/*
Theme Name: Niuniu Toolbox 牛牛工具箱主题
Theme URI: https://bigmi0123.cc/
Author: DDbot Admin
Author URI: https://bigmi0123.cc/about/
Description: 牛牛工具箱官方专属独立主题（100%自主可控），专为「文章教程 + 软件下载」双板块极简博客设计。完全符合 WordPress Theme Handbook 官方开发规范，彻底摆脱第三方主题后续更新覆盖风险。包含：顶部极简导航（永不空菜单兜底）、首屏 Hero Header、首页 66/33 双栏、下载详情页游客直出按钮、分类卡片、移动端全响应式适配。
Version: 1.0.8
Requires at least: 6.0
Tested up to: 6.7
Requires PHP: 7.4
License: GNU General Public License v3 or later
License URI: http://www.gnu.org/licenses/gpl-3.0.html
Text Domain: niuniu-toolbox
Domain Path: /languages
Tags: blog, download, two-columns, grid-layout, custom-menu, custom-logo, custom-header, custom-background, sticky-post, threaded-comments, translation-ready, wide-blocks, featured-images
*/

/* =========================================================
   0. 变量 & 重置（彻底去 Bootstrap / Envo 依赖）
   ========================================================= */
:root {
    --niu-primary: #1e3a8a;
    --niu-primary-light: #38bdf8;
    --niu-accent: #f97316;
    --niu-accent-2: #fb923c;
    --niu-green: #15803d;
    --niu-red: #dc2626;
    --niu-bg: #ffffff;
    --niu-bg-gray: #f8fafc;
    --niu-border: #e2e8f0;
    --niu-text: #1e293b;
    --niu-text-light: #64748b;
    --niu-radius: 12px;
    --niu-radius-sm: 8px;
    --niu-shadow: 0 10px 30px rgba(15,23,42,.08);
    --niu-shadow-lg: 0 20px 60px rgba(15,23,42,.15);
    --niu-max-w: 1280px;
    --niu-font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { font-family: var(--niu-font); color: var(--niu-text); background: var(--niu-bg-gray); line-height: 1.65; font-size: 16px; -webkit-font-smoothing: antialiased; }
a { color: var(--niu-primary); text-decoration: none; transition: all .2s; }
a:hover { color: var(--niu-accent); }
img { max-width: 100%; height: auto; display: block; }
h1,h2,h3,h4,h5,h6 { font-weight: 700; line-height: 1.3; color: #0f172a; }
h1 { font-size: clamp(1.8rem, 3vw, 2.5rem); }
h2 { font-size: clamp(1.4rem, 2vw, 1.8rem); margin-bottom: 1rem; }
h3 { font-size: 1.25rem; margin-bottom: .75rem; }
ul, ol { padding-left: 1.2rem; margin-bottom: 1rem; }
p { margin-bottom: 1rem; }
button, .btn, input[type="submit"] { cursor: pointer; border: none; font-family: inherit; }
.screen-reader-text { position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden; }
.alignleft { display: inline; float: left; margin-right: 1.5em; }
.alignright { display: inline; float: right; margin-left: 1.5em; }
.aligncenter { clear: both; display: block; margin-left: auto; margin-right: auto; }
.wp-caption { max-width: 100%; }
.wp-caption-text, .gallery-caption { font-size: .85rem; color: var(--niu-text-light); }
.sticky { }
.bypostauthor { }

