:root {
    --primary: #87CEEB;
    --primary-dark: #000080;
    --text-main: #111827;
    --text-muted: #6B7280;
    --bg-light: #F9FAFB;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --maxWidth: 1100px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-main);
    line-height: 1.5;
    background: white;
    overflow-x: hidden;
    width: 100%;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    width: 100%;
    max-width: var(--maxWidth);
    margin: 0 auto;
    padding: 0 16px;
}

/* Header */
header {
    min-height: 60px;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    height: 100%;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 10px;
    padding-bottom: 10px;
    flex-wrap: nowrap;
    gap: 16px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 900;
    font-size: 1.1rem;
    letter-spacing: -0.5px;
}

.logo img {
    width: 28px;
    height: 28px;
    border-radius: 6px;
}

.menu-toggle {
    display: block;
    background: transparent;
    border: none;
    font-size: 1.5rem;
    color: var(--text-main);
    cursor: pointer;
    padding: 5px;
    z-index: 101;
}

nav.nav-menu {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 20px;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-in-out, padding 0.3s ease-in-out;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

nav.nav-menu.active {
    max-height: 400px;
    padding: 20px 0;
}

nav a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.9rem;
}

/* Hero */
.hero {
    padding: clamp(40px, 8vw, 100px) 0;
}

.hero .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: clamp(32px, 6vw, 60px);
}

.hero-content { 
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-image { 
    width: 100%; 
    display: flex; 
    justify-content: center; 
}

.hero-image .icon-card {
    width: clamp(150px, 40vw, 200px);
    height: clamp(150px, 40vw, 200px);
    background: white;
    border-radius: clamp(24px, 8vw, 44px);
    box-shadow: 0 20px 40px rgba(135, 206, 235, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

h1 {
    font-size: clamp(2.2rem, 8vw, 3.5rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: clamp(16px, 4vw, 24px);
}

.hero p {
    font-size: clamp(1rem, 3vw, 1.15rem);
    color: var(--text-muted);
    margin-bottom: clamp(24px, 6vw, 40px);
    max-width: 600px;
}

/* Features */
.features {
    background: var(--bg-light);
    padding: clamp(50px, 8vw, 80px) 0;
}

.features h2 {
    text-align: center;
    font-size: clamp(1.75rem, 5vw, 2rem);
    font-weight: 900;
    margin-bottom: clamp(32px, 6vw, 48px);
}

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

.feature-card {
    background: white;
    padding: clamp(20px, 4vw, 28px);
    border-radius: 20px;
    border: 1px solid rgba(0,0,0,0.05);
    transition: transform 0.2s;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.feature-card:hover { transform: translateY(-5px); }

.feature-card i {
    font-size: 1.75rem;
    color: var(--primary);
    margin-bottom: 20px;
    display: block;
}

.feature-card h3 {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Showcase */
.showcase {
    padding: clamp(60px, 10vw, 120px) 0;
}

.showcase .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: clamp(40px, 8vw, 60px);
}

.showcase-content { 
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.showcase-content h2 {
    font-size: clamp(2rem, 7vw, 3rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 24px;
}

.showcase-content p {
    font-size: clamp(1rem, 3vw, 1.15rem);
    color: var(--text-muted);
    margin-bottom: 30px;
    max-width: 600px;
}

.showcase-visual {
    width: 100%;
    overflow-x: auto;
    display: flex;
    gap: 16px;
    padding: 20px 0;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
}

.showcase-visual::-webkit-scrollbar { height: 6px; }
.showcase-visual::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.15); border-radius: 3px; }

.screenshot {
    width: clamp(140px, 40vw, 220px);
    flex-shrink: 0;
    border-radius: 16px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    overflow: hidden;
}

.btn-join {
    background: black;
    color: white;
    padding: 14px 32px;
    border-radius: 8px;
    font-weight: bold;
    border: none;
    cursor: pointer;
    margin-top: clamp(20px, 4vw, 40px);
}

