/* ==========================================================
   PlayBox 官网样式
   设计要点：iOS 风格 / 蓝紫渐变 / 圆角卡片 / 平滑动效
   ========================================================== */

:root {
    --c-bg: #ffffff;
    --c-bg-soft: #f5f7fb;
    --c-bg-dark: #0b1020;
    --c-text: #1a1f36;
    --c-text-soft: #5b6478;
    --c-text-mute: #8b93a7;
    --c-border: #e6eaf2;
    --c-primary: #3b7bff;
    --c-primary-2: #6e57ff;
    --c-accent: #00c2ff;

    --grad-brand: linear-gradient(135deg, #00c2ff 0%, #3b7bff 50%, #6e57ff 100%);
    --grad-blue:  linear-gradient(135deg, #6ad6ff 0%, #3b7bff 100%);
    --grad-purple:linear-gradient(135deg, #a18cff 0%, #6e57ff 100%);
    --grad-cyan:  linear-gradient(135deg, #7ee8fa 0%, #4facfe 100%);
    --grad-orange:linear-gradient(135deg, #ffd17a 0%, #ff8a3d 100%);
    --grad-pink:  linear-gradient(135deg, #ffb1d8 0%, #ff5f9e 100%);
    --grad-green: linear-gradient(135deg, #a6f0c2 0%, #34c98c 100%);

    --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.06);
    --shadow-md: 0 8px 24px rgba(16, 24, 40, 0.08);
    --shadow-lg: 0 24px 48px rgba(16, 24, 40, 0.12);
    --shadow-xl: 0 40px 80px rgba(16, 24, 40, 0.18);

    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    --container: 1180px;
}

/* ---- Reset & Base ---- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
                 "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { font-family: inherit; cursor: pointer; }

.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---- Header ---- */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.78);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(230, 234, 242, 0.6);
}
.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
    gap: 32px;
}
.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 18px;
    letter-spacing: -0.01em;
    color: var(--c-text);
}
.logo-mark {
    width: 34px;
    height: 34px;
    display: block;
    border-radius: 9px;
    object-fit: contain;
    filter: drop-shadow(0 4px 10px rgba(110, 87, 255, 0.28));
}
.footer .logo-mark { width: 32px; height: 32px; }
.nav-links {
    display: flex;
    gap: 28px;
    margin-left: auto;
}
.nav-links a {
    font-size: 15px;
    color: var(--c-text-soft);
    transition: color .2s ease;
}
.nav-links a:hover { color: var(--c-text); }

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 22px;
    border-radius: 999px;
    font-size: 15px;
    font-weight: 600;
    border: none;
    transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
    text-align: center;
    line-height: 1;
}
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-lg { padding: 16px 28px; font-size: 16px; }
.btn-primary {
    background: var(--grad-brand);
    color: #fff;
    box-shadow: 0 8px 24px rgba(59, 123, 255, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(59, 123, 255, 0.42); }
.btn-ghost {
    background: transparent;
    color: var(--c-text);
    border: 1px solid var(--c-border);
}
.btn-ghost:hover { background: var(--c-bg-soft); }
.btn-dark {
    background: #0b1020;
    color: #fff;
    padding: 14px 26px;
}
.btn-dark:hover { transform: translateY(-2px); background: #1a2240; }
.btn-stack {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    line-height: 1.1;
}
.btn-stack small { font-size: 11px; opacity: .7; }
.btn-stack strong { font-size: 17px; font-weight: 600; }

