:root {
    --primary: #007aff;
    --primary-glow: rgba(0, 122, 255, 0.3);
    --bg: #ffffff;
    --text: #1d1d1f;
    --text-secondary: #86868b;
    --card-bg: #f5f5f7;
    --nav-bg: rgba(255, 255, 255, 0.8);
    --border: #d2d2d7;
    --accent-red: #ff3b30;
    --accent-blue: #007aff;
    --accent-purple: #af52de;
    --accent-orange: #ff9500;
    --accent-green: #34c759;
}

body.dark-mode {
    --bg: #000000;
    --text: #f5f5f7;
    --text-secondary: #86868b;
    --card-bg: #1c1c1e;
    --nav-bg: rgba(0, 0, 0, 0.8);
    --border: #38383a;
}

body.light-mode {
    --bg: #ffffff;
    --text: #1d1d1f;
    --text-secondary: #86868b;
    --card-bg: #f5f5f7;
    --nav-bg: rgba(255, 255, 255, 0.8);
    --border: #d2d2d7;
}

@media (prefers-color-scheme: dark) {
    body:not(.light-mode) {
        --bg: #000000;
        --text: #f5f5f7;
        --text-secondary: #86868b;
        --card-bg: #1c1c1e;
        --nav-bg: rgba(0, 0, 0, 0.8);
        --border: #38383a;
    }
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.47059;
    font-weight: 400;
    letter-spacing: -0.022em;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1040px;
    margin: 0 auto;
    padding: 0 22px;
}

/* Navigation */
nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 52px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--text);
    font-weight: 700;
    font-size: 1.1rem;
    letter-spacing: -0.01em;
}

.logo img {
    height: 24px;
    width: 24px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 24px;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text);
    font-size: 12px;
    font-weight: 400;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.nav-links a:hover {
    opacity: 1;
}

/* Theme Toggle Button */
.theme-toggle-btn {
    width: 36px;
    height: 36px;
    background-color: transparent;
    border: 1px solid var(--border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    color: var(--text);
    padding: 0;
}

.theme-toggle-btn:hover {
    border-color: var(--text);
    background-color: var(--card-bg);
    transform: scale(1.05);
}

.theme-toggle-btn svg {
    display: block;
    width: 20px;
    height: 20px;
}

/* Hero */
.hero {
    padding: 140px 0 100px;
    text-align: center;
    animation: fadeIn 1s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero h1 {
    font-size: 56px;
    font-weight: 700;
    letter-spacing: -0.015em;
    line-height: 1.07143;
    margin-bottom: 18px;
}

.hero .subtitle {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: 600;
    color: var(--text-secondary);
    max-width: 800px;
    margin: 0 auto 30px;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 16px;
}

.btn {
    display: inline-block;
    padding: 12px 22px;
    border-radius: 980px;
    font-size: 17px;
    font-weight: 400;
    text-decoration: none;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background-color: #0071e3;
}

.btn-outline {
    border: 1px solid var(--primary);
    color: var(--primary);
}

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

/* Privacy Features Grid */
.privacy-features {
    padding: 120px 0;
}

.grid-2x2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.privacy-card {
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.icon-circle {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background-color: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.privacy-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
}

.privacy-card p {
    font-size: 17px;
    color: var(--text-secondary);
    line-height: 1.47059;
}

/* Control Section */
.control-section {
    padding: 120px 0;
}

.grid-2-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.control-text h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: -0.01em;
}

.control-text p {
    font-size: 19px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.checklist {
    list-style: none;
}

.checklist li {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 16px;
}

.permissions-box {
    background-color: var(--card-bg);
    border-radius: 32px;
    padding: 40px;
    border: 1px solid var(--border);
}

.permissions-box h3 {
    text-align: center;
    font-size: 21px;
    margin-bottom: 32px;
}

.privacy-hero-icon {
    display: flex;
    justify-content: center;
    margin-bottom: 24px;
}

.permissions-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.perm-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.perm-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.perm-item span {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

.bg-red { background-color: var(--accent-red); }
.bg-blue { background-color: var(--accent-blue); }
.bg-purple { background-color: var(--accent-purple); }
.bg-orange { background-color: var(--accent-orange); }
.bg-green { background-color: var(--accent-green); }

/* Gallery Section */
.gallery-section {
    padding: 120px 0;
    background-color: var(--bg);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
}

.section-header p {
    font-size: 21px;
    color: var(--text-secondary);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.gallery-item {
    background-color: var(--card-bg);
    border-radius: 32px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    border-bottom: 1px solid var(--border);
}

.gallery-caption {
    padding: 32px;
}

.gallery-caption h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
}

.gallery-caption p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.gallery-item:nth-child(5) {
    grid-column: span 2;
}

/* Help Section */
.help-section {
    padding: 120px 0;
    background-color: var(--bg);
}

.help-header {
    text-align: center;
    margin-bottom: 60px;
}

.help-header h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
}

.help-header p {
    font-size: 21px;
    color: var(--text-secondary);
}

.grid-4-col {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.help-card {
    background-color: var(--card-bg);
    padding: 32px;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
}

.help-icon {
    color: var(--primary);
    margin-bottom: 20px;
}

.help-card h3 {
    font-size: 19px;
    font-weight: 700;
    margin-bottom: 12px;
}

.help-card p {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 24px;
    flex-grow: 1;
}

.action-link {
    text-decoration: none;
    color: var(--primary);
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 4px;
}

.action-link:hover .chevron {
    transform: translateX(4px);
}

.chevron {
    transition: transform 0.2s;
}

/* Footer */
.main-footer {
    padding: 80px 0 40px;
    border-top: 1px solid var(--border);
    background-color: var(--bg);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 60px;
}

.footer-col h4 {
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.footer-col li {
    margin-bottom: 8px;
}

.footer-col a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 12px;
    transition: color 0.2s;
}

.footer-col a:hover {
    color: var(--text);
    text-decoration: underline;
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 12px;
    color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 900px) {
    .grid-2x2, .grid-2-col, .grid-4-col, .footer-grid, .gallery-grid {
        grid-template-columns: 1fr 1fr;
    }
    .gallery-item:nth-child(5) {
        grid-column: span 1;
    }
    .hero h1 { font-size: 40px; }
    .hero .subtitle { font-size: 20px; }
}

@media (max-width: 600px) {
    .grid-2x2, .grid-2-col, .grid-4-col, .footer-grid, .gallery-grid {
        grid-template-columns: 1fr;
    }
    .control-section .grid-2-col {
        gap: 40px;
    }
    .permissions-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero h1 { font-size: 32px; }
}