/* ========================================
   CSS Variables & Root Styles
   ======================================== */

:root {
    /* Color Palette */
    --bg: #171717;
    --surface: #1F1F1F;
    --surface-alt: #262626;
    --deep-bg: #071019;
    --deep-alt: #0A141F;
    --accent: #3DB7C7;
    --cta: #D94673;
    --cta-hover: #C83D68;
    --text: #F4F8FB;
    --muted: #9BB0C2;
    --border: #22384A;

    /* Typography */
    --font-primary: 'Noto Sans SC', sans-serif;
    --font-display: 'Space Grotesk', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   Reset & Base Styles
   ======================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    font-size: 16px;
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ========================================
   Typography
   ======================================== */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
}

p {
    margin-bottom: var(--spacing-md);
}

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

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

/* ========================================
   Container & Layout
   ======================================== */

.container {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

/* ========================================
   Header & Navigation
   ======================================== */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(31, 31, 31, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.header-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
    gap: var(--spacing-lg);
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 700;
    font-size: 1.25rem;
    font-family: var(--font-display);
    color: var(--text);
    transition: color var(--transition-base);
}

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

.logo-image {
    width: 36px;
    height: 36px;
    display: block;
}

.logo-text {
    display: none;
}

@media (min-width: 640px) {
    .logo-text {
        display: inline;
    }
}

/* Navigation */
.nav {
    display: none;
    gap: var(--spacing-lg);
}

@media (min-width: 1024px) {
    .nav {
        display: flex;
    }
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--muted);
    font-weight: 500;
    transition: color var(--transition-base);
    font-size: 0.95rem;
}

.nav-link:hover,
.nav-link:focus {
    color: var(--accent);
    outline: none;
}

.nav-link i {
    font-size: 1.1rem;
}

@media (max-width: 1023px) {
    .nav {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-md);
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--surface);
        border-bottom: 1px solid var(--border);
        padding: var(--spacing-lg);
        max-height: 0;
        overflow: hidden;
        transition: max-height var(--transition-base);
    }

    .nav.active {
        max-height: 400px;
    }

    .header {
        position: relative;
    }
}

/* Menu Toggle */
.menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    color: var(--text);
    font-size: 1.5rem;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--text);
    transition: all var(--transition-base);
    display: block;
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(10px, 10px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(9px, -9px);
}

@media (min-width: 1024px) {
    .menu-toggle {
        display: none;
    }
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
    outline-offset: 2px;
}

.btn:focus {
    outline: 2px solid var(--accent);
}

.btn-primary {
    background-color: var(--cta);
    color: var(--text);
}

.btn-primary:hover {
    background-color: var(--cta-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
}

.btn-secondary:hover {
    background-color: var(--accent);
    color: var(--bg);
}

.btn-large {
    padding: 1rem 1.75rem;
    font-size: 1.05rem;
}

@media (max-width: 768px) {
    .header .btn-primary {
        display: none;
    }
}

/* ========================================
   Hero Section
   ======================================== */

.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--bg) 0%, var(--deep-bg) 50%, var(--bg) 100%);
    border-bottom: 1px solid var(--border);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

@media (max-width: 768px) {
    .hero-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .hero-sidebar {
        order: -1;
    }
}

.hero-subtitle {
    display: inline-block;
    font-size: 0.875rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-title {
    margin-bottom: var(--spacing-lg);
    color: var(--text);
}

.hero-description {
    font-size: 1.1rem;
    color: var(--muted);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background-color: rgba(61, 183, 199, 0.1);
    color: var(--accent);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid rgba(61, 183, 199, 0.2);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
    }

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

.hero-sidebar {
    display: flex;
    align-items: stretch;
}

.sidebar-panel {
    width: 100%;
    background-color: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.sidebar-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--accent);
}

.sidebar-text {
    color: var(--muted);
    line-height: 1.8;
    font-size: 0.95rem;
}

/* ========================================
   About Section
   ======================================== */

.about {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    margin-bottom: var(--spacing-xl);
    text-align: center;
    background: linear-gradient(135deg, var(--text), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.about-text {
    font-size: 1.05rem;
    color: var(--muted);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.about-text:last-child {
    margin-bottom: 0;
}

/* ========================================
   Features Section
   ======================================== */

.features {
    padding: var(--spacing-2xl) 0;
    background-color: rgba(7, 16, 25, 0.3);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

@media (min-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 768px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}

.feature-card {
    background-color: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    transition: all var(--transition-base);
}

