
    font-size: 0.8rem;
    color: var(--text-light);
}

.guestbook-card-text {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-main);
    word-break: break-all;
    white-space: pre-wrap; /* Preserve spaces & linebreaks in message */
}

.guestbook-card-footer {
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-light);
}

.btn-message-delete {
    color: var(--text-light);
    font-weight: 700;
    transition: color var(--transition-fast);
}

.btn-message-delete:hover {
    color: #e91e63;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   10. ABOUT ARTICLE SPECIFIC
   ========================================================================== */
.about-article {
    border-top: 5px solid var(--primary);
}

.about-header {
    padding: 3rem 3rem 2rem;
}

.about-badge {
    color: var(--primary);
    background-color: var(--primary-light);
    font-weight: 800;
    letter-spacing: 2px;
    font-size: 0.8rem;
    padding: 0.3rem 0.8rem;
    border-radius: 4px;
    margin-bottom: 1rem;
    display: inline-block;
}

.about-banner {
    background-color: var(--primary-light);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 3rem 0;
    border-bottom: 1px solid var(--border);
}

.about-banner-logo {
    width: 140px;
    height: 140px;
    color: var(--primary);
}

.logo-svg-large {
    width: 100%;
    height: 100%;
}

/* ==========================================================================
   11. SITE FOOTER
   ========================================================================== */
.site-footer {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 4rem 1.5rem 3rem;
    margin-top: 5rem;
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 0.5fr 1fr;
    gap: 3rem;
}

.footer-brand .footer-logo {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--primary);
    display: block;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

.footer-links h4 {
    font-size: 1rem;
    font-weight: 800;
    margin-bottom: 1.25rem;
    color: var(--text-main);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    font-size: 0.9rem;
}

.footer-links a {
    color: var(--text-muted);
    font-weight: 700;
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-copyright {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    text-align: right;
    font-size: 0.85rem;
    color: var(--text-light);
}

.eco-friendly-text {
    font-weight: 800;
    color: var(--primary);
    margin-top: 1rem;
}

/* ==========================================================================
   12. RESPONSIVE MEDIA QUERIES (Breakpoints)
   ========================================================================== */
@media (max-width: 1024px) {
    .hero-section {
        grid-template-columns: 1fr;
        gap: 4rem;
        padding: 4rem 1.5rem;
        text-align: center;
    }

    .hero-content {
        align-items: center;
    }

    .hero-title {
        font-size: 3rem;
    }

    .hero-buttons {
        justify-content: center;
    }

    .home-layout {
        grid-template-columns: 1fr;
        gap: 4rem;
    }

    .guestbook-layout {
        grid-template-columns: 1fr;
        gap: 4rem;
    }

    .guestbook-form-card {
        position: static;
    }

    .footer-container {
        grid-template-columns: 1fr 1fr;
    }

    .footer-copyright {
        grid-column: span 2;
        text-align: left;
        border-top: 1px solid var(--border);
        padding-top: 1.5rem;
        margin-top: 1.5rem;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 70px;
    }

    .desktop-nav {
        display: none;
    }

    .mobile-nav-toggle {
        display: flex;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .posts-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

    .article-header {
        padding: 2rem 1.5rem 1.25rem;
    }

    .article-title-main {
        font-size: 1.8rem;
    }

    .markdown-body {
        padding: 1.5rem;
    }

    .article-footer {
        padding: 0 1.5rem 2rem;
    }

    .article-comments-section {
        padding: 1.5rem;
    }

    .form-row-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .comment-form {
        padding: 1.25rem;
    }

    .footer-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-copyright {
        grid-column: span 1;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }

    .hero-buttons .btn {
        width: 100%;
    }

    .search-box {
        width: 100%;
    }

    .avatar-selector {
        gap: 0.35rem;
    }

    .avatar-option {
        width: 36px;
        height: 36px;
    }
}