* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background-color: #ffffff;
    color: #000000;
    line-height: 1.6;
    padding: 0;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-weight: 400;
    display: flex;
}

.sidebar {
    width: 240px;
    border-right: 1px solid #e5e5e5;
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    background-color: #ffffff;
    z-index: 10;
}

.sidebar-content {
    padding: 120px 40px 40px 40px;
}

.sidebar-title {
    font-size: 0.9375rem;
    font-weight: 600;
    color: #000000;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 32px;
}

.topic-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.topic-item {
    background: none;
    border: none;
    text-align: left;
    font-size: 1rem;
    font-weight: 400;
    color: #666666;
    padding: 8px 0;
    cursor: pointer;
    transition: color 0.2s ease;
    font-family: inherit;
    letter-spacing: -0.01em;
}

.topic-item:hover {
    color: #000000;
}

.topic-item.active {
    color: #000000;
    font-weight: 500;
}

.main-content {
    flex: 1;
    margin-left: 240px;
}

.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 120px 40px;
}

.page-title {
    font-size: clamp(3.5rem, 8vw, 6rem);
    font-weight: 600;
    color: #000000;
    margin-bottom: 40px;
    letter-spacing: -0.04em;
    line-height: 1.05;
}

.page-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    color: #000000;
    line-height: 1.5;
    margin-bottom: 120px;
    max-width: 800px;
    letter-spacing: -0.01em;
}

.ideas-list {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.idea-item {
    border-top: 1px solid #e5e5e5;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.idea-item.hidden {
    display: none;
}

.idea-item:last-child {
    border-bottom: 1px solid #e5e5e5;
}

.idea-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    padding: 40px 0;
    cursor: pointer;
    transition: opacity 0.2s ease;
    gap: 24px;
    user-select: none;
}

.idea-header:hover {
    opacity: 0.6;
}

.idea-item.coming-soon .idea-header {
    cursor: default;
}

.idea-item.coming-soon .idea-header:hover {
    opacity: 1;
}

.idea-item.expanded .idea-header {
    opacity: 1;
}

.caret {
    flex-shrink: 0;
    width: 12px;
    height: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
    margin-top: 0.15em;
    align-self: flex-start;
}

.caret svg {
    display: block;
}

.idea-item.expanded .caret {
    transform: rotate(90deg);
}

.caret.inactive {
    opacity: 0.3;
    cursor: default;
}

.idea-item.coming-soon .caret {
    opacity: 0.3;
}

.idea-title-date {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.idea-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 600;
    color: #000000;
    margin: 0;
    letter-spacing: -0.02em;
    line-height: 1.2;
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.topic-tag {
    font-size: 0.75rem;
    font-weight: 500;
    color: #666666;
    background-color: #f5f5f5;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: inline-block;
}

.coming-soon-tag {
    font-size: 0.75rem;
    font-weight: 500;
    color: #ffffff;
    background-color: #000000;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: inline-block;
}

.idea-date {
    font-size: 0.9375rem;
    color: #666666;
    font-weight: 400;
    letter-spacing: 0;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.idea-preview {
    font-size: 1.25rem;
    color: #444444;
    font-weight: 400;
    line-height: 1.6;
    margin: 0;
    letter-spacing: -0.01em;
    margin-top: 4px;
}

.idea-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0;
}

.idea-item.expanded .idea-content {
    max-height: 5000px;
    padding: 0 0 40px 0;
}

.idea-body {
    color: #000000;
    font-size: 1.125rem;
    line-height: 1.7;
    margin: 0;
    padding-top: 0;
    letter-spacing: -0.01em;
    font-weight: 400;
}

.idea-body p {
    margin: 0 0 1.7em 0;
}

.idea-body p:last-child {
    margin-bottom: 0;
}

.idea-links {
    margin-top: 32px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.idea-body .link-preview {
    margin: 1.7em 0;
    display: block;
}

.link-preview {
    display: flex;
    border: 1px solid #e5e5e5;
    border-radius: 8px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: border-color 0.2s ease, opacity 0.2s ease;
    background-color: #ffffff;
}

.link-preview:hover {
    border-color: #000000;
    opacity: 0.8;
}

.link-preview-image {
    width: 200px;
    min-width: 200px;
    height: 150px;
    overflow: hidden;
    background-color: #f5f5f5;
}

.link-preview-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.link-preview-content {
    flex: 1;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.link-preview-site {
    font-size: 0.75rem;
    color: #666666;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
}

.link-preview-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: #000000;
    line-height: 1.4;
    letter-spacing: -0.01em;
}

.link-preview-description {
    font-size: 0.9375rem;
    color: #666666;
    line-height: 1.6;
    margin-top: 4px;
}

.link-preview-url {
    font-size: 0.875rem;
    color: #666666;
    margin-top: 8px;
    word-break: break-all;
}

.link-preview-loading {
    padding: 20px;
    text-align: center;
    color: #666666;
    font-size: 0.9375rem;
}

@media (max-width: 768px) {
    .link-preview {
        flex-direction: column;
    }

    .link-preview-image {
        width: 100%;
        min-width: 100%;
        height: 200px;
    }

    .link-preview-content {
        padding: 16px;
    }
}

@media (max-width: 1024px) {
    .sidebar {
        width: 200px;
    }

    .sidebar-content {
        padding: 100px 32px 32px 32px;
    }

    .main-content {
        margin-left: 200px;
    }
}

@media (max-width: 768px) {
    body {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        border-right: none;
        border-bottom: 1px solid #e5e5e5;
    }

    .sidebar-content {
        padding: 40px 32px;
    }

    .topic-list {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 12px;
    }

    .topic-item {
        padding: 6px 12px;
        background-color: #f5f5f5;
        border-radius: 16px;
    }

    .topic-item.active {
        background-color: #000000;
        color: #ffffff;
    }

    .main-content {
        margin-left: 0;
    }

    .container {
        padding: 80px 32px;
    }

    .page-title {
        margin-bottom: 32px;
    }

    .page-subtitle {
        font-size: 1.25rem;
        margin-bottom: 80px;
    }

    .idea-header {
        padding: 32px 0;
        gap: 20px;
    }

    .idea-preview {
        font-size: 0.9375rem;
    }

    .idea-title {
        font-size: 1.5rem;
    }

    .idea-item.expanded .idea-content {
        padding: 0 0 32px 0;
    }
}

@media (max-width: 480px) {
    .sidebar-content {
        padding: 32px 24px;
    }

    .container {
        padding: 60px 24px;
    }

    .page-subtitle {
        font-size: 1.125rem;
        margin-bottom: 60px;
    }

    .idea-header {
        padding: 24px 0;
        gap: 16px;
    }

    .idea-title {
        font-size: 1.375rem;
    }

    .idea-preview {
        font-size: 0.875rem;
    }

    .idea-body {
        font-size: 1rem;
    }
}