/* ============================================
   甜橙TV 下载官网 - 样式文件
   主色调: #FF6600 (橙色)
   ============================================ */

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

:root {
    --orange:           #FF6600;
    --orange-light:     #FF8533;
    --orange-dark:      #CC5200;
    --orange-bg:        #FFF5EB;
    --orange-gradient:  linear-gradient(135deg, #FF6600, #FF8533);
    --orange-gradient-v: linear-gradient(180deg, #FF6600, #FF8533);
    --gray-50:          #F9FAFB;
    --gray-100:         #F3F4F6;
    --gray-200:         #E5E7EB;
    --gray-300:         #D1D5DB;
    --gray-500:         #6B7280;
    --gray-700:         #374151;
    --gray-900:         #111827;
    --white:            #FFFFFF;

    --shadow-xs:        0 1px 2px rgba(0,0,0,.05);
    --shadow-sm:        0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
    --shadow-md:        0 4px 16px rgba(0,0,0,.1), 0 1px 4px rgba(0,0,0,.06);
    --shadow-lg:        0 10px 40px rgba(0,0,0,.12), 0 4px 12px rgba(0,0,0,.08);
    --shadow-xl:        0 20px 60px rgba(0,0,0,.15), 0 8px 20px rgba(0,0,0,.1);
    --shadow-orange:    0 4px 16px rgba(255,102,0,.35);
    --shadow-orange-hv: 0 8px 32px rgba(255,102,0,.45);

    --radius-sm:        8px;
    --radius:           12px;
    --radius-lg:        20px;
    --radius-xl:        28px;
    --transition:       .3s cubic-bezier(.4,0,.2,1);
    --transition-slow:  .5s cubic-bezier(.4,0,.2,1);
}

html { scroll-behavior: smooth; font-size: 16px; background: #FF6600; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--gray-900);
    background: #FF6600;
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font: inherit; }

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    will-change: transform;
}
.btn:active { transform: scale(.97); }
.btn svg { flex-shrink: 0; }
.btn-primary {
    background: var(--orange);
    color: var(--white);
    box-shadow: var(--shadow-orange);
}
.btn-primary::after {
    content: ''; position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,.25), transparent);
    opacity: 0;
    transition: var(--transition);
}
.btn-primary:hover {
    background: var(--orange-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-orange-hv);
}
.btn-primary:hover::after { opacity: 1; }
.btn-outline {
    border: 2px solid var(--orange);
    color: var(--orange);
    background: transparent;
}
.btn-outline:hover {
    background: var(--orange);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-orange);
}

/* ---------- 导航栏 ---------- */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
    /* 适配刘海屏/安全区域 */
    padding-top: env(safe-area-inset-top);
    top: 0;
}
.navbar.scrolled {
    border-bottom-color: rgba(0,0,0,.06);
    box-shadow: var(--shadow-sm);
    background: rgba(255,255,255,.97);
}
.nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 72px;
}
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon svg { display: block; }
.logo-icon img { display: block; height: 36px; width: auto; object-fit: contain; }
.logo-text {
    font-size: 1.5rem; font-weight: 800;
    background: var(--orange-gradient);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.nav-links { display: flex; gap: 36px; }
.nav-links a {
    font-size: .95rem; font-weight: 500; color: var(--gray-700);
    position: relative; padding: 4px 0;
}
.nav-links a::after {
    content: ''; position: absolute; bottom: -2px; left: 0;
    width: 0; height: 2px;
    background: var(--orange-gradient);
    border-radius: 1px;
    transition: var(--transition);
}
.nav-links a:hover::after { width: 100%; }
.nav-links a:hover { color: var(--orange); }

/* 移动端菜单按钮 */
.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.nav-toggle span {
    display: block; width: 24px; height: 2px;
    background: var(--gray-900); border-radius: 2px;
    transition: var(--transition);
}
.nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ============================================
   Hero — 增强版
   ============================================ */
.hero {
    position: relative;
    background:
        radial-gradient(ellipse at 30% 0%, rgba(255,163,102,.5) 0%, transparent 60%),
        radial-gradient(ellipse at 90% 100%, rgba(255,102,0,.4) 0%, transparent 50%),
        radial-gradient(ellipse at 0% 80%, rgba(255,133,51,.3) 0%, transparent 50%),
        linear-gradient(160deg, #FF6600 0%, #FF7B22 35%, #FF8533 65%, #FF9A4D 100%);
    padding: 140px 0 80px;
    overflow: hidden;
    min-height: 100vh;
    display: flex; align-items: center;
}

