/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* Base */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                 "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #333;
    background: #fff;
}

a {
    color: #333;
    text-decoration: none;
}

a:hover {
    color: #000;
}

/* Layout */
header, main, footer {
    max-width: 720px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Nav */
nav {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding-top: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #eee;
}

.site-title {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    font-size: 0.9rem;
    color: #666;
}

.nav-links a:hover {
    color: #000;
}

/* Main */
main {
    padding-top: 2rem;
    padding-bottom: 3rem;
    min-height: 60vh;
}

h1 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 2rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

/* Report cards on index */
.report-card {
    padding: 1.5rem 0;
    border-bottom: 1px solid #eee;
}

.report-card:first-of-type {
    padding-top: 0;
}

.report-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.tag {
    font-size: 0.7rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.15rem 0.5rem;
    border-radius: 2px;
}

.tag-model {
    background: #f0f0f0;
    color: #555;
}

.tag-dataset {
    background: #e8f5e9;
    color: #2e7d32;
}

.date {
    font-size: 0.8rem;
    color: #999;
}

.report-card h2 {
    margin-bottom: 0.25rem;
}

.report-card h2 a {
    color: #111;
}

.report-card h2 a:hover {
    color: #555;
}

.item-name {
    font-size: 0.85rem;
    color: #888;
    margin-bottom: 0.5rem;
}

.summary {
    font-size: 0.9rem;
    color: #555;
    line-height: 1.5;
}

.empty {
    color: #999;
    font-style: italic;
}

/* Report detail */
article h1 {
    margin-bottom: 0.25rem;
}

.item-link {
    margin-bottom: 1.5rem;
}

.item-link a {
    font-size: 0.85rem;
    color: #666;
    border-bottom: 1px solid #ddd;
    padding-bottom: 1px;
}

.item-link a:hover {
    color: #000;
    border-color: #000;
}

.report-summary {
    margin-bottom: 2rem;
}

.report-summary p {
    margin-bottom: 1rem;
    line-height: 1.7;
}

article h2 {
    margin-bottom: 1rem;
}

.ideas-list {
    margin-bottom: 2.5rem;
    padding-left: 1.25rem;
}

.ideas-list li {
    margin-bottom: 0.75rem;
    line-height: 1.5;
    padding-left: 0.25rem;
}

.back-link {
    display: inline-block;
    font-size: 0.85rem;
    color: #888;
    border-bottom: 1px solid #ddd;
    padding-bottom: 1px;
}

.back-link:hover {
    color: #000;
    border-color: #000;
}

/* About */
main p {
    margin-bottom: 1rem;
    line-height: 1.7;
}

main p a {
    border-bottom: 1px solid #ccc;
}

main p a:hover {
    border-color: #000;
}

/* Footer */
footer {
    padding: 2rem 1.5rem;
    border-top: 1px solid #eee;
    text-align: center;
}

footer small {
    display: block;
    font-size: 0.8rem;
    color: #bbb;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
}

.page-header .countdown {
    font-size: 0.8rem;
    color: #bbb;
    letter-spacing: 0.02em;
}

.created-by {
    margin-top: 0.25rem;
}

.created-by a {
    color: #aaa;
    border-bottom: 1px solid #ddd;
}

.created-by a:hover {
    color: #666;
    border-color: #999;
}