/* =========================================================
   1. 顶栏（极简导航，永不空）
   ========================================================= */
.niu-header {
    position: sticky; top: 0; z-index: 100;
    background: #ffffff;
    border-bottom: 1px solid var(--niu-border);
    box-shadow: 0 2px 8px rgba(15,23,42,.05);
}
.niu-header-inner {
    max-width: var(--niu-max-w); margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.niu-logo h1, .niu-logo p { font-size: 1.35rem; font-weight: 800; color: #0f172a; letter-spacing: -.5px; }
.niu-logo a { color: inherit; }
.niu-logo a:hover { color: var(--niu-primary); }
.custom-logo-link img { max-height: 56px; width: auto; }
.niu-nav ul { display: flex; gap: 6px; list-style: none; padding: 0; margin: 0; flex-wrap: wrap; justify-content: flex-end; }
.niu-nav li a { display: block; padding: 8px 16px; border-radius: var(--niu-radius-sm); color: #334155; font-weight: 600; font-size: .95rem; }
.niu-nav li a:hover,
.niu-nav li.current-menu-item a,
.niu-nav li.current_page_item a { background: var(--niu-primary); color: #ffffff; }
.niu-nav-toggle { display: none; background: var(--niu-primary); color: #fff; border: none; width: 44px; height: 44px; border-radius: 8px; font-size: 1.2rem; }
@media (max-width: 768px) {
    .niu-header-inner { height: 64px; padding: 0 16px; }
    .niu-nav { display: none; position: absolute; left: 0; right: 0; top: 64px; background: #fff; border-bottom: 1px solid var(--niu-border); padding: 12px 16px 20px; }
    .niu-nav.open { display: block; }
    .niu-nav ul { flex-direction: column; gap: 4px; }
    .niu-nav li a { padding: 12px 16px; }
    .niu-nav-toggle { display: block; }
}

/* =========================================================
   2. Hero Header（首屏高大上）
   ========================================================= */
.niu-hero {
    position: relative; width: 100%; overflow: hidden; color: #fff;
    background:
        linear-gradient(90deg, rgba(15,23,42,.90) 0%, rgba(15,23,42,.58) 55%, rgba(15,23,42,.25) 100%),
        radial-gradient(circle at 85% 45%, rgba(148,163,184,.22) 0 160px, transparent 161px),
        radial-gradient(circle at 72% 30%, rgba(148,163,184,.16) 0 220px, transparent 221px),
        linear-gradient(135deg, #0b1a3a 0%, #1e3a8a 55%, #38bdf8 100%);
    min-height: 560px;
    padding: 80px 24px 120px;
}
.niu-hero::after {
    content: "";
    position: absolute; left: 0; right: 0; bottom: -1px; height: 80px; z-index: 3;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1920 80' preserveAspectRatio='none'><path d='M0,80 L1920,80 L1920,0 C1500,40 1200,10 960,30 C720,50 420,15 0,40 Z' fill='%23f8fafc'/></svg>");
    background-size: 100% 100%;
}
.niu-hero-bg { position: absolute; inset: 0; z-index: 0; background-size: cover; background-position: center; background-repeat: no-repeat; opacity: .9; mix-blend-mode: luminosity; }
.niu-hero-inner { position: relative; z-index: 2; max-width: var(--niu-max-w); margin: 0 auto; display: grid; grid-template-columns: 7fr 5fr; gap: 36px; align-items: center; min-height: 440px; }
.niu-hero-tag { display: inline-block; letter-spacing: 4px; font-size: 15px; font-weight: 600; margin-bottom: 16px; color: #93c5fd; text-transform: uppercase; }
.niu-hero-title { font-size: clamp(2.2rem, 4.5vw, 3.6rem); font-weight: 800; line-height: 1.02; color: #fff; }
.niu-hero-title-accent {
    display: inline-block; margin-top: 10px;
    padding: 14px 32px; border: 4px solid #fff; border-radius: 10px;
    font-size: clamp(3.2rem, 8vw, 5.8rem);
    font-weight: 900; letter-spacing: 1px; color: #fff; line-height: 1;
    text-shadow: 0 6px 20px rgba(0,0,0,.35);
    background: linear-gradient(180deg, rgba(255,255,255,.08), rgba(255,255,255,.02));
    backdrop-filter: blur(3px);
}
.niu-hero-desc { max-width: 600px; margin: 28px auto 36px 0; font-size: 1.05rem; line-height: 1.7; color: #cbd5e1; }
.niu-hero-ctas { display: flex; gap: 16px; flex-wrap: wrap; }
.niu-btn { display: inline-flex; align-items: center; gap: 10px; padding: 14px 28px; font-size: 1rem; font-weight: 700; border-radius: var(--niu-radius-sm); transition: all .2s; }
.niu-btn-outline { background: transparent; color: #ffffff; border: 2px solid #ffffff; }
.niu-btn-outline:hover { background: #ffffff; color: var(--niu-primary); }
.niu-btn-solid { background: linear-gradient(135deg, var(--niu-accent), var(--niu-accent-2)); color: #fff; box-shadow: 0 8px 24px rgba(249,115,22,.35); }
.niu-btn-solid:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(249,115,22,.45); }
.niu-btn-solid-big {
    display: inline-flex; align-items: center; gap: 10px;
    background: linear-gradient(135deg, #16a34a, #15803d);
    color: #ffffff; padding: 20px 40px; font-size: 1.2rem; font-weight: 800;
    border-radius: var(--niu-radius);
    box-shadow: 0 12px 32px rgba(22,163,74,.3);
}
.niu-btn-solid-big:hover { transform: translateY(-2px); color: #fff; box-shadow: 0 16px 40px rgba(22,163,74,.4); }
.niu-hero-art { max-width: 100%; height: auto; animation: niu-float 5s ease-in-out infinite; filter: drop-shadow(0 20px 40px rgba(0,0,0,.25)); }
@keyframes niu-float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-18px); } }
@media (max-width: 960px) {
    .niu-hero-inner { grid-template-columns: 1fr; gap: 24px; }
    .niu-hero-right { order: -1; text-align: center; }
    .niu-hero-art { max-height: 260px; margin: 0 auto; }
}

