/* ===== 基础重置 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background-color: #0b0f19;
    color: #b0b0b0;
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

/* ===== 导航栏 ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(11, 15, 25, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    color: #d0d0d0;
    letter-spacing: 0.5px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav a {
    font-size: 15px;
    color: #b0b0b0;
    transition: color 0.2s;
}

.nav a:hover {
    color: #d0d0d0;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 6px;
    padding: 5px 12px;
    color: #ffffff;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.14);
}

.flag {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 16px;
    border-radius: 2px;
    overflow: hidden;
    line-height: 1;
}

.flag svg {
    width: 100%;
    height: 100%;
    display: block;
}

/* ===== Hero 区域 ===== */
.hero {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 120px 24px 60px;
}

.hero-content {
    max-width: 700px;
    margin: 0 auto 50px;
}

.brand-logo {
    margin-bottom: 24px;
}

.logo-img {
    width: 220px;
    height: auto;
    display: block;
    margin: 0 auto 8px;
}

.brand-sub {
    font-size: 20px;
    color: #3b82f6;
    font-weight: 600;
    margin-top: 4px;
    letter-spacing: 4px;
}

.brand-en {
    font-size: 12px;
    color: #666;
    letter-spacing: 3px;
    margin-top: 2px;
    text-transform: uppercase;
}

.hero-tagline {
    font-size: 17px;
    color: #a0a0a0;
    line-height: 1.8;
    margin-bottom: 28px;
}

.btn-trial {
    display: inline-block;
    background: #2563eb;
    color: #c8d8f0;
    padding: 12px 40px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    transition: background 0.2s, transform 0.15s;
}

.btn-trial:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.hero-image-wrap {
    position: relative;
    max-width: 960px;
    margin: 0 auto;
}

.hero-glow {
    position: absolute;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 150%;
    height: 110%;
    background: radial-gradient(ellipse at center, rgba(59, 130, 246, 0.7) 0%, rgba(59, 130, 246, 0.4) 20%, rgba(59, 130, 246, 0.15) 45%, transparent 70%);
    filter: blur(35px);
    pointer-events: none;
    z-index: 0;
}

.hero-image {
    position: relative;
    z-index: 1;
    border-radius: 12px;
    overflow: hidden;
}

.hero-image img {
    width: 100%;
    border-radius: 12px;
    display: block;
}

.hero-notes-left,
.hero-notes-right {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: calc(45% + 24px);
    height: 110%;
    background-size: contain;
    background-repeat: no-repeat;
    pointer-events: none;
    z-index: 0;
    opacity: 0.43;
    mix-blend-mode: screen;
}

.hero-notes-left {
    left: -24px;
    background-image: url('../images/背景音符透明左.png');
    background-position: left center;
}

.hero-notes-right {
    right: -24px;
    background-image: url('../images/背景音符透明右.png');
    background-position: right center;
}

.envelope-stack {
    display: flex;
    flex-direction: column;
    box-shadow: none;
}

.envelope-stack img {
    width: 100%;
    display: block;
    mix-blend-mode: screen;
}

.envelope-stack img:first-child {
    border-radius: 10px 10px 0 0;
}

.envelope-stack img:last-child {
    border-radius: 0 0 10px 10px;
}

/* ===== 功能区域通用 ===== */
.feature-section {
    position: relative;
    z-index: 1;
    padding: 60px 24px;
    max-width: 1100px;
    margin: 0 auto;
}

.feature-title {
    text-align: center;
    font-size: 22px;
    font-weight: 600;
    color: #c0c0c0;
    margin-bottom: 32px;
    letter-spacing: 1px;
}

.feature-image-wrap {
    border-radius: 10px;
    overflow: hidden;
}

.feature-image-wrap img {
    width: 100%;
    border-radius: 10px;
    transition: transform 0.3s;
}

.feature-image-wrap:hover img {
    transform: scale(1.01);
}

/* 全宽区域 */
.feature-section.full-width {
    max-width: 900px;
}

/* ===== 两栏布局 ===== */
.feature-section.two-col {
    max-width: 1100px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 120px;
    align-items: start;
}

.feature-card {
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

.feature-card .feature-image-wrap {
    flex: 1;
    display: flex;
    align-items: center;
}

