/* ========================================
   眼多多品牌官网 - 全站样式
   ======================================== */

/* --- 1. 设计令牌 --- */
:root {
    /* 色板 */
    --color-primary: #1756D4;
    --color-primary-dark: #0A3A9A;
    --color-primary-light: #E8EFFE;
    --color-accent: #FF6B35;
    --color-text-1: #1A1A1A;
    --color-text-2: #5F6877;
    --color-text-3: #9AA0AB;
    --color-bg-1: #FFFFFF;
    --color-bg-2: #F6F7FA;
    --color-border: #E8E9ED;

    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, #1756D4 0%, #0A3A9A 100%);

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(23, 86, 212, 0.06);
    --shadow-md: 0 8px 24px rgba(23, 86, 212, 0.1);
    --shadow-lg: 0 16px 48px rgba(23, 86, 212, 0.14);

    /* 字号（桌面） */
    --fs-h1: 56px;
    --fs-h2: 40px;
    --fs-h3: 20px;
    --fs-body: 16px;
    --fs-small: 12px;

    /* 间距 */
    --section-pad-y: 96px;
    --container-max: 1200px;
    --container-pad-x: 24px;

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;

    /* 导航栏高度 */
    --nav-h: 64px;
}

/* --- 2. 重置 --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-h);
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
    font-size: var(--fs-body);
    line-height: 1.6;
    color: var(--color-text-1);
    background: var(--color-bg-1);
    -webkit-font-smoothing: antialiased;
}

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

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

button {
    font: inherit;
    border: none;
    background: none;
    cursor: pointer;
    color: inherit;
}

h1, h2, h3 {
    font-weight: 700;
    line-height: 1.2;
}

/* 数字用等宽数字 */
.tnum {
    font-variant-numeric: tabular-nums;
}

/* --- 3. 容器 --- */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-pad-x);
}

.section {
    padding: var(--section-pad-y) 0;
}

.section--alt {
    background: var(--color-bg-2);
}

/* --- 4. 响应式基础 --- */
@media (max-width: 640px) {
    :root {
        --fs-h1: 32px;
        --fs-h2: 26px;
        --fs-h3: 18px;
        --fs-body: 14px;
        --section-pad-y: 56px;
    }
}

/* ========================================
   导航栏
   ======================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-h);
    z-index: 100;
    background: rgba(255, 255, 255, 0);
    transition: background 0.2s, box-shadow 0.2s;
}

.nav.scrolled {
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
}

.nav__inner {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.nav__brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    color: #FFF;
    transition: color 0.2s;
}

.nav.scrolled .nav__brand {
    color: var(--color-text-1);
}

.nav__logo {
    width: 32px;
    height: 32px;
    border-radius: 6px;
}

.nav__title {
    font-size: 16px;
}

.nav__links {
    display: flex;
    gap: 32px;
    margin-left: auto;
    margin-right: 16px;
}

.nav__links a {
    color: #FFF;
    font-size: 15px;
    transition: color 0.2s;
    position: relative;
}

.nav__links a:hover {
    opacity: 0.8;
}

.nav.scrolled .nav__links a {
    color: var(--color-text-1);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    border-radius: 999px;
    font-weight: 600;
    font-size: 15px;
    transition: transform 0.1s, box-shadow 0.2s, background 0.2s;
    cursor: pointer;
}

.btn--primary {
    background: var(--color-primary);
    color: #FFF;
}

.btn--primary:hover {
    background: var(--color-primary-dark);
    box-shadow: var(--shadow-md);
}

.btn--primary:active {
    transform: scale(0.98);
}

.nav.scrolled .nav__cta {
    box-shadow: var(--shadow-sm);
}

.nav__menu-btn {
    display: none;
    width: 32px;
    height: 32px;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
}

.nav__menu-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background: #FFF;
    border-radius: 2px;
    transition: background 0.2s;
    margin: 0 auto;
}

.nav.scrolled .nav__menu-btn span {
    background: var(--color-text-1);
}

.nav__mobile {
    display: none;
    flex-direction: column;
    background: #FFF;
    padding: 16px 24px 24px;
    box-shadow: var(--shadow-md);
    gap: 18px;
}

.nav__mobile a {
    color: var(--color-text-1);
    font-size: 16px;
    font-weight: 500;
}

.nav__mobile .btn {
    margin-top: 8px;
}

@media (max-width: 768px) {
    .nav__links, .nav__cta {
        display: none;
    }

