/* ================================
   CSS RESET & BASE
   ================================ */

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

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #1A1A1A;
    background: #FFFFFF;
}

/* ================================
   TYPOGRAPHY (Mobile-First)
   ================================ */

h1 {
    font-size: 36px;
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.025em;
    color: #000000;
}

h2 {
    font-size: 32px;
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    color: #000000;
}

h3 {
    font-size: 20px;
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.01em;
    color: #000000;
}

p {
    line-height: 1.65;
    color: #4A4A4A;
}

/* ================================
   HEADER (Mobile-First)
   ================================ */

header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent;
    z-index: 100;
    transition: all 0.3s ease;
}

header.scrolled {
    border-bottom-color: rgba(0, 0, 0, 0.08);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 22px;
    font-weight: 700;
    color: #000000;
    letter-spacing: -0.02em;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* Language Selector */
.language-selector {
    position: relative;
}

.language-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    background: #FFFFFF;
    border: 1px solid #E5E5E5;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: #1A1A1A;
    transition: all 0.2s ease;
}

.language-btn:hover {
    border-color: #D1D1D1;
    background: #FAFAFA;
}

.language-code {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.02em;
}

.language-btn svg {
    width: 12px;
    height: 8px;
    opacity: 0.6;
    transition: transform 0.2s ease;
}

.language-selector.open .language-btn svg {
    transform: rotate(180deg);
}

.language-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: #FFFFFF;
    border: 1px solid #E5E5E5;
    border-radius: 12px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    padding: 6px;
    min-width: 160px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s ease;
    z-index: 1000;
}

.language-selector.open .language-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.language-option {
    display: flex;
    align-items: center;
    width: 100%;
    padding: 10px 12px;
    background: transparent;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 500;
    color: #1A1A1A;
    text-align: left;
    transition: background 0.15s ease;
}

.language-option:hover {
    background: #F5F5F5;
}

.language-option.active {
    background: #FEE2E2;
    color: #DC2626;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    padding: 10px 20px;
    background: #DC2626;
    color: #FFFFFF;
    text-decoration: none;
    font-size: 15px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.2s ease;
    min-height: 44px;
}

.btn-download:hover {
    background: #B91C1C;
    transform: translateY(-1px);
}

.btn-download:active {
    transform: translateY(0);
}

/* ================================
   HERO (Mobile-First)
   ================================ */

.hero {
    padding: 48px 20px 64px;
    background: #FAFAFA;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
}

.hero-content {
    text-align: center;
    margin-bottom: 48px;
}

.hero h1 {
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 18px;
    line-height: 1.6;
    color: #4A4A4A;
    margin-bottom: 32px;
    max-width: 540px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 320px;
    padding: 16px 32px;
    background: #DC2626;
    color: #FFFFFF;
    text-decoration: none;
    font-size: 17px;
    font-weight: 600;
    border-radius: 10px;
    transition: all 0.25s ease;
    box-shadow: 0 4px 16px rgba(220, 38, 38, 0.25);
    min-height: 52px;
}

.btn-primary:hover {
    background: #B91C1C;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(220, 38, 38, 0.35);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    color: #DC2626;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.2s ease;
    min-height: 44px;
}

.btn-secondary:hover {
    color: #B91C1C;
}

.hero-visual {
    display: flex;
    justify-content: center;
}

.phone-frame {
    width: 280px;
    height: 560px;
    background: #000000;
    border-radius: 40px;
    padding: 10px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.2);
}

.phone-frame img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 32px;
    background: #F5F5F5;
}

/* ================================
   MARQUEE (Mobile-First)
   ================================ */

.marquee {
    padding: 40px 0;
    background: linear-gradient(to right, #E8E8EA 0%, #DCDCDE 50%, #E8E8EA 100%);
    overflow: hidden;
    border-top: 1px solid rgba(0, 0, 0, 0.08);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    position: relative;
}

.marquee::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 60px;
    background: linear-gradient(to right, #E8E8EA 0%, transparent 100%);
    z-index: 2;
    pointer-events: none;
}

.marquee::after {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    width: 60px;
    background: linear-gradient(to left, #E8E8EA 0%, transparent 100%);
    z-index: 2;
    pointer-events: none;
}

.marquee-track {
    display: flex;
    overflow: hidden;
    user-select: none;
}

.marquee-content {
    display: flex;
    gap: 80px;
    white-space: nowrap;
    animation: marquee-scroll 60s linear infinite;
    will-change: transform;
}

.marquee-content span {
    font-size: 24px;
    font-weight: 600;
    color: #6B6B6B;
    letter-spacing: 0.01em;
}

@keyframes marquee-scroll {
    0% { transform: translate3d(0, 0, 0); }
    100% { transform: translate3d(-50%, 0, 0); }
}

/* ================================
   FEATURES (Mobile-First)
   ================================ */

.features {
    padding: 64px 20px;
    background: #FFFFFF;
}

.features-container {
    max-width: 1200px;
    margin: 0 auto;
}

.features h2 {
    text-align: center;
    margin-bottom: 48px;
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.feature-card {
    padding: 28px;
    background: #FAFAFA;
    border: 1px solid #E5E5E5;
    border-radius: 12px;
    transition: all 0.25s ease;
}

.feature-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border-color: rgba(220, 38, 38, 0.2);
}

.feature-card h3 {
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 16px;
    line-height: 1.65;
    color: #4A4A4A;
}

/* ================================
   TESTIMONIALS (Mobile-First)
   ================================ */

.testimonials {
    padding: 64px 20px;
    background: #FAFAFA;
}

.testimonials-container {
    max-width: 1000px;
    margin: 0 auto;
}

.testimonials h2 {
    text-align: center;
    margin-bottom: 48px;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