.feature-card:hover {
    border-color: var(--accent);
    box-shadow: 0 8px 32px rgba(61, 183, 199, 0.15);
    transform: translateY(-4px);
}

.card-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, rgba(61, 183, 199, 0.2), rgba(217, 70, 115, 0.2));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--accent);
}

.card-title {
    font-size: 1.1rem;
    color: var(--text);
}

.card-description {
    color: var(--muted);
    font-size: 0.95rem;
    flex-grow: 1;
}

.card-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--accent);
    font-weight: 600;
    width: fit-content;
    padding-bottom: 4px;
    border-bottom: 2px solid transparent;
    transition: all var(--transition-base);
}

.card-link:hover {
    border-bottom-color: var(--accent);
    transform: translateX(4px);
}

/* ========================================
   Getting Started Section
   ======================================== */

.getting-started {
    padding: var(--spacing-2xl) 0;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

@media (min-width: 1024px) {
    .steps {
        grid-template-columns: repeat(3, 1fr);
    }
}

.step {
    display: flex;
    gap: var(--spacing-lg);
    position: relative;
}

.step-number {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--cta), #B8296A);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text);
}

.step-content {
    flex: 1;
}

.step-title {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text);
}

.step-description {
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.7;
}

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

/* ========================================
   Help Section
   ======================================== */

.help-section {
    padding: var(--spacing-2xl) 0;
}

.help-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-lg);
}

@media (min-width: 1024px) {
    .help-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 768px) {
    .help-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .help-grid {
        grid-template-columns: 1fr;
    }
}

.help-card {
    background-color: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-base);
}

.help-card:hover {
    border-color: var(--accent);
    background-color: rgba(61, 183, 199, 0.05);
}

.help-icon {
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: var(--spacing-md);
}

.help-title {
    font-size: 1rem;
    color: var(--text);
    margin-bottom: var(--spacing-md);
}

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

/* ========================================
   Testimonials Section
   ======================================== */

.testimonials {
    padding: var(--spacing-2xl) 0;
    background-color: rgba(7, 16, 25, 0.3);
}

.testimonials-card {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
}

.testimonials-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.testimonials-empty i {
    font-size: 3rem;
    color: var(--accent);
    opacity: 0.5;
}

.testimonials-empty h3 {
    color: var(--text);
    font-size: 1.25rem;
}

.testimonials-empty p {
    color: var(--muted);
    max-width: 400px;
}

/* ========================================
   FAQ Section
   ======================================== */

.faq {
    padding: var(--spacing-2xl) 0;
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
    display: grid;
    gap: var(--spacing-sm);
}

.faq-item {
    background-color: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all var(--transition-base);
}

.faq-item[open] {
    border-color: var(--accent);
    background-color: rgba(61, 183, 199, 0.05);
}

.faq-summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    cursor: pointer;
    user-select: none;
    transition: all var(--transition-base);
    background-color: var(--surface-alt);
}

.faq-summary:hover {
    background-color: rgba(61, 183, 199, 0.1);
}

.faq-summary:focus {
    outline: none;
    box-shadow: inset 0 0 0 2px var(--accent);
}

.faq-question {
    font-weight: 600;
    color: var(--text);
    flex: 1;
    text-align: left;
}

.faq-summary i {
    color: var(--accent);
    transition: transform var(--transition-base);
    margin-left: var(--spacing-md);
    flex-shrink: 0;
}

.faq-item[open] .faq-summary i {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 var(--spacing-lg) var(--spacing-lg) var(--spacing-lg);
    color: var(--muted);
    line-height: 1.8;
    animation: slideDown var(--transition-base) ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.faq-answer p {
    margin-bottom: 0;
}

/* ========================================
   Final CTA Section
   ======================================== */

.final-cta {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--deep-alt) 0%, rgba(61, 183, 199, 0.1) 50%, var(--deep-alt) 100%);
    border: 1px solid var(--border);
    border-top: 1px solid rgba(61, 183, 199, 0.2);
    border-bottom: 1px solid rgba(61, 183, 199, 0.2);
}

.cta-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.cta-title {
    margin-bottom: var(--spacing-lg);
    color: var(--text);
}

.cta-subtitle {
    font-size: 1.05rem;
    color: var(--muted);
    margin-bottom: var(--spacing-2xl);
    line-height: 1.7;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background-color: var(--surface);
    border-top: 1px solid var(--border);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-2xl);
    border-bottom: 1px solid var(--border);
}

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

.footer-title {
    font-size: 1.1rem;
    color: var(--text);
    font-weight: 700;
}

