/* ==================================
   DPTV Landing Page - Main Styles
   深色科技风 / 靛蓝主色
================================== */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 90px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #0b0f19;
    color: #ffffff;
    overflow-x: hidden;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

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

button {
    border: none;
    outline: none;
    cursor: pointer;
    font-family: inherit;
}

ul {
    list-style: none;
}

/* ==================================
   VARIABLES
================================== */

:root {
    --primary: #4F46E5;
    --primary-light: #6D63FF;
    --dark: #0b0f19;
    --dark-2: #111827;
    --dark-3: #1f2937;
    --text: #ffffff;
    --text-soft: #b5bfd1;
    --border: rgba(255, 255, 255, .08);
    --shadow: 0 20px 40px rgba(0, 0, 0, .35);
    --glow: 0 0 20px rgba(79, 70, 229, .45);
    --radius: 24px;
}

/* ==================================
   CONTAINER
================================== */

.container {
    width: 100%;
    max-width: 1200px;
    margin: auto;
    padding: 0 20px;
}

.section {
    padding: 120px 0;
}

/* ==================================
   HEADER
================================== */

.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 999;
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
    background: rgba(10, 15, 25, .75);
    border-bottom: 1px solid rgba(255, 255, 255, .05);
    transition: box-shadow .3s, background .3s;
}

.header.scrolled {
    background: rgba(10, 15, 25, .92);
    box-shadow: 0 10px 40px rgba(0, 0, 0, .35);
}

.header-container {
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 24px;
    font-weight: 800;
}

.logo img {
    width: 84px;
    height: 42px;
    object-fit: contain;
}

.nav {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav a {
    color: #d7def0;
    font-size: 15px;
    font-weight: 500;
    transition: color .3s;
    position: relative;
}

.nav a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--primary-light);
    transition: width .3s;
}

.nav a:hover {
    color: #ffffff;
}

.nav a:hover::after {
    width: 100%;
}

.header-download-btn {
    padding: 12px 24px;
    background: var(--primary);
    border-radius: 12px;
    font-weight: 600;
    transition: transform .3s, box-shadow .3s;
    white-space: nowrap;
}

.header-download-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--glow);
}

/* ==================================
   MOBILE MENU
================================== */

.mobile-menu-btn {
    display: none;
    width: 42px;
    height: 42px;
    background: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    padding: 0 8px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: transform .3s, opacity .3s;
}

.mobile-menu-btn.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.mobile-menu-btn.open span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    background: #111827;
    z-index: 998;
    border-bottom: 1px solid rgba(255, 255, 255, .05);
}

.mobile-menu.active {
    display: block;
}

.mobile-menu a {
    display: block;
    padding: 16px 24px;
    border-bottom: 1px solid rgba(255, 255, 255, .05);
    transition: background .2s, color .2s;
}

.mobile-menu a:hover {
    background: rgba(79, 70, 229, .15);
    color: #d9dcff;
}

/* ==================================
   HERO
================================== */

.hero {
    position: relative;
    min-height: calc(100vh - 80px);
    margin-top: 80px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
    background:
        radial-gradient(circle at top right, rgba(79, 70, 229, .35), transparent 42%),
        radial-gradient(circle at bottom left, rgba(99, 102, 241, .25), transparent 42%),
        linear-gradient(rgba(255, 255, 255, .025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, .025) 1px, transparent 1px);
    background-size: auto, auto, 56px 56px, 56px 56px;
    -webkit-mask-image: radial-gradient(ellipse at center, #000 35%, transparent 78%);
    mask-image: radial-gradient(ellipse at center, #000 35%, transparent 78%);
}

.hero-container {
    display: grid;
    grid-template-columns: 1.1fr .9fr;
    gap: 60px;
    align-items: center;
    padding-top: 40px;
    padding-bottom: 40px;
}

.hero-badge {
    display: inline-flex;
    padding: 10px 18px;
    border-radius: 999px;
    background: rgba(79, 70, 229, .15);
    border: 1px solid rgba(79, 70, 229, .3);
    margin-bottom: 25px;
    color: #d9dcff;
    font-size: 14px;
}

.hero h1 {
    font-size: 50px;
    line-height: 1.1;
    font-weight: 600;
    margin-bottom: 25px;
}

.hero h1 span {
    display: block;
    color: var(--primary-light);
    font-size: .72em;
    font-weight: 600;
    margin-top: 10px;
}

