/* --- Global Resets & Variables --- */
:root {
    --bg-light: #fcfcfc;
    --text-light: #1c1c1e;
    --text-secondary-light: #6b6b70;
    --border-light: #e5e5e6;
    --primary-light: #007aff;
    --primary-hover-light: #005ecb;

    --bg-dark: #000000;
    --text-dark: #f0f0f5;
    --text-secondary-dark: #a0a0b0;
    --border-dark: #2a2a2e;
    --primary-dark: #0a84ff;
    --primary-hover-dark: #379aff;

    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --transition-speed: 0.3s;
    --content-width: 1100px;
    --border-radius: 12px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
    padding-bottom: 120px; /* Space for footer */
    position: relative;
}

body.light-mode {
    --bg-color: var(--bg-light);
    --text-color: var(--text-light);
    --text-secondary-color: var(--text-secondary-light);
    --border-color: var(--border-light);
    --primary-color: var(--primary-light);
    --primary-hover-color: var(--primary-hover-light);
}

body.dark-mode {
    --bg-color: var(--bg-dark);
    --text-color: var(--text-dark);
    --text-secondary-color: var(--text-secondary-dark);
    --border-color: var(--border-dark);
    --primary-color: var(--primary-dark);
    --primary-hover-color: var(--primary-hover-dark);
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
}

/* --- NEW: Aurora Gradient Background --- */
.aurora-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: radial-gradient(ellipse at 20% 25%, hsla(215, 80%, 30%, 0.3) 0%, transparent 50%),
                radial-gradient(ellipse at 80% 30%, hsla(260, 70%, 40%, 0.3) 0%, transparent 50%),
                radial-gradient(ellipse at 50% 90%, hsla(320, 70%, 40%, 0.3) 0%, transparent 50%);
    z-index: -1;
    animation: aurora-anim 20s linear infinite;
    opacity: 0;
    transition: opacity 1s ease;
}
.dark-mode .aurora-bg {
    opacity: 1;
}

@keyframes aurora-anim {
    0% { background-position: 0% 50%, 0% 50%, 0% 50%; }
    25% { background-position: 20% 0%, 50% 50%, 0% 50%; }
    50% { background-position: 100% 50%, 100% 50%, 100% 50%; }
    75% { background-position: 50% 100%, 0% 20%, 50% 0%; }
    100% { background-position: 0% 50%, 0% 50%, 0% 50%; }
}

/* --- Main content wrapper to sit above background */
main, .main-footer-bottom {
    position: relative;
    z-index: 2;
}


/* --- Utility & Reusable Components --- */
.content-section {
    width: 100%;
    max-width: var(--content-width);
    margin: 0 auto;
    padding: 120px 24px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    border-radius: var(--border-radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--bg-light);
    border-color: var(--primary-color);
}
.dark-mode .btn-primary {
    color: var(--bg-dark);
}
.btn-primary:hover {
    background-color: var(--primary-hover-color);
    border-color: var(--primary-hover-color);
}

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

.btn-icon {
    background: none;
    border: none;
    color: var(--text-secondary-color);
    padding: 8px;
    border-radius: 50%;
    line-height: 0;
}
.btn-icon:hover {
    color: var(--text-color);
    background-color: rgba(128, 128, 128, 0.1);
}

.btn-google-signin {
    gap: 12px;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    border: 1px solid var(--border-dark);
}
.light-mode .btn-google-signin {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.btn-google-signin:hover {
    background-color: rgba(255, 255, 255, 0.15);
    border-color: var(--text-secondary-dark);
}
.light-mode .btn-google-signin:hover {
    background-color: rgba(0, 0, 0, 0.03);
    border-color: var(--text-secondary-color);
}

.google-icon {
    width: 18px;
    height: 18px;
}

/* --- Header --- */
.main-header {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: calc(var(--content-width) + 48px);
    z-index: 1000;
    padding: 0 24px;
    transition: top 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    background-color: transparent;
    border: 1px solid transparent;
    border-radius: var(--border-radius);
    transition: background-color 0.4s ease, border-color 0.4s ease, backdrop-filter 0.4s ease;
}

