:root {
    --bg: #050505;
    --surface: #0D0D0D;
    --border: #1A1A1A;
    --indigo: #4F46E5;
    --indigo-bright: #818CF8;
    --text-main: #F3F4F6;
    --text-sub: #9CA3AF;
    --radius: 6px;
}

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

body {
    background: var(--bg);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    -webkit-font-smoothing: antialiased;
    line-height: 1.6;
}

h1,
h2,
h3,
.serif {
    font-family: 'Source Serif Pro', serif;
}

.top-nav {
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    border-bottom: 1px solid var(--border);
    background: rgba(5, 5, 5, 0.85);
    backdrop-filter: blur(20px);
    position: sticky;
    top: 0;
    z-index: 1100;
}

.logo {
    font-family: 'Outfit', sans-serif;
    font-weight: 900;
    letter-spacing: -0.5px;
    color: var(--text-main);
    font-size: 1.5rem;
    position: relative;
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--indigo);
    border-radius: 50%;
    box-shadow: 0 0 10px var(--indigo);
}

nav a {
    text-decoration: none;
    color: var(--text-sub);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color 0.2s;
    margin-left: 25px;
}

nav a:hover {
    color: var(--indigo-bright);
}

.hero {
    padding: 160px 20px 100px;
    text-align: center;
    max-width: 1100px;
    margin: 0 auto;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 400px;
    background: radial-gradient(circle, rgba(79, 70, 229, 0.08) 0%, transparent 70%);
    pointer-events: none;
    z-index: -1;
}

.hero h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 7rem;
    font-weight: 900;
    letter-spacing: -4px;
    margin-bottom: 10px;
    color: #fff;
    background: linear-gradient(to bottom, #fff 40%, #888 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero .subtitle {
    font-family: 'Source Serif Pro', serif;
    font-size: 1.8rem;
    color: var(--text-sub);
    font-style: italic;
    margin-bottom: 60px;
    opacity: 0.8;
}

.manifesto {
    font-family: 'Source Serif Pro', serif;
    font-size: 1.4rem;
    line-height: 2.1;
    color: #AAA;
    max-width: 800px;
    margin: 60px auto 0;
    text-align: center;
}

.btn-main {
    background: var(--indigo);
    color: #fff;
    border: 1px solid rgba(129, 140, 248, 0.3);
    padding: 16px 40px;
    font-size: 13px;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 2px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 10px 25px rgba(79, 70, 229, 0.2), inset 0 0 15px rgba(79, 70, 229, 0.1);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: 'Inter', sans-serif;
}

a.btn-main {
    display: inline-flex;
    text-decoration: none;
}

.btn-main:hover {
    transform: translateY(-2px);
    background: #6366f1;
    border-color: rgba(129, 140, 248, 0.6);
    box-shadow: 0 15px 35px rgba(79, 70, 229, 0.4), inset 0 0 20px rgba(79, 70, 229, 0.2);
}

.btn-main:active {
    transform: scale(0.98) translateY(0);
}

.demo-stage-container {
    max-width: 1100px;
    margin: 40px auto 120px;
    position: relative;
}

/* Demo Stage Fixes */
.demo-stage {
    width: 100%;
    height: 720px;
    background: #000;
    border: 1px solid var(--border);
    border-radius: 8px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 60px 150px rgba(0, 0, 0, 1);
}

.demo-subtitle {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    background: linear-gradient(to top, rgba(0, 0, 0, 1) 0%, rgba(0, 0, 0, 0.8) 70%, transparent 100%);
    backdrop-filter: blur(12px);
    color: #fff;
    padding: 50px 80px 35px;
    font-size: 17px;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.4s;
    text-align: center;
    font-family: 'Source Serif Pro', serif;
    line-height: 1.6;
}

/* Badge (底部置中) */
.feature-badge {
    position: absolute;
    bottom: -40px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(79, 70, 229, 0.1);
    color: var(--indigo-bright);
    padding: 6px 14px;
    border-radius: 4px;
    border: 1px solid rgba(79, 70, 229, 0.5);
    font-size: 10px;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 2px;
    z-index: 1001;
    opacity: 0;
    transition: all 0.5s;
}

.demo-ui-mock {
    display: grid;
    grid-template-columns: 44px 220px 1fr 280px;
    height: 100%;
    width: 100%;
}

.pane {
    border-right: 1px solid #111;
    position: relative;
    background: #000;
    overflow: hidden;
}

.file-item {
    font-size: 11px;
    padding: 8px 20px;
    color: #fff;
    display: flex;
    align-items: center;
    gap: 8px;
}

.file-item.active {
    background: rgba(79, 70, 229, 0.15);
    color: #fff;
    border-left: 3px solid var(--indigo);
}