/* ---- Section common ---- */
.section { padding: 120px 0; }
.section-head {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 64px;
}
.eyebrow {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.18em;
    color: var(--c-primary);
    margin-bottom: 16px;
    text-transform: uppercase;
}
.eyebrow.light { color: rgba(255, 255, 255, 0.7); }
.section-head h2 {
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}
.section-head p {
    font-size: 17px;
    color: var(--c-text-soft);
}
.gradient-text {
    background: var(--grad-brand);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* ---- Hero ---- */
.hero {
    position: relative;
    padding: 80px 0 120px;
    overflow: hidden;
    background:
        radial-gradient(circle at 20% 0%, rgba(110, 87, 255, 0.10), transparent 40%),
        radial-gradient(circle at 80% 30%, rgba(0, 194, 255, 0.10), transparent 40%),
        var(--c-bg-soft);
}
.hero-grid {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 60px;
    align-items: center;
}
.badge {
    display: inline-block;
    padding: 8px 14px;
    background: rgba(59, 123, 255, 0.08);
    color: var(--c-primary);
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 24px;
}
.hero-text h1 {
    font-size: clamp(36px, 5.5vw, 60px);
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
    font-weight: 700;
}
.lead {
    font-size: 18px;
    color: var(--c-text-soft);
    max-width: 520px;
    margin-bottom: 36px;
}
.hero-actions {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
    margin-bottom: 48px;
}
.hero-meta {
    display: flex;
    align-items: center;
    gap: 28px;
    flex-wrap: wrap;
}
.meta-item { display: flex; flex-direction: column; gap: 4px; }
.meta-item strong { font-size: 24px; letter-spacing: -0.01em; }
.meta-item span { font-size: 13px; color: var(--c-text-mute); }
.meta-divider { width: 1px; height: 32px; background: var(--c-border); }

/* Hero visual: 双手机 + 浮卡 */
.hero-visual {
    position: relative;
    height: 620px;
    perspective: 1200px;
}
.phone-frame {
    position: absolute;
    width: 280px;
    border-radius: 42px;
    background: #111;
    padding: 10px;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    transition: transform .5s ease;
}
.phone-frame img {
    border-radius: 32px;
    display: block;
    width: 100%;
}
.phone-front {
    z-index: 2;
    bottom: 0;
    left: 50%;
    transform: translateX(-65%) rotate(-4deg);
}
.phone-back {
    z-index: 1;
    top: 0;
    left: 50%;
    transform: translateX(-15%) rotate(6deg);
    opacity: 0.95;
}
.phone-front:hover { transform: translateX(-65%) rotate(-2deg) translateY(-8px); }
.phone-back:hover { transform: translateX(-15%) rotate(4deg) translateY(-8px); }

.floating-card {
    position: absolute;
    background: #fff;
    border-radius: 14px;
    padding: 12px 18px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: 8px;
    z-index: 3;
    animation: float 4s ease-in-out infinite;
}
.card-ai {
    top: 60px;
    right: -10px;
    color: var(--c-primary);
}
.card-ai .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--c-primary);
    animation: pulse 1.4s ease-in-out infinite;
}
.card-cast {
    bottom: 80px;
    left: -20px;
    animation-delay: 1.5s;
    color: var(--c-text);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}
@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.4; transform: scale(1.4); }
}

/* ---- Features ---- */
.features { background: var(--c-bg); }
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.feature-card {
    background: var(--c-bg-soft);
    border-radius: var(--radius-lg);
    padding: 36px 32px;
    transition: transform .3s ease, box-shadow .3s ease;
    border: 1px solid transparent;
}
.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    background: #fff;
    border-color: var(--c-border);
}
.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    margin-bottom: 24px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}
.feature-icon svg { width: 26px; height: 26px; }
.icon-blue   { background: var(--grad-blue);   box-shadow: 0 8px 20px rgba(59, 123, 255, 0.3); }
.icon-purple { background: var(--grad-purple); box-shadow: 0 8px 20px rgba(110, 87, 255, 0.3); }
.icon-cyan   { background: var(--grad-cyan);   box-shadow: 0 8px 20px rgba(79, 172, 254, 0.3); }
.icon-orange { background: var(--grad-orange); box-shadow: 0 8px 20px rgba(255, 138, 61, 0.3); }
.icon-pink   { background: var(--grad-pink);   box-shadow: 0 8px 20px rgba(255, 95, 158, 0.3); }
.icon-green  { background: var(--grad-green);  box-shadow: 0 8px 20px rgba(52, 201, 140, 0.3); }
.feature-card h3 {
    font-size: 19px;
    margin-bottom: 12px;
    letter-spacing: -0.01em;
}
.feature-card p {
    color: var(--c-text-soft);
    font-size: 15px;
    line-height: 1.65;
}

