/* ============================================
   National PhD Registry – Design System
   Archival • Minimal • Authoritative
   ============================================ */

/* CSS Custom Properties */
:root {
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Lora', Georgia, 'Times New Roman', serif;

    /* Font Sizes - Modular Scale */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;

    /* Colors - Archival Palette */
    --color-paper: #FAFAF8;
    --color-paper-warm: #F5F4F0;
    --color-ink: #1A1A1A;
    --color-ink-light: #4A4A4A;
    --color-ink-muted: #6B6B6B;
    --color-ink-faint: #9A9A9A;
    --color-border: #E5E5E0;
    --color-border-dark: #CCCCCC;
    --color-accent: #8B4513;
    --color-accent-hover: #6B3410;
    --color-highlight: #FFF8DC;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Layout */
    --max-width-content: 680px;
    --max-width-page: 1100px;
    --header-height: 72px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
}


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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    transition: background-color var(--transition-base), color var(--transition-base);
    font-family: var(--font-primary);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-ink);
    background-color: var(--color-paper);
    min-height: 100vh;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-serif);
    font-weight: 500;
    line-height: 1.25;
    color: var(--color-ink);
}

h1 {
    font-size: var(--text-4xl);
    letter-spacing: -0.02em;
}

h2 {
    font-size: var(--text-3xl);
    letter-spacing: -0.015em;
}

h3 {
    font-size: var(--text-2xl);
}

h4 {
    font-size: var(--text-xl);
}

h5 {
    font-size: var(--text-lg);
}

h6 {
    font-size: var(--text-base);
}

p {
    margin-bottom: var(--space-4);
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
    text-decoration: underline;
}

/* Global keyboard focus */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: 2px;
}

/* Layout Components */
.container {
    width: 100%;
    max-width: var(--max-width-page);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container--narrow {
    max-width: var(--max-width-content);
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--color-paper-warm);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
    display: flex;
    align-items: center;
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.site-logo {
    font-family: var(--font-serif);
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--color-ink);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.site-logo:hover {
    color: var(--color-ink);
    text-decoration: none;
}

.site-logo span {
    color: var(--color-ink-muted);
    font-weight: 400;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.site-nav__link {
    font-size: var(--text-sm);
    color: var(--color-ink-light);
    text-decoration: none;
    letter-spacing: 0.02em;
    text-transform: uppercase;
    transition: color var(--transition-fast);
}

.site-nav__link:hover,
.site-nav__link--active {
    color: var(--color-ink);
    text-decoration: none;
}

/* Hamburger toggle — hidden on desktop, shown <=768px */
.nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 10px;
    background: none;
    border: 1px solid transparent;
    border-radius: 4px;
    cursor: pointer;
}

.nav-toggle__bar {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--color-ink);
    border-radius: 1px;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
    transform-origin: center;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
    opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}


/* Main Content */
main {
    padding: var(--space-16) 0;
    min-height: calc(100vh - var(--header-height) - 200px);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--space-12) 0;
    margin-top: var(--space-16);
    background-color: var(--color-paper-warm);
}

.site-footer__inner {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-4);
}

.site-footer__text {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

.site-footer__nav {
    display: flex;
    gap: var(--space-4);
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: var(--space-3);
}

.site-footer__nav a {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    text-decoration: none;
}

.site-footer__nav a:hover {
    color: var(--color-ink);
    text-decoration: underline;
}

.browse-hubs {
    margin-top: var(--space-16);
    padding-top: var(--space-8);
    border-top: 1px solid var(--color-border);
}

.browse-hubs__group {
    margin-bottom: var(--space-8);
}

.browse-hubs__group h2 {
    font-size: var(--text-xl);
    margin-bottom: var(--space-4);
}

.browse-hubs__list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2) var(--space-4);
}

.browse-hubs__list--letters a {
    font-weight: 600;
}

.browse-hubs__list--columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--space-2);
}

.hub-count {
    color: var(--color-ink-muted);
    font-size: var(--text-xs);
}

.hub-list {
    list-style: none;
    padding: 0;
    display: grid;
    gap: var(--space-2);
    margin-bottom: var(--space-8);
}

.hub-breadcrumb {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    margin-bottom: var(--space-4);
}