/* 叠加动态光效 */
.hero::before {
    content: ''; position: absolute; inset: 0;
    background:
        radial-gradient(circle at 25% 40%, rgba(255,255,255,.12) 0%, transparent 50%),
        radial-gradient(circle at 75% 60%, rgba(255,255,255,.08) 0%, transparent 40%);
    animation: heroShimmer 8s ease-in-out infinite alternate;
    pointer-events: none;
}
@keyframes heroShimmer {
    0%   { opacity: .6; }
    100% { opacity: 1; }
}

/* 浮动光球 */
.hero::after {
    content: ''; position: absolute;
    width: 400px; height: 400px;
    background: radial-gradient(circle, rgba(255,255,255,.15), transparent 70%);
    border-radius: 50%;
    top: 30%; left: 10%;
    animation: heroOrb 12s ease-in-out infinite;
    pointer-events: none;
}
@keyframes heroOrb {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33%      { transform: translate(80px, -40px) scale(1.15); }
    66%      { transform: translate(-40px, 30px) scale(.9); }
}

.hero-inner {
    display: grid; grid-template-columns: 1fr 1fr; gap: 60px;
    align-items: center; position: relative; z-index: 1;
}
.hero-content { color: var(--white); }
.hero-title {
    font-size: 3.5rem; font-weight: 900; line-height: 1.1;
    margin-bottom: 16px; letter-spacing: -1px;
    text-shadow: 0 2px 12px rgba(0,0,0,.12);
}
.highlight {
    color: #FFE0B2;
    text-shadow: 0 0 20px rgba(255,224,178,.4);
}
.hero-slogan {
    font-size: 1.5rem; font-weight: 600;
    margin-bottom: 12px; opacity: .95;
    text-shadow: 0 1px 4px rgba(0,0,0,.08);
}
.hero-desc {
    font-size: 1.05rem; line-height: 1.8;
    margin-bottom: 32px; opacity: .88;
}

/* Hero 按钮 */
.hero-buttons { display: flex; gap: 16px; margin-bottom: 48px; flex-wrap: wrap; }
.hero-buttons .btn-primary {
    background: var(--white); color: var(--orange);
    box-shadow: 0 4px 20px rgba(0,0,0,.15), 0 2px 8px rgba(0,0,0,.1);
}
.hero-buttons .btn-primary:hover {
    background: #FFF8F0;
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0,0,0,.2), 0 4px 12px rgba(0,0,0,.12);
}
.hero-buttons .btn-outline {
    border-color: rgba(255,255,255,.65);
    color: var(--white);
}
.hero-buttons .btn-outline:hover {
    background: rgba(255,255,255,.18);
    border-color: var(--white);
    box-shadow: 0 4px 16px rgba(0,0,0,.1);
}

/* Hero 统计卡片 — 毛玻璃效果 */
.hero-stats { display: flex; gap: 16px; }
.stat-item {
    flex: 1;
    background: rgba(255,255,255,.15);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255,255,255,.2);
    border-radius: var(--radius-lg);
    padding: 18px 16px;
    text-align: center;
    transition: var(--transition);
    will-change: transform;
}
.stat-item:hover {
    background: rgba(255,255,255,.22);
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0,0,0,.1);
}
.stat-item strong {
    display: block;
    font-size: 1.8rem; font-weight: 800;
    letter-spacing: -.5px;
}
.stat-item span { font-size: .85rem; opacity: .85; }

