/* ========================================
   点思科技 — 极简风格
   色彩系统：白 + 极浅灰 + 深墨 + 蓝色点缀
   ======================================== */

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

:root {
    --color-bg:      #ffffff;
    --color-surface: #f7f7f8;
    --color-text:    #1d1d1f;
    --color-text-2:  #6e6e73;
    --color-text-3:  #86868b;
    --color-accent:  #0071e3;
    --color-accent-hover: #0077ed;
    --color-border:  #d2d2d7;
    --color-green:   #34c759;
    --radius-sm:     10px;
    --radius-md:     20px;
    --radius-lg:     28px;
    --nav-h:         56px;
    --font:          -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Helvetica Neue', 'Microsoft YaHei', sans-serif;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: var(--font);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
}

.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 24px;
}

img {
    display: block;
    max-width: 100%;
}

a {
    color: inherit;
    text-decoration: none;
}

/* ---------- Navigation ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--nav-h);
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    transition: background 0.3s;
}

.nav-container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-weight: 600;
    font-size: 18px;
    letter-spacing: 0.02em;
    color: var(--color-text);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-menu a {
    font-size: 14px;
    font-weight: 400;
    color: var(--color-text-2);
    transition: color 0.25s;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    cursor: pointer;
    width: 20px;
    height: 20px;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 1.5px;
    background: var(--color-text);
    border-radius: 1px;
    transition: transform 0.3s, opacity 0.3s;
}

.hamburger.active span:first-child {
    transform: translateY(3.25px) rotate(45deg);
}

.hamburger.active span:last-child {
    transform: translateY(-3.25px) rotate(-45deg);
}

/* ---------- Hero ---------- */
.hero {
    padding: calc(var(--nav-h) + 80px) 24px 100px;
    text-align: center;
    background: var(--color-bg);
}

.hero-inner {
    max-width: 680px;
    margin: 0 auto;
}

.hero-label {
    display: inline-block;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: 20px;
}

.hero-title {
    font-size: clamp(2.2rem, 5vw, 3.4rem);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    color: var(--color-text);
    margin-bottom: 24px;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--color-text-2);
    line-height: 1.7;
    max-width: 500px;
    margin: 0 auto 40px;
}

.hero-cta {
    display: inline-block;
    font-size: 15px;
    font-weight: 500;
    color: var(--color-accent);
    border-bottom: 1px solid var(--color-accent);
    padding-bottom: 2px;
    transition: opacity 0.25s;
}

.hero-cta:hover {
    opacity: 0.7;
}

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

.section-label {
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-text-3);
    text-align: center;
    margin-bottom: 56px;
}

/* ---------- Product Card ---------- */
.products {
    background: var(--color-surface);
}

.product-card {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 56px;
    align-items: center;
    padding: 48px;
    border-radius: var(--radius-lg);
    background: var(--color-bg);
    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.03),
        0 8px 40px rgba(0, 0, 0, 0.04);
    margin-bottom: 48px;
}

.product-card:last-child {
    margin-bottom: 0;
}

.product-card.reverse {
    grid-template-columns: 1fr 320px;
}

.product-card.reverse .product-visual {
    order: 2;
}

.product-card.reverse .product-body {
    order: 1;
}

.product-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.product-visual img {
    width: 240px;
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.08);
    transition: transform 0.4s ease;
}

.product-visual img:hover {
    transform: translateY(-6px);
}

.product-badge {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-accent);
    background: rgba(0, 113, 227, 0.08);
    padding: 4px 12px;
    border-radius: 999px;
    margin-bottom: 16px;
}

.product-badge.android {
    color: var(--color-green);
    background: rgba(52, 199, 89, 0.1);
}

.product-name {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--color-text);
    margin-bottom: 6px;
}

.product-tagline {
    font-size: 0.95rem;
    color: var(--color-text-3);
    margin-bottom: 20px;
}

.product-desc {
    font-size: 0.95rem;
    color: var(--color-text-2);
    line-height: 1.75;
    margin-bottom: 12px;
}

.product-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 24px 0 28px;
}

.product-tags span {
    font-size: 12px;
    font-weight: 500;
    color: var(--color-text-2);
    background: var(--color-surface);
    padding: 6px 14px;
    border-radius: 999px;
    border: 1px solid var(--color-border);
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 500;
    color: #fff;
    background: var(--color-accent);
    padding: 12px 28px;
    border-radius: 999px;
    transition: background 0.25s, transform 0.25s;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: translateY(-1px);
}

.btn-android {
    background: var(--color-green);
}

.btn-android:hover {
    background: #2db84e;
}

.btn-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

/* ---------- About ---------- */
.about {
    background: var(--color-bg);
}

.about-grid {
    max-width: 640px;
    margin: 0 auto;
    text-align: center;
}

.about-main p {
    font-size: 1rem;
    color: var(--color-text-2);
    line-height: 1.85;
    margin-bottom: 20px;
}

.about-main p:last-child {
    margin-bottom: 0;
}

/* ---------- Footer ---------- */
.footer {
    padding: 40px 0;
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    background: var(--color-bg);
}

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

.footer-email {
    font-size: 14px;
    color: var(--color-text-2);
    margin-bottom: 8px;
}

.footer-copy {
    font-size: 12px;
    color: var(--color-text-3);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: var(--nav-h);
        left: 0;
        right: 0;
        flex-direction: column;
        align-items: center;
        gap: 0;
        background: rgba(255, 255, 255, 0.96);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        padding: 16px 0;
        border-bottom: 1px solid rgba(0, 0, 0, 0.06);
        transform: translateY(-120%);
        opacity: 0;
        transition: transform 0.35s ease, opacity 0.35s ease;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
    }

    .nav-menu a {
        display: block;
        padding: 12px 0;
        font-size: 15px;
    }

    .hero {
        padding: calc(var(--nav-h) + 56px) 24px 72px;
    }

    .section {
        padding: 72px 0;
    }

    .product-card,
    .product-card.reverse {
        grid-template-columns: 1fr;
        gap: 32px;
        padding: 28px;
        text-align: center;
    }

    .product-card.reverse .product-visual {
        order: 0;
    }

    .product-card.reverse .product-body {
        order: 0;
    }

    .product-visual img {
        width: 200px;
    }

    .product-tags {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.8rem;
    }

    .product-visual img {
        width: 180px;
    }

    .product-card,
    .product-card.reverse {
        padding: 20px;
    }
}