/* =========================================================
   3. 主容器 / 卡片 / 双栏66-33
   ========================================================= */
.niu-page-header {
    background: linear-gradient(135deg, #0b1a3a 0%, #1e3a8a 55%, #38bdf8 100%);
    color: #fff; padding: 60px 24px; text-align: center;
}
.niu-page-header h1 { color: #fff; max-width: var(--niu-max-w); margin: 0 auto; }
.niu-page-header p { color: #cbd5e1; max-width: var(--niu-max-w); margin: 16px auto 0; }
.niu-main { max-width: var(--niu-max-w); margin: 0 auto; padding: 32px 24px 60px; }
.niu-card { background: #fff; border-radius: var(--niu-radius); box-shadow: var(--niu-shadow); padding: 28px; margin-bottom: 24px; border: 1px solid var(--niu-border); }
.niu-card h1.niu-mt-0 { margin-top: 0; }
.niu-grid-66-33 { display: grid; grid-template-columns: 66.66% 33.33%; gap: 24px; }
.niu-grid-66-33 > div > h2 { margin-top: 0; padding-bottom: 10px; border-bottom: 3px solid var(--niu-primary); }
@media (max-width: 960px) {
    .niu-grid-66-33 { grid-template-columns: 1fr; }
    .niu-card { padding: 20px; }
}
.niu-list { list-style: none; padding: 0; }
.niu-list-item { padding: 14px 0; border-bottom: 1px dashed var(--niu-border); display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; }
.niu-list-item:last-child { border-bottom: none; }
.niu-list-item a.niu-title { font-weight: 600; font-size: 1rem; flex: 1; }
.niu-list-meta { color: var(--niu-text-light); font-size: .85rem; white-space: nowrap; }
.niu-mt-20 { margin-top: 20px; }
.niu-mb-0 { margin-bottom: 0; }

/* =========================================================
   4. 文章 / 软件 卡片网格
   ========================================================= */
.niu-post-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 24px; }
.niu-post-card { background: #fff; border-radius: var(--niu-radius); border: 1px solid var(--niu-border); overflow: hidden; transition: all .2s; display: flex; flex-direction: column; }
.niu-post-card:hover { transform: translateY(-4px); box-shadow: var(--niu-shadow-lg); border-color: var(--niu-primary-light); }
.niu-post-thumb { height: 200px; background: linear-gradient(135deg, var(--niu-primary), var(--niu-primary-light)); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 3.5rem; background-size: cover; background-position: center; }
.niu-post-body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.niu-post-body h3 { font-size: 1.15rem; }
.niu-post-body h3 a { color: inherit; }
.niu-post-body h3 a:hover { color: var(--niu-accent); }
.niu-post-meta { color: var(--niu-text-light); font-size: .85rem; margin-bottom: 10px; }
.niu-post-excerpt { color: var(--niu-text); font-size: .95rem; flex: 1; margin-bottom: 14px; }
.niu-readmore { display: inline-block; font-weight: 700; color: var(--niu-primary); }
.niu-dl-tag { display: inline-block; padding: 3px 10px; background: #dcfce7; color: #166534; border-radius: 4px; font-size: .8rem; font-weight: 700; margin-right: 6px; }

