/* ============================================================
   QStreamTech — 高科技主题样式
   ============================================================ */
:root {
    --bg: #060a16;
    --bg2: #0a0f22;
    --card: rgba(17, 25, 48, 0.72);
    --border: rgba(56, 189, 248, 0.18);
    --border-strong: rgba(56, 189, 248, 0.45);
    --text: #e6ecf5;
    --text-dim: #94a3b8;
    --accent: #38bdf8;
    --accent2: #818cf8;
    --accent3: #22d3ee;
    --grad: linear-gradient(120deg, #22d3ee, #38bdf8 40%, #818cf8);
    --radius: 14px;
}

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

html { scroll-behavior: smooth; scroll-padding-bottom: 120px; }
main { padding-bottom: 50vh; }

/* 反馈表单输入框聚焦时，浏览器自动滚动预留顶部空间 */
.feedback-form input,
.feedback-form select,
.feedback-form textarea {
    scroll-margin-top: 120px;
}

body {
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
}

/* ---------- 背景特效层 ---------- */
#bg-canvas {
    position: fixed; inset: 0;
    width: 100%; height: 100%;
    z-index: -2;
}
.bg-grid {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background-image:
        linear-gradient(rgba(56,189,248,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(56,189,248,0.04) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
}

.container { width: 1180px; max-width: 92%; margin: 0 auto; }

/* ---------- 头部 ---------- */
.site-header {
    position: sticky; top: 0; z-index: 100;
    background: rgba(6, 10, 22, 0.82);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; gap: 28px; height: 68px; }

.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-mark,
.logo-img {
    width: 38px; height: 38px; border-radius: 10px;
    object-fit: contain;
    background: var(--grad);
    box-shadow: 0 0 18px rgba(56, 189, 248, 0.55);
}
.logo-mark {
    display: flex; align-items: center; justify-content: center;
    font-weight: 800; font-size: 20px; color: #04101f;
}
.logo-text {
    font-size: 20px; font-weight: 700; letter-spacing: 0.5px;
    background: var(--grad);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
}

.main-nav { display: flex; gap: 26px; flex: 1; }
.main-nav a {
    color: var(--text-dim); text-decoration: none; font-size: 15px;
    transition: color .2s;
}
.main-nav a:hover { color: var(--accent); }

.header-right { display: flex; align-items: center; gap: 14px; }
.lang-switch {
    color: var(--text-dim); text-decoration: none; font-size: 13px;
    border: 1px solid var(--border); border-radius: 999px;
    padding: 4px 14px; transition: all .2s;
}
.lang-switch:hover { color: var(--accent); border-color: var(--border-strong); }

.nav-toggle {
    display: none; background: none; border: 1px solid var(--border);
    color: var(--text); font-size: 20px; border-radius: 8px; padding: 4px 12px; cursor: pointer;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 13px 30px; border-radius: 999px;
    font-size: 16px; font-weight: 600; text-decoration: none;
    cursor: pointer; border: none; transition: all .25s;
}
.btn-sm { padding: 8px 20px; font-size: 14px; }
.btn-primary {
    background: var(--grad); color: #04101f;
    box-shadow: 0 0 22px rgba(56, 189, 248, 0.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 0 34px rgba(56, 189, 248, 0.7); }
.btn-ghost {
    background: transparent; color: var(--text);
    border: 1px solid var(--border-strong);
}
.btn-ghost:hover { background: rgba(56, 189, 248, 0.1); transform: translateY(-2px); }

/* ---------- Hero ---------- */
.hero { padding: 110px 0 80px; text-align: center; position: relative; }
.hero-badge {
    display: inline-block; padding: 6px 20px; border-radius: 999px;
    border: 1px solid var(--border-strong); color: var(--accent3);
    font-size: 13px; letter-spacing: 2px; text-transform: uppercase;
    background: rgba(34, 211, 238, 0.06);
    animation: pulse-border 3s ease-in-out infinite;
}
@keyframes pulse-border {
    0%, 100% { box-shadow: 0 0 0 rgba(34, 211, 238, 0.0); }
    50% { box-shadow: 0 0 24px rgba(34, 211, 238, 0.35); }
}
.hero h1 {
    margin: 26px auto 18px; font-size: 52px; line-height: 1.2; max-width: 820px;
    background: linear-gradient(180deg, #fff 30%, #7dd3fc);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero p { max-width: 680px; margin: 0 auto 36px; color: var(--text-dim); font-size: 18px; }
.hero-actions { display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; }

