/* ============================================
   Clean Modern Design - Light & Professional
   Inspired by Stripe, Apple, Dropbox
   ============================================ */

/* ============================================
   CSS Variables - Light & Clean Palette
   ============================================ */
:root {
    /* Primary Colors - Vibrant but Professional */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    
    /* Accent Colors - Subtle & Professional */
    --accent-green: #10b981;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --accent-orange: #f59e0b;
    
    /* Background Colors - Light & Clean */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-hover: #f8fafc;
    
    /* Text Colors - High Contrast */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    
    /* Border Colors - Subtle */
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    --border-light: #f1f5f9;
    
    /* Shadow - Subtle & Professional */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
    
    /* Spacing - Generous */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius - Modern */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions - Smooth */
    --transition-fast: 0.15s ease;
    --transition-base: 0.2s ease;
    --transition-slow: 0.3s ease;
}

/* ============================================
   Reset & Base
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    padding-top: 32px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Main Layout - 2 Column với Sidebar */
.main-layout {
    display: block;
    width: 100%;
}

.main-content-wrapper {
    width: 100%;
    max-width: 100%;
    margin: 0;
    padding: 0;
}

/* Nếu main-content-wrapper nằm trong tool-content-section, không cần margin-left riêng */
.tool-content-section .main-content-wrapper {
    margin-left: 0;
    padding: 0;
}

/* Subtle Background Pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 0% 0%, rgba(99, 102, 241, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 100% 100%, rgba(139, 92, 246, 0.03) 0%, transparent 50%),
        var(--bg-secondary);
    z-index: -1;
    pointer-events: none;
}

/* ============================================
   Disclaimer Banner
   ============================================ */
.disclaimer-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 10000;
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
    padding: 10px 0;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border-bottom: none;
}

.disclaimer-wrapper {
    display: flex;
    width: 100%;
    overflow: hidden;
    position: relative;
}

.disclaimer-content {
    display: inline-flex;
    align-items: center;
    justify-content: flex-start;
    gap: 10px;
    white-space: nowrap;
    animation: scroll-banner 30s linear infinite;
    padding: 0 50px;
    flex-shrink: 0;
}

.disclaimer-icon {
    font-size: 1rem;
}

.disclaimer-text {
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.2px;
}

@keyframes scroll-banner {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

.disclaimer-banner:hover .disclaimer-content {
    animation-play-state: paused;
}

/* ============================================
   Navigation - Clean & Modern
   ============================================ */
.navbar {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 32px;
    z-index: 1000;
    padding: 1rem 0;
    transition: var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-sm);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
    transition: var(--transition-base);
}

.nav-logo:hover {
    color: var(--primary);
    transform: translateY(-1px);
}

.logo-icon {
    font-size: 1.75rem;
}

.nav-menu {
    display: flex;
    gap: 2.5rem;
    align-items: center;
    list-style: none;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition-base);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition-base);
    border-radius: var(--radius-full);
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: var(--transition-base);
}

/* ============================================
   Hero Section - Clean & Spacious
   ============================================ */
.hero-section {
    background: linear-gradient(135deg, #f8fafc 0%, #ffffff 100%);
    position: relative;
    padding: 6rem 0 5rem;
    overflow: hidden;
    margin-top: 32px;
    border-bottom: 1px solid var(--border-light);
    margin-left: 0;
    transition: var(--transition-base);
}

/* Desktop: Hero section cần margin-left để không bị sidebar che */
body:has(.sidebar-desktop) .hero-section,
.layout-desktop .hero-section {
    margin-left: 280px;
    padding-left: 3rem;
    padding-right: 3rem;
}

.layout-mobile .hero-section {
    margin-left: 0;
    padding-left: 1rem;
    padding-right: 1rem;
}

/* Fallback nếu browser không support :has() */
@media (min-width: 769px) {
    .hero-section {
        margin-left: 280px;
        padding-left: 3rem;
        padding-right: 3rem;
    }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
    width: 100%;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-weight: 400;
    line-height: 1.6;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Tool Tabs - Clean Cards */
.tool-tabs {
    margin-top: 3rem;
}

.tab-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    max-width: 100%;
    margin: 0 auto;
    width: 100%;
}

.tab-btn {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 1.5rem 2.5rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition-base);
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 1rem;
    min-width: 200px;
    max-width: 300px;
    width: 100%;
    flex: 0 1 auto;
    justify-content: center;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    box-sizing: border-box;
}