.footer-description {
    color: var(--muted);
    font-size: 0.9rem;
}

.footer-heading {
    font-size: 1rem;
    color: var(--text);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: var(--muted);
    font-size: 0.9rem;
    transition: color var(--transition-base);
    display: inline-block;
    width: fit-content;
}

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

.footer-legal {
    text-align: center;
    color: var(--muted);
    font-size: 0.85rem;
    line-height: 1.7;
}

.footer-copyright {
    margin-top: var(--spacing-md);
    font-weight: 600;
}

/* ========================================
   Responsive Design - Tablet
   ======================================== */

@media (max-width: 768px) {
    .hero-tags {
        gap: var(--spacing-sm);
    }

    .tag {
        font-size: 0.85rem;
        padding: 4px 10px;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .help-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

/* ========================================
   Responsive Design - Mobile
   ======================================== */

@media (max-width: 480px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-2xl: 2.5rem;
    }

    .container {
        padding: 0 var(--spacing-md);
    }

    .header-wrapper {
        padding: var(--spacing-md) 0;
        gap: var(--spacing-md);
    }

    .logo-image {
        width: 32px;
        height: 32px;
    }

    .hero {
        padding: var(--spacing-xl) 0;
    }

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

    .tag {
        width: 100%;
        justify-content: center;
    }

    .sidebar-panel {
        padding: var(--spacing-md);
    }

    .about {
        padding: var(--spacing-xl) 0;
    }

    .features {
        padding: var(--spacing-xl) 0;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .getting-started {
        padding: var(--spacing-xl) 0;
    }

    .steps {
        gap: var(--spacing-lg);
    }

    .help-section {
        padding: var(--spacing-xl) 0;
    }

    .help-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .help-card {
        padding: var(--spacing-md);
    }

    .help-title {
        font-size: 0.95rem;
    }

    .testimonials {
        padding: var(--spacing-xl) 0;
    }

    .testimonials-card {
        padding: var(--spacing-lg);
    }

    .faq {
        padding: var(--spacing-xl) 0;
    }

    .faq-summary {
        padding: var(--spacing-md);
    }

    .faq-answer {
        padding: 0 var(--spacing-md) var(--spacing-md) var(--spacing-md);
    }

    .final-cta {
        padding: var(--spacing-xl) 0;
    }

    .cta-subtitle {
        font-size: 1rem;
    }

    .footer {
        padding: var(--spacing-xl) 0 var(--spacing-md);
    }

    .footer-content {
        gap: var(--spacing-lg);
        margin-bottom: var(--spacing-lg);
        padding-bottom: var(--spacing-lg);
    }

    .footer-legal {
        font-size: 0.8rem;
    }
}

/* ========================================
   Accessibility
   ======================================== */

/* High Contrast Mode Support */
@media (prefers-contrast: more) {
    .btn-primary {
        border: 2px solid var(--text);
    }

    .btn-secondary {
        border-width: 3px;
    }

    .feature-card,
    .help-card {
        border-width: 2px;
    }
}

/* Dark Mode (Already implemented) */
@media (prefers-color-scheme: dark) {
    body {
        color-scheme: dark;
    }
}

/* Light Mode Fallback (if ever needed) */
@media (prefers-color-scheme: light) {
    body {
        color-scheme: light;
    }
}

/* Skip to Main Content Link */
.skip-to-main {
    position: absolute;
    top: -40px;
    left: 0;
    background-color: var(--cta);
    color: var(--text);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: 100;
}

.skip-to-main:focus {
    top: 0;
}

/* Focus Visible for Better Keyboard Navigation */
button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* ========================================
   Friendly Links Section
   ======================================== */

.footer-section:nth-child(4) {
    border-top: 1px solid var(--border);
    padding-top: var(--spacing-lg);
}

.footer-section:nth-child(4) .footer-heading {
    color: var(--accent);
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
}

.footer-section:nth-child(4) .footer-links a {
    display: inline-block;
    padding: 4px 8px;
    margin: 2px 2px;
    background-color: rgba(61, 183, 199, 0.1);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.85rem;
    transition: all var(--transition-base);
}

.footer-section:nth-child(4) .footer-links a:hover {
    background-color: var(--accent);
    color: var(--bg);
    border-color: var(--accent);
    text-decoration: none;
}

@media (max-width: 768px) {
    .footer-section:nth-child(4) .footer-links {
        display: flex;
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }

    .footer-section:nth-child(4) .footer-links li {
        display: inline;
        margin: 0;
    }
}