.testimonial-card {
    padding: 32px;
    background: #FFFFFF;
    border: 1px solid #E5E5E5;
    border-radius: 12px;
}

.testimonial-quote {
    font-size: 18px;
    line-height: 1.6;
    color: #1A1A1A;
    margin-bottom: 16px;
    font-weight: 500;
}

.testimonial-author {
    font-size: 15px;
    color: #6B6B6B;
    font-weight: 600;
}

/* ================================
   DOWNLOAD CTA (Mobile-First)
   ================================ */

.download-cta {
    padding: 72px 20px;
    background: linear-gradient(135deg, #DC2626 0%, #B91C1C 100%);
    text-align: center;
}

.download-container {
    max-width: 600px;
    margin: 0 auto;
}

.download-cta h2 {
    color: #FFFFFF;
    margin-bottom: 12px;
}

.download-cta p {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 40px;
}

.store-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}

.store-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    max-width: 280px;
    padding: 14px 28px;
    background: #FFFFFF;
    color: #1A1A1A;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    border-radius: 10px;
    transition: all 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    min-height: 52px;
}

.store-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.store-btn:active {
    transform: translateY(0);
}

.store-btn svg {
    flex-shrink: 0;
}

/* ================================
   FOOTER (Mobile-First)
   ================================ */

footer {
    padding: 56px 20px 32px;
    background: #0A0A0A;
    color: #FFFFFF;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    margin-bottom: 8px;
}

.footer-logo {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
}

.footer-tagline {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.5;
}

.footer-links h4 {
    font-size: 13px;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 16px;
}

.footer-links a {
    display: block;
    font-size: 15px;
    color: rgba(255, 255, 255, 0.75);
    text-decoration: none;
    margin-bottom: 12px;
    transition: color 0.2s ease;
    min-height: 44px;
    display: flex;
    align-items: center;
}

.footer-links a:hover {
    color: #FFFFFF;
}

.footer-legal {
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-legal p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

/* ================================
   MOBILE-SPECIFIC ADJUSTMENTS
   ================================ */

@media (max-width: 599px) {
    .header-right {
        gap: 8px;
    }
    
    .language-btn {
        padding: 6px 10px;
        font-size: 13px;
    }
    
    .language-code {
        font-size: 12px;
    }
    
    .btn-download {
        padding: 8px 16px;
        font-size: 14px;
    }
    
    .language-dropdown {
        right: 0;
        left: auto;
        min-width: 140px;
    }
}

/* ================================
   TABLET BREAKPOINT (≥ 600px)
   ================================ */

@media (min-width: 600px) {
    h1 {
        font-size: 48px;
    }
    
    h2 {
        font-size: 40px;
    }
    
    .hero {
        padding: 64px 32px 80px;
    }
    
    .hero-subtitle {
        font-size: 20px;
    }
    
    .hero-cta {
        flex-direction: row;
        gap: 16px;
    }
    
    .btn-primary {
        width: auto;
    }
    
    .phone-frame {
        width: 320px;
        height: 640px;
    }
    
    .marquee {
        padding: 48px 0;
    }
    
    .marquee::before,
    .marquee::after {
        width: 120px;
    }
    
    .marquee-content {
        gap: 120px;
    }
    
    .marquee-content span {
        font-size: 28px;
    }
    
    .features {
        padding: 80px 32px;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .testimonials {
        padding: 80px 32px;
    }
    
    .download-cta {
        padding: 88px 32px;
    }
    
    .store-buttons {
        flex-direction: row;
        gap: 16px;
    }
    
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1fr;
        gap: 48px;
    }
}

/* ================================
   DESKTOP BREAKPOINT (≥ 1024px)
   ================================ */

@media (min-width: 1024px) {
    h1 {
        font-size: 64px;
    }
    
    h2 {
        font-size: 48px;
    }
    
    h3 {
        font-size: 22px;
    }
    
    .header-container {
        padding: 20px 48px;
    }
    
    .hero {
        padding: 96px 48px;
    }
    
    .hero-container {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 64px;
        align-items: center;
    }
    
    .hero-content {
        text-align: left;
        margin-bottom: 0;
    }
    
    .hero h1 {
        margin-bottom: 24px;
    }
    
    .hero-subtitle {
        font-size: 21px;
        margin-left: 0;
        margin-bottom: 40px;
    }
    
    .hero-cta {
        justify-content: flex-start;
    }
    
    .hero-visual {
        justify-content: flex-end;
    }
    
    .phone-frame {
        width: 360px;
        height: 720px;
    }
    
    .marquee {
        padding: 56px 0;
    }
    
    .marquee::before,
    .marquee::after {
        width: 200px;
    }
    
    .marquee-content {
        gap: 140px;
    }
    
    .marquee-content span {
        font-size: 32px;
    }
    
    .features {
        padding: 96px 48px;
    }
    
    .features h2 {
        margin-bottom: 64px;
    }
    
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 32px;
    }
    
    .feature-card {
        padding: 36px;
    }
    
    .testimonials {
        padding: 96px 48px;
    }
    
    .testimonials h2 {
        margin-bottom: 64px;
    }
    
    .testimonials-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 32px;
    }
    
    .testimonial-card {
        padding: 36px;
    }
    
    .testimonial-quote {
        font-size: 19px;
    }
    
    .download-cta {
        padding: 104px 48px;
    }
    
    .download-cta h2 {
        margin-bottom: 16px;
    }
    
    .download-cta p {
        font-size: 20px;
        margin-bottom: 48px;
    }
    
    footer {
        padding: 72px 48px 40px;
    }
}

/* ================================
   ACCESSIBILITY & POLISH
   ================================ */

a:focus-visible,
button:focus-visible {
    outline: 3px solid #DC2626;
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}