/* 手机模型 — 增强版 */
.hero-visual { display: flex; justify-content: center; position: relative; }
.phone-mockup {
    width: 260px; height: 520px;
    background: var(--white);
    border-radius: 36px;
    box-shadow:
        0 25px 70px rgba(0,0,0,.25),
        0 8px 20px rgba(0,0,0,.12),
        inset 0 0 0 3px rgba(255,255,255,.3);
    padding: 12px; position: relative;
    transform: perspective(900px) rotateY(-10deg) rotateX(2deg);
    transition: var(--transition-slow);
    will-change: transform;
}
.phone-mockup::before {
    content: ''; position: absolute; top: 0; left: 50%;
    transform: translateX(-50%);
    width: 90px; height: 6px;
    background: rgba(0,0,0,.12);
    border-radius: 0 0 6px 6px;
    z-index: 2;
}
.phone-mockup:hover {
    transform: perspective(900px) rotateY(0deg) rotateX(0deg) translateY(-8px);
    box-shadow:
        0 35px 80px rgba(255,102,0,.3),
        0 12px 30px rgba(0,0,0,.15),
        inset 0 0 0 3px rgba(255,255,255,.4);
}
.phone-screen {
    width: 100%; height: 100%;
    background: var(--orange-gradient-v);
    border-radius: 28px; overflow: hidden;
    padding: 20px 12px;
    box-shadow: inset 0 0 40px rgba(0,0,0,.08);
}
.phone-screen img {
    width: 100%; height: 100%;
    object-fit: cover;
    display: block;
    border-radius: 4px;
}
.mockup-header {
    color: var(--white); font-weight: 700; font-size: 1.1rem;
    text-align: center; margin-bottom: 16px;
    letter-spacing: .5px;
}
.mockup-poster {
    width: 100%; height: 140px;
    background: rgba(255,255,255,.18);
    border-radius: 12px;
    margin-bottom: 10px;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.2);
}
.mockup-poster.small { height: 80px; margin-bottom: 12px; }
.mockup-row { display: flex; gap: 8px; }
.mockup-thumb {
    flex: 1; height: 60px;
    background: rgba(255,255,255,.18);
    border-radius: 8px;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.2);
}

/* Hero 光晕 */
.hero-glow {
    position: absolute;
    width: 380px; height: 380px;
    background: radial-gradient(circle, rgba(255,255,255,.18) 0%, transparent 70%);
    top: 50%; left: 50%; transform: translate(-50%,-50%);
    pointer-events: none;
    animation: glowPulse 6s ease-in-out infinite;
}
@keyframes glowPulse {
    0%, 100% { transform: translate(-50%,-50%) scale(1); opacity: .7; }
    50%      { transform: translate(-50%,-50%) scale(1.15); opacity: 1; }
}

/* 波浪 */
.hero-wave {
    position: absolute; bottom: -1px; left: 0; right: 0;
    line-height: 0; z-index: 2;
}
.hero-wave svg { width: 100%; height: 80px; }

/* ---------- Section 通用 ---------- */
.section-header {
    text-align: center; margin-bottom: 60px;
}
.section-header h2 {
    font-size: 2.2rem; font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: -.5px;
}
.section-header p { font-size: 1.1rem; color: var(--gray-500); }

/* ============================================
   功能介绍 — 增强版
   ============================================ */
.features {
    padding: 100px 0; background: var(--white);
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}
.feature-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    padding: 44px 32px 36px;
    text-align: center;
    transition: var(--transition-slow);
    position: relative; overflow: hidden;
    will-change: transform;
}

/* 顶部渐变条 */
.feature-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0;
    height: 4px;
    background: var(--orange-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-slow);
}
.feature-card:hover::before { transform: scaleX(1); }

/* 右下角装饰 */
.feature-card::after {
    content: ''; position: absolute; bottom: -30px; right: -30px;
    width: 100px; height: 100px;
    background: radial-gradient(circle, rgba(255,102,0,.06), transparent 70%);
    border-radius: 50%;
    transition: var(--transition-slow);
    opacity: 0;
}
.feature-card:hover::after { opacity: 1; transform: scale(1.5); }

.feature-card:hover {
    border-color: var(--orange-light);
    transform: translateY(-8px);
    box-shadow:
        0 20px 50px rgba(255,102,0,.13),
        0 6px 16px rgba(0,0,0,.06);
}

