/* roulang page: index */
:root {
      --bg-deep: #060B17;
      --bg-subtle: #0B132B;
      --card-bg: rgba(15, 23, 42, 0.72);
      --card-border: rgba(56, 189, 248, 0.16);
      --card-hover-border: rgba(56, 189, 248, 0.45);
      --primary-cyan: #00F2FE;
      --primary-blue: #4FACFE;
      --accent-purple: #7B61FF;
      --text-main: #F8FAFC;
      --text-muted: #94A3B8;
      --text-dim: #64748B;
    }
    body {
      background-color: var(--bg-deep);
      background-image: 
        radial-gradient(circle at 15% 15%, rgba(0, 242, 254, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 85% 65%, rgba(123, 97, 255, 0.08) 0%, transparent 45%),
        linear-gradient(180deg, #060B17 0%, #0B132B 100%);
      background-attachment: fixed;
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      overflow-x: hidden;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .glass-card:hover {
      border-color: var(--card-hover-border);
      box-shadow: 0 12px 32px -8px rgba(0, 242, 254, 0.15);
      transform: translateY(-2px);
    }
    .btn-glow {
      background: linear-gradient(135deg, var(--primary-cyan) 0%, var(--primary-blue) 100%);
      color: #030712;
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.35);
      transition: all 0.3s ease;
    }
    .btn-glow:hover {
      box-shadow: 0 0 32px rgba(0, 242, 254, 0.6);
      transform: translateY(-2px);
      color: #000;
    }
    .btn-outline-glow {
      border: 1px solid rgba(56, 189, 248, 0.3);
      color: var(--text-main);
      backdrop-filter: blur(12px);
      background: rgba(15, 23, 42, 0.4);
      transition: all 0.3s ease;
    }
    .btn-outline-glow:hover {
      border-color: var(--primary-cyan);
      background: rgba(0, 242, 254, 0.1);
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.25);
      transform: translateY(-2px);
    }
    .text-gradient {
      background: linear-gradient(135deg, #00F2FE 0%, #4FACFE 50%, #7B61FF 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    details summary::-webkit-details-marker {
      display: none;
    }
    .tech-border-b {
      border-bottom: 1px solid rgba(56, 189, 248, 0.12);
    }

/* roulang page: article */
:root {
      --bg-deep: #060B17;
      --bg-subtle: #0B132B;
      --card-bg: rgba(15, 23, 42, 0.72);
      --card-border: rgba(56, 189, 248, 0.16);
      --card-hover-border: rgba(56, 189, 248, 0.45);
      --primary-cyan: #00F2FE;
      --primary-blue: #4FACFE;
      --accent-purple: #7B61FF;
      --text-main: #F8FAFC;
      --text-muted: #94A3B8;
      --text-dim: #64748B;
    }
    body {
      background-color: var(--bg-deep);
      background-image: 
        radial-gradient(circle at 15% 15%, rgba(0, 242, 254, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 85% 65%, rgba(123, 97, 255, 0.08) 0%, transparent 45%),
        linear-gradient(180deg, #060B17 0%, #0B132B 100%);
      background-attachment: fixed;
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      overflow-x: hidden;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .glass-card:hover {
      border-color: var(--card-hover-border);
      box-shadow: 0 12px 32px -8px rgba(0, 242, 254, 0.15);
      transform: translateY(-2px);
    }
    .btn-glow {
      background: linear-gradient(135deg, var(--primary-cyan) 0%, var(--primary-blue) 100%);
      color: #030712;
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.35);
      transition: all 0.3s ease;
    }
    .btn-glow:hover {
      box-shadow: 0 0 32px rgba(0, 242, 254, 0.6);
      transform: translateY(-2px);
      color: #000;
    }
    .btn-outline-glow {
      border: 1px solid rgba(56, 189, 248, 0.3);
      color: var(--text-main);
      backdrop-filter: blur(12px);
      background: rgba(15, 23, 42, 0.4);
      transition: all 0.3s ease;
    }
    .btn-outline-glow:hover {
      border-color: var(--primary-cyan);
      background: rgba(0, 242, 254, 0.1);
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.25);
      transform: translateY(-2px);
    }
    .text-gradient {
