@import url('https://fonts.googleapis.com/css2?family=Great+Vibes&display=swap');

:root {
    --primary: #4f46e5;
    --primary-light: #6366f1;
    --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #ec4899 100%);
    --secondary: #10b981;
    --secondary-gradient: linear-gradient(135deg, #10b981 0%, #3b82f6 100%);
    --dark: #0f172a;
    --dark-lighter: #1e293b;
    --light: #f8fafc;
    --gray: #64748b;
    --gray-light: #e2e8f0;
    --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    --shadow-sm: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -2px rgba(0,0,0,0.025);
    --shadow-md: 0 10px 25px -3px rgba(0,0,0,0.05), 0 4px 6px -4px rgba(0,0,0,0.02);
    --shadow-lg: 0 25px 35px -5px rgba(0,0,0,0.07), 0 10px 15px -5px rgba(0,0,0,0.03);
    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 32px;
    --transition-fast: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif; color: var(--dark); background: var(--bg-gradient); line-height: 1.6; overflow-x: hidden; }
a { text-decoration: none; color: inherit; transition: var(--transition-fast); }
img { max-width: 100%; display: block; }
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--light); }
::-webkit-scrollbar-thumb { background: var(--gray); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 2rem; }
.navbar { position: fixed; top: 0; width: 100%; z-index: 1000; background: rgba(255, 255, 255, 0.4); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border-bottom: 1px solid rgba(255, 255, 255, 0.2); transition: var(--transition-normal); }
.navbar.scrolled { box-shadow: var(--shadow-sm); background: rgba(255, 255, 255, 0.92); border-bottom: 1px solid rgba(255, 255, 255, 0.5); }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 75px; gap: 1.5rem; }
.logo { display: flex; align-items: center; gap: 0.6rem; }
.logo i { background: var(--primary-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; font-size: 1.8rem; }
.logo a { display: flex; align-items: center; gap: 0.6rem; color: inherit; }
.logo span { 
    background: linear-gradient(135deg, #0f172a 0%, #4f46e5 100%); 
    -webkit-background-clip: text; 
    -webkit-text-fill-color: transparent; 
    font-family: 'Great Vibes', 'JetBrains Mono', 'Plus Jakarta Sans', sans-serif;
    font-size: 2.2rem;
    font-weight: 300;
    letter-spacing: 2px;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
    line-height: 1.3;
    white-space: nowrap;
}

.nav-menu { display: flex; list-style: none; gap: 0.3rem; align-items: center; }
.nav-item { position: relative; }
.nav-link { display: inline-flex; align-items: center; white-space: nowrap; padding: 0.46rem 0.78rem; border-radius: var(--radius-sm); font-weight: 500; font-size: 0.9rem; color: var(--gray); transition: var(--transition-fast); }
.nav-link:hover, .nav-link.active { color: #4338ca; background: linear-gradient(135deg, rgba(99, 102, 241, 0.16) 0%, rgba(129, 140, 248, 0.12) 100%); }
.nav-caret { font-size: 0.72rem; margin-left: 0.35rem; margin-top: 1px; opacity: 0.7; }

.dropdown-menu {
    position: absolute;
    top: calc(100% + 0.35rem);
    left: 0;
    min-width: 180px;
    padding: 0.45rem;
    background: linear-gradient(160deg, #ffffff 0%, #f8faff 100%);
    border: 1px solid rgba(0,0,0,0.08);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    display: none;
    z-index: 1001;
}
    .dropdown-menu::before {
        content: '';
        position: absolute;
        top: -0.5rem;
        left: 0;
        right: 0;
        height: 0.5rem;
    }

.nav-dropdown:hover .dropdown-menu { display: block; }
    .dropdown-menu::before {
        content: '';
        position: absolute;
        top: -0.5rem;
        left: 0;
        right: 0;
        height: 0.5rem;
    }

.dropdown-link {
    display: block;
    padding: 0.48rem 0.62rem;
    border-radius: 6px;
    color: var(--gray);
    font-size: 0.86rem;
    line-height: 1.35;
}
.dropdown-link:hover,
.dropdown-link.active {
    color: #4338ca;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.14) 0%, rgba(129, 140, 248, 0.1) 100%);
}