/* 图标 */
.feature-icon {
    width: 76px; height: 76px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, #FFF5EB, #FFE8D6);
    border-radius: 22px;
    display: flex; align-items: center; justify-content: center;
    transition: var(--transition-slow);
    position: relative;
    z-index: 1;
}
.feature-icon svg { width: 38px; height: 38px; transition: var(--transition); }
.feature-card:hover .feature-icon {
    background: var(--orange-gradient);
    border-radius: 24px;
    transform: scale(1.06);
    box-shadow: 0 8px 24px rgba(255,102,0,.25);
}
.feature-card:hover .feature-icon svg {
    filter: brightness(0) invert(1);
    transform: scale(1.1);
}
.feature-card h3 {
    font-size: 1.25rem; font-weight: 700;
    margin-bottom: 12px;
    transition: var(--transition);
}
.feature-card:hover h3 { color: var(--orange); }
.feature-card p { font-size: .95rem; color: var(--gray-500); line-height: 1.7; }

/* ============================================
   截图展示 — 增强版
   ============================================ */
.screenshots {
    padding: 100px 0;
    background: linear-gradient(180deg, var(--gray-50) 0%, #FFF8F3 50%, var(--white) 100%);
}
.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
}
.screenshot-item { text-align: center; }
.screenshot-mockup {
    width: 100%; max-width: 220px;
    margin: 0 auto 16px;
    aspect-ratio: 9/19;
    background: var(--white);
    border-radius: 28px;
    box-shadow: var(--shadow-md);
    overflow: hidden;
    border: 3px solid var(--gray-200);
    transition: var(--transition-slow);
    position: relative;
    will-change: transform;
}
.screenshot-mockup::before {
    content: ''; position: absolute; inset: 0;
    border-radius: 24px;
    background: linear-gradient(135deg, rgba(255,102,0,.06), transparent 60%, rgba(255,102,0,.03));
    opacity: 0;
    transition: var(--transition);
    z-index: 1; pointer-events: none;
}
.screenshot-mockup:hover {
    transform: translateY(-10px) scale(1.04);
    box-shadow:
        0 20px 60px rgba(255,102,0,.18),
        0 8px 20px rgba(0,0,0,.08);
    border-color: var(--orange);
}
.screenshot-mockup:hover::before { opacity: 1; }
.screenshot-mockup img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 24px;
    display: block;
}
.sc-content { padding: 10px; height: 100%; display: flex; flex-direction: column; gap: 6px; }

/* 首页截图 */
.sc-home .sc-topbar { height: 14px; background: var(--orange-gradient); border-radius: 4px; }
.sc-home .sc-banner {
    height: 40%;
    background: linear-gradient(135deg, #FFF5EB, #FFE0B2);
    border-radius: 8px;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.6);
}
.sc-home .sc-row { display: flex; gap: 4px; }
.sc-home .sc-card { flex: 1; height: 30px; background: var(--gray-100); border-radius: 4px; }

/* 播放截图 */
.sc-player .sc-topbar { height: 14px; background: rgba(0,0,0,.75); border-radius: 4px; }
.sc-player .sc-video {
    flex: 1; background: linear-gradient(135deg, #1a1a1a, #2a2a2a);
    border-radius: 8px; position: relative;
}
.sc-player .sc-video::after {
    content: '▶'; position: absolute; inset: 0;
    display: flex; align-items: center; justify-content: center;
    color: var(--white); font-size: 2rem; opacity: .55;
}
.sc-player .sc-progress { height: 4px; background: var(--gray-200); border-radius: 2px; position: relative; }
.sc-player .sc-progress::after {
    content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 40%;
    background: var(--orange-gradient); border-radius: 2px;
}
.sc-player .sc-controls { height: 20px; background: var(--gray-100); border-radius: 4px; }

/* 搜索截图 */
.sc-search .sc-topbar { height: 14px; background: var(--orange-gradient); border-radius: 4px; }
.sc-search .sc-searchbar { height: 20px; background: var(--gray-100); border-radius: 10px; }
.sc-search .sc-tags { display: flex; gap: 3px; }
.sc-search .sc-tags span { flex: 1; height: 10px; background: var(--orange-bg); border-radius: 3px; }
.sc-search .sc-list { flex: 1; display: flex; flex-direction: column; gap: 4px; }
.sc-search .sc-item { flex: 1; background: var(--gray-100); border-radius: 4px; }

