/* 1. 极致重置与字体设置 (对标 Apple/Manus) */
body, html {
    margin: 0; padding: 0; min-height: 100vh;
    background-color: #000000; /* 绝对纯黑 */
    color: #f8fafc;
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, sans-serif;
    overflow-x: hidden;
}

/* 背景氛围光晕 */
.ambient-glow {
    position: absolute; top: 30%; left: 50%; transform: translate(-50%, -50%);
    width: 80vw; height: 50vh;
    background: radial-gradient(ellipse at center, rgba(56, 189, 248, 0.12) 0%, rgba(0,0,0,0) 70%);
    z-index: 0; pointer-events: none;
}

/* 顶部导航 */
.navbar-custom {
    width: 100%; padding: 20px 40px; position: relative; z-index: 10;
    display: flex; justify-content: space-between; align-items: center;
}
.nav-brand { font-size: 1.25rem; font-weight: 700; letter-spacing: -0.5px; color: #fff; text-decoration: none; display: flex; align-items: center; gap: 8px;}
.nav-brand i { color: #e0e0e0; }

/* 2. 核心排版区 */
.hero-section {
    position: relative; z-index: 10; width: 100%;
    display: flex; flex-direction: column; align-items: center;
    margin-top: 4vh; padding: 0 20px;
}

/* 巨无霸标题，字间距收紧 */
.hero-title {
    font-size: clamp(3rem, 6vw, 5.5rem); /* 响应式巨型字体 */
    font-weight: 800; letter-spacing: -0.04em; line-height: 1.1;
    text-align: center; margin-bottom: 20px;
    background: linear-gradient(180deg, #ffffff 0%, #a1a1aa 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.3rem); color: #a1a1aa; text-align: center;
    margin-bottom: 50px; font-weight: 400; max-width: 600px;
}

/* 3. 真·巨幅发布会视频窗口 (z-index: 5) */
.video-presentation-layer {
    position: relative; z-index: 5; width: 100%; max-width: 1100px; /* 撑满屏幕主体 */
    aspect-ratio: 16 / 9; border-radius: 20px;
    background-color: #09090b;
    /* 钛金属边框与极度平滑的阴影 */
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 30px 100px -20px rgba(0,0,0,1), 0 0 80px rgba(255,255,255,0.05);
    overflow: hidden;
    transform: translateY(0); transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.video-presentation-layer:hover {
    transform: translateY(-8px) scale(1.01); /* 轻微上浮，极具张力 */
}

/* 绝对移除丑陋控件，只做纯粹展示 */
.video-presentation-layer video {
    width: 100%; height: 100%; object-fit: cover; filter: contrast(1.05) brightness(0.95);
}

/* 大厂专属：极简静音开关 (位于视频右下角内部) */
.custom-mute-btn {
    position: absolute; bottom: 20px; right: 20px;
    width: 40px; height: 40px; border-radius: 50%;
    background: rgba(0, 0, 0, 0.6); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    display: flex; justify-content: center; align-items: center; color: white;
    border: 1px solid rgba(255,255,255,0.2); cursor: pointer; transition: 0.2s;
}
.custom-mute-btn:hover { background: rgba(255, 255, 255, 0.2); transform: scale(1.1);}

/* 4. 科幻 Dock 登录/注册舱 (z-index: 10) */
.auth-dock-container {
    /* 终极修改：删除负 margin-top，改用正的上下留白，彻底消除遮挡，制造大气留白感 */
    margin-top: 25px; /* 这里换成正的，把胶囊向下移 */
    margin-bottom: 25px;

    position: relative; z-index: 10;
    width: 100%; max-width: 700px; /* 登录的宽度 */
    transition: max-width 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 当切换到注册时，胶囊自动变宽以容纳更多输入框 */
.auth-dock-container.register-mode {
    max-width: 900px;
}

.auth-dock {
    background: rgba(20, 20, 20, 0.7);
    backdrop-filter: blur(24px) saturate(150%); -webkit-backdrop-filter: blur(24px) saturate(150%);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 100px;
    padding: 12px 12px 12px 30px;
    display: flex; align-items: center; justify-content: space-between; gap: 15px;
    box-shadow: 0 25px 50px rgba(0,0,0,0.8), 0 0 0 1px rgba(255,255,255,0.05) inset;
}

.dock-input {
    background: transparent; border: none; color: #fff; flex: 1; font-size: 1.05rem; outline: none; width: 100%;
}
.dock-input::placeholder { color: #71717a; font-weight: 400; }

.dock-divider { width: 1px; height: 28px; background-color: rgba(255,255,255,0.15); flex-shrink: 0; }

.btn-dock-submit {
    background-color: #fff; color: #000; border: none; border-radius: 50px;
    padding: 14px 35px; font-weight: 600; font-size: 1rem; cursor: pointer;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1); display: flex; align-items: center; gap: 8px; flex-shrink: 0;
    white-space: nowrap;
}
.btn-dock-submit:hover {
    background-color: #e4e4e7; box-shadow: 0 0 20px rgba(255,255,255,0.4);
}

/* 隐藏和淡入动画 */
.fade-form { display: none; opacity: 0; transition: opacity 0.4s ease; }
.fade-form.active { display: flex; opacity: 1; }

/* 底部链接 */
.footer-links { margin-top: 40px; color: #71717a; font-size: 0.9rem; text-align: center; margin-bottom: 50px;}
.footer-links span { cursor: pointer; color: #a1a1aa; margin-left: 10px; transition: color 0.2s; border-bottom: 1px solid transparent;}
.footer-links span:hover { color: #fff; border-bottom-color: #fff;}

/* 消息提示样式 */
.message-container {
    text-align: center;
    margin-bottom: 12px;
    font-size: 14px;
}
.error-message {
    color: #f87171;
}
.success-message {
    color: #34d399;
}

@media (max-width: 768px) {
    .navbar-custom { padding: 15px 20px; }
    .hero-section { margin-top: 2vh; padding: 0 15px; }
    .hero-title { font-size: clamp(2rem, 8vw, 3rem); margin-bottom: 15px; }
    .hero-subtitle { font-size: 1rem; margin-bottom: 30px; padding: 0 10px; }
    .video-presentation-layer { border-radius: 12px; margin: 0 10px; width: calc(100% - 20px); }
    .auth-dock-container { margin-top: 20px; padding: 0 15px; max-width: 100%; }
    .auth-dock-container.register-mode { max-width: 100%; }
    /* 关键修复：移动端改为垂直布局 */
    .auth-dock { flex-direction: column !important; border-radius: 24px; padding: 20px; align-items: stretch; gap: 10px;}
    .dock-divider { width: 100%; height: 1px; margin: 5px 0;}
    /* 输入框字体 16px 防止 iOS 自动缩放 */
    .dock-input { padding: 10px 0; font-size: 16px !important; }
    .btn-dock-submit { justify-content: center; width: 100%; padding: 12px 24px; }
    .footer-links { margin-top: 30px; font-size: 0.85rem; padding: 0 20px; }
    .custom-mute-btn { width: 36px; height: 36px; bottom: 10px; right: 10px; }
}

@media (max-width: 480px) {
    .hero-title { font-size: 1.8rem; }
    .hero-subtitle { font-size: 0.9rem; }
    .auth-dock { padding: 15px; }
    .btn-dock-submit { font-size: 0.95rem; padding: 10px 20px; }
}