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

:root {
    /* Modern Monochrome Color Palette */
    --primary: #1a1a1a; /* Pure dark for accents */
    --primary-light: #333333; /* Medium dark */
    --primary-dark: #000000; /* Pure black */
    --accent: #2a2a2a; /* Subtle dark accent */
    --accent-light: #444444; /* Light accent */
    
    /* Monochrome Grays */
    --white: #ffffff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
    
    /* Typography */
    --font-korean: 'Noto Sans KR', sans-serif;
    --font-english: 'Inter', sans-serif;
    
    /* Layout */
    --max-width: 1200px;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: var(--font-korean);
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--white);
    scroll-behavior: smooth;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 4rem;
}

.nav-brand h1 {
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 0.05em;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--gray-600);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s ease;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 24px;
    height: 3px;
    background: var(--gray-600);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    padding: 8rem 0 6rem;
    background: linear-gradient(135deg, var(--white) 0%, var(--gray-50) 50%, var(--gray-100) 100%);
    overflow: hidden;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 100%;
    height: 200%;
    background: radial-gradient(circle, rgba(26, 26, 26, 0.02) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    color: var(--gray-900);
}

.hero-title .accent {
    color: var(--primary);
    display: block;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--gray-600);
    margin-bottom: 2.5rem;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

/* Phone Mockup */
.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    position: relative;
    width: 280px;
    height: 560px;
    background: var(--gray-900);
    border-radius: 40px;
    padding: 8px;
    box-shadow: var(--shadow-lg);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--white);
    border-radius: 32px;
    overflow: hidden;
    position: relative;
}

.app-preview {
    padding: 2rem 1.5rem;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.preview-header {
    text-align: center;
    margin-bottom: 2rem;
}

.preview-time {
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-800);
}

.preview-progress {
    display: flex;
    justify-content: center;
    margin-bottom: 3rem;
}

.progress-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: conic-gradient(var(--gray-800) 75%, var(--gray-200) 75%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.progress-circle::before {
    content: '';
    position: absolute;
    width: 80px;
    height: 80px;
    background: var(--white);
    border-radius: 50%;
}

.progress-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-800);
    position: relative;
    z-index: 1;
}

.preview-routines {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.routine-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    gap: 1rem;
}

.routine-item.completed {
    background: rgba(26, 26, 26, 0.05);
    border-left: 4px solid var(--gray-700);
}

.routine-icon {
    font-size: 1.5rem;
}

.routine-name {
    flex: 1;
    font-weight: 500;
    color: var(--gray-700);
}

.routine-check {
    font-size: 1.25rem;
    color: var(--gray-700);
    font-weight: bold;
}

/* Features Section */
.features {
    padding: 6rem 0;
    background: var(--white);
}

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

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 1rem;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    border: 1px solid var(--gray-200);
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: block;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

/* Screenshots Section */
.screenshots {
    padding: 6rem 0;
    background: var(--gray-50);
}

.screenshots-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.screenshot-placeholder {
    aspect-ratio: 9/16;
    background: linear-gradient(135deg, var(--gray-700), var(--gray-600));
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    text-align: center;
    padding: 2rem;
}

.placeholder-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.placeholder-content p {
    opacity: 0.9;
}

/* Download Section */
.download {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--gray-900), var(--gray-800));
    color: var(--white);
    text-align: center;
}

.download-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.download-content p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.download-buttons {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--white);
    color: var(--gray-900);
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.download-btn:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.btn-icon svg {
    width: 32px;
    height: 32px;
    color: var(--gray-700);
}

.btn-text {
    text-align: left;
}

.btn-subtitle {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.btn-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
}

.download-note {
    font-size: 0.875rem;
    opacity: 0.8;
    margin-top: 1.5rem;
}

/* Privacy Section */
.privacy {
    padding: 6rem 0;
    background: var(--white);
}

.privacy-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.privacy-card {
    background: var(--gray-50);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    border-left: 4px solid var(--gray-700);
}

.privacy-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 1rem;
}

.privacy-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--white);
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand h3 {
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-300);
    margin-bottom: 0.5rem;
    letter-spacing: 0.05em;
}

.footer-brand p {
    color: var(--gray-400);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
}

.footer-section h4 {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--white);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--gray-200);
}

.footer-bottom {
    border-top: 1px solid var(--gray-800);
    padding-top: 1.5rem;
    text-align: center;
    color: var(--gray-400);
}

.footer-tech {
    margin-top: 0.5rem;
    font-size: 0.875rem;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        padding: 6rem 0 4rem;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .phone-mockup {
        width: 240px;
        height: 480px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-card {
        padding: 2rem;
    }
    
    .screenshots-gallery {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .footer-links {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
    
    .hero {
        padding: 5rem 0 3rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }
    
    .phone-mockup {
        width: 200px;
        height: 400px;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .download-content h2 {
        font-size: 2rem;
    }
    
    .download-btn {
        padding: 0.875rem 1.5rem;
    }
}

/* Smooth Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content,
.feature-card,
.privacy-card {
    animation: fadeInUp 0.6s ease-out;
}

/* Focus States for Accessibility */
.nav-link:focus,
.btn:focus,
.download-btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .navbar,
    .download,
    .footer {
        display: none;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    * {
        background: white !important;
        color: black !important;
    }
}