/* 个人中心截图 */
.sc-profile .sc-topbar { height: 14px; background: var(--orange-gradient); border-radius: 4px; }
.sc-profile .sc-avatar {
    width: 40px; height: 40px; border-radius: 50%;
    background: linear-gradient(135deg, var(--orange-bg), #FFE0B2);
    margin: 0 auto;
}
.sc-profile .sc-menu { flex: 1; display: flex; flex-direction: column; gap: 4px; }
.sc-profile .sc-menu div { flex: 1; background: var(--gray-100); border-radius: 4px; }

.screenshot-label {
    font-size: .9rem; font-weight: 600; color: var(--gray-700);
    transition: var(--transition);
}
.screenshot-mockup:hover + .screenshot-label,
.screenshot-item:hover .screenshot-label { color: var(--orange); }

/* ============================================
   下载区域 — 增强版
   ============================================ */
.download {
    padding: 100px 0;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(255,255,255,.1) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(255,255,255,.08) 0%, transparent 40%),
        linear-gradient(150deg, #FF6600 0%, #FF7B22 40%, #FF8533 70%, #FF9A4D 100%);
    position: relative; overflow: hidden;
}
.download::before {
    content: ''; position: absolute; inset: 0;
    background:
        radial-gradient(circle at 85% 15%, rgba(255,255,255,.15) 0%, transparent 60%),
        radial-gradient(circle at 10% 90%, rgba(255,255,255,.1) 0%, transparent 50%);
    pointer-events: none;
}
.download .section-header h2 { color: var(--white); }
.download .section-header p { color: rgba(255,255,255,.82); }
.download-cards {
    display: grid; grid-template-columns: repeat(2, 1fr);
    gap: 32px; max-width: 800px; margin: 0 auto 48px;
    position: relative; z-index: 1;
}
.download-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: 48px 32px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    transition: var(--transition-slow);
    position: relative; overflow: hidden;
    will-change: transform;
}
.download-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0;
    height: 4px;
    background: var(--orange-gradient);
    transform: scaleX(0);
    transform-origin: center;
    transition: var(--transition-slow);
}
.download-card:hover {
    transform: translateY(-8px);
    box-shadow:
        0 24px 60px rgba(0,0,0,.2),
        0 8px 20px rgba(0,0,0,.1);
}
.download-card:hover::before { transform: scaleX(1); }
.dc-icon {
    margin-bottom: 20px; color: var(--orange);
    transition: var(--transition);
}
.dc-icon svg { width: 56px; height: 56px; transition: var(--transition); }
.download-card:hover .dc-icon svg { transform: scale(1.1); }
.download-card h3 { font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; }
.dc-version {
    font-size: .9rem; color: var(--orange); font-weight: 600;
    margin-bottom: 8px; padding: 4px 16px;
    background: var(--orange-bg); border-radius: 20px;
    display: inline-block;
}
.download-card p { font-size: .95rem; color: var(--gray-500); margin-bottom: 24px; }
.download-card .btn { width: 100%; justify-content: center; }
.dc-hint { font-size: .8rem; color: var(--gray-300); margin-top: 12px; margin-bottom: 0; }

/* 二维码 */
.download-qr { text-align: center; position: relative; z-index: 1; }
.download-qr p { color: rgba(255,255,255,.82); margin-bottom: 16px; font-size: .95rem; }
.qr-code {
    width: 128px; height: 128px; margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 12px;
    box-shadow:
        0 8px 30px rgba(0,0,0,.15),
        0 2px 8px rgba(0,0,0,.08);
    transition: var(--transition);
}
.qr-code:hover { transform: scale(1.05); box-shadow: var(--shadow-lg); }
.qr-code svg { width: 100%; height: 100%; }