/* ============================================
   Homepage - Search First
   ============================================ */

.hero {
    text-align: center;
    padding: var(--space-24) 0 var(--space-10);
}

.hero__title {
    font-size: var(--text-5xl);
    margin-bottom: var(--space-4);
    font-weight: 400;
}

.hero__subtitle {
    font-size: var(--text-lg);
    color: var(--color-ink-muted);
    max-width: 640px;
    margin: 0 auto var(--space-12);
    font-family: var(--font-serif);
    line-height: 1.65;
}

/* Search Component */
.search-container {
    max-width: 560px;
    margin: 0 auto;
}

.search-box {
    position: relative;
}

.search-input {
    width: 100%;
    padding: var(--space-5) var(--space-6);
    padding-left: var(--space-12);
    font-size: var(--text-lg);
    font-family: var(--font-primary);
    border: 2px solid var(--color-border-dark);
    border-radius: 4px;
    background-color: #fff;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-input:focus {
    outline: none;
    border-color: var(--color-ink);
    box-shadow: var(--shadow-md);
}

.search-input::placeholder {
    color: var(--color-ink-faint);
}

.search-icon {
    position: absolute;
    left: var(--space-5);
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--color-ink-muted);
    pointer-events: none;
}

.search-hint {
    margin-top: var(--space-3);
    font-size: var(--text-sm);
    color: var(--color-ink-faint);
    text-align: center;
}

.hero__stat {
    margin-top: var(--space-4);
    font-size: var(--text-sm);
    color: var(--color-ink-faint);
    text-align: center;
    letter-spacing: 0.03em;
}

/* Search Results */
.search-results {
    margin-top: var(--space-8);
    text-align: left;
}

.search-results__header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: var(--space-6);
    padding-bottom: var(--space-3);
    border-bottom: 1px solid var(--color-border);
}

.search-results__count {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

.search-results__clear {
    font-size: var(--text-sm);
    cursor: pointer;
    background: none;
    border: none;
    color: var(--color-accent);
    font-family: var(--font-primary);
}

.search-results__clear:hover {
    text-decoration: underline;
}

.search-results__list {
    list-style: none;
}

.search-results__empty {
    text-align: center;
    padding: var(--space-12) 0;
    color: var(--color-ink-muted);
}

/* Result Item */
.result-item {
    display: block;
    padding: var(--space-5) 0;
    border-bottom: 1px solid var(--color-border);
    text-decoration: none;
    transition: background-color var(--transition-fast);
}

.result-item:hover {
    background-color: var(--color-highlight);
    text-decoration: none;
    margin: 0 calc(-1 * var(--space-4));
    padding-left: var(--space-4);
    padding-right: var(--space-4);
}

.result-item:last-child {
    border-bottom: none;
}

.result-item__name {
    font-family: var(--font-serif);
    font-size: var(--text-xl);
    color: var(--color-ink);
    margin-bottom: var(--space-1);
}

.result-item__field {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

/* Browse Links */
.browse-section {
    margin-top: var(--space-4);
    text-align: center;
}

.browse-all-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: 0;
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-sm);
    font-weight: 500;
    font-family: var(--font-primary);
    color: var(--color-accent);
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    text-decoration: none;
    letter-spacing: 0.02em;
    transition: all var(--transition-fast);
}

.browse-all-link:hover {
    background-color: var(--color-accent);
    color: #fff;
    text-decoration: none;
}

.browse-section--fields {
    margin-top: var(--space-12);
}

.field-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-3);
    max-width: 800px;
    margin: 0 auto;
}

.field-nav__link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-light);
    background-color: #fff;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    text-decoration: none;
    transition: all var(--transition-fast);
}

.field-nav__link:hover {
    background-color: var(--color-ink);
    color: #fff;
    border-color: var(--color-ink);
    text-decoration: none;
}

/* ============================================
   Person Page
   ============================================ */

.person-page {
    max-width: var(--max-width-content);
    margin: 0 auto;
}

.person-header {
    margin-bottom: var(--space-10);
}

.person-header__name {
    font-size: var(--text-4xl);
    margin-bottom: var(--space-3);
    font-weight: 400;
}

.person-header__field {
    font-size: var(--text-lg);
    color: var(--color-ink-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-family: var(--font-primary);
}