.tab-btn:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.tab-btn.active {
    background: var(--primary-gradient);
    border-color: transparent;
    color: white;
    box-shadow: var(--shadow-lg);
}

.tab-btn.active:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.tab-icon {
    font-size: 1.75rem;
}

.tab-name {
    font-size: 1.1rem;
}

/* ============================================
   Tool Content Section
   ============================================ */
.tool-content-section {
    padding: 5rem 0;
    background: var(--bg-primary);
    margin-left: 0;
    transition: var(--transition-base);
    width: 100%;
    box-sizing: border-box;
}

/* Desktop: Tool content section cần margin-left và padding GIỐNG HẾT hero section */
@media (min-width: 769px) {
    .tool-content-section {
        margin-left: 280px;
        padding-left: 3rem;
        padding-right: 3rem;
    }
}

@media (max-width: 768px) {
    .tool-content-section {
        margin-left: 0;
        padding-left: 1rem;
        padding-right: 1rem;
        padding-top: 3rem;
        padding-bottom: 3rem;
    }
}

/* Nội dung bên trong tool-content-section - CÙNG max-width với hero-content để align đúng */
.tool-content-section .main-content-wrapper {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
    box-sizing: border-box;
}

/* Đảm bảo tất cả content trong tool-content-section align đúng - KHÔNG có max-width riêng, để main-content-wrapper kiểm soát */
.tool-content-section .tool-header,
.tool-content-section .brands-grid,
.tool-content-section .rom-section,
.tool-content-section .guidelines-section {
    width: 100%;
    max-width: 100%;
    margin-left: 0;
    margin-right: 0;
    padding-left: 0;
    padding-right: 0;
    box-sizing: border-box;
}

.tool-header {
    text-align: center;
    margin-bottom: 4rem;
    max-width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    width: 100%;
    box-sizing: border-box;
    /* Đảm bảo tool-header align giống hero-content */
    display: block;
}

/* Đảm bảo tool-header và hero-content có cùng alignment */
@media (min-width: 769px) {
    .hero-content {
        max-width: 1200px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .tool-content-section .main-content-wrapper {
        max-width: 1200px;
        margin-left: auto;
        margin-right: auto;
    }
}

.tool-name {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.tool-description {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.tool-intro {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-2xl);
    padding: 3rem;
    margin: 3rem auto;
    max-width: 900px;
    box-shadow: var(--shadow-sm);
}

.intro-content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-weight: 700;
}

.intro-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ============================================
   Quick Links - Clean Cards
   ============================================ */
.quick-links {
    margin-top: 4rem;
    padding: 0 2rem;
}

.section-subtitle {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-primary);
}

.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.quick-link-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: var(--transition-base);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.quick-link-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: var(--transition-base);
}

.quick-link-card:hover {
    background: var(--bg-hover);
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.quick-link-card:hover::before {
    transform: scaleX(1);
}

.quick-link-icon {
    font-size: 4rem;
    transition: var(--transition-base);
}

.quick-link-card:hover .quick-link-icon {
    transform: scale(1.1);
}

.quick-link-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ============================================
   Features Section
   ============================================ */
.features-section {
    padding: 6rem 0;
    background: var(--bg-secondary);
    position: relative;
    margin-left: 0;
    transition: var(--transition-base);
    width: 100%;
}

/* Desktop: Features section cần margin-left giống hero section */
@media (min-width: 769px) {
    .features-section {
        margin-left: 280px;
        padding-left: 3rem;
        padding-right: 3rem;
    }
}

@media (max-width: 768px) {
    .features-section {
        margin-left: 0;
        padding-left: 1rem;
        padding-right: 1rem;
        padding-top: 4rem;
        padding-bottom: 4rem;
    }
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.75rem);
    text-align: center;
    margin-bottom: 4rem;
    color: var(--text-primary);
    font-weight: 700;
    position: relative;
    letter-spacing: -0.01em;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -1rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 100%;
    margin: 0;
    padding: 0;
    width: 100%;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    text-align: center;
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-hover);
}

.feature-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    transition: var(--transition-base);
    display: inline-block;
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ============================================
   Content Pages
   ============================================ */
.content-page {
    padding: 4rem 0;
    background: var(--bg-primary);
}

