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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: #f9fafb;
    min-height: 100vh;
}

/* Header Styles */
.header {
    padding: 1rem 1.5rem;
}

.header-container {
    max-width: 80rem;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-3d {
    width: 1.5rem;
    height: 1.5rem;
    background: linear-gradient(145deg, #2a2a2a 0%, #1a1a1a 100%);
    border: 1px solid #404040;
    border-radius: 0.375rem;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: 0 3px 0 #333, 0 4px 8px rgba(0, 0, 0, 0.3);
    padding: 2px;
}

.logo-3d::before {
    content: "";
    position: absolute;
    top: 1px;
    left: 1px;
    right: 1px;
    height: 50%;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);
    border-radius: 4px 4px 0 0;
    pointer-events: none;
    z-index: 1;
}

.logo-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 2px;
    position: relative;
    z-index: 0;
}

.logo-text {
    font-size: 1.125rem;
    font-weight: 500;
    color: #111827;
}

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

.nav-link {
    color: #6b7280;
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s ease;
}

.nav-link:hover {
    color: #111827;
}

.nav-icon {
    width: 1rem;
    height: 1rem;
    margin-right: 0.25rem;
    flex-shrink: 0;
    vertical-align: middle;
    transform: translateY(-1px);
}

/* Hero Section */
.hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 5rem 1.5rem 3rem;
    text-align: center;
}

.app-icon-container {
    margin-bottom: 2rem;
}

.app-icon-3d {
    width: 6rem;
    height: 6rem;
    background: linear-gradient(145deg, #2a2a2a 0%, #1a1a1a 100%);
    border: 1px solid #404040;
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: 0 8px 0 #333, 0 12px 20px rgba(0, 0, 0, 0.3);
    padding: 8px;
}

.app-icon-3d::before {
    content: "";
    position: absolute;
    top: 1px;
    left: 1px;
    right: 1px;
    height: 50%;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);
    border-radius: 15px 15px 0 0;
    pointer-events: none;
    z-index: 1;
}

.app-icon-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 8px;
    position: relative;
    z-index: 0;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: #111827;
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.25rem;
    color: #6b7280;
    margin-bottom: 2rem;
    max-width: 28rem;
}

.download-container {
    position: relative;
    margin-bottom: 0.5rem;
}

.download-button {
    background: linear-gradient(145deg, #2a2a2a 0%, #1a1a1a 100%);
    border: 1px solid #404040;
    color: white;
    padding: 1rem 2rem;
    border-radius: 1rem;
    font-weight: 500;
    font-size: 1.125rem;
    cursor: pointer;
    position: relative;
    user-select: none;
    transition: all 0.15s ease-out;
    transform: translateZ(0);
    box-shadow: 0 8px 0 #333, 0 12px 20px rgba(0, 0, 0, 0.3);
}

.download-button::before {
    content: "";
    position: absolute;
    top: 1px;
    left: 1px;
    right: 1px;
    height: 50%;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);
    border-radius: 15px 15px 0 0;
    pointer-events: none;
}

.download-button:hover {
    box-shadow: 0 6px 0 #333, 0 10px 16px rgba(0, 0, 0, 0.3);
    transform: translateY(2px);
}

.download-button:active {
    box-shadow: 0 2px 0 #333, 0 4px 8px rgba(0, 0, 0, 0.3);
    transform: translateY(6px) scale(0.98);
}

.download-button:active::before {
    opacity: 0.5;
}

/* Download Form Styles */
.download-form-container {
    margin-top: 2rem;
    animation: fadeIn 0.3s ease-in-out;
}

.download-form {
    background: white;
    border: 1px solid #dee2e6;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    max-width: 24rem;
    margin: 0 auto;
}

.form-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: #111827;
    margin-bottom: 0.5rem;
    text-align: center;
}

.form-description {
    font-size: 0.875rem;
    color: #6b7280;
    text-align: center;
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.form-input-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.form-input:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-submit-btn {
    width: 100%;
    background: linear-gradient(145deg, #2a2a2a 0%, #1a1a1a 100%);
    border: 1px solid #404040;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.15s ease-out;
    box-shadow: 0 4px 0 #333, 0 6px 12px rgba(0, 0, 0, 0.2);
}

.form-submit-btn:hover {
    box-shadow: 0 2px 0 #333, 0 4px 8px rgba(0, 0, 0, 0.2);
    transform: translateY(2px);
}