/* =========================================================
   5. 下载详情页（WPDM CPT single-wpdmpro）
   ========================================================= */
.niu-dl-wrap { background: #fff; border-radius: var(--niu-radius); border: 1px solid var(--niu-border); padding: 32px; }
.niu-dl-wrap h1 { margin-top: 0; margin-bottom: 16px; }
.niu-dl-info-grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px;
    margin: 20px 0 24px;
    background: #0f172a; border-radius: var(--niu-radius); padding: 18px; color: #e2e8f0;
}
.niu-dl-info-grid > div { background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.08); padding: 12px 14px; border-radius: var(--niu-radius-sm); }
.niu-dl-info-grid .label { display: block; color: #94a3b8; font-size: .8rem; margin-bottom: 4px; }
.niu-dl-info-grid .val { font-weight: 700; color: #f1f5f9; word-break: break-all; }
.niu-force-download {
    background: linear-gradient(135deg, #ecfdf5, #dcfce7);
    border: 2px solid #86efac; border-radius: var(--niu-radius);
    padding: 28px; text-align: center; margin: 0 0 28px;
}
.niu-force-download h3 { color: #14532d; margin-bottom: 16px; }
.niu-force-download small { display: block; margin-top: 14px; color: #166534; font-size: .9rem; }
@media (max-width: 720px) {
    .niu-dl-info-grid { grid-template-columns: 1fr 1fr; }
    .niu-force-download { padding: 20px; }
}

/* =========================================================
   6. 文章单页 / Page
   ========================================================= */
.niu-single { background: #fff; border-radius: var(--niu-radius); border: 1px solid var(--niu-border); padding: 32px; }
.niu-single .entry-title { margin-top: 0; margin-bottom: 10px; }
.niu-entry-meta { color: var(--niu-text-light); font-size: .9rem; margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid var(--niu-border); }
.niu-entry-meta a { color: inherit; }
.niu-post-thumbnail { margin-bottom: 24px; border-radius: var(--niu-radius-sm); overflow: hidden; }
.niu-entry-content img { border-radius: var(--niu-radius-sm); }
.niu-entry-content h2 { margin-top: 2rem; }
.niu-entry-content blockquote { border-left: 4px solid var(--niu-primary); padding: 10px 20px; color: var(--niu-text-light); background: var(--niu-bg-gray); border-radius: 0 var(--niu-radius-sm) var(--niu-radius-sm) 0; }
.niu-entry-content table { width: 100%; border-collapse: collapse; margin-bottom: 1rem; }
.niu-entry-content table th, .niu-entry-content table td { border: 1px solid var(--niu-border); padding: 10px; }
.niu-entry-nav { display: flex; justify-content: space-between; gap: 16px; margin: 28px 0 0; padding-top: 20px; border-top: 1px solid var(--niu-border); flex-wrap: wrap; }
.niu-entry-nav a { background: var(--niu-bg-gray); padding: 10px 16px; border-radius: var(--niu-radius-sm); border: 1px solid var(--niu-border); }
.niu-tags { margin: 24px 0 0; }
.niu-tags a { display: inline-block; padding: 4px 12px; background: var(--niu-bg-gray); border: 1px solid var(--niu-border); border-radius: 999px; font-size: .85rem; margin: 0 4px 6px 0; }

