@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
    /* Color Palette */
    --bg-dark: #09090b;
    --bg-light: #121216;
    --accent-indigo: #6366f1;
    --accent-violet: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
    --accent-glow: rgba(99, 102, 241, 0.15);
    
    /* Text Colors */
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* UI Elements */
    --border-light: rgba(255, 255, 255, 0.08);
    --border-focus: rgba(99, 102, 241, 0.5);
    --glass-bg: rgba(15, 15, 20, 0.7);
    --glass-card-bg: rgba(20, 20, 28, 0.4);
    --card-hover-bg: rgba(255, 255, 255, 0.02);
    
    /* Fonts */
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    
    /* Status Colors */
    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.1);
    --error: #ef4444;
    --error-bg: rgba(239, 68, 68, 0.1);
    
    /* Spacing & Borders */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Base resets & styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    position: relative;
    -webkit-font-smoothing: antialiased;
}

/* Ambient Radial Glows */
body::before {
    content: '';
    position: absolute;
    top: -10%;
    left: 20%;
    width: 60%;
    height: 50vh;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.12) 0%, transparent 70%);
    z-index: 0;
    pointer-events: none;
}

body::after {
    content: '';
    position: absolute;
    bottom: -10%;
    right: 10%;
    width: 50%;
    height: 50vh;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.08) 0%, transparent 70%);
    z-index: 0;
    pointer-events: none;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-indigo);
}

/* Typography */
h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

p {
    color: var(--text-secondary);
}

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

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

/* Header & Navigation */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(9, 9, 11, 0.7);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.25rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: var(--transition-fast);
}

.logo-group:hover {
    opacity: 0.9;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background: var(--accent-gradient);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: 0 0 15px rgba(99, 102, 241, 0.4);
}

.logo-icon::before {
    content: '';
    width: 12px;
    height: 12px;
    background: white;
    border-radius: 3px;
}

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

.nav-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition-fast);
    position: relative;
    padding: 0.25rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: var(--transition-fast);
}

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

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

.nav-cta {
    background: var(--accent-gradient);
    color: white;
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition-normal);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.25);
}

.nav-cta:hover {
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(99, 102, 241, 0.4);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Layout Main Container */
main {
    flex: 1;
    padding-top: 80px; /* Offset for sticky header */
    z-index: 1;
}

/* Hero Section */
.hero {
    padding: 6rem 2rem 4rem;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.badge {
    display: inline-flex;
    align-items: center;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    color: var(--accent-indigo);
    padding: 0.4rem 1rem;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 2rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    backdrop-filter: blur(8px);
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #ffffff 40%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto 3rem;
    color: var(--text-secondary);
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 0.9rem 2rem;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    border: none;
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px rgba(99, 102, 241, 0.45);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-light);
    backdrop-filter: blur(8px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.2);
}

/* App Mock Mockup */
.app-preview-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0.5rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    box-shadow: 0 30px 100px rgba(0, 0, 0, 0.8), 0 0 40px rgba(99, 102, 241, 0.1);
    backdrop-filter: blur(12px);
    transition: var(--transition-normal);
}

.app-preview-container:hover {
    box-shadow: 0 30px 120px rgba(0, 0, 0, 0.9), 0 0 60px rgba(99, 102, 241, 0.15);
    transform: scale(1.01);
}

.mac-window {
    background: #18181e;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    text-align: left;
    height: 550px;
}

.mac-titlebar {
    background: #111115;
    padding: 0.8rem 1.2rem;
    display: flex;
    align-items: center;
    border-bottom: 1px solid rgba(0, 0, 0, 0.3);
}

.mac-dots {
    display: flex;
    gap: 8px;
    margin-right: 2rem;
}

.mac-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.mac-dot-red { background: #ff5f56; }
.mac-dot-yellow { background: #ffbd2e; }
.mac-dot-green { background: #27c93f; }

.mac-title {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
    margin: 0 auto;
    transform: translateX(-24px); /* Adjust due to dots offset */
}

.mac-layout {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.mac-sidebar {
    width: 220px;
    background: #141419;
    border-right: 1px solid rgba(0, 0, 0, 0.2);
    padding: 1.5rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.sidebar-section h4 {
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
    padding-left: 0.5rem;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-item {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: var(--transition-fast);
}

.sidebar-item:hover {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-primary);
}

.sidebar-item.active {
    background: rgba(99, 102, 241, 0.12);
    color: var(--accent-indigo);
    font-weight: 600;
}

.mac-content {
    flex: 1;
    background: #1a1a22;
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    overflow-y: auto;
}

.content-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.todo-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.todo-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    padding: 0.9rem 1.25rem;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: var(--transition-fast);
}