.nav-search {
    position: relative;
    display: flex;
    align-items: center;
    width: min(280px, 28vw);
    margin-left: 0.6rem;
}
.nav-search-icon {
    position: absolute;
    left: 0.7rem;
    color: #64748b;
    font-size: 0.84rem;
    pointer-events: none;
}
.nav-search-input {
    width: 100%;
    border: 1px solid rgba(79, 70, 229, 0.2);
    border-radius: 999px;
    padding: 0.42rem 0.8rem 0.42rem 2rem;
    font-size: 0.85rem;
    background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
    color: #0f172a;
    outline: none;
}
.nav-search-input:focus {
    border-color: rgba(79, 70, 229, 0.45);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}
.nav-search-results {
    position: absolute;
    top: calc(100% + 0.4rem);
    left: 0;
    right: 0;
    display: none;
    background: #ffffff;
    border: 1px solid rgba(15, 23, 42, 0.12);
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    max-height: 300px;
    overflow: auto;
    z-index: 1002;
}
.nav-search-results.active { display: block; }
.nav-search-result {
    display: block;
    padding: 0.55rem 0.72rem;
    font-size: 0.86rem;
    color: #334155;
    border-bottom: 1px solid rgba(15, 23, 42, 0.06);
}
.nav-search-result:last-child { border-bottom: none; }
.nav-search-result:hover {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.14) 0%, rgba(129, 140, 248, 0.1) 100%);
    color: #4338ca;
}
.nav-search-empty {
    padding: 0.65rem 0.72rem;
    font-size: 0.83rem;
    color: #64748b;
}