/* ---- Screens ---- */
.screens {
    background: var(--c-bg-soft);
    overflow: hidden;
}
.screens-scroll {
    display: flex;
    gap: 28px;
    padding: 16px 4px 32px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
    scrollbar-color: var(--c-border) transparent;
}
.screens-scroll::-webkit-scrollbar { height: 8px; }
.screens-scroll::-webkit-scrollbar-track { background: transparent; }
.screens-scroll::-webkit-scrollbar-thumb { background: var(--c-border); border-radius: 4px; }
.screen-item {
    flex: 0 0 240px;
    scroll-snap-align: start;
    text-align: center;
}
.screen-item img {
    border-radius: 28px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 20px;
    transition: transform .3s ease;
    border: 6px solid #fff;
}
.screen-item:hover img { transform: translateY(-8px); }
.screen-item figcaption {
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.screen-item figcaption strong {
    font-size: 16px;
    letter-spacing: -0.01em;
}
.screen-item figcaption span {
    font-size: 13px;
    color: var(--c-text-soft);
}

/* ---- AI Section ---- */
.ai-section {
    background: var(--c-bg-dark);
    color: #fff;
    position: relative;
    overflow: hidden;
}
.ai-section::before {
    content: "";
    position: absolute;
    top: -200px;
    right: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(110, 87, 255, 0.5), transparent 70%);
    filter: blur(60px);
}
.ai-section::after {
    content: "";
    position: absolute;
    bottom: -200px;
    left: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(0, 194, 255, 0.4), transparent 70%);
    filter: blur(60px);
}
.ai-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
    position: relative;
    z-index: 1;
}
.ai-text h2 {
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}
.ai-text > p {
    font-size: 17px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 32px;
}
.ai-list { display: flex; flex-direction: column; gap: 20px; }
.ai-list li {
    display: flex;
    gap: 14px;
    align-items: flex-start;
}
.check {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--grad-brand);
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 700;
    margin-top: 2px;
}
.ai-list strong {
    display: block;
    font-size: 16px;
    margin-bottom: 4px;
}
.ai-list p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.6;
}

.ai-card {
    background: rgba(255, 255, 255, 0.06);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-lg);
    padding: 32px;
}
.ai-card-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}
.ai-tag {
    background: var(--grad-brand);
    color: #fff;
    padding: 4px 12px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.05em;
}
.ai-time {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
}
.ai-card h4 {
    font-size: 22px;
    margin-bottom: 12px;
    letter-spacing: -0.01em;
}
.ai-card > p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 20px;
}
.ai-keywords {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 24px;
}
.ai-keywords span {
    background: rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.85);
    padding: 4px 12px;
    border-radius: 999px;
    font-size: 13px;
}
.ai-progress {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 999px;
    overflow: hidden;
    margin-bottom: 20px;
}
.ai-progress-bar {
    width: 78%;
    height: 100%;
    background: var(--grad-brand);
    border-radius: 999px;
    animation: progress 3s ease-in-out infinite;
}
@keyframes progress {
    0%, 100% { width: 60%; }
    50% { width: 90%; }
}
.ai-foot {
    display: flex;
    justify-content: space-between;
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
}

/* ---- Download CTA ---- */
.download { background: var(--c-bg); padding: 80px 0; }
.download-card {
    background: var(--grad-brand);
    border-radius: var(--radius-xl);
    padding: 64px;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
    flex-wrap: wrap;
    box-shadow: 0 24px 60px rgba(59, 123, 255, 0.4);
    position: relative;
    overflow: hidden;
}
.download-card::before {
    content: "";
    position: absolute;
    top: -100px;
    right: -100px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.18), transparent 70%);
}
.download-text { position: relative; z-index: 1; }
.download-text h2 {
    font-size: clamp(26px, 3.5vw, 38px);
    line-height: 1.2;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}
.download-text p {
    font-size: 16px;
    opacity: 0.9;
}
.download-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: flex-end;
    position: relative;
    z-index: 1;
}
.device-tip {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
}