    .nav__menu-btn {
        display: flex;
    }

    .nav__mobile.open {
        display: flex;
    }
}

/* ========================================
   Hero
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    padding: calc(var(--nav-h) + 48px) 0 80px;
    background: var(--gradient-primary);
    color: #FFF;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: -10%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255,255,255,0.12), transparent 70%);
    pointer-events: none;
}

.hero__inner {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 48px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero__content {
    animation: heroFadeIn 0.8s ease-out;
}

.hero__title {
    font-size: var(--fs-h1);
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: 0.02em;
}

.hero__subtitle {
    font-size: 20px;
    line-height: 1.6;
    opacity: 0.88;
    margin-bottom: 40px;
}

.hero__actions {
    margin-bottom: 20px;
}

.btn--lg {
    padding: 16px 40px;
    font-size: 17px;
}

.hero .btn--primary {
    background: #FFF;
    color: var(--color-primary);
}

.hero .btn--primary:hover {
    background: #F0F4FF;
    box-shadow: var(--shadow-lg);
}

.hero__meta {
    font-size: 13px;
    opacity: 0.7;
}

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

.phone-frame {
    width: 280px;
    aspect-ratio: 9 / 19;
    background: #1A1A1A;
    border-radius: 36px;
    padding: 10px;
    box-shadow: 0 40px 80px rgba(0, 0, 0, 0.35), 0 0 0 2px rgba(255,255,255,0.05);
    position: relative;
    transform: perspective(1200px) rotateY(-6deg) rotateX(2deg);
}

.phone-frame::before {
    content: "";
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 22px;
    background: #1A1A1A;
    border-radius: 0 0 14px 14px;
    z-index: 2;
}

.phone-frame__screen {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 28px;
    display: block;
}

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

@media (max-width: 768px) {
    .hero {
        min-height: auto;
        padding: calc(var(--nav-h) + 32px) 0 56px;
        text-align: center;
    }

    .hero__inner {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .hero__subtitle {
        font-size: 16px;
        margin-bottom: 32px;
    }

    .phone-frame {
        width: 220px;
        transform: none;
    }
}

/* ========================================
   通用区段标题
   ======================================== */
.section__title {
    font-size: var(--fs-h2);
    text-align: center;
    margin-bottom: 12px;
}

.section__subtitle {
    text-align: center;
    color: var(--color-text-2);
    font-size: 17px;
    margin-bottom: 56px;
}

@media (max-width: 640px) {
    .section__subtitle {
        font-size: 14px;
        margin-bottom: 40px;
    }
}

/* ========================================
   Features
   ======================================== */
.features {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature {
    background: #FFF;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px 24px;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.feature:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
}

.feature__icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 20px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
    background: var(--color-primary-light);
}

.feature__icon svg {
    width: 28px;
    height: 28px;
}

.feature__icon--heat {
    color: var(--color-accent);
    background: #FFF2EC;
}

.feature__title {
    font-size: var(--fs-h3);
    margin-bottom: 10px;
}

.feature__desc {
    color: var(--color-text-2);
    font-size: 14px;
    line-height: 1.7;
}

@media (max-width: 960px) {
    .features {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .features {
        gap: 16px;
    }

    .feature {
        padding: 24px 16px;
    }
}

/* ========================================
   Screens
   ======================================== */
.screens {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.screen__phone {
    width: 220px;
    aspect-ratio: 9 / 19;
    background: #1A1A1A;
    border-radius: 28px;
    padding: 8px;
    box-shadow: var(--shadow-md);
    cursor: zoom-in;
    transition: transform 0.2s;
    position: relative;
}

.screen__phone::before {
    content: "";
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 16px;
    background: #1A1A1A;
    border-radius: 0 0 10px 10px;
    z-index: 2;
}

.screen__phone:hover {
    transform: translateY(-4px);
}

.screen__phone img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 22px;
    display: block;
}

.screen figcaption {
    text-align: center;
}

.screen figcaption h3 {
    font-size: var(--fs-h3);
    margin-bottom: 4px;
}

.screen figcaption p {
    color: var(--color-text-2);
    font-size: 14px;
}

@media (max-width: 960px) {
    .screens {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
}

@media (max-width: 640px) {
    .screens {
        /* 手机端改为横滑 */
        display: flex;
        grid-template-columns: unset;
        overflow-x: auto;
        scroll-snap-type: x mandatory;
        gap: 16px;
        padding-bottom: 12px;
        margin: 0 calc(-1 * var(--container-pad-x));
        padding-left: var(--container-pad-x);
        padding-right: var(--container-pad-x);
    }

    .screen {
        flex: 0 0 auto;
        width: 180px;
        scroll-snap-align: start;
    }

    .screen__phone {
        width: 180px;
    }
}

/* ========================================
   About
   ======================================== */
.about__inner {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
}

