:root {
    /* Color Palette */
    --primary: #3B82F6;
    --primary-dark: #2563EB;
    --primary-light: #60A5FA;
    --secondary: #1E293B;
    --text-main: #334155;
    --text-light: #64748B;
    --bg-white: #FFFFFF;
    --bg-gray: #F8FAFC;
    --accent-red: #EF4444;
    --accent-green: #10B981;
    --accent-orange: #F59E0B;

    /* Spacing & Layout */
    --container-width: 1140px;
    --header-height: 70px;
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 40px rgba(59, 130, 246, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    color: var(--text-main);
    background-color: var(--bg-white);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button,
input {
    font-family: inherit;
    border: none;
    outline: none;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

.text-highlight {
    color: var(--primary);
}

/* Typography */
h1,
h2,
h3 {
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: -0.02em;
}

.hero-title {
    font-size: 2.5rem;
    line-height: 1.2;
    margin-bottom: 1rem;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: 3.5rem;
    }

    .section-title {
        font-size: 2.5rem;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: white;
    color: var(--text-main);
    border: 1px solid #E2E8F0;
}

.btn-secondary:hover {
    background-color: var(--bg-gray);
    transform: translateY(-1px);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    border-radius: var(--radius-md);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    z-index: 1000;
}

.navbar-container {
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    width: 32px;
    height: 32px;
    border-radius: 6px;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--secondary);
}

.nav-links {
    display: none;
    gap: 2rem;
}

.nav-link {
    color: var(--text-light);
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-actions {
    display: none;
}

.menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    cursor: pointer;
}

.bar {
    width: 24px;
    height: 2px;
    background-color: var(--secondary);
    transition: 0.3s;
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    height: 100vh;
    background: white;
    z-index: 2000;
    transition: 0.3s ease;
    padding: 2rem;
    display: flex;
    flex-direction: column;
}

.mobile-menu.active {
    right: 0;
}

.close-menu {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    font-size: 2rem;
    background: none;
    cursor: pointer;
}

.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 3rem;
    font-size: 1.2rem;
    font-weight: 600;
}

.mobile-nav-btn {
    margin-top: 1rem;
    text-align: center;
    background: var(--primary);
    color: white;
    padding: 1rem;
    border-radius: 8px;
}

/* Hero Section */
.hero {
    padding: 3rem 0;
    background: linear-gradient(180deg, #EFF6FF 0%, #FFFFFF 100%);
    overflow: hidden;
}

.hero-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 3rem;
}

.badge-new {
    display: inline-block;
    padding: 0.4rem 1rem;
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.hero-subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.hero-cta-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    color: var(--text-light);
    font-size: 0.9rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-item strong {
    color: var(--secondary);
    font-size: 1.2rem;
    font-family: 'Poppins', sans-serif;
}

.separator {
    width: 1px;
    height: 30px;
    background: #CBD5E1;
}

.hero-visual {
    position: relative;
    width: 100%;
    max-width: 400px;
    padding: 0 1rem;
}

.phone-frame {
    position: relative;
    border-radius: clamp(20px, 4vw, 40px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    background: white;
    z-index: 1;
    border: 8px solid #1E293B;
    /* simplified dark bezel */
    overflow: hidden;
}

.app-screenshot {
    display: block;
    width: 100%;
    height: auto;
}

.glow-bg {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 100%;
    transform: translate(-50%, -50%);
    background: radial-gradient(circle, rgba(59, 130, 246, 0.4) 0%, rgba(255, 255, 255, 0) 70%);
    z-index: -1;
    filter: blur(40px);
}

/* Problem Section */
.problem-section {
    padding: 4rem 0;
    background-color: white;
}

.comparison-grid {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    align-items: center;
}

.comparison-card {
    background: var(--bg-gray);
    padding: 2rem;
    border-radius: var(--radius-md);
    width: 100%;
    max-width: 400px;
}

.comparison-card.good {
    background: #ECFDF5;
    border: 1px solid #A7F3D0;
}