/* ---------- 区块标题 ---------- */
.section { padding: 80px 0; }
.section-head { text-align: center; margin-bottom: 50px; }
.section-head h2 { font-size: 36px; margin-bottom: 8px; }
.section-head h2 span {
    background: var(--grad);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
}
.section-head p { color: var(--text-dim); }

/* ---------- 精选应用横幅（顶部显著入口） ---------- */
.featured-banner {
    display: flex; align-items: center; gap: 40px;
    background: var(--card); border: 1px solid var(--border-strong);
    border-radius: 22px; padding: 40px; position: relative; overflow: hidden;
    backdrop-filter: blur(10px);
}
.featured-banner::before {
    content: ""; position: absolute; top: -60%; right: -15%;
    width: 420px; height: 420px; border-radius: 50%;
    background: radial-gradient(circle, rgba(99,102,241,0.28), transparent 70%);
}
.featured-banner img.app-icon-lg {
    width: 128px; height: 128px; border-radius: 28px;
    box-shadow: 0 0 30px rgba(56, 189, 248, 0.45); flex-shrink: 0;
}
.featured-info { flex: 1; position: relative; }
.featured-info .tag {
    display: inline-block; font-size: 12px; color: var(--accent3);
    border: 1px solid var(--border-strong); border-radius: 999px;
    padding: 2px 12px; margin-bottom: 10px; letter-spacing: 1px;
}
.featured-info h3 { font-size: 30px; margin-bottom: 8px; }
.featured-info p { color: var(--text-dim); margin-bottom: 22px; max-width: 560px; }
.featured-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- 应用卡片 ---------- */
.apps-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 26px; }
.app-card {
    background: var(--card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px;
    backdrop-filter: blur(8px);
    transition: transform .25s, border-color .25s, box-shadow .25s;
    display: flex; flex-direction: column; gap: 14px;
}
.app-card:hover {
    transform: translateY(-6px);
    border-color: var(--border-strong);
    box-shadow: 0 12px 40px rgba(56, 189, 248, 0.18);
}
.app-card-head { display: flex; align-items: center; gap: 16px; }
.app-card-head img { width: 64px; height: 64px; border-radius: 16px; }
.app-card-head h3 { font-size: 20px; }
.app-card-head .meta { color: var(--text-dim); font-size: 13px; }
.app-card > p { color: var(--text-dim); font-size: 15px; flex: 1; }
.app-card-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- 应用详情页 ---------- */
.app-hero { display: flex; gap: 36px; align-items: flex-start; padding: 60px 0 30px; flex-wrap: wrap; }
.app-hero img.app-icon-lg { width: 140px; height: 140px; border-radius: 30px; box-shadow: 0 0 30px rgba(56,189,248,0.4); }
.app-hero-info { flex: 1; min-width: 280px; }
.app-hero-info h1 { font-size: 40px; margin-bottom: 10px; }
.app-hero-info .short { color: var(--text-dim); font-size: 18px; margin-bottom: 18px; }
.app-meta { display: flex; gap: 24px; color: var(--text-dim); font-size: 14px; margin-bottom: 24px; flex-wrap: wrap; }
.app-meta b { color: var(--accent); }

.lang-tabs { display: flex; gap: 10px; flex-wrap: wrap; margin: 20px 0 26px; }
.lang-tab {
    padding: 7px 18px; border-radius: 999px; font-size: 14px; cursor: pointer;
    border: 1px solid var(--border); color: var(--text-dim);
    background: transparent; text-decoration: none; transition: all .2s;
}
.lang-tab:hover, .lang-tab.active {
    color: #04101f; background: var(--grad); border-color: transparent;
    box-shadow: 0 0 16px rgba(56,189,248,0.4);
}
.lang-select {
    display: flex; align-items: center; gap: 14px;
    margin: 20px 0 26px; padding: 10px 14px;
    background: var(--card); border: 1px solid var(--border);
    border-radius: var(--radius); width: fit-content;
}
.lang-select label { color: var(--text-dim); font-size: 14px; white-space: nowrap; }
.lang-select select {
    background: var(--bg2, #0a0f22); color: var(--text);
    border: 1px solid var(--border-strong); border-radius: 10px;
    padding: 8px 14px; font-size: 14px; min-width: 190px; cursor: pointer;
    outline: none; transition: border-color .2s;
}
.lang-select select:focus { border-color: var(--accent); }

.desc-box {
    background: var(--card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 34px;
    white-space: pre-line; color: #cbd5e1;
}