.form-submit-btn:active {
    box-shadow: 0 1px 0 #333, 0 2px 4px rgba(0, 0, 0, 0.2);
    transform: translateY(3px);
}

.form-message {
    text-align: center;
    font-size: 0.875rem;
    min-height: 1.25rem;
    margin-top: 0.5rem;
}

.form-message.error {
    color: #dc2626;
}

.form-message.success {
    color: #059669;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.system-requirement {
    font-size: 0.875rem;
    color: #6b7280;
}

/* Demo Video Section */
.demo-section {
    display: flex;
    justify-content: center;
    padding: 0 1.5rem 5rem;
}

.demo-container {
    max-width: 60rem;
    width: 100%;
}

.video-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 10;
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    background-color: #000;
}

.demo-video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border: none;
    outline: none;
}

.demo-video:focus {
    outline: 2px solid #3b82f6;
    outline-offset: 2px;
}

/* Charity Section */
.charity-section {
    background: linear-gradient(145deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 4rem 1.5rem;
    margin-top: 2rem;
}

.charity-container {
    max-width: 60rem;
    margin: 0 auto;
    text-align: center;
}

.charity-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #111827;
    margin-bottom: 1.5rem;
}

.charity-description {
    font-size: 1.125rem;
    color: #6b7280;
    line-height: 1.6;
    margin-bottom: 2.5rem;
    max-width: 48rem;
    margin-left: auto;
    margin-right: auto;
}

.charity-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.charity-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background: white;
    border: 1px solid #dee2e6;
    border-radius: 0.75rem;
    text-decoration: none;
    color: #111827;
    font-weight: 500;
    font-size: 1rem;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.charity-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-color: #adb5bd;
}

.link-icon {
    font-size: 1.25rem;
    width: 1.25rem;
    height: 1.25rem;
    flex-shrink: 0;
    vertical-align: middle;
    transform: translateY(-1px);
}

/* Footer Styles */
.footer {
    background: white;
    padding: 2rem 1.5rem;
    margin-top: 2rem;
}

.footer-container {
    max-width: 80rem;
    margin: 0 auto;
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.copyright {
    font-size: 0.875rem;
    color: #6b7280;
    font-weight: 400;
    letter-spacing: 0.025em;
    margin: 0;
    transition: color 0.2s ease;
}

.copyright:hover {
    color: #374151;
}

.footer-twitter-link {
    color: #6b7280;
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 400;
    transition: color 0.2s ease;
}

.footer-twitter-link:hover {
    color: #111827;
}

.footer-icon {
    width: 0.875rem;
    height: 0.875rem;
    margin-right: 0.25rem;
    flex-shrink: 0;
    vertical-align: middle;
    transform: translateY(-1px);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
    }

    .navigation {
        gap: 1rem;
    }

    .hero {
        padding: 3rem 1.5rem 2rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-description {
        font-size: 1.125rem;
    }

    .demo-container {
        max-width: 100%;
    }

    .video-wrapper {
        aspect-ratio: 16 / 9;
    }

    .charity-title {
        font-size: 2rem;
    }

    .charity-description {
        font-size: 1rem;
    }

    .charity-links {
        flex-direction: column;
        align-items: center;
    }

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

    .form-submit-btn {
        width: 100%;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .download-button {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }

    .video-wrapper {
        aspect-ratio: 4 / 3;
    }
}

.installation-guide {
    padding: 4rem 2rem;
    background-color: #f9fafb;
    margin: 0 auto;
    max-width: 1200px;
}

.guide-container {
    display: flex;
    gap: 3rem;
    align-items: center;
}

.guide-video {
    flex: 1;
}

.guide-video video {
    width: 100%;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.guide-text {
    flex: 1;
}

.guide-text h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: #111827;
}

.guide-steps {
    list-style-type: none;
    padding: 0;
    margin-bottom: 2rem;
}

.guide-steps li {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e5e7eb;
    font-size: 1.1rem;
    color: #4b5563;
}

.guide-steps li:last-child {
    border-bottom: none;
}

.guide-steps strong {
    color: #111827;
}

.guide-note {
    font-size: 0.9rem;
    color: #6b7280;
    font-style: italic;
}

@media (max-width: 768px) {
    .guide-container {
        flex-direction: column;
    }

    .guide-video, .guide-text {
        width: 100%;
    }
}