.comparison-card.bad {
    border: 1px solid #E2E8F0;
}

.card-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.comparison-card h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.comparison-card ul li {
    margin-bottom: 0.5rem;
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 0.95rem;
}

.comparison-card ul li::before {
    content: "•";
    color: var(--text-light);
}

.comparison-card.good ul li::before {
    content: "✓";
    color: var(--accent-green);
    font-weight: bold;
}

.arrow-icon {
    font-size: 2rem;
    color: var(--text-light);
    transform: rotate(90deg);
}

/* Features Section */
.features-section {
    padding: 5rem 0;
    background-color: var(--bg-gray);
}

.section-tag {
    color: var(--primary);
    font-weight: 700;
    font-size: 0.9rem;
    letter-spacing: 1px;
    display: block;
    text-align: center;
    margin-bottom: 0.5rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.icon-box {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin: 0 auto 1.5rem;
}

.color-blue {
    background: #EFF6FF;
}

.color-red {
    background: #FEF2F2;
}

.color-green {
    background: #ECFDF5;
}

.color-orange {
    background: #FFFBEB;
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.feature-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* Steps Section */
.steps-section {
    padding: 5rem 0;
}

.steps-container {
    display: flex;
    flex-direction: column;
    gap: 3rem;
    margin-top: 3rem;
}

.step-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.step-number {
    font-family: 'Poppins', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    color: #E2E8F0;
    line-height: 1;
    min-width: 60px;
}

.step-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--secondary);
}

.step-content p {
    color: var(--text-light);
}

/* CTA Section */
.cta-section {
    padding: 5rem 0;
}

.cta-container {
    background: var(--secondary);
    border-radius: var(--radius-xl);
    padding: 3rem 1.5rem;
    color: white;
    text-align: center;
}

.cta-title {
    color: white;
    margin-bottom: 1rem;
}

.cta-text {
    color: #94A3B8;
    margin-bottom: 2rem;
}

.notify-form {
    max-width: 500px;
    margin: 0 auto;
}

.input-group {
    display: flex;
    background: white;
    padding: 4px;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.input-group input {
    flex: 1;
    padding: 0.8rem 1rem;
    font-size: 1rem;
    border-radius: 6px;
}

.form-check {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.85rem;
    color: #94A3B8;
}

/* FAQ Section */
.faq-section {
    padding: 5rem 0;
    background: var(--bg-gray);
}

.faq-list {
    max-width: 800px;
    margin: 3rem auto 0;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: white;
    border-radius: var(--radius-sm);
    padding: 1rem 1.5rem;
}

.faq-item summary {
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--primary);
}

.faq-item[open] summary::after {
    content: '-';
}

.faq-answer {
    margin-top: 1rem;
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
    border-top: 1px solid #F1F5F9;
    padding-top: 1rem;
}

/* Footer */
.footer {
    padding: 3rem 0;
    background: white;
    border-top: 1px solid #E2E8F0;
}

.footer-container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    align-items: center;
    text-align: center;
}

.footer-desc {
    color: var(--text-light);
    margin: 0.5rem 0;
}

.copyright {
    color: #CBD5E1;
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: #333;
    color: white;
    padding: 1rem 2rem;
    border-radius: 50px;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    z-index: 3000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Desktop Responsive */
@media (min-width: 768px) {
    .navbar .menu-toggle {
        display: none;
    }

    .nav-links,
    .nav-actions {
        display: flex;
    }

    .hero-container {
        flex-direction: row;
        text-align: left;
        justify-content: space-between;
    }

    .hero-content {
        align-items: flex-start;
        max-width: 50%;
    }

    .hero-cta-group {
        justify-content: flex-start;
    }

    .hero-stats {
        justify-content: flex-start;
    }

    .hero-visual {
        max-width: 45%;
    }

    .comparison-grid {
        flex-direction: row;
        justify-content: center;
        align-items: stretch;
    }

    .arrow-icon {
        transform: rotate(0);
    }

    .steps-container {
        flex-direction: row;
    }

    .step-item {
        flex: 1;
    }

    .footer-container {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
        align-items: flex-start;
    }
}