.hero-description {
    font-size: 20px;
    color: var(--text-soft);
    max-width: 650px;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-bottom: 40px;
}

.stat strong {
    display: block;
    font-size: 30px;
    font-weight: 800;
}

.stat span {
    color: var(--text-soft);
    font-size: 14px;
}

.hero-buttons {
    display: flex;
    gap: 18px;
    margin-bottom: 35px;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 18px 34px;
    border-radius: 14px;
    background: var(--primary);
    font-weight: 700;
    transition: transform .3s, box-shadow .3s;
}

.btn-primary:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 35px rgba(79, 70, 229, .5);
}

.btn-secondary {
    padding: 18px 34px;
    border-radius: 14px;
    border: 1px solid rgba(255, 255, 255, .1);
    background: rgba(255, 255, 255, .04);
    transition: background .3s, border-color .3s;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, .08);
    border-color: rgba(255, 255, 255, .2);
}

.download-icon {
    width: 24px;
    height: 24px;
    display: inline-block;
    flex-shrink: 0;
    animation: downloadFloat 2s ease-in-out infinite;
}

.hero-features {
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
    color: #9ca3af;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image img {
    max-height: 720px;
    width: auto;
    animation: float 5s ease-in-out infinite;
    filter: drop-shadow(0 20px 50px rgba(79, 70, 229, .4));
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

@keyframes downloadFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(4px); }
}

/* ==================================
   SECTION HEADING
================================== */

.section-heading {
    text-align: center;
    margin-bottom: 60px;
}

.section-heading h2 {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 16px;
}

.section-heading p {
    color: var(--text-soft);
    max-width: 700px;
    margin: auto;
}

/* ==================================
   SCREENSHOTS
================================== */

.screenshotSwiper {
    padding-bottom: 60px;
}

.swiper-slide {
    display: flex;
    justify-content: center;
}

.swiper-slide img {
    width: 280px;
    max-width: 100%;
    border-radius: 28px;
    box-shadow: 0 25px 60px rgba(0, 0, 0, .5);
}

.swiper-pagination-bullet {
    background: #fff !important;
    opacity: .45;
}

.swiper-pagination-bullet-active {
    opacity: 1;
}

/* ==================================
   FEATURES
================================== */

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.feature-card {
    background: rgba(255, 255, 255, .03);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 35px;
    transition: transform .35s, border-color .35s, box-shadow .35s;
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: rgba(79, 70, 229, .4);
    box-shadow: 0 20px 40px rgba(79, 70, 229, .15);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-soft);
}

/* ==================================
   REVIEWS
================================== */

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.review-card {
    background: rgba(255, 255, 255, .03);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 35px;
    transition: border-color .35s, transform .35s;
}

.review-card:hover {
    transform: translateY(-5px);
    border-color: rgba(79, 70, 229, .35);
}

.stars {
    color: #FFD700;
    margin-bottom: 15px;
    font-size: 22px;
    letter-spacing: 2px;
}

.review-card p {
    margin-bottom: 20px;
    color: #dbe2f1;
}

.review-card span {
    color: #9ca3af;
}

/* ==================================
   DOWNLOAD
================================== */

.download-section {
    padding: 120px 0;
}

.download-box {
    background: linear-gradient(135deg, rgba(79, 70, 229, .25), rgba(79, 70, 229, .08));
    border: 1px solid rgba(79, 70, 229, .25);
    border-radius: 30px;
    text-align: center;
    padding: 70px 40px;
}

.download-box h2 {
    font-size: 52px;
    margin-bottom: 20px;
}

.download-box > p {
    color: #c9d2e4;
    margin-bottom: 40px;
}

.download-info {
    display: flex;
    justify-content: center;
    gap: 60px;
    margin-bottom: 50px;
}

.download-info div {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.download-info strong {
    font-size: 20px;
}

.download-info span {
    color: #bfc8d8;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    white-space: nowrap;
    padding: 22px 60px;
    border-radius: 18px;
    background: var(--primary);
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 20px;
    transition: transform .3s, box-shadow .3s;
}

.btn-download:hover {
    transform: translateY(-4px);
    box-shadow: 0 0 40px rgba(79, 70, 229, .6);
}

