:root {
      --bg-color: #0d1117;
      --card-bg: #161b22;
      --text-main: #c9d1d9;
      --text-muted: #8b949e;
      --accent: #58a6ff;
      --border: #30363d;
      --notion-bg: #ffffff;
      --github-bg: #21262d;
    }

    body {
      font-family: 'Pretendard', -apple-system, sans-serif;
      background-color: var(--bg-color);
      color: var(--text-main);
      margin: 0;
      padding: 0;
    }

    header {
      background-color: var(--card-bg);
      border-bottom: 1px solid var(--border);
      padding: 3rem 1rem;
      text-align: center;
    }

    header h1 { margin: 0; color: var(--accent); font-size: 2rem; }
    header p { color: var(--text-muted); margin-top: 0.5rem; }

    main {
      max-width: 900px;
      margin: 2rem auto;
      padding: 0 1rem;
    }

    /* 🚀 Quick Links 전용 버튼 스타일 */
    .link-buttons {
      display: flex;
      gap: 15px;
      margin-bottom: 3rem;
    }

    .nav-btn {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      padding: 16px;
      border-radius: 12px;
      text-decoration: none;
      font-weight: bold;
      font-size: 1rem;
      transition: all 0.2s ease;
    }

    .nav-btn.github {
      background-color: var(--github-bg);
      color: white;
      border: 1px solid var(--border);
    }

    .nav-btn.notion {
      background-color: var(--notion-bg);
      color: #000000;
      border: 1px solid #e0e0e0;
    }

    .nav-btn:hover {
      transform: translateY(-3px);
      filter: brightness(1.2);
      box-shadow: 0 8px 20px rgba(0,0,0,0.4);
    }

    .nav-btn img { width: 22px; height: 22px; }

    /* 📅 월별 네비게이션 스타일 */
    .month-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 15px;
      margin-bottom: 3rem;
    }

    .month-card {
      background-color: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 25px 15px;
      text-align: center;
      text-decoration: none;
      color: var(--text-main);
      transition: all 0.3s ease;
    }

    .month-card:hover {
      border-color: var(--accent);
      background-color: rgba(88, 166, 255, 0.05);
      transform: translateY(-3px);
    }

    .month-card .number { font-size: 1.6rem; font-weight: bold; color: var(--accent); display: block; }
    .month-card .label { font-size: 0.9rem; color: var(--text-muted); margin-top: 8px; display: block; }

    /* 섹션 제목 */
    .section-title {
      font-size: 1.2rem;
      margin-bottom: 1.5rem;
      border-left: 4px solid var(--accent);
      padding-left: 12px;
      font-weight: bold;
    }

    /* 깃허브 잔디 섹션 */
    .github-section {
      margin-bottom: 3.5rem;
      padding: 1.5rem;
      background: var(--card-bg);
      border-radius: 12px;
      border: 1px solid var(--border);
      text-align: center;
    }

    .github-section img { width: 100%; height: auto; border-radius: 4px; }

    /* 최근 업데이트 */
    .recent-box {
      opacity: 0.7;
      padding: 30px;
      text-align: center;
      border: 2px dashed var(--border);
      border-radius: 12px;
      color: var(--text-muted);
    }

    @media (max-width: 600px) {
      .month-grid { grid-template-columns: repeat(2, 1fr); }
      .link-buttons { flex-direction: column; }
    }