.feature-card .feature-title {
    text-align: left;
    font-size: 18px;
    margin-bottom: 20px;
}

.feature-section.two-col .feature-card img {
    max-width: 420px;
}

/* K歌区域麦克风图标 */
.karaoke-wrap {
    position: relative;
}

.karaoke-wrap .karaoke-img {
    object-position: left bottom;
    object-fit: cover;
    max-height: 320px;
}

.mic-icon {
    position: absolute;
    right: 20px;
    bottom: 20px;
    width: 56px;
    height: 56px;
    background: rgba(11, 15, 25, 0.7);
    border: 2px solid #3b82f6;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
}

.mic-icon svg {
    width: 28px;
    height: 28px;
}

/* ===== 页脚 ===== */
.footer {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 40px 24px 50px;
    color: #888;
    font-size: 14px;
}

.footer-tech,
.footer-copyright,
.footer-icp {
    margin: 8px 0;
}

.footer-email {
    color: #3b82f6;
}

/* ===== 开场动画遮罩 ===== */
.intro-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #0b0f19;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    pointer-events: none;
}

/* 遮罩背景淡出 */
.intro-overlay {
    animation: overlayBgOut 1s ease-in-out 2.2s forwards;
}

@keyframes overlayBgOut {
    0% { background: #0b0f19; }
    100% { background: transparent; }
}

/* 开屏内容整体缩小上移 */
.intro-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    animation: introShrink 1.2s ease-in-out 2s forwards;
}

@keyframes introShrink {
    0% {
        transform: scale(1) translateY(0);
        opacity: 1;
    }
    100% {
        transform: scale(0.45) translateY(-320px);
        opacity: 0;
    }
}

.intro-logo {
    width: 260px;
    height: auto;
    margin-bottom: 8px;
}

.intro-brand-sub {
    font-size: 28px;
    color: #3b82f6;
    font-weight: 600;
    letter-spacing: 6px;
    margin-bottom: 8px;
}

.intro-brand-en {
    font-size: 14px;
    color: #666;
    letter-spacing: 5px;
    text-transform: uppercase;
    margin-bottom: 40px;
}

.intro-tagline {
    font-size: 20px;
    color: #a0a0a0;
    line-height: 1.8;
    text-align: center;
    margin-bottom: 36px;
}

/* ===== 页面元素入场动画 ===== */

/* 导航栏淡入 */
.header {
    opacity: 0;
    animation: fadeIn 0.6s ease-out 2.6s forwards;
}

/* Hero 区域淡入上移 */
.hero {
    opacity: 0;
    transform: translateY(30px);
    animation: slideUpFade 0.8s ease-out 2.4s forwards;
}

/* 功能模块依次淡入 */
.feature-section {
    opacity: 0;
    transform: translateY(30px);
}

.anim-item-1 { animation: slideUpFade 0.7s ease-out 2.8s forwards; }
.anim-item-2 { animation: slideUpFade 0.7s ease-out 3.0s forwards; }
.anim-item-3 { animation: slideUpFade 0.7s ease-out 3.2s forwards; }
.anim-item-4 { animation: slideUpFade 0.7s ease-out 3.4s forwards; }
.anim-item-5 { animation: slideUpFade 0.7s ease-out 3.6s forwards; }

/* 页脚淡入 */
.footer {
    opacity: 0;
    animation: fadeIn 0.6s ease-out 3.8s forwards;
}

@keyframes fadeIn {
    0% { opacity: 0; }
    100% { opacity: 1; }
}

@keyframes slideUpFade {
    0% {
        opacity: 0;
        transform: translateY(30px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== 悬浮购买按钮 ===== */
.float-buy-btn {
    position: fixed;
    top: 80px;
    right: 24px;
    width: 44px;
    height: 44px;
    background: rgba(37, 99, 235, 0.9);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    z-index: 999;
    transition: background 0.2s, transform 0.15s;
    backdrop-filter: blur(8px);
    cursor: grab;
    user-select: none;
    -webkit-user-select: none;
}
.float-buy-btn:hover {
    background: rgba(37, 99, 235, 1);
    transform: scale(1.1);
}
.float-buy-btn.dragging {
    cursor: grabbing;
    transition: none;
    transform: scale(1.15);
}