.todo-item:hover {
    border-color: rgba(99, 102, 241, 0.3);
    background: rgba(255, 255, 255, 0.03);
    transform: translateX(4px);
}

.todo-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.todo-checkbox {
    width: 18px;
    height: 18px;
    border: 2px solid var(--text-muted);
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition-fast);
}

.todo-item.completed .todo-checkbox {
    background: var(--success);
    border-color: var(--success);
    position: relative;
}

.todo-item.completed .todo-checkbox::after {
    content: '✓';
    color: black;
    font-size: 0.75rem;
    font-weight: 800;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.todo-title {
    font-size: 0.95rem;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.todo-item.completed .todo-title {
    text-decoration: line-through;
    color: var(--text-muted);
}

.todo-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.todo-tag {
    font-size: 0.75rem;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
}

.todo-tag.tag-high {
    background: rgba(239, 68, 68, 0.1);
    color: #f87171;
}

.todo-tag.tag-reminders {
    background: rgba(99, 102, 241, 0.1);
    color: #818cf8;
}

/* Features Section */
.features {
    padding: 6rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #ffffff 50%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-header p {
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--glass-card-bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2.5rem 2rem;
    transition: var(--transition-normal);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at top left, rgba(99, 102, 241, 0.08), transparent 50%);
    opacity: 0;
    transition: var(--transition-normal);
}

.feature-card:hover {
    border-color: rgba(99, 102, 241, 0.25);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.05);
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--accent-indigo);
    font-size: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.feature-card p {
    font-size: 0.95rem;
}

/* Document & Info Template Page (Support & Privacy) */
.page-header {
    padding: 5rem 2rem 3rem;
    text-align: center;
    border-bottom: 1px solid var(--border-light);
    background: radial-gradient(circle at 50% 100%, var(--accent-glow), transparent 60%);
    margin-bottom: 4rem;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

.doc-layout {
    max-width: 900px;
    margin: 0 auto 6rem;
    padding: 0 2rem;
}

.glass-box {
    background: var(--glass-bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 3.5rem;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
}

.doc-content h2 {
    font-size: 1.75rem;
    margin: 2.5rem 0 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.doc-content h2:first-of-type {
    margin-top: 0;
}

.doc-content p {
    margin-bottom: 1.25rem;
    font-size: 1.05rem;
    color: var(--text-secondary);
}

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

.doc-content li {
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.privacy-badge {
    background: var(--success-bg);
    border: 1px solid rgba(16, 185, 129, 0.2);
    color: var(--success);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 2rem;
}

.privacy-badge::before {
    content: '✓';
}

/* FAQ Accordion Section */
.faq-section {
    margin-bottom: 4rem;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.faq-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition-normal);
}

.faq-item:hover {
    border-color: rgba(99, 102, 241, 0.25);
    background: rgba(255, 255, 255, 0.03);
}

.faq-question {
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
}

.faq-question h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0;
}

.faq-icon {
    width: 24px;
    height: 24px;
    position: relative;
    transition: var(--transition-normal);
    flex-shrink: 0;
}

.faq-icon::before, .faq-icon::after {
    content: '';
    position: absolute;
    background-color: var(--text-secondary);
    transition: var(--transition-normal);
}

.faq-icon::before {
    width: 14px;
    height: 2px;
    top: 11px;
    left: 5px;
}

.faq-icon::after {
    width: 2px;
    height: 14px;
    top: 5px;
    left: 11px;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-item.active .faq-icon::before, .faq-item.active .faq-icon::after {
    background-color: var(--accent-indigo);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq-answer-inner {
    padding: 0 1.5rem 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.03);
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.faq-answer-inner p {
    margin-bottom: 0.75rem;
}
.faq-answer-inner p:last-child {
    margin-bottom: 0;
}

/* Contact Form Section */
.contact-section {
    position: relative;
}

.contact-section h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.form-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.form-control {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    padding: 0.85rem 1rem;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: var(--transition-fast);
}

.form-control::placeholder {
    color: var(--text-muted);
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-indigo);
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.25);
    background: rgba(0, 0, 0, 0.3);
}

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

.form-submit-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 0.5rem;
    gap: 1.5rem;
}

.form-direct-mail {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.form-direct-mail a {
    color: var(--text-secondary);
    font-weight: 500;
    border-bottom: 1px dashed var(--text-muted);
}

.form-direct-mail a:hover {
    color: var(--accent-indigo);
    border-color: var(--accent-indigo);
}