/* =========================================================
   7. 评论
   ========================================================= */
.niu-comments { margin-top: 32px; }
.niu-comments-title { padding-bottom: 10px; border-bottom: 2px solid var(--niu-primary); }
.niu-comment-list { list-style: none; padding: 0; }
.niu-comment-list > li { padding: 20px 0; border-bottom: 1px solid var(--niu-border); }
.niu-comment-list .children { list-style: none; padding-left: 40px; margin-top: 12px; }
.niu-comment-author { font-weight: 700; }
.niu-comment-meta { font-size: .85rem; color: var(--niu-text-light); margin-bottom: 8px; }
.niu-comment-avatar { float: left; margin-right: 16px; border-radius: 50%; }
.niu-comment-body { overflow: hidden; }
.niu-comment-respond { margin-top: 28px; background: var(--niu-bg-gray); padding: 24px; border-radius: var(--niu-radius); }
.niu-comment-respond input[type="text"], .niu-comment-respond input[type="email"], .niu-comment-respond input[type="url"], .niu-comment-respond textarea {
    width: 100%; padding: 10px 14px; border: 1px solid var(--niu-border); border-radius: var(--niu-radius-sm); font-family: inherit; font-size: 1rem; background: #fff;
}
.niu-comment-respond textarea { min-height: 140px; }
.niu-comment-respond .form-submit input[type="submit"] {
    background: var(--niu-primary); color: #fff; padding: 12px 24px; border-radius: var(--niu-radius-sm); font-weight: 700;
}

/* =========================================================
   8. Footer
   ========================================================= */
.niu-footer { background: linear-gradient(180deg, #0b1a3a, #020617); color: #cbd5e1; padding: 40px 24px 28px; margin-top: 40px; border-top: 4px solid var(--niu-primary); }
.niu-footer-inner { max-width: var(--niu-max-w); margin: 0 auto; }
.niu-footer-widgets { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; margin-bottom: 24px; }
.niu-footer-links { margin-bottom: 18px; display: flex; gap: 18px; flex-wrap: wrap; }
.niu-footer-links a { color: #e2e8f0; font-weight: 600; }
.niu-footer-links a:hover { color: var(--niu-accent-2); }
.niu-footer-copyright { font-size: .9rem; color: #94a3b8; border-top: 1px solid rgba(255,255,255,.08); padding-top: 18px; }
.niu-footer-copyright strong { color: #fff; }
.niu-back-top {
    position: fixed; right: 24px; bottom: 24px; z-index: 99;
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--niu-primary); color: #fff;
    display: none; align-items: center; justify-content: center;
    box-shadow: var(--niu-shadow-lg); font-weight: 900;
}
.niu-back-top.show { display: flex; }
.niu-back-top:hover { background: var(--niu-accent); color: #fff; transform: translateY(-2px); }

/* =========================================================
   9. 搜索 / 404
   ========================================================= */
.niu-search-form { display: flex; gap: 8px; margin-bottom: 20px; }
.niu-search-form input[type="search"] {
    flex: 1; padding: 12px 16px; border: 1px solid var(--niu-border); border-radius: var(--niu-radius-sm); font-family: inherit; font-size: 1rem;
}
.niu-search-form input[type="submit"] {
    background: var(--niu-primary); color: #fff; padding: 12px 20px; border-radius: var(--niu-radius-sm); font-weight: 700;
}
.niu-404 { text-align: center; padding: 60px 24px; }
.niu-404 h1 { font-size: clamp(3rem, 10vw, 6rem); background: linear-gradient(135deg, var(--niu-primary), var(--niu-accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

/* =========================================================
   10. Pagination / 通用
   ========================================================= */
.pagination, .nav-links { display: flex; gap: 6px; justify-content: center; flex-wrap: wrap; margin: 20px 0; }
.pagination a, .pagination span, .nav-links a, .nav-links .current {
    display: inline-block; padding: 8px 14px; border: 1px solid var(--niu-border); border-radius: var(--niu-radius-sm); background: #fff; color: var(--niu-text);
}
.pagination .current, .nav-links .current { background: var(--niu-primary); color: #fff; border-color: var(--niu-primary); }
.pagination a:hover, .nav-links a:hover { background: var(--niu-primary-light); color: #fff; border-color: var(--niu-primary-light); }

/* WordPress core block styles support */
.wp-block-button__link { border-radius: var(--niu-radius-sm); }
.has-very-light-gray-color { color: #f8fafc; }
.has-very-light-gray-background-color { background-color: #f8fafc; }