:root {
    --bg-color: #ffffff;
    --text-color: #0a192f;
    --text-muted: #64748b;
    --primary-color: #0a192f;
    /* Deep Navy */
    --accent-color: #1e3a8a;
    /* Brighter Navy */
    --card-bg: rgba(255, 255, 255, 0.8);
    --card-border: #e2e8f0;
    --font-main: 'Inter', 'Noto Sans JP', sans-serif;
    --section-spacing: 60px;
    --nav-height: 80px;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.8;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* Layout */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 40px;
    color: var(--primary-color);
    letter-spacing: -0.5px;
    text-align: center;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--card-border);
    display: flex;
    align-items: center;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    letter-spacing: 0.5px;
    color: var(--primary-color);
}

.nav ul {
    display: flex;
    gap: 30px;
}

.nav a {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-muted);
}

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

/* Hero */
.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: var(--nav-height);
    position: relative;
    background: radial-gradient(circle at 50% 50%, #f1f5f9 0%, #ffffff 70%);
}

.hero-title {
    font-size: 5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 20px;
    color: var(--primary-color);
    letter-spacing: -2px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    font-weight: 500;
}

/* App Window Mockup */
.app-window {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 20px 50px rgba(10, 25, 47, 0.15);
    border: 1px solid #e2e8f0;
    overflow: hidden;
    position: relative;
    height: 100%;
    min-height: 400px;
}

.window-header {
    height: 36px;
    background: #f1f5f9;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    padding: 0 16px;
    gap: 8px;
}

.window-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot-red {
    background: #ff5f56;
    border: 1px solid #e0443e;
}

.dot-yellow {
    background: #ffbd2e;
    border: 1px solid #dea123;
}

.dot-green {
    background: #27c93f;
    border: 1px solid #1aab29;
}

.window-title {
    flex: 1;
    text-align: center;
    font-size: 12px;
    color: #64748b;
    font-weight: 500;
}

.window-content {
    height: calc(100% - 36px);
    width: 100%;
    background: #000;
    /* App background color */
}

/* Cards */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.glass-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    transition: all 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
    border-color: #cbd5e1;
}

.card-title {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--primary-color);
    font-weight: 700;
}

.card-desc {
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1.7;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 40px;
    font-weight: 600;
    font-size: 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
    cursor: pointer;
}

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

.primary-btn:hover {
    background: var(--accent-color);
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(10, 25, 47, 0.2);
}

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

.secondary-btn:hover {
    background: #f1f5f9;
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Footer */
.footer {
    padding: 60px 0;
    text-align: center;
    border-top: 1px solid var(--card-border);
    color: var(--text-muted);
    font-size: 0.9rem;
    background: #f8fafc;
}

/* Responsive */
@media (max-width: 768px) {
    .section-title {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 3rem;
    }

    .grid-2 {
        grid-template-columns: 1fr;
    }

    .btn {
        width: 100%;
        margin-bottom: 10px;
    }
}