/* Form Toast Notification */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 1000;
    background: #121216;
    border: 1px solid var(--border-light);
    border-left: 4px solid var(--success);
    border-radius: var(--radius-sm);
    padding: 1rem 1.5rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transform: translateY(100px);
    opacity: 0;
    transition: var(--transition-normal);
    pointer-events: none;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
}

.toast-icon {
    color: var(--success);
    font-weight: 800;
    font-size: 1.2rem;
}

.toast-message {
    font-size: 0.9rem;
    font-weight: 500;
}

/* Footer Section */
footer {
    background: #060608;
    border-top: 1px solid var(--border-light);
    padding: 4rem 2rem;
    z-index: 1;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.2rem;
}

.footer-logo-box {
    width: 24px;
    height: 24px;
    background: var(--accent-gradient);
    border-radius: 5px;
}

.footer-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.footer-link {
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition-fast);
}

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

.copyright {
    color: var(--text-muted);
    font-size: 0.85rem;
    width: 100%;
    text-align: center;
    margin-top: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.03);
    padding-top: 2rem;
}

/* Responsive Styles */
@media (max-width: 992px) {
    .hero h1 {
        font-size: 3rem;
    }
    .hero p {
        font-size: 1.1rem;
    }
    .glass-box {
        padding: 2.5rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: #09090b;
        border-bottom: 1px solid var(--border-light);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        box-shadow: 0 10px 20px rgba(0,0,0,0.5);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .hero {
        padding: 4rem 1rem 3rem;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
        max-width: 320px;
        margin: 0 auto 3rem;
    }
    
    .mac-window {
        height: 480px;
    }
    
    .mac-sidebar {
        display: none;
    }
    
    .footer-container {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 1rem;
    }
    
    .glass-box {
        padding: 1.5rem;
    }
    
    .form-submit-row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn-submit {
        order: -1;
        width: 100%;
    }
}

/* ==========================================
   User Guide & Documentation Styles
   ========================================== */

.lang-switch-wrapper {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-light);
    padding: 0.3rem 0.85rem;
    border-radius: 100px;
    margin-left: 1.5rem;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.lang-link {
    color: var(--text-secondary);
    font-weight: 600;
    transition: var(--transition-fast);
    text-decoration: none;
}

.lang-link.active {
    color: var(--accent-indigo);
    pointer-events: none;
}

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

.lang-sep {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.guide-container {
    max-width: 1200px;
    margin: 3rem auto 6rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 3rem;
    position: relative;
    z-index: 2;
}

.guide-sidebar {
    position: sticky;
    top: 110px;
    height: calc(100vh - 160px);
    overflow-y: auto;
    padding-right: 1rem;
}

.guide-sidebar::-webkit-scrollbar {
    width: 4px;
}

.guide-sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-sm);
}

.sidebar-nav-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-bottom: 1.25rem;
    font-weight: 700;
}

.guide-nav-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.guide-nav-item a {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    padding: 0.55rem 0.75rem;
    border-radius: var(--radius-sm);
    border-left: 2px solid transparent;
    transition: var(--transition-fast);
    text-decoration: none;
}

.guide-nav-item a:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.02);
}

.guide-nav-item.active a {
    color: var(--text-primary);
    background: rgba(99, 102, 241, 0.08);
    border-left-color: var(--accent-indigo);
    font-weight: 600;
}

.guide-content {
    background: var(--glass-bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 4rem;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
}

.guide-section {
    scroll-margin-top: 110px;
    border-bottom: 1px solid var(--border-light);
    padding-bottom: 3rem;
    margin-bottom: 3rem;
}

.guide-section:last-of-type {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}

.guide-content h1 {
    font-size: 2.75rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #ffffff 40%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.guide-content h2 {
    font-size: 1.75rem;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
    border-bottom: none;
    padding-bottom: 0;
}

.guide-content h3 {
    font-size: 1.2rem;
    margin: 2rem 0 0.75rem;
    color: var(--text-primary);
}

.guide-content p {
    margin-bottom: 1.25rem;
    font-size: 1.02rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

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

.guide-content li {
    margin-bottom: 0.6rem;
    font-size: 1rem;
    line-height: 1.6;
}

.guide-content strong {
    color: var(--text-primary);
}

.guide-content hr {
    border: none;
    border-top: 1px solid var(--border-light);
    margin: 2.5rem 0;
}

/* Callout Panels */
.callout {
    border-radius: var(--radius-md);
    padding: 1.25rem 1.5rem;
    margin: 1.75rem 0;
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    border: 1px solid transparent;
}

.callout-icon {
    font-size: 1.25rem;
    line-height: 1;
    margin-top: 0.1rem;
    flex-shrink: 0;
}