.hamburger { display: none; font-size: 1.5rem; color: var(--dark); cursor: pointer; padding: 0.5rem; }
.page-wrapper { padding-top: 70px; min-height: 100vh; }
.page-header { background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #171e2e 100%); color: white; padding: 5rem 0 4rem; text-align: center; position: relative; overflow: hidden; box-shadow: 0 10px 30px rgba(0,0,0,0.15); border-bottom: 1px solid rgba(255,255,255,0.05); }
.page-header::before { content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; background-image: radial-gradient(rgba(255,255,255,0.06) 1px, transparent 1px); background-size: 40px 40px; pointer-events: none; opacity: 0.8; }
.page-header h1 { font-size: 2.8rem; font-weight: 700; margin-bottom: 0.8rem; position: relative; }
.page-header p { font-size: 1.1rem; color: rgba(255,255,255,0.75); max-width: 600px; margin: 0 auto; position: relative; }
.section { padding: 5rem 0; }
.section-header { text-align: center; margin-bottom: 3rem; }
.section-title { font-size: 2.2rem; font-weight: 700; margin-bottom: 0.8rem; position: relative; display: inline-block; color: var(--dark); letter-spacing: -0.02em; }
.section-title::after { content: ''; position: absolute; bottom: -10px; left: 50%; transform: translateX(-50%); width: 40px; height: 3px; background: var(--primary); border-radius: 4px; transition: width 0.3s ease; }
.section-desc { font-size: 1.05rem; color: var(--gray); max-width: 650px; margin: 0 auto; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 2.5rem; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); gap: 2.5rem; }
.card { background: rgba(255, 255, 255, 0.7); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-radius: var(--radius-md); overflow: hidden; box-shadow: var(--shadow-sm); transition: var(--transition-normal); border: 1px solid rgba(255, 255, 255, 0.8); position: relative; display: flex; flex-direction: column; }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: rgba(99, 102, 241, 0.3); background: rgba(255, 255, 255, 0.9); }
.card-content { padding: 2rem; flex-grow: 1; display: flex; flex-direction: column; background: inherit; border-radius: inherit; }
.card-title { font-size: 1.2rem; font-weight: 600; margin-bottom: 0.8rem; display: flex; align-items: center; gap: 0.5rem; color: var(--dark); }
.card-title i { color: var(--primary); font-size: 1.3rem; }
.card-desc { color: var(--gray); line-height: 1.7; margin-bottom: 1.2rem; font-size: 0.95rem; }
.card-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 1.2rem; }
.tag { padding: 0.25rem 0.7rem; border-radius: var(--radius-sm); font-size: 0.82rem; font-weight: 500; }
.tag-primary { background: rgba(79, 70, 229, 0.1); color: var(--primary); }
.tag-secondary { background: rgba(16, 185, 129, 0.1); color: var(--secondary); }
.card-link { display: inline-flex; align-items: center; gap: 0.5rem; color: var(--primary); font-weight: 500; font-size: 0.95rem; transition: var(--transition-fast); }
.card-link:hover { color: var(--primary-light); transform: translateX(4px); }
.placeholder-box { background: rgba(79, 70, 229, 0.04); border: 2px dashed var(--gray-light); border-radius: var(--radius-md); padding: 3rem 2rem; text-align: center; color: var(--gray); }
.placeholder-box i { font-size: 3rem; margin-bottom: 1rem; color: var(--primary); opacity: 0.5; }
.folder-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 1.8rem; list-style: none; }
.folder-item { background: rgba(255, 255, 255, 0.75); backdrop-filter: blur(8px); border-radius: var(--radius-md); padding: 1.6rem; box-shadow: var(--shadow-sm); border: 1px solid rgba(255, 255, 255, 0.9); transition: var(--transition-normal); position: relative; }
.folder-item:hover { transform: translateY(-5px) scale(1.02); box-shadow: var(--shadow-md); border-color: rgba(99, 102, 241, 0.25); background: #ffffff; }
.folder-item a { display: flex; align-items: center; gap: 1rem; width: 100%; color: var(--dark); font-weight: 600; position: relative; z-index: 1; }
.folder-item i { font-size: 1.8rem; color: var(--primary); flex-shrink: 0; }
.folder-item .folder-info { display: flex; flex-direction: column; }
.folder-item .folder-name { font-weight: 600; font-size: 1rem; }
.folder-item .folder-desc { font-size: 0.82rem; color: var(--gray); margin-top: 0.2rem; }
.study-tree { display: flex; flex-direction: column; gap: 1.4rem; }
.tree-level {
    background: white;
    border: 1px solid rgba(0,0,0,0.06);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.4rem;
}
.tree-level-title { font-size: 1.08rem; font-weight: 700; color: var(--dark); }
.tree-level-note { margin-top: 0.35rem; color: var(--gray); font-size: 0.9rem; }
.tree-level-parallel {
    background: linear-gradient(180deg, #ffffff 0%, #fbfcfe 100%);
    border-style: dashed;
}
.tree-node-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; list-style: none; margin-top: 1rem; }
.tree-node-list.compact { grid-template-columns: 1fr; margin-top: 0.8rem; }
.tree-node-item { list-style: none; }
.tree-node {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    width: 100%;
    min-height: 92px;
    padding: 1rem 1.05rem;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    border: 1px solid rgba(0,0,0,0.06);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-normal);
}
.tree-node:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}
.tree-node-subtle {
    background: linear-gradient(180deg, #ffffff 0%, #fbfcfe 100%);
    border-color: rgba(100, 116, 139, 0.12);
}
.tree-node-subtle i { color: var(--gray); }
.tree-node i { font-size: 1.6rem; color: var(--primary); flex-shrink: 0; }
.tree-node-info { display: flex; flex-direction: column; min-width: 0; }
.tree-node-name { font-weight: 700; font-size: 0.98rem; color: var(--dark); }
.tree-node-desc { margin-top: 0.2rem; font-size: 0.84rem; color: var(--gray); line-height: 1.5; }
.tree-trunk {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
}
.tree-trunk::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, rgba(79, 70, 229, 0.2) 0%, rgba(79, 70, 229, 0.65) 50%, rgba(79, 70, 229, 0.2) 100%);
}
.tree-trunk.small { min-height: 34px; }
.tree-connector-label {
    position: relative;
    z-index: 1;
    padding: 0.15rem 0.7rem;
    background: var(--light);
    color: var(--gray);
    font-size: 0.82rem;
    border-radius: 999px;
    border: 1px solid rgba(79, 70, 229, 0.12);
}
.tree-columns { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.tree-branch {
    padding: 1rem;
    border-radius: var(--radius-md);
    background: rgba(79, 70, 229, 0.03);
    border: 1px solid rgba(79, 70, 229, 0.08);
}
.tree-branch-title { font-size: 1rem; font-weight: 700; color: var(--dark); }
.tree-node-featured {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1) 0%, rgba(99, 102, 241, 0.14) 100%);
    border-color: rgba(79, 70, 229, 0.28);
    box-shadow: 0 10px 24px rgba(79, 70, 229, 0.12);
}
.tree-node-badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 0.18rem 0.55rem;
    border-radius: 999px;
    background: rgba(79, 70, 229, 0.14);
    color: #4338ca;
    font-size: 0.76rem;
    font-weight: 700;
    margin-bottom: 0.28rem;
}
.sub-branch {
    margin-top: 1rem;
    padding-left: 1rem;
    border-left: 2px solid rgba(79, 70, 229, 0.18);
}
.side-list { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.repo-note {
    margin-top: 1rem;
    padding: 0.95rem 1rem;
    border-left: 3px solid #2563eb;
    border-radius: 8px;
    background: #eff6ff;
    color: #1e3a8a;
    font-size: 0.92rem;
    line-height: 1.7;
}
.repo-note a {
    color: #1d4ed8;
    font-weight: 600;
}
.link-card { background: white; border-radius: var(--radius-md); padding: 1.5rem; box-shadow: var(--shadow-sm); border: 1px solid rgba(0,0,0,0.05); transition: var(--transition-normal); display: flex; align-items: flex-start; gap: 1rem; }
.link-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--primary); }
.link-card .link-icon { width: 48px; height: 48px; border-radius: var(--radius-sm); background: rgba(79, 70, 229, 0.08); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.link-card .link-icon i { font-size: 1.3rem; color: var(--primary); }
.link-card .link-body { flex: 1; min-width: 0; }
.link-card .link-title { font-weight: 600; font-size: 1rem; margin-bottom: 0.3rem; color: var(--dark); }
.link-card .link-url { font-size: 0.82rem; color: var(--gray); word-break: break-all; }
.link-card .link-desc { font-size: 0.88rem; color: var(--gray); margin-top: 0.4rem; line-height: 1.5; }