.page-header {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 2rem;
    padding-right: 2rem;
}

.page-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.page-description {
    color: var(--text-secondary);
    font-size: 1.125rem;
    line-height: 1.8;
}

/* ROM Section */
.rom-section {
    margin-top: 4rem;
    margin-bottom: 4rem;
    padding: 0 !important;
    width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    box-sizing: border-box;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
    width: 100%;
    padding: 0 !important;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    box-sizing: border-box;
}

.section-header .section-title {
    font-size: clamp(1.75rem, 3vw, 2.25rem);
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.section-description {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* ROM Grid */
.rom-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
    max-width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    width: 100%;
    box-sizing: border-box;
}

/* ROM Card Large với Image */
.rom-card-large {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: var(--transition-base);
    text-decoration: none;
    color: inherit;
    display: block;
    box-shadow: var(--shadow-sm);
}

.rom-card-large:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.rom-image-wrapper {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--bg-secondary);
}

.rom-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.rom-card-large:hover .rom-image {
    transform: scale(1.05);
}

.rom-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, transparent 0%, rgba(0,0,0,0.3) 100%);
    display: flex;
    align-items: flex-end;
    justify-content: flex-end;
    padding: 1rem;
}

.rom-android-badge {
    background: var(--primary-gradient);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
}

.rom-card-content {
    padding: 1.5rem;
}

.rom-card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.rom-card-meta {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.rom-device-badge {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

/* Guidelines Section */
.guidelines-section {
    margin-top: 5rem;
    padding: 4rem 0;
    background: var(--bg-secondary);
    border-radius: var(--radius-2xl);
    width: 100%;
}

/* Desktop: Guidelines section cần margin-left */
@media (min-width: 769px) {
    .guidelines-section {
        margin-left: 280px;
        padding-left: 3rem;
        padding-right: 3rem;
    }
}

@media (max-width: 768px) {
    .guidelines-section {
        margin-left: 0;
        padding-left: 1rem;
        padding-right: 1rem;
    }
}

.guidelines-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
    max-width: 100%;
    margin-left: 0;
    margin-right: 0;
    width: 100%;
}

/* Content Page Styles */
.content-page {
    padding: 5rem 0;
    background: var(--bg-primary);
    margin-left: 0;
    transition: var(--transition-base);
    width: 100%;
    box-sizing: border-box;
}

@media (min-width: 769px) {
    .content-page {
        margin-left: 280px;
        padding-left: 3rem;
        padding-right: 3rem;
    }
}

@media (max-width: 768px) {
    .content-page {
        margin-left: 0;
        padding-left: 1rem;
        padding-right: 1rem;
        padding-top: 3rem;
        padding-bottom: 3rem;
    }
}

.page-header {
    max-width: 1200px;
    margin: 0 auto 3rem auto;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.page-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.page-description {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.page-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
}

.rom-content-wrapper {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 3rem;
    box-shadow: var(--shadow-sm);
    line-height: 1.8;
    color: var(--text-primary);
}

.rom-content-wrapper img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    margin: 1.5rem 0;
}

.rom-content-wrapper h1,
.rom-content-wrapper h2,
.rom-content-wrapper h3,
.rom-content-wrapper h4 {
    color: var(--text-primary);
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.rom-content-wrapper p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.rom-content-wrapper ul,
.rom-content-wrapper ol {
    margin: 1rem 0;
    padding-left: 2rem;
    color: var(--text-secondary);
}

.rom-content-wrapper li {
    margin-bottom: 0.5rem;
}

.rom-content-wrapper code {
    background: var(--bg-secondary);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.rom-content-wrapper pre {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin: 1.5rem 0;
}

.rom-content-wrapper a {
    color: var(--primary);
    text-decoration: none;
}

.rom-content-wrapper a:hover {
    text-decoration: underline;
}

.guideline-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2rem;
    transition: var(--transition-base);
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    box-shadow: var(--shadow-sm);
    gap: 1rem;
}

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

.guideline-icon-large {
    font-size: 4rem;
    line-height: 1;
    transition: var(--transition-base);
}