.main-header.scrolled .header-container {
    background-color: rgba(28, 28, 30, 0.5);
    border-color: var(--border-dark);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.light-mode .main-header.scrolled .header-container {
    background-color: rgba(255, 255, 255, 0.7);
    border-color: var(--border-light);
}


.header-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 600;
    color: var(--text-color);
    text-decoration: none;
}

.header-logo img {
    height: 28px;
    width: 28px;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

#theme-toggle .icon-dark { display: none; }
#theme-toggle .icon-light { display: block; }
.light-mode #theme-toggle .icon-dark { display: block; }
.light-mode #theme-toggle .icon-light { display: none; }


/* --- Hero Section --- */
.hero-section {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 100vh;
    min-height: 100svh;
    padding: 24px;
}

.hero-content h1 {
    font-size: clamp(3rem, 10vw, 6.5rem);
    font-weight: 600;
    letter-spacing: -0.04em;
    line-height: 1.1;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: clamp(1.125rem, 3vw, 1.5rem);
    color: var(--text-secondary-color);
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.5;
}

.hero-subtitle::after {
    content: '|';
    animation: blink 1s step-start infinite;
}

@keyframes blink { 50% { opacity: 0; } }

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    color: var(--text-secondary-color);
}
.mouse-icon {
    width: 24px;
    height: 40px;
    border: 2px solid var(--text-secondary-color);
    border-radius: 12px;
    position: relative;
}
.scroller {
    width: 2px;
    height: 6px;
    background-color: var(--text-secondary-color);
    border-radius: 2px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll-anim 2s infinite;
}
@keyframes scroll-anim {
    0% { top: 6px; opacity: 1; }
    100% { top: 20px; opacity: 0; }
}

/* --- Intro Section --- */
.intro-text {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    line-height: 1.4;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    color: var(--text-secondary-color);
}

/* --- Feature Sections --- */
.feature-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 80px;
    align-items: center;
}

@media (min-width: 768px) {
    .feature-section {
        grid-template-columns: repeat(2, 1fr);
        gap: 60px;
    }
}

.feature-content h2 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -0.03em;
}

.feature-content p {
    font-size: 1.125rem;
    line-height: 1.6;
    color: var(--text-secondary-color);
    margin-bottom: 32px;
}

.feature-list {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1rem;
    font-weight: 500;
}

.feature-list .material-symbols-outlined {
    color: var(--primary-color);
}

.video-container {
    width: 100%;
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}
.dark-mode .video-container {
     box-shadow: 0 20px 50px rgba(0,0,0,0.3);
}

.video-container video {
    display: block;
    width: 100%;
    height: auto;
}

/* --- NEW Full-width feature layout --- */
.feature-section-fullwidth {
    padding-top: 60px;
    padding-bottom: 60px;
    position: relative;
    text-align: center;
}
.feature-media-fullwidth {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    border-radius: 20px;
    overflow: hidden;
}
.feature-media-fullwidth video {
    width: 100%;
    display: block;
}
.feature-content-overlay {
    max-width: 700px;
    margin: 0 auto;
    margin-top: -120px; /* Pull text up over the video */
    position: relative;
    z-index: 3;
    padding: 32px;
    background: rgba(18, 18, 20, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: var(--border-radius);
}
.light-mode .feature-content-overlay {
    background: rgba(255, 255, 255, 0.6);
    border-color: rgba(0, 0, 0, 0.1);
}

/* --- Features Grid Section --- */
.features-grid-section {
    border-top: 1px solid var(--border-color);
}

.features-grid-section .section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px auto;
}

.features-grid-section .section-header h2 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.features-grid-section .section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary-color);
    line-height: 1.6;
}

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

@media (min-width: 640px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 960px) {
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.feature-item {
    background-color: transparent;
    padding: 24px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease, background-color 0.3s ease;
    z-index: 1;
}