/* ---- Footer ---- */
.footer {
    background: var(--c-bg-soft);
    padding: 80px 0 32px;
    border-top: 1px solid var(--c-border);
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--c-border);
}
.footer-brand p {
    color: var(--c-text-soft);
    font-size: 14px;
    max-width: 300px;
    margin-top: 16px;
}
.footer-col h5 {
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--c-text);
}
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a {
    color: var(--c-text-soft);
    font-size: 14px;
    transition: color .2s ease;
}
.footer-col a:hover { color: var(--c-primary); }
.footer-bottom {
    display: flex;
    justify-content: space-between;
    padding-top: 24px;
    color: var(--c-text-mute);
    font-size: 13px;
}

/* ============================
   Legal Pages (privacy / terms)
   ============================ */
.legal {
    padding: 80px 0 100px;
    background: var(--c-bg);
}
.legal-header {
    max-width: 760px;
    margin: 0 auto 48px;
    text-align: center;
}
.legal-header h1 {
    font-size: clamp(32px, 4vw, 44px);
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}
.legal-meta {
    display: inline-flex;
    align-items: center;
    gap: 16px;
    color: var(--c-text-mute);
    font-size: 14px;
}
.legal-meta span { display: inline-flex; align-items: center; gap: 6px; }
.legal-content {
    max-width: 800px;
    margin: 0 auto;
    background: var(--c-bg-soft);
    border-radius: var(--radius-lg);
    padding: 48px 56px;
    border: 1px solid var(--c-border);
}
.legal-content h2 {
    font-size: 22px;
    letter-spacing: -0.01em;
    margin-top: 36px;
    margin-bottom: 14px;
    color: var(--c-text);
    display: flex;
    align-items: center;
    gap: 10px;
}
.legal-content h2:first-child { margin-top: 0; }
.legal-content h2 .num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: 8px;
    background: var(--grad-brand);
    color: #fff;
    font-size: 14px;
    font-weight: 700;
    flex-shrink: 0;
}
.legal-content h3 {
    font-size: 16px;
    margin-top: 20px;
    margin-bottom: 8px;
    color: var(--c-text);
}
.legal-content p {
    color: var(--c-text-soft);
    font-size: 15px;
    line-height: 1.8;
    margin-bottom: 12px;
}
.legal-content ul {
    margin: 8px 0 16px 0;
    padding-left: 4px;
}
.legal-content ul li {
    position: relative;
    padding-left: 22px;
    margin-bottom: 8px;
    color: var(--c-text-soft);
    font-size: 15px;
    line-height: 1.7;
}
.legal-content ul li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--c-primary);
}
.legal-content strong { color: var(--c-text); font-weight: 600; }
.legal-back {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 24px;
    color: var(--c-primary);
    font-size: 14px;
    font-weight: 500;
}
.legal-back:hover { text-decoration: underline; }

.permission-block {
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: var(--radius-md);
    padding: 20px 24px;
    margin: 16px 0;
}
.permission-block h3 {
    margin-top: 0;
    color: var(--c-primary);
}

/* ==========================
   Reveal animation
   ========================== */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .8s ease, transform .8s ease;
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================
   响应式 — 平板
   ========================== */
@media (max-width: 960px) {
    .section { padding: 80px 0; }
    .hero { padding: 56px 0 80px; }
    .hero-grid { grid-template-columns: 1fr; gap: 56px; }
    .hero-visual { height: 540px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .ai-grid { grid-template-columns: 1fr; gap: 48px; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .nav-links { display: none; }
    .download-card { padding: 48px 36px; flex-direction: column; align-items: flex-start; text-align: left; }
    .download-actions { align-items: flex-start; }
}

/* ==========================
   响应式 — 手机
   ========================== */
@media (max-width: 600px) {
    .container { padding: 0 20px; }
    .section { padding: 64px 0; }
    .hero { padding: 40px 0 60px; }
    .hero-text h1 { font-size: 36px; }
    .lead { font-size: 16px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn { width: 100%; }
    .hero-meta { justify-content: space-between; gap: 16px; }
    .meta-divider { display: none; }
    .hero-visual { height: 460px; }
    .phone-frame { width: 220px; }
    .features-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
    .footer-brand { grid-column: 1 / -1; }
    .footer-bottom { flex-direction: column; gap: 8px; align-items: flex-start; }
    .legal-content { padding: 32px 24px; }
    .download-card { padding: 36px 28px; }
    .card-ai { right: 10px; }
    .card-cast { left: 10px; }
}