.callout-body {
    flex: 1;
}

.callout-body p {
    font-size: 0.95rem;
    margin-bottom: 0;
    line-height: 1.6;
}

.callout-tip {
    background: rgba(99, 102, 241, 0.05);
    border-color: rgba(99, 102, 241, 0.15);
}

.callout-tip .callout-icon {
    color: #818cf8;
}

.callout-tip .callout-body p {
    color: #c7d2fe;
}

.callout-note {
    background: rgba(139, 92, 246, 0.05);
    border-color: rgba(139, 92, 246, 0.15);
}

.callout-note .callout-icon {
    color: #a78bfa;
}

.callout-note .callout-body p {
    color: #ddd6fe;
}

/* Flowchart Diagram */
.flowchart {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    margin: 2.5rem auto;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.01);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    max-width: 500px;
}

.flowchart-step {
    background: rgba(20, 20, 28, 0.8);
    border: 1px solid var(--border-light);
    padding: 0.75rem 1.75rem;
    border-radius: 100px;
    font-weight: 600;
    font-size: 0.95rem;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    transition: var(--transition-normal);
    min-width: 240px;
}

.flowchart-step:hover {
    box-shadow: 0 4px 20px var(--accent-glow);
    transform: translateY(-2px);
}

.flowchart-step-1 { border-color: rgba(99, 102, 241, 0.5); color: #818cf8; }
.flowchart-step-2 { border-color: rgba(139, 92, 246, 0.5); color: #a78bfa; }
.flowchart-step-3 { border-color: rgba(236, 72, 153, 0.5); color: #f472b6; }
.flowchart-step-4 { border-color: rgba(20, 184, 166, 0.5); color: #2dd4bf; }
.flowchart-step-5 { border-color: rgba(16, 185, 129, 0.5); color: #34d399; }

.flowchart-arrow {
    color: var(--text-muted);
    font-size: 1.2rem;
    line-height: 1;
    display: flex;
    justify-content: center;
    height: 20px;
    align-items: center;
}

/* Keyboard Table & Keycaps */
.keyboard-table-wrapper {
    overflow-x: auto;
    margin: 2rem 0;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
}

.keyboard-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.keyboard-table th, .keyboard-table td {
    padding: 1rem 1.25rem;
    text-align: left;
    border-bottom: 1px solid var(--border-light);
}

.keyboard-table th {
    background: rgba(255, 255, 255, 0.02);
    font-weight: 600;
    color: var(--text-primary);
}

.keyboard-table tr:last-child td {
    border-bottom: none;
}

.keyboard-table tr {
    transition: var(--transition-fast);
}

.keyboard-table tr:hover {
    background: rgba(255, 255, 255, 0.01);
}

kbd {
    background-color: #222227;
    border: 1px solid #3c3c42;
    border-bottom: 3px solid #3c3c42;
    border-radius: 5px;
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.4);
    color: #f4f4f5;
    display: inline-block;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 0.82rem;
    font-weight: 600;
    line-height: 1.1;
    padding: 0.25rem 0.5rem;
    margin: 0 0.15rem;
    text-shadow: 0 1px 0 rgba(0, 0, 0, 0.5);
}

/* Responsive Guide Styles */
@media (max-width: 992px) {
    .guide-container {
        grid-template-columns: 1fr;
        gap: 2.5rem;
        margin-top: 2rem;
    }
    
    .guide-sidebar {
        position: relative;
        top: 0;
        height: auto;
        overflow-y: visible;
        padding-right: 0;
        border-bottom: 1px solid var(--border-light);
        padding-bottom: 1.5rem;
    }
    
    .guide-nav-list {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.5rem;
    }
    
    .guide-nav-item a {
        font-size: 0.85rem;
        padding: 0.45rem 0.75rem;
        border-left: none;
        border-bottom: 2px solid transparent;
        border-radius: var(--radius-sm);
    }
    
    .guide-nav-item.active a {
        background: rgba(99, 102, 241, 0.08);
        border-bottom-color: var(--accent-indigo);
    }
    
    .guide-content {
        padding: 3rem 2.5rem;
    }
}

@media (max-width: 768px) {
    .lang-switch-wrapper {
        margin-left: 0;
        margin-right: 1.5rem;
    }
    
    .guide-content {
        padding: 2.5rem 1.5rem;
    }
    
    .guide-content h1 {
        font-size: 2.2rem;
    }
    
    .guide-content h2 {
        font-size: 1.5rem;
    }
}

@media (max-width: 576px) {
    .flowchart-step {
        min-width: auto;
        width: 100%;
    }
    
    .keyboard-table th, .keyboard-table td {
        padding: 0.75rem 0.85rem;
        font-size: 0.85rem;
    }
}