.person-bio {
    font-family: var(--font-serif);
    font-size: var(--text-lg);
    line-height: 1.75;
    text-align: justify;
    hyphens: auto;
    margin-bottom: var(--space-10);
}

.person-bio::after {
    content: "";
    display: block;
    clear: both;
}

.bio-cutoff-note {
    margin-top: calc(var(--space-10) * -1 + var(--space-2));
    margin-bottom: var(--space-10);
    font-family: var(--font-serif);
    font-size: var(--text-sm);
    font-style: italic;
    color: var(--color-ink-muted);
    text-align: right;
}

/* Citation Block */
.citation-block {
    background-color: var(--color-paper-warm);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-accent);
    padding: var(--space-6);
    margin: var(--space-10) 0;
}

.citation-block__title {
    font-size: var(--text-sm);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-ink-muted);
    margin-bottom: var(--space-4);
    font-family: var(--font-primary);
}

.citation-block__tabs {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
    padding-bottom: var(--space-3);
    border-bottom: 1px solid var(--color-border);
}

.citation-block__tab {
    padding: var(--space-2) var(--space-4);
    font-family: var(--font-primary);
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    background: none;
    border: 1px solid transparent;
    border-radius: 4px;
    cursor: pointer;
    transition: color var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
}

.citation-block__tab:hover {
    color: var(--color-ink);
    background-color: rgba(0, 0, 0, 0.04);
}

.citation-block__tab:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.citation-block__tab--active,
.citation-block__tab--active:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
    background-color: #fff;
}

.citation-block__text {
    font-family: var(--font-serif);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-ink);
    margin-bottom: var(--space-4);
    padding: var(--space-4);
    background-color: #fff;
    border: 1px solid var(--color-border);
    user-select: all;
}

.citation-block__actions {
    display: flex;
    gap: var(--space-4);
}

.citation-block__btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
    font-family: var(--font-primary);
    color: var(--color-accent);
    background: none;
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.citation-block__btn:hover {
    background-color: var(--color-accent);
    color: #fff;
}

.citation-block__btn--copied {
    background-color: #2E7D32;
    border-color: #2E7D32;
    color: #fff;
}

/* Report Link */
.report-link {
    margin-top: var(--space-6);
    padding-top: var(--space-6);
    border-top: 1px solid var(--color-border);
}

.report-link a {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

.report-link a:hover {
    color: var(--color-accent);
}

/* ============================================
   Browse Page
   ============================================ */

.browse-header {
    margin-bottom: var(--space-10);
}

.browse-header__title {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-2);
}

.browse-header__subtitle {
    color: var(--color-ink-muted);
}

.browse-search-group {
    margin-bottom: var(--space-4);
}

.browse-search__input {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    font-family: var(--font-primary);
    border: 1px solid var(--color-border-dark);
    border-radius: 4px;
    background-color: #fff;
    color: var(--color-ink);
    outline: none;
    transition: border-color var(--transition-fast);
}

.browse-search__input:focus {
    border-color: var(--color-ink);
}

.browse-filters {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
    margin-bottom: var(--space-8);
}

/* Tier */
.filter-tier {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.filter-tier[hidden] {
    display: none;
}

.filter-tier__label {
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

/* Chips row */
.filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.filter-chip {
    display: inline-flex;
    align-items: center;
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
    font-family: var(--font-primary);
    color: var(--color-ink-light);
    background-color: #fff;
    border: 1px solid var(--color-border-dark);
    border-radius: 999px;
    cursor: pointer;
    transition: border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
    white-space: nowrap;
}

.filter-chip:hover {
    border-color: var(--color-ink);
    color: var(--color-ink);
}

.filter-chip--active {
    background-color: var(--color-ink);
    border-color: var(--color-ink);
    color: #fff;
}

.filter-chip--active:hover {
    background-color: var(--color-ink-light);
    border-color: var(--color-ink-light);
    color: #fff;
}

.filter-chip__count {
    opacity: 0.65;
    font-size: var(--text-xs);
}

.filter-chip--active .filter-chip__count {
    opacity: 0.8;
}

/* Result count + clear row */
.filter-meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    padding-top: var(--space-2);
    border-top: 1px solid var(--color-border);
}