.doc-viewer-wrap { margin-top: 1.25rem; }
.doc-viewer {
    width: 100%;
    height: min(78vh, 980px);
    border: 1px solid rgba(15, 23, 42, 0.12);
    border-radius: var(--radius-md);
    background: white;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.08);
}
.doc-actions { margin-top: 0.9rem; display: flex; gap: 0.75rem; flex-wrap: wrap; }
.doc-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 0.9rem;
    border: 1px solid rgba(37, 99, 235, 0.25);
    border-radius: var(--radius-sm);
    color: #1d4ed8;
    background: #eff6ff;
    font-size: 0.92rem;
    font-weight: 600;
}
.doc-tip { margin-top: 0.6rem; color: #475569; font-size: 0.88rem; }

.text-file-panel {
    margin-top: 1.25rem;
    background: white;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.text-file-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 0.9rem 1rem;
    background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
    border-bottom: 1px solid rgba(15, 23, 42, 0.08);
}

.text-file-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: #0f172a;
    word-break: break-all;
}

.text-file-open {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    font-size: 0.85rem;
    color: #1d4ed8;
    padding: 0.36rem 0.62rem;
    border: 1px solid rgba(37, 99, 235, 0.25);
    border-radius: var(--radius-sm);
    background: #eff6ff;
    flex-shrink: 0;
}

.text-file-content {
    max-height: min(72vh, 920px);
    overflow: auto;
    margin: 0;
    padding: 1rem;
    background: #f8fafc;
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 0.92rem;
    line-height: 1.7;
}

.text-file-tip {
    margin-top: 0.7rem;
    color: #64748b;
    font-size: 0.88rem;
}

