/* HotAI.Tools — 内容页共用样式（工具页 / 分类页）
   设计变量与首页保持一致，确保视觉连贯 */

:root {
    --bg: #fbfbfd;
    --bg-grad-top: #ffffff;
    --bg-grad-bottom: #f5f5f7;
    --card: #ffffff;
    --tile: #f5f5f7;
    --border: rgba(0, 0, 0, 0.08);
    --border-soft: rgba(0, 0, 0, 0.06);
    --primary: #0071e3;
    --primary-hover: #0077ed;
    --text: #1d1d1f;
    --text-dim: #6e6e73;
    --text-faint: #86868b;
    --radius: 20px;
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
    --shadow-hover: 0 14px 40px -12px rgba(0, 0, 0, 0.18);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: "SF Pro Display", "SF Pro Text", -apple-system, BlinkMacSystemFont,
        "Segoe UI", Roboto, "Microsoft YaHei", Helvetica, Arial, sans-serif;
}

html { scroll-behavior: smooth; }

body {
    background: linear-gradient(180deg, var(--bg-grad-top), var(--bg-grad-bottom) 420px);
    background-color: var(--bg);
    color: var(--text);
    min-height: 100vh;
    padding-bottom: 80px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    line-height: 1.6;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 6%;
    border-bottom: 1px solid var(--border-soft);
    position: sticky;
    top: 0;
    background: rgba(251, 251, 253, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    z-index: 100;
}

.logo {
    font-size: 1.35rem;
    font-weight: 600;
    letter-spacing: -0.4px;
    color: var(--text);
    text-decoration: none;
}
.logo span { color: var(--primary); }

.nav-links { display: flex; gap: 18px; align-items: center; font-size: 0.9rem; }
.nav-links a { color: var(--text-dim); text-decoration: none; transition: color 0.2s; }
.nav-links a:hover { color: var(--primary); }

.wrap { max-width: 820px; margin: 0 auto; padding: 0 6%; }

/* 面包屑 */
.crumb { font-size: 0.85rem; color: var(--text-faint); padding: 28px 0 0; }
.crumb a { color: var(--text-dim); text-decoration: none; }
.crumb a:hover { color: var(--primary); }
.crumb span { margin: 0 7px; opacity: 0.5; }

/* 头部 */
header.hero { padding: 22px 0 34px; }

h1 {
    font-size: clamp(2.1rem, 4.6vw, 3rem);
    font-weight: 600;
    letter-spacing: -1.4px;
    line-height: 1.1;
    margin-bottom: 12px;
}

.tagline { font-size: 1.18rem; color: var(--text-dim); margin-bottom: 22px; }

.meta { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 26px; }

.chip {
    font-size: 13px;
    padding: 6px 14px;
    border-radius: 980px;
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-dim);
    text-decoration: none;
    transition: background 0.2s;
}
a.chip:hover { background: rgba(0, 113, 227, 0.12); color: var(--primary); }

.btn-visit {
    display: inline-block;
    background: var(--primary);
    color: #fff;
    padding: 12px 26px;
    border-radius: 980px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: background 0.2s, transform 0.2s;
}
.btn-visit:hover { background: var(--primary-hover); transform: scale(1.02); }

/* 正文分节 */
section { margin-bottom: 38px; }

h2 {
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: -0.5px;
    margin-bottom: 14px;
}

p { color: var(--text-dim); margin-bottom: 14px; }

ul.features { list-style: none; }
ul.features li {
    color: var(--text-dim);
    padding: 9px 0 9px 28px;
    position: relative;
    border-bottom: 1px solid var(--border-soft);
}
ul.features li:last-child { border-bottom: none; }
ul.features li::before {
    content: "";
    position: absolute;
    left: 6px;
    top: 18px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--primary);
}

/* 双栏卡片 */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 640px) { .split { grid-template-columns: 1fr; } }

.panel {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 24px;
    box-shadow: var(--shadow-card);
}
.panel h3 { font-size: 1rem; font-weight: 600; margin-bottom: 8px; }
.panel p { font-size: 0.94rem; margin-bottom: 0; }

/* 工具卡片网格 */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
}

.tool-card {
    display: block;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px;
    text-decoration: none;
    box-shadow: var(--shadow-card);
    transition: transform 0.22s ease, box-shadow 0.22s ease;
}
.tool-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.tool-card .name { font-size: 1.06rem; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.tool-card .desc { font-size: 0.88rem; color: var(--text-faint); line-height: 1.5; }

footer {
    text-align: center;
    padding: 46px 6% 0;
    color: var(--text-faint);
    font-size: 13px;
    border-top: 1px solid var(--border-soft);
    margin-top: 56px;
}
footer a { color: var(--primary); text-decoration: none; }