.filter-meta__count {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

.filter-clear {
    font-size: var(--text-sm);
    font-family: var(--font-primary);
    color: var(--color-accent);
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    text-decoration: underline;
    text-underline-offset: 2px;
}

.filter-clear:hover {
    color: var(--color-accent-hover);
}

/* Entry cards */
.entry-card {
    padding: var(--space-5) 0;
    border-bottom: 1px solid var(--color-border);
}

.entry-card:last-child {
    border-bottom: none;
}

.entry-card__header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: var(--space-4);
    margin-bottom: var(--space-1);
}

.entry-card__name {
    font-family: var(--font-serif);
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--color-ink);
}

.entry-card__name:hover {
    color: var(--color-accent);
}

.entry-card__degree-badge {
    flex-shrink: 0;
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

.entry-card__raw-degree {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    font-style: italic;
    margin-bottom: var(--space-1);
}

.entry-card__meta {
    font-size: var(--text-sm);
    color: var(--color-ink-light);
}

.entry-card__group {
    font-weight: 500;
}

.entry-card__discipline,
.entry-card__spec {
    color: var(--color-ink-muted);
}

.entry-card__sep {
    color: var(--color-ink-faint);
    margin: 0 var(--space-1);
}

.entry-card__notes {
    margin-top: var(--space-2);
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
    font-style: italic;
}

.letter-section {
    margin-bottom: var(--space-12);
}

.letter-section__heading {
    font-size: var(--text-4xl);
    color: var(--color-ink-faint);
    padding-bottom: var(--space-4);
    border-bottom: 2px solid var(--color-border);
    margin-bottom: var(--space-6);
}

.person-list {
    list-style: none;
}

.person-list__item {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding: var(--space-4) 0;
    border-bottom: 1px solid var(--color-border);
}

.person-list__item:last-child {
    border-bottom: none;
}

.person-list__name {
    font-family: var(--font-serif);
    font-size: var(--text-lg);
    color: var(--color-ink);
}

.person-list__name:hover {
    color: var(--color-accent);
}

.person-list__field {
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

/* ============================================
   About Page
   ============================================ */

.about-content {
    max-width: var(--max-width-content);
    margin: 0 auto;
}

.about-content h1 {
    margin-bottom: var(--space-8);
}

.about-content h2 {
    margin-top: var(--space-10);
    margin-bottom: var(--space-4);
    font-size: var(--text-2xl);
}

.about-content p {
    font-family: var(--font-serif);
    font-size: var(--text-lg);
    line-height: 1.75;
}

.author-portrait {
    float: right;
    width: 200px;
    margin-left: var(--space-8);
    margin-bottom: var(--space-4);
}

.author-portrait img {
    width: 100%;
    border: 1px solid var(--color-border);
}

/* ============================================
   Report/Correction Form
   ============================================ */

.report-page {
    max-width: var(--max-width-content);
    margin: 0 auto;
}

.report-page h1 {
    margin-bottom: var(--space-4);
}

.report-page__intro {
    color: var(--color-ink-muted);
    margin-bottom: var(--space-10);
    font-size: var(--text-lg);
}

.report-form {
    background-color: #fff;
    border: 1px solid var(--color-border);
    padding: var(--space-8);
}

.form-group {
    margin-bottom: var(--space-6);
}

.form-group label {
    display: block;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink);
    margin-bottom: var(--space-2);
}

.form-group label span {
    color: var(--color-ink-faint);
    font-weight: 400;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    font-family: var(--font-primary);
    border: 1px solid var(--color-border-dark);
    border-radius: 4px;
    background-color: #fff;
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-ink);
}

.form-group input:disabled {
    background-color: var(--color-paper-warm);
    color: var(--color-ink-muted);
}

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.form-submit {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-base);
    font-family: var(--font-primary);
    font-weight: 500;
    color: #fff;
    background-color: var(--color-ink);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.form-submit:hover {
    background-color: var(--color-ink-light);
}

.form-note {
    margin-top: var(--space-6);
    padding: var(--space-4);
    background-color: var(--color-paper-warm);
    border-left: 3px solid var(--color-ink-faint);
    font-size: var(--text-sm);
    color: var(--color-ink-muted);
}