.md-panel {
    margin-top: 1.25rem;
    background: white;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.25rem 1.5rem;
}
.md-content {
    color: var(--dark);
    line-height: 1.75;
    word-break: break-word;
}
.md-content h1, .md-content h2, .md-content h3, .md-content h4 {
    margin-top: 1.4rem;
    margin-bottom: 0.7rem;
    line-height: 1.35;
}
.md-content p, .md-content ul, .md-content ol, .md-content blockquote {
    margin: 0.75rem 0;
}
.md-content ul, .md-content ol {
    padding-left: 1.4rem;
}
.md-content pre {
    margin: 0.9rem 0;
    padding: 0.9rem 1rem;
    border-radius: var(--radius-sm);
    background: #0f172a;
    color: #e2e8f0;
    overflow-x: auto;
}
.md-content code {
    font-family: Consolas, 'Courier New', monospace;
}
.md-content :not(pre) > code {
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    background: #e2e8f0;
    color: #1e293b;
}
.md-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 0.9rem 0;
    font-size: 0.92rem;
}
.md-content th, .md-content td {
    border: 1px solid #cbd5e1;
    padding: 0.5rem 0.6rem;
}
.md-content blockquote {
    padding-left: 0.9rem;
    border-left: 3px solid var(--primary);
    color: #334155;
}
.md-hint {
    margin-top: 0.75rem;
    color: var(--gray);
    font-size: 0.88rem;
}

.footer { background: var(--dark); color: rgba(255,255,255,0.7); padding: 3rem 0 1.5rem; margin-top: auto; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
.footer-social { display: flex; gap: 0.8rem; }
.footer-social a { width: 36px; height: 36px; border-radius: 50%; background: rgba(255,255,255,0.1); display: flex; align-items: center; justify-content: center; color: rgba(255,255,255,0.7); transition: var(--transition-fast); }
.footer-social a:hover { background: var(--primary); color: white; transform: translateY(-2px); }
.footer-copy { font-size: 0.85rem; }
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 1180px) {
    .logo { font-size: 1.2rem; }
    .logo i { font-size: 1.6rem; }
    .nav-link { padding: 0.42rem 0.62rem; font-size: 0.86rem; }
    .nav-search { width: min(210px, 23vw); }
}

@media (max-width: 1024px) {
    .nav-search { display: none; }
}

@media (max-width: 768px) {
    .hamburger { display: block; }
    .nav-search {
        width: min(56vw, 240px);
        margin-left: auto;
        margin-right: 0.35rem;
    }
    .nav-menu { position: fixed; top: 70px; left: -100%; width: 100%; height: calc(100vh - 70px); background: rgba(255,255,255,0.98); backdrop-filter: blur(10px); flex-direction: column; align-items: center; justify-content: flex-start; padding-top: 2rem; gap: 0.5rem; transition: var(--transition-normal); z-index: 998; }
    .nav-menu.active { left: 0; }
    .nav-item { width: min(92vw, 420px); }
    .nav-item .nav-link { display: block; text-align: center; width: 100%; }
    .dropdown-menu {
        position: static;
        display: block;
        min-width: 0;
        margin-top: 0.2rem;
        padding: 0.35rem;
        box-shadow: none;
        border: 1px dashed rgba(79, 70, 229, 0.2);
        background: rgba(79, 70, 229, 0.03);
    }
    .dropdown-menu::before {
        content: '';
        position: absolute;
        top: -0.5rem;
        left: 0;
        right: 0;
        height: 0.5rem;
    }

    .dropdown-link { text-align: center; }
    .page-header h1 { font-size: 2rem; }
    .section { padding: 3rem 0; }
    .grid, .grid-2, .folder-list, .tree-node-list, .side-list { grid-template-columns: 1fr; }
    .tree-level { padding: 1rem; }
    .tree-columns { grid-template-columns: 1fr; }
    .tree-node { min-height: 82px; }
    .tree-trunk { min-height: 24px; }
    .tree-connector-label { font-size: 0.78rem; }
    .sub-branch { padding-left: 0.8rem; }
    .doc-viewer { height: 68vh; }
    .text-file-toolbar { flex-direction: column; align-items: flex-start; }
    .text-file-content { max-height: 64vh; font-size: 0.88rem; }
    .footer-inner { flex-direction: column; text-align: center; }
}