      background: linear-gradient(135deg, #00F2FE 0%, #4FACFE 50%, #7B61FF 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .tech-border-b {
      border-bottom: 1px solid rgba(56, 189, 248, 0.12);
    }
    .prose-article {
      color: #CBD5E1;
      line-height: 1.85;
      font-size: 1.05rem;
    }
    .prose-article h2 {
      color: #F8FAFC;
      font-size: 1.5rem;
      font-weight: 700;
      margin-top: 2.25rem;
      margin-bottom: 1rem;
      padding-left: 0.85rem;
      border-left: 4px solid var(--primary-cyan);
      letter-spacing: -0.01em;
    }
    .prose-article h3 {
      color: #E2E8F0;
      font-size: 1.25rem;
      font-weight: 600;
      margin-top: 1.75rem;
      margin-bottom: 0.75rem;
    }
    .prose-article p {
      margin-bottom: 1.35rem;
      text-align: justify;
    }
    .prose-article blockquote {
      margin: 1.75rem 0;
      padding: 1.25rem 1.5rem;
      background: rgba(15, 23, 42, 0.6);
      border-left: 4px solid var(--accent-purple);
      border-radius: 0 0.75rem 0.75rem 0;
      color: #94A3B8;
      font-style: italic;
    }
    .prose-article ul, .prose-article ol {
      margin: 1.25rem 0;
      padding-left: 1.5rem;
      color: #94A3B8;
    }
    .prose-article li {
      margin-bottom: 0.5rem;
    }
    .prose-article img {
      border-radius: 0.75rem;
      border: 1px solid rgba(56, 189, 248, 0.2);
      margin: 2rem auto;
      max-width: 100%;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    }
    .prose-article code {
      background: rgba(56, 189, 248, 0.1);
      color: var(--primary-cyan);
      padding: 0.2rem 0.45rem;
      border-radius: 0.25rem;
      font-size: 0.9em;
      font-family: monospace;
    }
    .toc-link.active {
      color: var(--primary-cyan);
      border-left: 2px solid var(--primary-cyan);
      background: rgba(0, 242, 254, 0.05);
    }

/* roulang page: category1 */
:root {
      --bg-deep: #060B17;
      --bg-subtle: #0B132B;
      --card-bg: rgba(15, 23, 42, 0.72);
      --card-border: rgba(56, 189, 248, 0.16);
      --card-hover-border: rgba(56, 189, 248, 0.45);
      --primary-cyan: #00F2FE;
      --primary-blue: #4FACFE;
      --accent-purple: #7B61FF;
      --text-main: #F8FAFC;
      --text-muted: #94A3B8;
      --text-dim: #64748B;
    }
    body {
      background-color: var(--bg-deep);
      background-image: 
        radial-gradient(circle at 15% 15%, rgba(0, 242, 254, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 85% 65%, rgba(123, 97, 255, 0.08) 0%, transparent 45%),
        linear-gradient(180deg, #060B17 0%, #0B132B 100%);
      background-attachment: fixed;
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      overflow-x: hidden;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .glass-card:hover {
      border-color: var(--card-hover-border);
      box-shadow: 0 12px 32px -8px rgba(0, 242, 254, 0.15);
      transform: translateY(-2px);
    }
    .btn-glow {
      background: linear-gradient(135deg, var(--primary-cyan) 0%, var(--primary-blue) 100%);
      color: #030712;
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.35);
      transition: all 0.3s ease;
    }
    .btn-glow:hover {
      box-shadow: 0 0 32px rgba(0, 242, 254, 0.6);
      transform: translateY(-2px);
      color: #000;
    }
    .btn-outline-glow {
      border: 1px solid rgba(56, 189, 248, 0.3);
      color: var(--text-main);
      backdrop-filter: blur(12px);
      background: rgba(15, 23, 42, 0.4);
      transition: all 0.3s ease;
    }
    .btn-outline-glow:hover {
      border-color: var(--primary-cyan);
      background: rgba(0, 242, 254, 0.1);
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.25);
      transform: translateY(-2px);
    }
    .text-gradient {
      background: linear-gradient(135deg, #00F2FE 0%, #4FACFE 50%, #7B61FF 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .tech-border-b {
      border-bottom: 1px solid rgba(56, 189, 248, 0.12);
    }
    .filter-chip-active {
      background: rgba(0, 242, 254, 0.15);
      border-color: #00F2FE;
      color: #00F2FE;
      box-shadow: 0 0 12px rgba(0, 242, 254, 0.2);
    }