.guideline-card:hover .guideline-icon-large {
    transform: scale(1.1);
}

.guideline-content {
    flex: 1;
}

.guideline-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.guideline-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ============================================
   Sidebar Navigation
   ============================================ */
.sidebar {
    position: fixed;
    top: 100px; /* Below navbar + disclaimer */
    left: 0;
    width: 280px;
    height: calc(100vh - 100px);
    background: var(--bg-card);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    overflow-x: hidden;
    z-index: 100;
    transition: var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.sidebar-desktop {
    display: block;
    transform: translateX(0) !important;
}

.sidebar-mobile {
    display: block;
    transform: translateX(-100%);
    box-shadow: var(--shadow-xl);
}

.sidebar-mobile.active {
    transform: translateX(0);
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-secondary);
    position: sticky;
    top: 0;
    z-index: 10;
}

.sidebar-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.sidebar-close {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    transition: var(--transition-base);
}

.sidebar-close:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.sidebar-nav {
    padding: 1rem 0;
}

.sidebar-section {
    margin-bottom: 2rem;
}

.sidebar-section-title {
    padding: 0.75rem 1.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    line-height: 1.4;
    word-break: break-word;
}

.sidebar-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition-base);
    border-left: 3px solid transparent;
    position: relative;
}

.sidebar-item:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-left-color: var(--primary);
}

.sidebar-item.active {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}

.sidebar-icon {
    font-size: 1.25rem;
    width: 24px;
    text-align: center;
    flex-shrink: 0;
}

.sidebar-text {
    flex: 1;
    font-size: 0.95rem;
}

.sidebar-count {
    font-size: 0.75rem;
    background: var(--bg-secondary);
    color: var(--text-muted);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-full);
}

.sidebar-item.active .sidebar-count {
    background: var(--primary);
    color: white;
}

.sidebar-brand {
    font-weight: 600;
}

/* Brand Group và Submenu */
.sidebar-brand-group {
    position: relative;
}

.sidebar-brand-toggle {
    width: 100%;
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    font-family: inherit;
    font-size: inherit;
    color: inherit;
}

.sidebar-brand-toggle .sidebar-arrow {
    margin-left: auto;
    font-size: 0.75rem;
    transition: transform 0.3s ease;
    color: var(--text-muted);
}

.sidebar-brand-group.expanded .sidebar-brand-toggle .sidebar-arrow {
    transform: rotate(180deg);
}

.sidebar-submenu {
    margin-left: 1rem;
    margin-top: 0.25rem;
    padding-left: 0.5rem;
    border-left: 2px solid var(--border-color);
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        max-height: 0;
    }
    to {
        opacity: 1;
        max-height: 500px;
    }
}

.sidebar-submenu-item {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-submenu-item:hover {
    color: var(--primary);
    background: var(--bg-hover);
}

.sidebar-submenu-item.active {
    color: var(--primary);
    font-weight: 600;
    background: var(--bg-hover);
}

/* Mobile Sidebar Overlay */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    position: fixed;
    top: 100px;
    left: 1rem;
    z-index: 101;
    background: var(--primary);
    color: white;
    border: none;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: var(--transition-base);
}

.mobile-menu-toggle:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-xl);
}

.mobile-menu-toggle span {
    width: 24px;
    height: 3px;
    background: white;
    border-radius: var(--radius-full);
    transition: var(--transition-base);
}

/* Brand Cards */
.brands-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
    margin-bottom: 3rem;
    width: 100%;
    max-width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    box-sizing: border-box;
    /* Đảm bảo grid items căn giữa khi không fill hết width */
    justify-items: center;
}

/* Đảm bảo brand cards có cùng alignment với hero buttons */
@media (min-width: 769px) {
    .brands-grid {
        /* Sử dụng auto-fit thay vì auto-fill để center items khi không đủ */
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        /* Hoặc dùng justify-content để center toàn bộ grid */
        justify-content: center;
    }
}

.brand-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: var(--transition-base);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-sm);
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    /* Đảm bảo brand cards có cùng sizing behavior như tab buttons */
    min-width: 250px;
}

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

.brand-card-icon {
    font-size: 4rem;
    transition: var(--transition-base);
}

.brand-card:hover .brand-card-icon {
    transform: scale(1.1);
}

.brand-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.brand-card-count {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin: 0;
}

.brand-header {
    margin-top: 3rem;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    box-sizing: border-box;
}

.brand-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.brand-icon {
    font-size: 2.5rem;
}

.brand-description {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin: 0;
}