.app-banner {
    width: 100%;
    aspect-ratio: 1024 / 500;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--border);
    background: #0d1526;
}
.app-banner img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}

.gallery { display: flex; flex-direction: column; gap: 18px; }
.gallery-row { display: grid; gap: 18px; }
.gallery-item {
    border-radius: 12px; overflow: hidden; border: 1px solid var(--border);
    cursor: zoom-in; transition: transform .25s, box-shadow .25s;
    background: #0d1526;
}
.gallery-item:hover { transform: scale(1.03); box-shadow: 0 8px 30px rgba(56,189,248,0.25); }
.gallery-item img { width: 100%; height: auto; display: block; object-fit: contain; }
.gallery-item .caption {
    padding: 8px 12px; font-size: 12px; color: var(--text-dim); text-align: center;
}

/* ---------- 反馈 ---------- */
.feedback-wrap { max-width: 640px; margin: 0 auto; }
.feedback-form {
    background: var(--card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 36px;
    backdrop-filter: blur(8px);
}
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 7px; color: var(--text-dim); font-size: 14px; }
.form-group input, .form-group select, .form-group textarea {
    width: 100%; padding: 12px 14px; border-radius: 10px;
    border: 1px solid var(--border); background: rgba(6, 10, 22, 0.7);
    color: var(--text); font-size: 15px; font-family: inherit;
    transition: border-color .2s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none; border-color: var(--border-strong);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.12);
}
.form-group textarea { min-height: 130px; resize: vertical; }
.captcha-row { display: flex; gap: 12px; align-items: center; }
.captcha-q { color: var(--accent3); font-weight: 700; white-space: nowrap; }

.alert { border-radius: 10px; padding: 14px 18px; margin-bottom: 22px; font-size: 15px; }
.alert-ok { background: rgba(16, 185, 129, 0.12); border: 1px solid rgba(16,185,129,0.4); color: #6ee7b7; }
.alert-err { background: rgba(239, 68, 68, 0.12); border: 1px solid rgba(239,68,68,0.4); color: #fca5a5; }

/* ---------- 页脚 ---------- */
.site-footer { border-top: 1px solid var(--border); padding: 56px 0 26px; margin-top: 60px; background: rgba(6,10,22,0.85); }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; margin-bottom: 36px; }
.footer-logo { margin-bottom: 12px; }
.footer-slogan { color: var(--text-dim); font-size: 14px; }
.site-footer h4 { margin-bottom: 16px; color: var(--text); font-size: 16px; }
.social-links { display: flex; gap: 12px; margin-bottom: 18px; flex-wrap: wrap; }
.social-link {
    display: inline-flex; align-items: center; gap: 8px;
    color: var(--text-dim); text-decoration: none; font-size: 14px;
    border: 1px solid var(--border); border-radius: 999px; padding: 8px 18px;
    transition: all .2s;
}
.social-link:hover { color: var(--accent); border-color: var(--border-strong); box-shadow: 0 0 16px rgba(56,189,248,0.25); }
.footer-email { color: var(--text-dim); font-size: 14px; }
.footer-email a { color: var(--accent); text-decoration: none; }
.footer-bottom { text-align: center; color: #475569; font-size: 13px; border-top: 1px solid rgba(56,189,248,0.08); padding-top: 22px; }

/* ---------- 灯箱 ---------- */
.lightbox {
    display: none; position: fixed; inset: 0; z-index: 999;
    background: rgba(3, 6, 14, 0.92); align-items: center; justify-content: center;
}
.lightbox.open { display: flex; }
.lightbox img { max-width: 88%; max-height: 88%; border-radius: 12px; box-shadow: 0 0 60px rgba(56,189,248,0.3); }
.lightbox-close {
    position: absolute; top: 26px; right: 40px; font-size: 42px;
    color: var(--text-dim); cursor: pointer; transition: color .2s;
}
.lightbox-close:hover { color: #fff; }

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
    .hero h1 { font-size: 34px; }
    .hero { padding: 70px 0 50px; }
    .featured-banner { flex-direction: column; text-align: center; }
    .featured-actions { justify-content: center; }
    .main-nav, .header-right .btn { display: none; }
    .main-nav.open {
        display: flex; position: absolute; top: 68px; left: 0; right: 0;
        flex-direction: column; gap: 0; background: rgba(6,10,22,0.97);
        border-bottom: 1px solid var(--border); padding: 10px 0;
    }
    .main-nav.open a { padding: 14px 5%; }
    .nav-toggle { display: block; margin-left: auto; }
    .footer-grid { grid-template-columns: 1fr; }
}