.download-box small {
    display: block;
    color: #9ca3af;
}

/* ==================================
   FAQ
================================== */

.faq-list {
    max-width: 900px;
    margin: auto;
}

.faq-item {
    margin-bottom: 16px;
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    background: #111827;
    transition: border-color .3s;
}

.faq-item.active {
    border-color: rgba(79, 70, 229, .4);
}

.faq-question {
    width: 100%;
    padding: 24px;
    background: transparent;
    color: #fff;
    text-align: left;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.faq-arrow {
    width: 10px;
    height: 10px;
    border-right: 2px solid #9ca3af;
    border-bottom: 2px solid #9ca3af;
    transform: rotate(45deg);
    flex-shrink: 0;
    transition: transform .3s;
    margin-right: 6px;
}

.faq-item.active .faq-arrow {
    transform: rotate(-135deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height .35s ease;
    background: #0f172a;
}

.faq-answer p {
    padding: 0 24px 24px;
    color: #bfc8d8;
}

/* ==================================
   FOOTER
================================== */

.footer {
    padding: 60px 0;
    border-top: 1px solid rgba(255, 255, 255, .05);
    text-align: center;
}

.footer img {
    width: 70px;
    margin: auto auto 20px;
}

.footer p {
    color: #9ca3af;
    margin-bottom: 20px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 25px;
}

.footer-links a {
    color: #cfd5e1;
    transition: color .3s;
}

.footer-links a:hover {
    color: #ffffff;
}

/* ==================================
   REVEAL ANIMATION
================================== */

.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity .7s ease, transform .7s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==================================
   TABLET
================================== */

@media (max-width: 992px) {
    .hero {
        padding-top: 10px;
        min-height: auto;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

    .hero-content {
        order: 1;
    }

    .hero-image {
        order: 2;
    }

    .hero-image img {
        max-height: 520px;
    }

    .hero-stats,
    .hero-buttons,
    .hero-features {
        justify-content: center;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }
}

/* ==================================
   MOBILE
================================== */

@media (max-width: 768px) {
    .nav,
    .header-download-btn {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .section {
        padding: 70px 0;
    }

    .container {
        padding: 0 18px;
    }

    .hero {
        padding-bottom: 50px;
    }

    .hero-badge {
        font-size: 13px;
    }

    .hero h1 {
        font-size: 38px;
        line-height: 1.15;
    }

    .hero h1 span {
        font-size: .8em;
    }

    .hero-description {
        font-size: 16px;
        margin-bottom: 30px;
    }

    .hero-image img {
        max-height: 420px;
    }

    .hero-stats {
        gap: 20px;
        flex-wrap: wrap;
    }

    .stat {
        min-width: 90px;
    }

    .stat strong {
        font-size: 24px;
    }

    .hero-buttons {
        flex-direction: column;
        gap: 12px;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        text-align: center;
        justify-content: center;
    }

    .hero-features {
        gap: 12px;
        font-size: 14px;
    }

    .section-heading {
        margin-bottom: 40px;
    }

    .section-heading h2 {
        font-size: 32px;
    }

    .section-heading p {
        font-size: 15px;
    }

    .swiper-slide img {
        width: 220px;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .feature-card {
        padding: 28px;
    }

    .reviews-grid {
        grid-template-columns: 1fr;
    }

    .download-box {
        padding: 40px 24px;
    }

    .download-box h2 {
        font-size: 34px;
    }

    .download-info {
        flex-direction: column;
        gap: 20px;
    }

    .btn-download {
        width: 100%;
        padding: 18px;
        font-size: 18px;
    }

    .faq-question {
        padding: 18px;
        font-size: 16px;
    }

    .faq-answer p {
        padding: 0 18px 18px;
    }

    .footer-links {
        flex-wrap: wrap;
        gap: 15px;
    }
}

/* ==================================
   SMALL PHONE
================================== */

@media (max-width: 480px) {
    .hero h1 {
        font-size: 30px;
    }

    .hero-description {
        font-size: 15px;
    }

    .hero-image img {
        max-height: 340px;
    }

    .hero-stats {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }

    .stat strong {
        font-size: 20px;
    }

    .stat span {
        font-size: 12px;
    }

    .feature-card {
        padding: 22px;
    }

    .feature-card h3 {
        font-size: 20px;
    }

    .download-box h2 {
        font-size: 28px;
    }

    .download-box {
        padding: 30px 20px;
    }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .hero-image img,
    .download-icon {
        animation: none;
    }

    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }
}