.about__eyebrow {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 14px;
    letter-spacing: 0.08em;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.about__slogan {
    font-size: 56px;
    line-height: 1.15;
    margin-bottom: 28px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.about__desc {
    color: var(--color-text-2);
    font-size: 17px;
    line-height: 1.9;
    margin-bottom: 40px;
}

.about__tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.about__tags span {
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-size: 13px;
    font-weight: 500;
    padding: 6px 16px;
    border-radius: 999px;
}

@media (max-width: 640px) {
    .about__slogan {
        font-size: 36px;
    }

    .about__desc {
        font-size: 15px;
    }
}

/* ========================================
   Download CTA
   ======================================== */
.download {
    background: var(--gradient-primary);
    color: #FFF;
    padding: 96px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.download::before {
    content: "";
    position: absolute;
    top: -50%;
    left: -20%;
    width: 60%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.14), transparent 60%);
    pointer-events: none;
}

.download__inner {
    position: relative;
    z-index: 1;
}

.download__title {
    font-size: var(--fs-h2);
    margin-bottom: 12px;
}

.download__subtitle {
    font-size: 18px;
    opacity: 0.88;
    margin-bottom: 40px;
}

.btn--download {
    gap: 10px;
    background: #FFF;
    color: var(--color-primary);
    padding: 18px 44px;
    font-size: 18px;
}

.btn--download:hover {
    background: #F0F4FF;
    box-shadow: var(--shadow-lg);
}

.btn--download svg {
    flex-shrink: 0;
}

.download__meta {
    margin-top: 20px;
    font-size: 14px;
    opacity: 0.75;
}

@media (max-width: 640px) {
    .download {
        padding: 56px 0;
    }

    .download__subtitle {
        font-size: 15px;
        margin-bottom: 28px;
    }

    .btn--download {
        padding: 14px 32px;
        font-size: 16px;
    }
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: #FFF;
    border-top: 1px solid var(--color-border);
    padding: 32px 0;
    color: var(--color-text-2);
    font-size: 13px;
}

.footer__inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}

.footer__brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    color: var(--color-text-1);
}

.footer__logo {
    width: 24px;
    height: 24px;
    border-radius: 5px;
}

.footer__meta {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.footer__sep {
    color: var(--color-text-3);
}

.footer__link {
    color: var(--color-text-2);
    transition: color 0.2s;
}

.footer__link:hover {
    color: var(--color-primary);
}

@media (max-width: 640px) {
    .footer__inner {
        flex-direction: column;
        align-items: flex-start;
        text-align: left;
    }

    .footer__meta {
        font-size: 12px;
    }
}

/* ========================================
   Dialog / Lightbox
   ======================================== */
.dialog {
    border: none;
    border-radius: var(--radius-lg);
    padding: 0;
    max-width: 400px;
    width: calc(100% - 32px);
    box-shadow: 0 40px 80px rgba(0, 0, 0, 0.3);
}

.dialog::backdrop {
    background: rgba(10, 20, 40, 0.5);
    backdrop-filter: blur(4px);
}

.dialog__content {
    padding: 32px 28px 24px;
    text-align: center;
}

.dialog__title {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--color-text-1);
}

.dialog__body {
    color: var(--color-text-2);
    line-height: 1.7;
    margin-bottom: 24px;
    font-size: 14px;
}

.dialog__close {
    width: 100%;
    padding: 12px;
}

.lightbox {
    border: none;
    padding: 0;
    background: transparent;
    max-width: 100vw;
    max-height: 100vh;
    width: 100vw;
    height: 100vh;
}

.lightbox::backdrop {
    background: rgba(0, 0, 0, 0.92);
}

.lightbox__img {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    max-width: 90vw;
    max-height: 90vh;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.lightbox__close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 44px;
    height: 44px;
    font-size: 28px;
    color: #FFF;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    line-height: 1;
    z-index: 2;
}

.lightbox__close:hover {
    background: rgba(255, 255, 255, 0.2);
}

.lightbox__nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 52px;
    height: 52px;
    color: #FFF;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    font-size: 32px;
    line-height: 1;
    z-index: 2;
}

.lightbox__nav:hover {
    background: rgba(255, 255, 255, 0.2);
}

.lightbox__nav--prev {
    left: 20px;
}

.lightbox__nav--next {
    right: 20px;
}

@media (max-width: 640px) {
    .lightbox__nav {
        width: 40px;
        height: 40px;
        font-size: 24px;
    }

    .lightbox__nav--prev {
        left: 8px;
    }

    .lightbox__nav--next {
        right: 8px;
    }
}