.editor-header {
    height: 35px;
    background: #000;
    border-bottom: 1px solid #111;
    display: flex;
    align-items: center;
    padding: 0 15px;
    font-size: 10px;
    color: #444;
    font-family: monospace;
}

.status-bar {
    height: 24px;
    background: #000;
    border-top: 1px solid #111;
    color: #333;
    font-size: 9px;
    display: flex;
    align-items: center;
    padding: 0 15px;
    justify-content: space-between;
    font-family: monospace;
}

.features-marquee-wrapper {
    overflow: hidden;
    position: relative;
    width: 100%;
    margin-top: 60px;
}

.features-marquee {
    display: flex;
    width: max-content;
    animation: scroll-left 40s linear infinite;
}

.features-marquee:hover {
    animation-play-state: paused;
}

.features-grid {
    display: flex;
    gap: 20px;
    padding-bottom: 30px;
    padding-right: 20px;
    /* spacing between duplicates */
}

@keyframes scroll-left {
    0% {
        transform: translateX(0);
    }

    100% {
        transform: translateX(calc(-50%));
    }
}

.features-grid::-webkit-scrollbar-thumb {
    background: var(--indigo);
    border-radius: 4px;
}

.feature-card {
    flex: 0 0 340px;
    scroll-snap-align: center;
    background: #000;
    border: 1px solid #222;
    padding: 40px 30px;
    border-radius: 8px;
    transition: transform 0.3s, border-color 0.3s;
    display: flex;
    flex-direction: column;
}

.feature-card.wow {
    border-color: rgba(79, 70, 229, 0.3);
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.08), #080808);
}

.feature-card:hover {
    border-color: var(--indigo);
    transform: translateY(-5px);
}

.feature-tag {
    font-size: 10px;
    font-weight: 800;
    color: var(--indigo-bright);
    letter-spacing: 2.5px;
    margin-bottom: 20px;
    display: block;
    text-transform: uppercase;
}

.feature-card h4 {
    color: #fff;
    font-size: 1.7rem;
    margin-bottom: 15px;
    font-family: 'Source Serif Pro', serif;
}

.feature-card p {
    color: var(--text-sub);
    font-family: 'Source Serif Pro', serif;
    font-size: 1.1rem;
    line-height: 1.8;
}


.pricing-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.price-card {
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 60px 40px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    text-align: center;
}

.price-card.featured {
    border: 2px solid var(--indigo);
    box-shadow: 0 20px 50px rgba(79, 70, 229, 0.1);
}

.download-links {
    display: flex;
}

.faq-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    margin-bottom: 20px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item details {
    width: 100%;
}

.faq-item summary {
    cursor: pointer;
    padding: 25px 30px;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    outline: none;
    transition: background 0.2s;
}

.faq-item summary:hover {
    background: rgba(255, 255, 255, 0.02);
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-q {
    color: #fff;
    font-weight: bold;
    font-family: 'Source Serif Pro';
    font-size: 1.15rem;
}

.faq-item summary::after {
    content: '+';
    color: var(--indigo-bright);
    font-size: 1.5rem;
    transition: transform 0.3s;
}

.faq-item details[open] summary::after {
    content: '−';
    transform: rotate(180deg);
}

.faq-a {
    padding: 0 30px 30px;
    color: var(--text-sub);
    font-size: 1rem;
    line-height: 1.7;
    font-family: 'Source Serif Pro';
}

.faq-item details[open] {
    background: rgba(79, 70, 229, 0.05);
}

.legal-footer {
    border-top: 1px solid var(--border);
    padding: 40px 20px 60px;
    text-align: center;
    background: #000;
}

.legal-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 18px;
    margin-bottom: 14px;
}

.legal-links a {
    color: var(--text-sub);
    text-decoration: none;
    font-size: 12px;
    letter-spacing: 0.4px;
}

.legal-links a:hover {
    color: #fff;
}

.legal-note {
    color: #666;
    font-size: 12px;
}

.legal-note a {
    color: var(--indigo-bright);
    text-decoration: none;
}

#lang-select {
    background: transparent;
    color: var(--text-sub);
    border: 1px solid var(--border);
    font-size: 11px;
    border-radius: 4px;
    padding: 4px 8px;
    outline: none;
    cursor: pointer;
}

.form-input {
    width: 100%;
    background: #000;
    border: 1px solid var(--border);
    color: #fff;
    border-radius: var(--radius);
    padding: 14px 16px;
    font-size: 14px;
}

.form-input:focus {
    outline: none;
    border-color: var(--indigo);
}

@media (max-width: 900px) {
    .demo-ui-mock {
        grid-template-columns: 44px 0 1fr 0;
    }

    .pricing-grid,
    .download-links {
        grid-template-columns: 1fr;
        display: grid;
    }

    .feature-card,
    .feature-card.wow {
        grid-column: span 1;
    }

    .hero h1 {
        font-size: 4rem;
    }
}