/* ---------- 页脚 ---------- */
.footer {
    background: linear-gradient(180deg, #1a1f2e, var(--gray-900));
    color: var(--gray-300);
    padding: 60px 0 24px;
}
.footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px; margin-bottom: 40px;
}
.footer-brand .logo-text {
    font-size: 1.5rem; font-weight: 800; display: block; margin-bottom: 12px;
    -webkit-text-fill-color: var(--white);
}
.footer-brand p { font-size: .9rem; line-height: 1.7; }
.footer-links h4 {
    color: var(--white); font-size: .95rem; font-weight: 700;
    margin-bottom: 16px;
}
.footer-links a {
    display: block; font-size: .9rem; margin-bottom: 10px;
    transition: var(--transition);
    padding: 2px 0;
}
.footer-links a:hover { color: var(--orange); padding-left: 6px; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.08);
    padding-top: 24px; text-align: center;
}
.footer-bottom p { font-size: .85rem; }

/* ---------- 返回顶部 ---------- */
.back-to-top {
    position: fixed; bottom: 32px; right: 32px; z-index: 999;
    width: 48px; height: 48px;
    background: var(--orange-gradient);
    color: var(--white);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    box-shadow: var(--shadow-orange);
    opacity: 0; visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
}
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-orange-hv);
}

/* ---------- 动画 ---------- */
.animate-hidden {
    opacity: 0; transform: translateY(30px);
    transition: opacity .7s cubic-bezier(.4,0,.2,1), transform .7s cubic-bezier(.4,0,.2,1);
}
.animate-visible {
    opacity: 1; transform: translateY(0);
}

/* 卡片入场延迟 */
.feature-card:nth-child(1) { transition-delay: 0s; }
.feature-card:nth-child(2) { transition-delay: .06s; }
.feature-card:nth-child(3) { transition-delay: .12s; }
.feature-card:nth-child(4) { transition-delay: .18s; }
.feature-card:nth-child(5) { transition-delay: .24s; }
.feature-card:nth-child(6) { transition-delay: .3s; }
.screenshot-item:nth-child(2) { transition-delay: .06s; }
.screenshot-item:nth-child(3) { transition-delay: .12s; }
.screenshot-item:nth-child(4) { transition-delay: .18s; }

/* ============================================
   响应式
   ============================================ */

/* ---------- ≤ 1024px ---------- */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .screenshots-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}

/* ---------- ≤ 768px ---------- */
@media (max-width: 768px) {
    /* 容器间距 */
    .container { padding: 0 16px; }

    /* Section 间距 */
    .features,
    .screenshots,
    .download { padding: 60px 0; }
    .section-header { margin-bottom: 40px; }

    /* 导航栏 */
    .nav-links {
        position: fixed; top: 72px; left: 0; right: 0;
        background: rgba(255,255,255,.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px; gap: 4px;
        box-shadow: var(--shadow-xl);
        transform: translateY(-120%); transition: var(--transition);
        z-index: 999;
    }
    .nav-links.active { transform: translateY(0); }
    .nav-toggle { display: flex; }
    .nav-links a {
        display: block; padding: 14px 16px;
        font-size: 1.05rem; font-weight: 600;
        border-radius: var(--radius);
        transition: var(--transition);
    }
    .nav-links a:active { background: var(--orange-bg); color: var(--orange); }

    /* Hero */
    .hero { padding: 120px 0 60px; min-height: auto; }
    .hero-inner { grid-template-columns: 1fr; text-align: center; gap: 40px; }
    .hero-title { font-size: 2.4rem; }
    .hero-slogan { font-size: 1.2rem; }
    .hero-buttons { justify-content: center; gap: 12px; }
    .hero-buttons .btn { min-height: 48px; padding: 14px 28px; }
    .hero-stats {
        justify-content: center;
        gap: 12px;
    }

    /* 隐藏手机模型 */
    .hero-visual { display: none; }
    .hero-wave svg { height: 40px; }

    /* 功能介绍 */
    .features-grid { grid-template-columns: 1fr; gap: 20px; }
    .feature-card { padding: 32px 24px; }

    /* 截图 */
    .screenshots-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
    .screenshot-mockup { max-width: 160px; }

    /* 下载 */
    .download-cards {
        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
        gap: 24px;
    }
    .download-card { padding: 36px 24px; }

