/* ============================================
   三角洲辅助网 - 黑红配色主题
   ============================================ */
:root {
    --bg: #0b0b0d;
    --bg-alt: #101013;
    --panel: #16161a;
    --panel-hover: #1d1d22;
    --border: #2a2a30;
    --text: #e8e8ec;
    --text-dim: #9a9aa4;
    --red: #e8232e;
    --red-bright: #ff3b45;
    --red-dark: #8f1017;
    --red-glow: rgba(232, 35, 46, 0.35);
    --radius: 14px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
}

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

html { scroll-behavior: smooth; }

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color 0.2s ease; }

.container {
    width: min(1120px, 92%);
    margin: 0 auto;
}
.container-narrow { width: min(820px, 92%); }

.accent { color: var(--red-bright); }

/* ===== 顶部导航 ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(11, 11, 13, 0.82);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px 24px;
    padding: 14px 0;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: 1px;
}

.logo-mark {
    width: 22px;
    height: 20px;
    background: linear-gradient(160deg, var(--red-bright), var(--red-dark));
    clip-path: polygon(50% 0, 100% 100%, 0 100%);
    box-shadow: 0 0 12px var(--red-glow);
}

.logo-accent { color: var(--red-bright); }

.site-nav {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px 22px;
    font-size: 0.95rem;
}

.site-nav a:not(.nav-cta) { color: var(--text-dim); }
.site-nav a:not(.nav-cta):hover { color: var(--text); }

.nav-cta {
    padding: 8px 20px;
    border-radius: 999px;
    font-weight: 700;
    color: #fff !important;
    background: linear-gradient(135deg, var(--red-bright), var(--red-dark));
    box-shadow: 0 4px 16px var(--red-glow);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.nav-cta:hover { transform: translateY(-2px); box-shadow: 0 8px 22px var(--red-glow); }

/* ===== Hero ===== */
.hero {
    position: relative;
    padding: 110px 0 90px;
    text-align: center;
    background:
        radial-gradient(ellipse 60% 55% at 50% 0%, rgba(232, 35, 46, 0.16), transparent 70%),
        radial-gradient(ellipse 45% 45% at 85% 80%, rgba(232, 35, 46, 0.08), transparent 70%),
        var(--bg);
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(232, 35, 46, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(232, 35, 46, 0.045) 1px, transparent 1px);
    background-size: 56px 56px;
    mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 30%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 30%, transparent 75%);
    pointer-events: none;
}

.hero-inner { position: relative; }

.hero-tagline {
    display: inline-block;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 4px;
    color: var(--red-bright);
    border: 1px solid rgba(232, 35, 46, 0.4);
    border-radius: 999px;
    padding: 6px 18px;
    margin-bottom: 26px;
    background: rgba(232, 35, 46, 0.07);
}

.hero h1 {
    font-size: clamp(1.9rem, 4.6vw, 3.4rem);
    font-weight: 900;
    line-height: 1.3;
    letter-spacing: 1px;
    margin-bottom: 22px;
}

.hero-sub {
    max-width: 720px;
    margin: 0 auto 36px;
    color: var(--text-dim);
    font-size: 1.05rem;
}

.hero-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 52px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 14px;
    max-width: 760px;
    margin: 0 auto;
    list-style: none;
}

.hero-stats li {
    background: rgba(22, 22, 26, 0.7);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 18px 10px;
    transition: border-color 0.25s ease, transform 0.25s ease;
}
.hero-stats li:hover { border-color: rgba(232, 35, 46, 0.5); transform: translateY(-3px); }

.hero-stats strong {
    display: block;
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--red-bright);
}
.hero-stats span { font-size: 0.85rem; color: var(--text-dim); }

/* ===== 通用 Section ===== */
.section { padding: 88px 0; }
.section-alt { background: var(--bg-alt); }

.section h2 {
    text-align: center;
    font-size: clamp(1.5rem, 3vw, 2.1rem);
    font-weight: 900;
    letter-spacing: 1px;
    margin-bottom: 12px;
}

.section-sub {
    text-align: center;
    color: var(--text-dim);
    max-width: 640px;
    margin: 0 auto 52px;
}

/* ===== 卡片 ===== */
.grid { display: grid; gap: 22px; }
.cards-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }

.card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 30px 26px;
    box-shadow: var(--shadow);
    transition: transform 0.25s ease, border-color 0.25s ease, background 0.25s ease;
}

