/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #7C3AED;
    --primary-light: #8B5CF6;
    --primary-dark: #6D28D9;
    --green: #22C55E;
    --blue: #3B82F6;
    --amber: #F59E0B;
}

[data-theme="dark"] {
    --bg: #0B0B0F;
    --bg-surface: #16161D;
    --bg-surface-hover: #1E1E28;
    --bg-surface-alt: #1A1A24;
    --text: #E8E8ED;
    --text-secondary: #9CA3AF;
    --text-muted: #6B7280;
    --border: #2A2A35;
    --code-bg: #1E1E28;
}

[data-theme="light"] {
    --bg: #FAFAFA;
    --bg-surface: #FFFFFF;
    --bg-surface-hover: #F3F4F6;
    --bg-surface-alt: #F9FAFB;
    --text: #1A1A2E;
    --text-secondary: #4B5563;
    --text-muted: #9CA3AF;
    --border: #E5E7EB;
    --code-bg: #F3F4F6;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

a {
    color: var(--primary-light);
    text-decoration: none;
    transition: color 0.2s;
}
a:hover {
    color: var(--primary);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(11, 11, 15, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: background 0.3s;
}

[data-theme="light"] .header {
    background: rgba(250, 250, 250, 0.85);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
}
.logo:hover { color: var(--text); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}
.nav-links a:hover {
    color: var(--text);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    transition: color 0.2s, border-color 0.2s;
}
.theme-toggle:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    padding: 4px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 12px 28px;
    border-radius: 10px;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--primary);
    color: white;
}
.btn-primary:hover {
    background: var(--primary-light);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 24px rgba(124, 58, 237, 0.4);
}

.btn-secondary {
    background: var(--bg-surface);
    color: var(--text);
    border: 1px solid var(--border);
}
.btn-secondary:hover {
    background: var(--bg-surface-hover);
    color: var(--text);
    transform: translateY(-1px);
}

/* Hero */
.hero {
    padding: 140px 0 80px;
    overflow: hidden;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary), #A78BFA, #60A5FA);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 32px;
    max-width: 520px;
}

.hero-cta {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
}

.hero-note {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* App Mockup */
.app-mockup {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 24px 80px rgba(0,0,0,0.3);
}

.mockup-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--bg-surface-alt);
    border-bottom: 1px solid var(--border);
}

.mockup-dots {
    display: flex;
    gap: 6px;
}
.mockup-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border);
}
.mockup-dots span:first-child { background: #EF4444; }
.mockup-dots span:nth-child(2) { background: #F59E0B; }
.mockup-dots span:last-child { background: #22C55E; }

.mockup-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

.mockup-body {
    display: grid;
    grid-template-columns: 200px 1fr;
    min-height: 340px;
}

.mockup-sidebar {
    border-right: 1px solid var(--border);
    padding: 8px;
}

.mockup-contact {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 8px;
    border-radius: 8px;
    cursor: default;
    position: relative;
}
.mockup-contact.active {
    background: var(--bg-surface-hover);
}

.mockup-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    flex-shrink: 0;
}

.mockup-contact-info {
    overflow: hidden;
    min-width: 0;
}

.mockup-name {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.mockup-preview {
    display: block;
    font-size: 0.7rem;
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.mockup-badge {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary);
    color: white;
    font-size: 0.65rem;
    font-weight: 700;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mockup-chat {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    justify-content: flex-end;
}

.mockup-msg {
    max-width: 75%;
    padding: 8px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    line-height: 1.4;
}
.mockup-msg.sent {
    align-self: flex-end;
    background: var(--primary);
    color: white;
    border-bottom-right-radius: 4px;
}
.mockup-msg.received {
    align-self: flex-start;
    background: var(--bg-surface-hover);
    color: var(--text);
    border-bottom-left-radius: 4px;
}
.mockup-time {
    display: block;
    font-size: 0.6rem;
    opacity: 0.6;
    margin-top: 2px;
    text-align: right;
}

.mockup-encrypt {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    font-size: 0.65rem;
    color: var(--text-muted);
    padding: 8px 0 0;
    border-top: 1px solid var(--border);
    margin-top: 8px;
}

/* Sections */
section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    text-align: center;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 60px;
}

/* Pillars */
.pillars {
    background: var(--bg-surface-alt);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.pillars-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.pillar {
    text-align: center;
}