/* Download Section */
.download-section {
    padding: clamp(60px, 8vw, 110px) 0;
    background: #FFFFFF;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.download-block {
    display: grid;
    grid-template-columns: 1fr;
    gap: clamp(32px, 6vw, 64px);
    align-items: center;
    margin-bottom: clamp(60px, 8vw, 100px);
}

.download-block:last-child {
    margin-bottom: 0;
}

.download-info h2 {
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 20px;
    color: var(--text-main);
    letter-spacing: -0.8px;
}

.download-desc-primary {
    font-size: clamp(1rem, 2vw, 1.15rem);
    color: #374151;
    line-height: 1.6;
    margin-bottom: 16px;
    max-width: 540px;
}

.download-desc-secondary {
    font-size: clamp(0.9rem, 1.8vw, 1rem);
    color: var(--text-muted);
    line-height: 1.5;
    margin-bottom: 32px;
    max-width: 520px;
}

/* Mobile Download Actions & QR Code */
.mobile-download-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 20px;
}

.qr-code-card {
    background: white;
    border: 1px solid #E5E7EB;
    border-radius: 18px;
    padding: 10px;
    width: 120px;
    height: 120px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.qr-code-card img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.mobile-button-wrapper {
    display: flex;
    align-items: center;
}

/* Pill Download Buttons (Matching ChatGPT screenshot design) */
.pill-download-btn {
    background: #111827;
    color: #FFFFFF !important;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: 9999px;
    font-weight: 700;
    font-size: 0.95rem;
    line-height: 1;
    transition: all 0.2s ease-in-out;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    border: none;
}

.pill-download-btn:hover {
    background: #000000;
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.18);
}

.pill-download-btn i {
    font-size: 1.25rem;
}

/* Visual Cards */
.visual-card {
    width: 100%;
    height: clamp(320px, 40vw, 440px);
    border-radius: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    overflow: hidden;
    position: relative;
}

.visual-card.mobile-bg {
    background: linear-gradient(135deg, #FFE4E6 0%, #FED7AA 40%, #CCFBF1 100%);
}

.visual-card.desktop-bg {
    background: linear-gradient(135deg, #C7D2FE 0%, #A5B4FC 50%, #DDD6FE 100%);
}

.mobile-preview-img {
    max-height: 88%;
    width: auto;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    object-fit: contain;
}

/* Desktop App Icon Card */
.desktop-icon-card {
    width: clamp(140px, 28vw, 190px);
    height: clamp(140px, 28vw, 190px);
    background: #FFFFFF;
    border-radius: clamp(28px, 6vw, 42px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.15), 0 4px 12px rgba(0, 0, 0, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 16px;
    transition: transform 0.3s ease;
}

.desktop-icon-card:hover {
    transform: scale(1.05);
}

.desktop-app-icon {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: clamp(20px, 4vw, 30px);
}

/* Modal Dialog Backdrop & Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(17, 24, 39, 0.6);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
}

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

/* Modal Card */
.modal-card {
    background: #FFFFFF;
    width: 100%;
    max-width: 540px;
    border-radius: 28px;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.22);
    padding: clamp(24px, 5vw, 36px);
    position: relative;
    transform: scale(0.94) translateY(10px);
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    border: 1px solid rgba(0, 0, 0, 0.08);
}

.modal-overlay.active .modal-card {
    transform: scale(1) translateY(0);
}

.modal-close-icon {
    position: absolute;
    top: 20px;
    right: 20px;
    background: #F3F4F6;
    border: none;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4B5563;
    font-size: 0.95rem;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.modal-close-icon:hover {
    background: #E5E7EB;
    color: #111827;
}

.modal-header {
    margin-bottom: 20px;
}

.modal-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #F3F4F6;
    color: #111827;
    padding: 6px 14px;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.modal-badge i {
    font-size: 0.9rem;
}