.feature-item::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: radial-gradient(circle at 50% 0, var(--glow-color, var(--primary-color)), transparent 70%);
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: -1;
}

.feature-item:hover {
    transform: translateY(-5px);
    background-color: var(--border-dark);
}
.light-mode .feature-item:hover {
    background-color: rgba(0,0,0,0.02);
}
.feature-item:hover::before {
    opacity: 0.15;
}

.feature-item-icon {
    display: inline-flex;
    padding: 12px;
    border-radius: 50%;
    margin-bottom: 16px;
    background-color: var(--border-dark);
}
.light-mode .feature-item-icon {
    background-color: rgba(0,0,0,0.05);
}

.feature-item .material-symbols-outlined {
    font-size: 1.75rem;
    color: var(--icon-color);
    display: block;
}

.feature-item h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-color);
}

.feature-item p {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary-color);
}

/* Feature Item Icon & Glow Colors */
.feature-item:nth-child(1) { --icon-color: #3498db; --glow-color: #3498db; }
.feature-item:nth-child(2) { --icon-color: #9b59b6; --glow-color: #9b59b6; }
.feature-item:nth-child(3) { --icon-color: #2ecc71; --glow-color: #2ecc71; }
.feature-item:nth-child(4) { --icon-color: #e67e22; --glow-color: #e67e22; }
.feature-item:nth-child(5) { --icon-color: #f1c40f; --glow-color: #f1c40f; }
.feature-item:nth-child(6) { --icon-color: #e74c3c; --glow-color: #e74c3c; }
.feature-item:nth-child(7) { --icon-color: #1abc9c; --glow-color: #1abc9c; }
.feature-item:nth-child(8) { --icon-color: #ff7675; --glow-color: #ff7675; }
.feature-item:nth-child(9) { --icon-color: #74b9ff; --glow-color: #74b9ff; }
.feature-item:nth-child(10){ --icon-color: #a29bfe; --glow-color: #a29bfe; }
.feature-item:nth-child(11){ --icon-color: #55efc4; --glow-color: #55efc4; }
.feature-item:nth-child(12){ --icon-color: #fdcb6e; --glow-color: #fdcb6e; }

/* --- CTA Section --- */
.cta-section {
    text-align: center;
    border-top: 1px solid var(--border-color);
    padding-top: 120px;
}

.cta-content h2 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: -0.03em;
}

.cta-content p {
    font-size: 1.25rem;
    color: var(--text-secondary-color);
    max-width: 600px;
    margin: 0 auto 40px auto;
}

/* --- Footer --- */
.main-footer-bottom {
    border-top: 1px solid var(--border-color);
    padding: 40px 24px;
}

.footer-container {
    max-width: var(--content-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary-color);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--text-secondary-color);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}

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

/* --- Sticky Floating Action Button --- */
.sticky-download-fab {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;

    display: flex;
    align-items: center;
    justify-content: center;
    
    height: 56px;
    width: 56px;
    padding: 0 16px;
    
    background-color: var(--primary-color);
    color: white;
    border-radius: 28px; /* half of height for pill shape */
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
    
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;

    transform: scale(0);
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), 
                width 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
                background-color 0.3s ease;
}
.dark-mode .sticky-download-fab {
    color: var(--bg-dark);
}

.sticky-download-fab.visible {
    transform: scale(1);
}

.sticky-download-fab:hover {
    width: 190px;
    background-color: var(--primary-hover-color);
}

.fab-icon {
    font-size: 24px;
}

.fab-text {
    font-size: 1rem;
    font-weight: 500;
    margin-left: 12px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.sticky-download-fab:hover .fab-text {
    opacity: 1;
    transition-delay: 0.2s; /* Text appears after button expands */
}

/* --- Animations --- */
.fade-in {
    animation: fadeIn 1s ease-out forwards;
}

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

.reveal-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.reveal-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Staggered animation for grid items */
.features-grid.is-visible .feature-item {
    transition-delay: calc(0.08s * var(--i));
}