/* ============================================
   Simple Memo - Dark Theme Landing Page
   Glassmorphism + Glow Effects
   ============================================ */

/* CSS Variables - Color Palette */
:root {
    --bg0: #000103;
    --bg1: #001A2B;
    --bg2: #002D4A;
    --text: #EAF2FF;
    --muted: #B7C7D9;
    --accent: #6AAAD0;
    --accent2: #3E85A2;
    --glow: rgba(106, 170, 208, 0.55);
    --glow-strong: rgba(106, 170, 208, 0.8);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, var(--bg0) 0%, var(--bg1) 30%, var(--bg2) 60%, var(--bg1) 100%);
    background-attachment: fixed;
    font-size: 16px;
    overflow-x: hidden;
}

/* Animated background with radial gradients */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(ellipse at 20% 50%, rgba(106, 170, 208, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(106, 170, 208, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

/* Ensure content is above background */
body > * {
    position: relative;
    z-index: 1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 0.5em;
}

h1 {
    font-size: 2rem;
}

h2 {
    font-size: 1.75rem;
}

h3 {
    font-size: 1.25rem;
}

p {
    margin-bottom: 1em;
    color: var(--muted);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

/* Container */
.container {
    width: 100%;
    max-width: 640px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
.header {
    background: rgba(18, 22, 28, 0.65);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(234, 242, 255, 0.1);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    margin: 0;
    filter: drop-shadow(0 0 8px var(--glow));
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
    color: var(--text);
    box-shadow: 0 0 20px var(--glow);
    filter: drop-shadow(0 0 8px var(--glow));
}

.btn-primary:hover {
    box-shadow: 0 0 30px var(--glow-strong);
    filter: drop-shadow(0 0 12px var(--glow-strong));
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(18, 22, 28, 0.65);
    color: var(--accent);
    border: 2px solid var(--accent);
    backdrop-filter: blur(10px);
    box-shadow: 0 0 15px rgba(106, 170, 208, 0.3);
}

.btn-secondary:hover {
    background: rgba(106, 170, 208, 0.15);
    box-shadow: 0 0 20px var(--glow);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
    width: 100%;
}

/* Hero Section */
.hero {
    padding: 3rem 0;
    text-align: center;
}

.hero-headline {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 1rem;
    line-height: 1.3;
    filter: drop-shadow(0 0 10px var(--glow));
}

.hero-subheadline {
    font-size: 1.125rem;
    color: var(--muted);
    margin-bottom: 2rem;
}

.hero-cta {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Features Section */
.features {
    padding: 3rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.5rem;
    color: var(--text);
    filter: drop-shadow(0 0 8px var(--glow));
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.feature-card {
    background: rgba(18, 22, 28, 0.65);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid rgba(234, 242, 255, 0.1);
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
}

.feature-card:hover {
    border-color: rgba(106, 170, 208, 0.3);
    box-shadow: 0 8px 32px rgba(106, 170, 208, 0.2);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1rem;
    color: var(--accent);
    filter: drop-shadow(0 0 8px var(--glow));
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

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

/* Data & Privacy Section */
.data-privacy {
    padding: 3rem 0;
}

.privacy-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.privacy-card {
    background: rgba(18, 22, 28, 0.65);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid rgba(234, 242, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
}

.privacy-card:hover {
    border-color: rgba(106, 170, 208, 0.3);
    box-shadow: 0 8px 32px rgba(106, 170, 208, 0.2);
}

.privacy-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1rem;
    color: var(--accent);
    filter: drop-shadow(0 0 8px var(--glow));
}

.privacy-icon svg {
    width: 100%;
    height: 100%;
}

.privacy-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    color: var(--text);
}

.privacy-card p {
    font-size: 0.95rem;
    color: var(--muted);
    margin: 0;
}

/* FAQ Section */
.faq {
    padding: 3rem 0;
}

.faq-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

.faq-item {
    background: rgba(18, 22, 28, 0.65);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(234, 242, 255, 0.1);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.faq-item summary {
    cursor: pointer;
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--text);
    user-select: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: color 0.2s ease;
}

.faq-item summary:hover {
    color: var(--accent);
}

.faq-item summary::after {
    content: "+";
    font-size: 1.5rem;
    color: var(--accent);
    transition: transform 0.2s ease;
    filter: drop-shadow(0 0 4px var(--glow));
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item p {
    margin-top: 1rem;
    color: var(--muted);
    font-size: 0.95rem;
}

/* Footer */
.footer {
    background: rgba(18, 22, 28, 0.8);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(234, 242, 255, 0.1);
    color: var(--text);
    padding: 2rem 0;
    margin-top: 3rem;
}

.footer-content {
    text-align: center;
}

.footer-nav {
    margin-bottom: 1rem;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
}

.footer-link {
    color: var(--text);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.footer-link:hover {
    color: var(--accent);
    filter: drop-shadow(0 0 6px var(--glow));
}

.footer-icon {
    width: 16px;
    height: 16px;
    color: var(--accent);
    filter: drop-shadow(0 0 4px var(--glow));
}

.divider {
    color: rgba(106, 170, 208, 0.5);
    margin: 0 0.5rem;
}

.footer-text {
    font-size: 0.85rem;
    color: rgba(234, 242, 255, 0.6);
    margin: 0;
}

/* ============================================
   Tablet & Desktop Breakpoints
   ============================================ */

@media (min-width: 768px) {
    .container {
        max-width: 768px;
        padding: 0 2rem;
    }

    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 2rem;
    }

    .hero-headline {
        font-size: 2rem;
    }

    .hero-subheadline {
        font-size: 1.25rem;
    }

    .hero-cta {
        flex-direction: row;
        justify-content: center;
        gap: 1rem;
    }

    .btn-lg {
        width: auto;
    }

    .features-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 2rem;
    }

    .privacy-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 1.5rem;
    }

    .faq-list {
        max-width: 600px;
        margin: 0 auto;
    }

    .footer-nav {
        gap: 1rem;
    }
}

@media (min-width: 1024px) {
    .container {
        max-width: 1024px;
    }

    .hero {
        padding: 4rem 0;
    }

    .features {
        padding: 4rem 0;
    }

    .data-privacy {
        padding: 4rem 0;
    }

    .faq {
        padding: 4rem 0;
    }
}

/* ============================================
   Accessibility & Print
   ============================================ */

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

@media print {
    .header,
    .footer {
        display: none;
    }

    body {
        background: #ffffff;
        color: #000;
    }

    a {
        text-decoration: underline;
    }
}