.modal-header h3 {
    font-size: clamp(1.35rem, 4vw, 1.75rem);
    font-weight: 900;
    color: #111827;
    line-height: 1.25;
}

.modal-body {
    margin-bottom: 28px;
}

.modal-notice-text {
    font-size: 0.95rem;
    color: #374151;
    line-height: 1.6;
    margin-bottom: 20px;
}

/* Why Box */
.modal-why-box {
    background: #EFF6FF;
    border: 1px solid #BFDBFE;
    border-radius: 16px;
    padding: 16px;
    margin-bottom: 20px;
}

.why-header {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #1E40AF;
    font-size: 0.9rem;
    margin-bottom: 6px;
}

.why-header i {
    font-size: 1rem;
}

.modal-why-box p {
    font-size: 0.85rem;
    color: #1E3A8A;
    line-height: 1.5;
}

/* Steps Box */
.modal-steps-box {
    background: #F9FAFB;
    border: 1px solid #E5E7EB;
    border-radius: 18px;
    padding: 18px;
}

.steps-heading {
    display: block;
    font-size: 0.9rem;
    font-weight: 700;
    color: #111827;
    margin-bottom: 14px;
}

.steps-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.steps-list li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 0.88rem;
    color: #374151;
    line-height: 1.5;
}

.step-num {
    background: #111827;
    color: #FFFFFF;
    font-weight: 700;
    font-size: 0.75rem;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 1px;
}

.step-path {
    display: inline-block;
    background: #E5E7EB;
    color: #111827;
    font-weight: 700;
    font-size: 0.8rem;
    padding: 4px 10px;
    border-radius: 8px;
    margin-top: 4px;
}

.step-path i {
    font-size: 0.65rem;
    margin: 0 4px;
    color: #6B7280;
}

/* Modal Footer Buttons */
.modal-footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 12px;
    flex-wrap: wrap;
}

.modal-btn-secondary {
    background: transparent;
    border: 1px solid #D1D5DB;
    color: #374151;
    padding: 12px 22px;
    border-radius: 9999px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s;
}

.modal-btn-secondary:hover {
    background: #F3F4F6;
    border-color: #9CA3AF;
}

.modal-btn-primary {
    background: #111827;
    color: #FFFFFF !important;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 9999px;
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    border: none;
    transition: background 0.2s, transform 0.2s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.modal-btn-primary:hover {
    background: #000000;
    transform: translateY(-1px);
}

.google-play-btn {
    background: black;
    color: white;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: clamp(8px, 2vw, 12px);
    padding: clamp(8px, 2vw, 12px) clamp(16px, 4vw, 24px);
    border-radius: 8px;
    text-decoration: none;
    transition: transform 0.2s;
    width: 100%;
    max-width: 280px;
}
.google-play-btn:hover { transform: scale(1.02); }

.google-play-btn i { font-size: clamp(1.2rem, 4vw, 1.8rem); }
.gp-text { text-align: left; }
.gp-text span { display: block; font-size: clamp(0.45rem, 1.5vw, 0.6rem); line-height: 1; margin-bottom: 2px; text-transform: uppercase; letter-spacing: 0.5px; }
.gp-text strong { display: block; font-size: clamp(0.9rem, 3vw, 1.2rem); font-weight: bold; line-height: 1; }

/* Footer */
footer {
    padding: clamp(30px, 6vw, 40px) 0;
    background: var(--bg-light);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 24px;
    border-top: 1px solid rgba(0,0,0,0.1);
    padding-top: 30px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    font-weight: 900;
}

.footer-logo {
    width: 20px;
    height: 20px;
    border-radius: 4px;
}

.footer-brand span { 
    color: var(--text-muted); 
    font-weight: normal; 
    font-size: 0.8rem; 
}

.footer-links { 
    display: flex; 
    flex-wrap: wrap;
    justify-content: center;
    gap: clamp(16px, 4vw, 24px); 
}
.footer-links a { text-decoration: none; color: var(--text-main); font-weight: 600; font-size: 0.85rem; }