.card:hover {
    transform: translateY(-6px);
    border-color: rgba(232, 35, 46, 0.55);
    background: var(--panel-hover);
}

.card h3 { font-size: 1.15rem; font-weight: 800; margin-bottom: 12px; }
.card p { color: var(--text-dim); font-size: 0.95rem; }

.card-icon {
    width: 54px;
    height: 54px;
    display: grid;
    place-items: center;
    font-size: 1.6rem;
    border-radius: 12px;
    margin-bottom: 18px;
    background: linear-gradient(150deg, rgba(232, 35, 46, 0.2), rgba(232, 35, 46, 0.05));
    border: 1px solid rgba(232, 35, 46, 0.3);
}

/* ===== 价格 ===== */
.pricing-grid { align-items: stretch; }

.price-card { display: flex; flex-direction: column; position: relative; }
.price-card h3 { text-align: center; }
.price-card .price-list { flex: 1; }

.price {
    text-align: center;
    font-size: 2.6rem;
    font-weight: 900;
    color: var(--red-bright);
    margin-bottom: 20px;
}
.price em { font-style: normal; font-size: 1.2rem; vertical-align: top; margin-right: 2px; }
.price small { font-size: 0.85rem; font-weight: 400; color: var(--text-dim); margin-left: 6px; }

.price-list { list-style: none; margin-bottom: 26px; }
.price-list li {
    padding: 9px 0 9px 26px;
    border-bottom: 1px dashed var(--border);
    color: var(--text-dim);
    font-size: 0.93rem;
    position: relative;
}
.price-list li::before {
    content: "✓";
    position: absolute;
    left: 2px;
    color: var(--red-bright);
    font-weight: 700;
}

.price-featured {
    border-color: rgba(232, 35, 46, 0.6);
    background: linear-gradient(180deg, rgba(232, 35, 46, 0.09), rgba(22, 22, 26, 1) 45%);
}

.badge {
    position: absolute;
    top: -13px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--red-bright), var(--red-dark));
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 2px;
    padding: 4px 16px;
    border-radius: 999px;
    box-shadow: 0 4px 14px var(--red-glow);
    white-space: nowrap;
}

.pricing-note {
    text-align: center;
    color: var(--text-dim);
    font-size: 0.82rem;
    margin-top: 34px;
}

/* ===== 使用流程 ===== */
.steps-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 22px;
    counter-reset: step;
}

.steps-list li {
    counter-increment: step;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 30px 24px 26px;
    position: relative;
    transition: transform 0.25s ease, border-color 0.25s ease;
}
.steps-list li:hover { transform: translateY(-5px); border-color: rgba(232, 35, 46, 0.55); }

.steps-list li::before {
    content: "0" counter(step);
    display: inline-block;
    font-size: 1.05rem;
    font-weight: 900;
    color: var(--red-bright);
    letter-spacing: 2px;
    margin-bottom: 14px;
    border-bottom: 2px solid var(--red);
    padding-bottom: 4px;
}

.steps-list h3 { font-size: 1.05rem; font-weight: 800; margin-bottom: 8px; }
.steps-list p { color: var(--text-dim); font-size: 0.9rem; }

/* ===== 用户评价 ===== */
.review-card { display: flex; flex-direction: column; gap: 14px; }
.review-card .stars { color: var(--red-bright); letter-spacing: 3px; font-size: 1.05rem; }
.review-card p:not(.stars) { color: var(--text); font-size: 0.96rem; flex: 1; }
.review-card footer { color: var(--text-dim); font-size: 0.85rem; }

/* ===== FAQ ===== */
.faq-item {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 14px;
    overflow: hidden;
    transition: border-color 0.25s ease;
}
.faq-item[open], .faq-item:hover { border-color: rgba(232, 35, 46, 0.5); }

.faq-item summary {
    cursor: pointer;
    list-style: none;
    padding: 18px 22px;
    font-weight: 700;
    font-size: 1rem;
    position: relative;
    padding-right: 48px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: "+";
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.3rem;
    color: var(--red-bright);
    transition: transform 0.2s ease;
}
.faq-item[open] summary::after { content: "−"; }

.faq-body { padding: 0 22px 20px; color: var(--text-dim); font-size: 0.95rem; }
.faq-body strong { color: var(--red-bright); font-weight: 700; }