    /* 页脚 */
    .footer { padding: 48px 0 20px; }
    .footer-grid { grid-template-columns: 1fr; gap: 28px; text-align: center; }

    /* 返回顶部 */
    .back-to-top { bottom: 24px; right: 20px; width: 44px; height: 44px; }
}

/* ---------- ≤ 480px ---------- */
@media (max-width: 480px) {
    /* Hero */
    .hero-title { font-size: 1.8rem; }
    .hero-slogan { font-size: 1.05rem; }
    .hero-desc { font-size: .95rem; margin-bottom: 24px; }

    /* 按钮竖向全宽 */
    .hero-buttons { flex-direction: column; align-items: center; gap: 12px; }
    .hero-buttons .btn { width: 100%; max-width: 280px; justify-content: center; }

    /* 统计 — 3 列水平 */
    .hero-stats {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }
    .stat-item { padding: 14px 10px; }
    .stat-item strong { font-size: 1.4rem; }
    .stat-item span { font-size: .78rem; }

    /* Section 标题 */
    .section-header h2 { font-size: 1.7rem; }
    .section-header p { font-size: .95rem; }

    /* 截图 — 单列居中 */
    .screenshots-grid { grid-template-columns: 1fr; justify-items: center; gap: 24px; }
    .screenshot-mockup { max-width: 180px; }

    /* 功能卡片 */
    .feature-card { padding: 28px 20px; }
    .feature-icon { width: 64px; height: 64px; }
    .feature-icon svg { width: 32px; height: 32px; }
    .feature-card h3 { font-size: 1.15rem; }
    .feature-card p { font-size: .9rem; }

    /* 下载卡片 */
    .download-card { padding: 28px 20px; }
    .download-card h3 { font-size: 1.2rem; }
    .dc-version { font-size: .85rem; }
    .download-card p { font-size: .9rem; }
    .download-card .btn { min-height: 48px; padding: 14px 24px; }
    .dc-icon svg { width: 48px; height: 48px; }

    /* 页脚链接触摸优化 */
    .footer-links a { padding: 8px 0; display: block; }
}

/* ---------- ≤ 375px ---------- */
@media (max-width: 375px) {
    .hero {
        padding: 100px 0 48px;
    }
    .hero-title { font-size: 1.55rem; letter-spacing: -.5px; }
    .hero-slogan { font-size: .9rem; }
    .hero-desc { font-size: .82rem; line-height: 1.55; margin-bottom: 20px; }

    /* 统计 — 紧凑 3 列 */
    .hero-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 6px;
    }
    .stat-item {
        padding: 10px 6px;
        border-radius: var(--radius);
    }
    .stat-item strong { font-size: 1.15rem; }
    .stat-item span { font-size: .68rem; }

    /* 按钮紧凑 */
    .hero-buttons .btn {
        padding: 12px 20px; font-size: .9rem;
        min-height: 44px;
    }
    .hero-buttons .btn svg { width: 18px; height: 18px; }

    /* Section 标题 */
    .section-header { margin-bottom: 32px; }
    .section-header h2 { font-size: 1.5rem; }
    .section-header p { font-size: .9rem; }

    /* 功能卡片继续压缩 */
    .features { padding: 48px 0; }
    .features-grid { gap: 16px; }
    .feature-card { padding: 24px 16px; }

    /* 截图 */
    .screenshots { padding: 48px 0; }
    .screenshot-mockup { max-width: 140px; }

    /* 下载 */
    .download { padding: 48px 0; }
    .download-cards { gap: 16px; }
    .download-card { padding: 24px 16px; }
    .download-card .btn { padding: 12px 18px; font-size: .88rem; min-height: 44px; }

    /* 二维码 */
    .qr-code { width: 108px; height: 108px; padding: 10px; }
    .download-qr p { font-size: .85rem; margin-bottom: 12px; }

    /* 返回顶部 */
    .back-to-top { bottom: 16px; right: 12px; width: 38px; height: 38px; }
    .back-to-top svg { width: 18px; height: 18px; }
}

/* ---------- ≤ 320px ---------- */
@media (max-width: 320px) {
    .hero { padding: 96px 0 40px; }
    .hero-title { font-size: 1.35rem; }
    .hero-slogan { font-size: .82rem; }
    .hero-desc { font-size: .76rem; line-height: 1.45; margin-bottom: 16px; }