/* Scrollbar cho Sidebar */
.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--border-hover);
    border-radius: var(--radius-full);
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-section,
    .tool-content-section,
    .features-section,
    .guidelines-section {
        margin-left: 0 !important;
        padding-left: 1rem !important;
        padding-right: 1rem !important;
    }
    
    .tool-content-section .main-content-wrapper {
        margin-left: 0;
        padding: 0;
    }
    
    .sidebar {
        width: 280px;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .brands-grid {
        grid-template-columns: 1fr;
    }
    
    .tab-btn {
        min-width: 100%;
        max-width: 100%;
    }
    
    .tab-buttons {
        flex-direction: column;
        align-items: stretch;
    }
}

@media (max-width: 1200px) and (min-width: 769px) {
    .tab-btn {
        min-width: 180px;
        max-width: 250px;
        padding: 1.25rem 2rem;
    }
    
    .hero-content {
        max-width: 900px;
    }
}

@media (min-width: 769px) {
    .mobile-menu-toggle {
        display: none;
    }
    
    .sidebar-overlay {
        display: none;
    }
}

.rom-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2rem;
    transition: var(--transition-base);
    text-decoration: none;
    color: inherit;
    display: block;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.rom-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: var(--transition-base);
}

.rom-card:hover {
    background: var(--bg-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.rom-card:hover::before {
    transform: scaleX(1);
}

.rom-card-title {
    font-size: 1.35rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.rom-card-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.rom-device,
.rom-android {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ROM Filter */
.rom-filter {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 2rem;
    margin-bottom: 3rem;
    box-shadow: var(--shadow-sm);
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 3rem;
}

.filter-group {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    align-items: center;
}

.filter-label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1rem;
}

.filter-select {
    padding: 0.75rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-base);
    outline: none;
}

.filter-select:hover {
    border-color: var(--primary);
}

.filter-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* ============================================
   Footer - Clean & Simple
   ============================================ */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 4rem 0 2rem;
    margin-top: 6rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding: 0 2rem;
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.footer-text {
    color: var(--text-secondary);
    line-height: 1.8;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 1rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition-base);
    display: inline-block;
}

.footer-links a:hover {
    color: var(--primary);
    transform: translateX(4px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
    max-width: 1200px;
    margin: 0 auto;
    padding-left: 2rem;
    padding-right: 2rem;
}

.footer-disclaimer {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============================================
   Page Content Styling
   ============================================ */
.page-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 3rem;
    box-shadow: var(--shadow-sm);
    line-height: 1.8;
    max-width: 900px;
    margin: 0 auto;
}

.page-content h1,
.page-content h2,
.page-content h3,
.page-content h4,
.page-content h5,
.page-content h6 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.page-content h2 {
    font-size: 1.75rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
    font-weight: 700;
}

.page-content p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.page-content ul,
.page-content ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
    color: var(--text-secondary);
}

.page-content li {
    margin-bottom: 0.75rem;
}

.page-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    margin: 2rem 0;
    box-shadow: var(--shadow-md);
}

.page-content code {
    background: var(--bg-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    color: var(--primary);
}

.page-content pre {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin: 1.5rem 0;
    border: 1px solid var(--border-color);
}

.page-content pre code {
    background: none;
    padding: 0;
    color: var(--text-primary);
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    body {
        padding-top: 36px;
    }
    
    .disclaimer-banner {
        padding: 8px 0;
    }
    
    .disclaimer-content {
        animation-duration: 25s;
        gap: 8px;
        padding: 0 30px;
    }
    
    .disclaimer-text {
        font-size: 0.75rem;
    }
    
    .navbar {
        top: 36px;
    }
    
    .nav-content {
        padding: 0 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 100px;
        left: -100%;
        width: 100%;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        transition: var(--transition-base);
        border: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-section {
        padding: 4rem 0 3rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .tab-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .tab-btn {
        width: 100%;
    }
    
    .features-grid,
    .quick-links-grid,
    .rom-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-intro {
        padding: 2rem;
    }
    
    .page-content {
        padding: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .feature-card,
    .quick-link-card,
    .rom-card {
        padding: 1.5rem;
    }
}

/* ============================================
   Utility Classes
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
    width: 100%;
}

/* Container trong sections có margin-left không cần padding thêm */
@media (min-width: 769px) {
    .features-section .container,
    .tool-content-section .container {
        padding: 0;
    }
}

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

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-hover);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}