.pillar-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    border-radius: 16px;
    background: rgba(124, 58, 237, 0.1);
    margin-bottom: 20px;
}

.pillar h3 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.pillar p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px 24px;
    transition: border-color 0.2s, transform 0.2s;
}

.feature-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: rgba(124, 58, 237, 0.1);
    color: var(--primary-light);
    margin-bottom: 16px;
}

.feature-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* How It Works */
.how-it-works {
    background: var(--bg-surface-alt);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.step {
    text-align: center;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.step h4 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.step p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.step-code {
    display: inline-block;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 16px;
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 0.82rem;
    color: var(--primary-light);
    word-break: break-all;
}

/* Security */
.security-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.security-item {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px;
}

.security-item h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--primary-light);
}

.security-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Download */
.download-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.download-section h3 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 20px;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text);
    transition: border-color 0.2s, transform 0.2s;
}
.download-btn:hover {
    border-color: var(--primary);
    color: var(--text);
    transform: translateX(4px);
}
.download-platform {
    display: block;
    font-weight: 600;
    font-size: 0.95rem;
}
.download-arch {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.download-note {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 16px;
}

.selfhost-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 20px;
}

.selfhost-specs {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.spec {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.9rem;
}
.spec-label {
    color: var(--text-muted);
}
.spec-value {
    font-weight: 600;
}

/* Support */
.support {
    background: var(--bg-surface-alt);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.support-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
    max-width: 700px;
    margin: 0 auto;
}

.support-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 40px;
}

.support-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: 14px;
    background: rgba(124, 58, 237, 0.1);
    color: var(--primary-light);
    margin-bottom: 20px;
}

.support-card h3 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.support-card > p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 24px;
}

.donate-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.donate-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.2s;
}

.donate-kofi {
    background: #FF5E5B;
    color: white;
}
.donate-kofi:hover {
    background: #e84e4b;
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(255, 94, 91, 0.35);
}

.donate-liberapay {
    background: #F6C915;
    color: #1A1A2E;
}
.donate-liberapay:hover {
    background: #e0b614;
    color: #1A1A2E;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(246, 201, 21, 0.35);
}


/* Footer */
.footer {
    border-top: 1px solid var(--border);
    padding: 60px 0 32px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 8px;
}

.footer-links {
    display: flex;
    gap: 80px;
}

.footer-col h4 {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.footer-col a {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 10px;
}
.footer-col a:hover {
    color: var(--text);
}

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

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 4px;
}

/* Invite Form */
.invite-form {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 8px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-input {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 16px;
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    color: var(--text);
    transition: border-color 0.2s;
    outline: none;
    resize: vertical;
}
.form-input:focus {
    border-color: var(--primary);
}
.form-input::placeholder {
    color: var(--text-muted);
}

.form-status {
    font-size: 0.85rem;
    text-align: center;
    margin-top: 4px;
    min-height: 1.2em;
}
.form-status.success {
    color: var(--green);
}
.form-status.error {
    color: #EF4444;
}

.nav-cta {
    background: var(--primary);
    color: white !important;
    padding: 6px 16px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.85rem;
}
.nav-cta:hover {
    background: var(--primary-light);
    color: white !important;
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
    .hero h1 { font-size: 2.75rem; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .security-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--bg-surface);
        border-bottom: 1px solid var(--border);
        padding: 24px;
        gap: 20px;
    }
    .mobile-toggle { display: block; }

    .hero { padding: 100px 0 60px; }
    .hero-content { grid-template-columns: 1fr; gap: 40px; }
    .hero h1 { font-size: 2.25rem; }
    .hero-visual { order: -1; }
    .mockup-body { grid-template-columns: 1fr; }
    .mockup-sidebar { display: none; }

    .pillars-grid { grid-template-columns: 1fr; gap: 32px; }
    .features-grid { grid-template-columns: 1fr; }
    .steps { grid-template-columns: 1fr; gap: 32px; }
    .security-grid { grid-template-columns: 1fr; }
    .download-grid { grid-template-columns: 1fr; gap: 40px; }
    .support-grid { grid-template-columns: 1fr; gap: 24px; }

    section { padding: 60px 0; }
    .section-title { font-size: 1.75rem; }
    .section-subtitle { margin-bottom: 40px; }

    .footer-content { flex-direction: column; gap: 32px; }
    .footer-links { gap: 40px; }
}