/* ===== 底部 CTA ===== */
.cta-band {
    padding: 80px 0;
    text-align: center;
    background:
        radial-gradient(ellipse 55% 80% at 50% 100%, rgba(232, 35, 46, 0.18), transparent 70%),
        var(--bg-alt);
    border-top: 1px solid var(--border);
}
.cta-band h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); font-weight: 900; margin-bottom: 12px; }
.cta-band p { color: var(--text-dim); margin-bottom: 30px; }

/* ===== 按钮 ===== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 999px;
    font-weight: 800;
    font-size: 0.98rem;
    letter-spacing: 1px;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn-lg { padding: 15px 40px; font-size: 1.08rem; }
.btn-block { display: block; text-align: center; width: 100%; }

.btn-primary {
    color: #fff;
    background: linear-gradient(135deg, var(--red-bright), var(--red-dark));
    box-shadow: 0 6px 20px var(--red-glow);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 10px 28px var(--red-glow); }

.btn-ghost {
    color: var(--text);
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.02);
}
.btn-ghost:hover { border-color: var(--red); color: var(--red-bright); transform: translateY(-3px); }

/* ===== 页脚 ===== */
.site-footer {
    background: #080809;
    border-top: 1px solid var(--border);
    padding: 56px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 36px;
    padding-bottom: 40px;
}

.footer-col p { color: var(--text-dim); font-size: 0.9rem; margin-top: 10px; }
.footer-col h3 { font-size: 1rem; font-weight: 800; margin-bottom: 14px; }

.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul a { color: var(--text-dim); font-size: 0.9rem; }
.footer-col ul a:hover { color: var(--red-bright); }

.footer-bottom {
    border-top: 1px solid var(--border);
    padding: 20px 0;
    text-align: center;
}
.footer-bottom p { color: #6d6d76; font-size: 0.8rem; }

/* ===== 响应式 ===== */
@media (max-width: 760px) {
    .hero { padding: 70px 0 60px; }
    .section { padding: 60px 0; }
    .footer-grid { grid-template-columns: 1fr; gap: 26px; }
    .header-inner { justify-content: center; }
    .site-nav { justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition: none !important; }
}

/* ===== 效果展示 ===== */
.showcase-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 22px;
}

.shot {
    position: relative;
    margin: 0;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--border);
    background: var(--panel);
    box-shadow: var(--shadow);
    cursor: zoom-in;
    transition: border-color 0.25s ease, transform 0.25s ease;
}

.shot:hover {
    border-color: rgba(232, 35, 46, 0.6);
    transform: translateY(-6px);
}

.shot img {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
    transition: transform 0.45s ease;
}

.shot:hover img { transform: scale(1.05); }

.shot figcaption {
    position: absolute;
    left: 0; right: 0; bottom: 0;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 30px 18px 12px;
    background: linear-gradient(transparent, rgba(5, 5, 6, 0.92));
    font-size: 0.92rem;
    font-weight: 700;
    pointer-events: none;
}

.shot figcaption span {
    color: var(--red-bright);
    border: 1px solid rgba(232, 35, 46, 0.55);
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 1px;
    padding: 1px 8px;
    background: rgba(232, 35, 46, 0.1);
}

/* ===== 灯箱大图 ===== */
.lightbox {
    position: fixed;
    inset: 0;
    z-index: 200;
    background: rgba(4, 4, 5, 0.92);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: grid;
    place-items: center;
    padding: 32px;
    cursor: zoom-out;
}
.lightbox[hidden] { display: none; }

.lightbox img {
    max-width: 100%;
    max-height: 100%;
    border-radius: 10px;
    border: 1px solid rgba(232, 35, 46, 0.5);
    box-shadow: 0 0 50px var(--red-glow);
}

.lightbox-close {
    position: absolute;
    top: 14px;
    right: 26px;
    font-size: 2.4rem;
    line-height: 1;
    color: var(--text-dim);
    transition: color 0.2s ease;
}
.lightbox-close:hover { color: var(--red-bright); }

@media (max-width: 760px) {
    .showcase-grid { grid-template-columns: 1fr; }
}

/* ===== 防复制保护：禁文本选择 + 禁图片拖拽 ===== */
/* 说明：仅作用于渲染层，不影响搜索引擎抓取 HTML 内容（不伤 SEO） */
body {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}
img { -webkit-user-drag: none; }
/* 输入框等仍允许选择，避免影响可用性（本页暂无表单，保留以备扩展） */
input, textarea {
    -webkit-user-select: text;
    user-select: text;
}