:root {
    --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
    --ease-in-out-quad: cubic-bezier(0.45, 0, 0.55, 1);
}

[data-theme="dark"] {
    --bg-color: #121212;
    --header-bg: rgba(18, 18, 18, 0.5);
    --text-primary: #EDEDED;
    --text-secondary: #A0A0A0;
    --accent-primary: #A3B899;
    --accent-secondary: #E5ADC8;
    --card-bg: #1C1C1C;
    --card-border-color: rgba(255, 255, 255, 0.1);
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    --header-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-color: #F7F7F7;
    --header-bg: rgba(247, 247, 247, 0.5);
    --text-primary: #1A1A1A;
    --text-secondary: #6B6B6B;
    --accent-primary: #7E9C70;
    --accent-secondary: #D98AAE;
    --card-bg: #FFFFFF;
    --card-border-color: rgba(0, 0, 0, 0.1);
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    --header-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color 0.3s var(--ease-in-out-quad), color 0.3s var(--ease-in-out-quad);
    overflow-x: hidden;
}

#aurora-cursor {
    position: fixed;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: radial-gradient(circle, var(--accent-primary) 0%, rgba(229, 173, 200, 0.5) 50%, transparent 70%);
    filter: blur(100px);
    z-index: -1;
    pointer-events: none;
    transition: transform 0.2s ease-out, opacity 0.3s ease-in-out;
    opacity: 0.15;
    transform: translate(-50%, -50%);
}

[data-theme="light"] #aurora-cursor {
    opacity: 0.25;
}

.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1rem 2rem;
    background-color: var(--header-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    z-index: 100;
    border-bottom: 1px solid var(--card-border-color);
    transition: box-shadow 0.3s var(--ease-in-out-quad), background-color 0.3s var(--ease-in-out-quad);
}

.main-header.scrolled { box-shadow: var(--header-shadow); }
.header-content { max-width: 1024px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; }
.header-content h1 { font-size: 1.3rem; font-weight: 600; }

.theme-switcher { display: flex; align-items: center; gap: 0.75rem; color: var(--text-secondary); }
.switch { position: relative; display: inline-block; width: 44px; height: 24px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #39393d; transition: 0.4s; border-radius: 24px; }
.slider:before { position: absolute; content: ""; height: 18px; width: 18px; left: 3px; bottom: 3px; background-color: white; transition: 0.4s var(--ease-out-quart); border-radius: 50%; }
input:checked + .slider { background-color: var(--accent-primary); }
input:checked + .slider:before { transform: translateX(20px); }

.content-wrapper { max-width: 1024px; margin: 0 auto; padding: 9rem 2rem 5rem; display: flex; flex-direction: column; gap: 6rem; }
.fade-in { animation: fadeIn 1s 0.2s var(--ease-out-quart) forwards; opacity: 0; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.reveal-on-scroll { opacity: 0; transform: translateY(30px) scale(0.98); transition: opacity 0.8s var(--ease-out-quart), transform 0.8s var(--ease-out-quart); }
.reveal-on-scroll.visible { opacity: 1; transform: translateY(0) scale(1); }

section { text-align: center; }
.hero-title { font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 700; line-height: 1.2; margin-bottom: 1.5rem; letter-spacing: -1.5px; }
.hero-subtitle { font-size: 1.15rem; max-width: 680px; margin: 0 auto 1.5rem; color: var(--text-secondary); }
.hero-subtitle strong { font-weight: 600; color: var(--text-primary); }
.hero-warning { font-size: 0.9rem; font-weight: 500; color: var(--accent-secondary); background: rgba(229, 173, 200, 0.1); padding: 0.5rem 1rem; border-radius: 8px; display: inline-block; border: 1px solid rgba(229, 173, 200, 0.2); }
.section-title { font-size: 1.8rem; font-weight: 600; margin-bottom: 3rem; text-align: center; }

.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }

@media (min-width: 900px) {
    .features-grid { grid-template-columns: repeat(3, 1fr); }
}

.feature-card {
    border-radius: 12px;
    border: 1px solid var(--card-border-color);
    position: relative;
    transition: transform 0.4s var(--ease-out-quart), border-color 0.4s var(--ease-out-quart);
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: var(--y);
    left: var(--x);
    width: 250px;
    height: 250px;
    border-radius: 50%;
    background: radial-gradient(circle, var(--accent-primary) 0%, transparent 60%);
    transform: translate(-50%, -50%);
    opacity: 0;
    transition: opacity 0.4s var(--ease-out-quart);
    z-index: 1;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: rgba(163, 184, 153, 0.4);
}
.feature-card:hover::before {
    opacity: 0.2;
}

.card-content {
    background: var(--card-bg);
    padding: 2rem;
    height: 100%;
    position: relative;
    z-index: 2;
}

.card-icon { font-size: 1.5rem; color: var(--accent-primary); margin-bottom: 1rem; }
.feature-card h4 { font-size: 1.15rem; font-weight: 600; margin-bottom: 0.5rem; }
.feature-card p { color: var(--text-secondary); font-size: 0.95rem; }

.requirements-list { list-style: none; max-width: 640px; margin: 0 auto; text-align: left; display: flex; flex-direction: column; gap: 1rem; }
.requirements-list li { background: var(--card-bg); border: 1px solid var(--card-border-color); border-radius: 10px; padding: 1rem 1.5rem; font-weight: 500; display: flex; align-items: center; gap: 1rem; transition: transform 0.3s var(--ease-out-quart), box-shadow 0.3s var(--ease-out-quart); }
.requirements-list li:hover { transform: translateY(-2px); box-shadow: var(--card-shadow); }
.requirements-list li i { color: var(--accent-primary); font-size: 1.1rem; width: 20px; text-align: center; }

.usage-steps { list-style: none; max-width: 720px; margin: 0 auto; text-align: left; display: flex; flex-direction: column; gap: 1.5rem; }
.usage-steps li { display: flex; align-items: flex-start; gap: 1.5rem; }
.step-number { background-color: var(--accent-primary); color: var(--bg-color); font-weight: 700; font-size: 1rem; width: 36px; height: 36px; border-radius: 50%; display: inline-flex; justify-content: center; align-items: center; flex-shrink: 0; }
.usage-steps li p { color: var(--text-secondary); }
.usage-steps li p strong { color: var(--text-primary); font-weight: 600; }

.main-footer { text-align: center; padding: 4rem 2rem 3rem; }
.main-footer p { color: var(--text-secondary); margin-bottom: 1.5rem; }
.main-footer p strong { color: var(--text-primary); font-weight: 600; }

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    background-color: var(--accent-primary);
    color: #FFF;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    padding: 0.8rem 1.8rem;
    border-radius: 10px;
    transition: transform 0.3s var(--ease-out-quart);
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 50%; left: 50%;
    width: 250%;
    padding-bottom: 250%;
    border-radius: 50%;
    background: radial-gradient(circle, var(--accent-secondary) 0%, transparent 60%);
    transform: translate(-50%, -50%) scale(0);
    transition: transform 0.5s var(--ease-out-quart), opacity 0.5s var(--ease-out-quart);
    opacity: 0;
    z-index: -1;
}
.cta-button:hover {
    transform: translateY(-3px);
}
.cta-button:hover::before {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
}
.cta-button i { font-size: 1.2rem; }
.footer-meta { margin-top: 3rem; font-size: 0.9rem; color: var(--text-secondary); }

@media (max-width: 768px) {
    .content-wrapper { padding: 7rem 1.5rem 4rem; gap: 4.5rem; }
    .header-content h1 { font-size: 1.1rem; }
    #aurora-cursor { display: none; }
}