/* Tablet (768px+) */
@media (min-width: 768px) {
    .container { padding: 0 24px; }
    
    .hero .container { flex-direction: row; text-align: left; }
    .hero-content { align-items: flex-start; flex: 1; }
    .hero-image { flex: 1; justify-content: flex-end; }
    
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    
    .showcase .container { flex-direction: row; text-align: left; }
    .showcase-content { align-items: flex-start; flex: 1; }
    .showcase-visual { flex: 1; }
    
    .download-block {
        grid-template-columns: 1fr 1fr;
    }

    .download-block.reverse-layout .download-visual {
        order: 1;
    }

    .download-block.reverse-layout .download-info {
        order: 2;
    }

    .footer-content { flex-direction: row; justify-content: space-between; text-align: left; flex-wrap: wrap; }
    .footer-brand { flex-direction: row; flex-wrap: wrap; }
    .footer-brand span { margin-left: 12px; }
    
    .google-play-btn { width: auto; }
    
    /* Navigation for Tablet+ */
    .menu-toggle { display: none; }
    nav.nav-menu {
        display: flex;
        flex-direction: row;
        position: static;
        max-height: none;
        background: transparent;
        backdrop-filter: none;
        padding: 0;
        width: auto;
        box-shadow: none;
        border: none;
        overflow: visible;
        gap: clamp(10px, 2vw, 20px);
    }
    nav.nav-menu.active { padding: 0; }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
    nav.nav-menu {
        gap: 30px;
    }
    
    .hero-content { flex: 7; }
    .hero-image { flex: 4; }
    
    .features-grid { grid-template-columns: repeat(4, 1fr); }
    
    .showcase-content { flex: 4; }
    .showcase-visual { flex: 6; }
}

/* Language Selector */
.lang-selector {
    display: flex;
    align-items: center;
    gap: 6px;
    background: #F3F4F6;
    padding: 6px 12px;
    border-radius: 8px;
    border: 1px solid rgba(0,0,0,0.08);
}

.lang-selector i {
    color: #87CEEB;
    font-size: 0.9rem;
}

.lang-selector select {
    background: transparent;
    border: none;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-main);
    cursor: pointer;
    outline: none;
}

/* FAQ Section */
.faq-section {
    padding: clamp(50px, 8vw, 80px) 0;
    background: white;
    border-top: 1px solid rgba(0,0,0,0.05);
}

.faq-section h2 {
    text-align: center;
    font-size: clamp(1.75rem, 5vw, 2.25rem);
    font-weight: 900;
    margin-bottom: 12px;
}

.faq-subtitle {
    text-align: center;
    color: var(--text-muted);
    font-size: clamp(0.95rem, 2.5vw, 1.1rem);
    max-width: 600px;
    margin: 0 auto clamp(32px, 5vw, 48px);
}

.faq-grid {
    display: flex;
    flex-direction: column;
    gap: 16px;
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-light);
    border-radius: 14px;
    border: 1px solid rgba(0, 0, 0, 0.06);
    overflow: hidden;
    transition: all 0.2s ease;
}

.faq-item:hover {
    border-color: rgba(135, 206, 235, 0.5);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
}

.faq-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 22px;
    cursor: pointer;
    user-select: none;
    gap: 16px;
}

.faq-header h3 {
    font-size: clamp(0.95rem, 2.5vw, 1.05rem);
    font-weight: 700;
    color: var(--text-main);
    line-height: 1.4;
}

.faq-icon {
    font-size: 0.9rem;
    color: var(--text-muted);
    transition: transform 0.3s ease, color 0.3s ease;
    flex-shrink: 0;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
    color: var(--primary-dark);
}

.faq-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease-in-out, padding 0.35s ease;
    padding: 0 22px;
}

.faq-item.active .faq-body {
    max-height: 300px;
    padding: 0 22px 20px;
}

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