:root {
    --bg-color: #F5F5F7;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --accent: #0071E3;
    --accent-hover: #0077ED;
    --card-bg: #FFFFFF;
    --glass-bg: rgba(255, 255, 255, 0.72);
    --border-color: rgba(0, 0, 0, 0.08);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Header & Glassmorphism */
.glass-header {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--glass-bg);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.header-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.5px;
}

nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

.nav-link-btn {
    background: var(--text-primary);
    color: white !important;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
}

.nav-link-btn:hover {
    opacity: 0.9;
}

/* Typography & Layout */
section {
    padding: 6rem 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

/* Hero */
.hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding-top: 10rem;
    padding-bottom: 4rem;
}

.hero h1 {
    font-size: 4.5rem;
    font-weight: 700;
    letter-spacing: -2px;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #1D1D1F 0%, #434345 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto 2.5rem;
}

/* Buttons */
.cta-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: scale(1.02);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--border-color);
}

/* Mockup UI */
.hero-mockup {
    margin-top: 4rem;
    width: 100%;
    max-width: 600px;
}

.mockup-window {
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    border: 1px solid var(--border-color);
    overflow: hidden;
    text-align: left;
}

.mockup-header {
    background: #f6f6f6;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    gap: 8px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}
.red { background: #FF5F56; }
.yellow { background: #FFBD2E; }
.green { background: #27C93F; }

.mockup-body {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.mockup-item {
    padding: 0.8rem 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.mockup-item.active {
    background: var(--accent);
    color: white;
}

/* Features */
.features {
    text-align: center;
}

.section-title {
    margin-bottom: 4rem;
}

.section-title h2 {
    font-size: 2.5rem;
    letter-spacing: -1px;
    margin-bottom: 0.5rem;
}

.section-title p {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

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

.feature-card {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.03);
    border: 1px solid var(--border-color);
    text-align: left;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

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

.feature-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

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

/* Privacy */
.privacy {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 4rem;
    margin: 4rem auto;
    border: 1px solid var(--border-color);
}

.privacy-container h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    letter-spacing: -0.5px;
}

.privacy-container p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Animations */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}