:root {
    color-scheme: light dark;
    --bg: #ffffff;
    --bg-alt: #f6f8fb;
    --text: #1a1f2b;
    --muted: #5c6473;
    --accent: #1f7a8c;
    --accent-dark: #135565;
    --border: #d9dfea;
    --shadow: rgba(26, 31, 43, 0.08);
    font-family: "SF Pro Display", "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover,
a:focus {
    text-decoration: underline;
}

.container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.site-header {
    background-color: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 10;
    backdrop-filter: blur(12px);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
    padding: 1.25rem 1.5rem;
}

.branding {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.branding h1 {
    margin: 0;
    font-size: 1.5rem;
}

.tagline {
    margin: 0.1rem 0 0;
    color: var(--muted);
    font-size: 0.95rem;
}

.app-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    border-radius: 0.9rem;
    background: linear-gradient(135deg, #1f7a8c, #42b4c3);
    color: #fff;
    font-size: 1.75rem;
    box-shadow: 0 12px 24px rgba(31, 122, 140, 0.25);
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.4rem;
    margin: 0;
    padding: 0;
    font-weight: 600;
}

.hero {
    padding: 6rem 0 4rem;
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.hero-text {
    flex: 1 1 320px;
}

.hero-text h2 {
    font-size: 2.4rem;
    margin-bottom: 1rem;
}

.hero-text p {
    max-width: 520px;
    font-size: 1.1rem;
    color: var(--muted);
}

.cta-group {
    margin-top: 2rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

.button {
    display: inline-block;
    padding: 0.9rem 1.8rem;
    border-radius: 999px;
    font-weight: 600;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    border: none;
    cursor: pointer;
}

.button.primary {
    background-color: var(--accent);
    color: #fff;
    box-shadow: 0 12px 24px rgba(31, 122, 140, 0.2);
}

.button.primary:hover {
    background-color: var(--accent-dark);
    transform: translateY(-2px);
}

.button.secondary {
    background-color: rgba(31, 122, 140, 0.12);
    color: var(--accent);
}

.cta-note {
    color: var(--muted);
    font-size: 0.9rem;
}

.hero-device {
    flex: 0 1 280px;
    display: flex;
    justify-content: center;
}

.watch-frame {
    width: 240px;
    height: 300px;
    border-radius: 60px;
    background: linear-gradient(145deg, #20242f, #181b24);
    padding: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 20px 50px rgba(26, 31, 43, 0.4);
    position: relative;
}

.watch-frame::after {
    content: "";
    position: absolute;
    inset: 12px;
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 52px;
    pointer-events: none;
}

.watch-photo {
    width: 100%;
    height: auto;
    border-radius: 36px;
    box-shadow: 0 14px 30px rgba(0, 0, 0, 0.25);
}

.section {
    padding: 4rem 0;
}

.section.alt {
    background-color: var(--bg-alt);
}

.section h2 {
    margin-bottom: 2rem;
    font-size: 2rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.8rem;
}

.feature-grid article {
    padding: 1.5rem;
    background: #fff;
    border-radius: 1.2rem;
    box-shadow: 0 18px 40px var(--shadow);
    border: 1px solid rgba(31, 122, 140, 0.08);
}

.feature-grid h3 {
    margin-top: 0;
}

.feature-grid p {
    color: var(--muted);
}

.screen-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}

.screen-image {
    width: 100%;
    display: block;
    border-radius: 1.5rem;
    box-shadow: 0 18px 40px var(--shadow);
    border: 1px solid rgba(31, 122, 140, 0.1);
    background-color: #fff;
}

.screen-image.phone {
    border-radius: 1.2rem;
}

figcaption {
    color: var(--muted);
    margin-top: 0.8rem;
}

.details-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.2rem;
}

.details-list li {
    background: #fff;
    border-radius: 1rem;
    padding: 1.2rem 1.4rem;
    border: 1px solid rgba(31, 122, 140, 0.12);
    box-shadow: 0 12px 24px var(--shadow);
}

.support-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}

.faq details {
    background: #fff;
    border-radius: 1rem;
    padding: 1rem 1.2rem;
    border: 1px solid rgba(31, 122, 140, 0.1);
    box-shadow: 0 10px 20px var(--shadow);
}

.faq summary {
    font-weight: 600;
    cursor: pointer;
}

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

.faq p {
    margin: 0.6rem 0 0;
    color: var(--muted);
}

.site-footer {
    border-top: 1px solid var(--border);
    background-color: #fafbfd;
    padding: 1.5rem 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.95rem;
    color: var(--muted);
}

@media (max-width: 720px) {
    nav ul {
        gap: 0.8rem;
        font-size: 0.9rem;
    }

    .site-header .container {
        flex-direction: column;
        align-items: flex-start;
    }

    .hero {
        padding-top: 4rem;
    }

    .hero-text h2 {
        font-size: 2rem;
    }
}