    .hero-buttons { gap: 8px; }
    .hero-buttons .btn {
        padding: 11px 16px; font-size: .82rem;
        min-height: 42px;
    }
    .hero-buttons .btn svg { width: 16px; height: 16px; }

    .hero-stats {
        gap: 4px;
    }
    .stat-item {
        padding: 8px 4px;
        border-radius: var(--radius-sm);
    }
    .stat-item strong { font-size: 1rem; }
    .stat-item span { font-size: .62rem; }

    .section-header h2 { font-size: 1.3rem; }
    .section-header p { font-size: .82rem; }

    .screenshot-mockup { max-width: 120px; border-radius: 20px; }
    .feature-card { padding: 20px 12px; }
    .feature-icon { width: 56px; height: 56px; border-radius: 16px; }
    .feature-icon svg { width: 28px; height: 28px; }
    .feature-card h3 { font-size: 1.05rem; margin-bottom: 8px; }
    .feature-card p { font-size: .82rem; line-height: 1.5; }

    .download-card { padding: 20px 12px; }
    .download-card h3 { font-size: 1.05rem; }
    .download-card p { font-size: .82rem; margin-bottom: 16px; }
    .dc-version { font-size: .78rem; padding: 3px 12px; }
    .dc-icon svg { width: 40px; height: 40px; }

    .qr-code { width: 96px; height: 96px; padding: 8px; border-radius: var(--radius); }

    .nav-links a { padding: 12px 12px; font-size: .95rem; }
    .container { padding: 0 12px; }
}

/* ============================================
   性能与无障碍
   ============================================ */

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: .01ms !important;
    }
    html { scroll-behavior: auto; }
}

/* GPU 加速 (给动画元素) */
.phone-mockup,
.feature-card,
.screenshot-mockup,
.download-card,
.back-to-top,
.stat-item {
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
}

/* 触摸优化 */
@media (hover: none) and (pointer: coarse) {
    /* 触摸设备使用 :active 代替 :hover */
    .feature-card:active,
    .screenshot-mockup:active,
    .download-card:active,
    .stat-item:active {
        transform: scale(.98) translateZ(0);
    }

    /* 确保触摸区域不小于 44px */
    .nav-links a,
    .footer-links a,
    .btn {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
    }
}

/* 管理后台样式 */
.screenshot-slot {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    padding: 20px;
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 20px;
    align-items: flex-start;
}
.screenshot-slot-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}
.slot-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px; height: 24px;
    background: var(--orange);
    color: var(--white);
    border-radius: 50%;
    font-size: .75rem;
    font-weight: 700;
    flex-shrink: 0;
}
.slot-label-input {
    flex: 1;
    padding: 6px 10px;
    border: 1px solid var(--gray-200);
    border-radius: 6px;
    font-size: .9rem;
    outline: none;
    transition: var(--transition);
}
.slot-label-input:focus {
    border-color: var(--orange);
    box-shadow: 0 0 0 3px rgba(255,102,0,.12);
}
.screenshot-slot-body {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    flex-wrap: wrap;
}
.screenshot-preview {
    width: 120px; height: 200px;
    border: 2px dashed var(--gray-200);
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--white);
    flex-shrink: 0;
    position: relative;
}
.screenshot-preview img {
    width: 100%; height: 100%; object-fit: cover;
}
.screenshot-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--gray-300);
    font-size: .75rem;
    gap: 6px; padding: 8px; text-align: center;
}
.screenshot-placeholder svg { width: 32px; height: 32px; opacity: .4; }
.screenshot-slot-actions {
    display: flex; flex-direction: column; gap: 8px;
}
.screenshot-slot-actions .file-upload-wrapper { width: 100%; }
.screenshot-slot-actions .btn { width: 100%; }
.screenshot-slots { display: flex; flex-direction: column; gap: 20px; }

@media (max-width: 640px) {
    .screenshot-slot { grid-template-columns: 1fr; }
    .screenshot-slot-body { flex-direction: column; }
}