.form-status {
    margin-top: var(--space-4);
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    border-radius: 4px;
}

.form-status:empty {
    display: none;
}

.form-status[data-kind="success"] {
    background-color: #e7f4ea;
    color: #1f5132;
    border-left: 3px solid #2e7d4f;
}

.form-status[data-kind="error"] {
    background-color: #fbeaea;
    color: #7a1d1d;
    border-left: 3px solid #b13a3a;
}

.form-submit[disabled] {
    opacity: 0.6;
    cursor: progress;
}

/* ============================================
   Utilities
   ============================================ */

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-center {
    text-align: center;
}

.text-muted {
    color: var(--color-ink-muted);
}

/* Back to top */
.back-to-top {
    position: fixed;
    bottom: var(--space-8);
    right: var(--space-8);
    width: 44px;
    height: 44px;
    background-color: var(--color-ink);
    color: #fff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top--visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--color-ink-light);
    transform: translateY(-2px);
}

.back-to-top--with-label {
    width: auto;
    height: auto;
    min-width: 44px;
    padding: 8px 12px 6px;
    border-radius: 22px;
    flex-direction: column;
    gap: 2px;
}

.back-to-top__label {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 0.04em;
    line-height: 1;
    text-transform: uppercase;
}

/* Loading state */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
    padding: var(--space-16) var(--space-4);
    text-align: center;
    color: var(--color-ink-muted);
    min-height: 50vh;
}

.loading-state__spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: loading-spin 0.8s linear infinite;
}

.loading-state__text {
    font-size: var(--text-sm);
    letter-spacing: 0.03em;
}

@keyframes loading-spin {
    to { transform: rotate(360deg); }
}


/* ============================================
   Libri (Book) Page
   ============================================ */

.libri-hero {
    padding: var(--space-20) 0 var(--space-12);
}

.libri-hero__inner {
    max-width: 720px;
}

.libri-hero__text .hero__title {
    text-align: left;
    margin-bottom: var(--space-4);
}

.libri-hero__text .hero__subtitle {
    margin-left: 0;
    margin-right: 0;
    text-align: left;
    margin-bottom: var(--space-4);
}

.libri-hero__byline {
    font-family: var(--font-serif);
    font-style: italic;
    color: var(--color-ink-muted);
    margin-bottom: var(--space-6);
}

.libri-hero__cta {
    display: inline-block;
    margin-top: var(--space-2);
}

.libri-stats {
    padding: var(--space-12) 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    background-color: var(--color-paper-warm);
}

.libri-stats__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-8);
    margin: 0;
}

.libri-stats__item {
    text-align: center;
}

.libri-stats__item dt {
    font-size: var(--text-sm);
    color: var(--color-ink-faint);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: var(--space-2);
}

.libri-stats__item dd {
    font-family: var(--font-serif);
    font-size: var(--text-3xl);
    color: var(--color-accent);
    margin: 0;
    line-height: 1.1;
}

.libri-author {
    padding: var(--space-16) 0;
}

.libri-order {
    padding: var(--space-12) 0 var(--space-20);
}

.libri-order__wrapper {
    max-width: var(--max-width-content);
    margin: 0 auto;
}

.libri-order__wrapper h2 {
    margin-bottom: var(--space-4);
}

.libri-order__intro {
    color: var(--color-ink-muted);
    font-size: var(--text-lg);
    margin-bottom: var(--space-10);
}

.libri-order__row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-5);
}

.libri-order__row .form-group {
    margin-bottom: 0;
}

/* ============================================
   Responsive
   ============================================ */

/* Tablet — smoother hero scaling */
@media (max-width: 1024px) {
    .hero {
        padding: var(--space-20) 0 var(--space-8);
    }

    .hero__title {
        font-size: var(--text-4xl);
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 60px;
    }

    /* Hamburger visible, header stays sticky and horizontal */
    .nav-toggle {
        display: flex;
    }

    /* Nav becomes a slide-down panel below the header */
    .site-nav {
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        background-color: var(--color-paper);
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
        padding: var(--space-2) 0;
        transform: translateY(-8px);
        opacity: 0;
        visibility: hidden;
        transition: transform var(--transition-fast), opacity var(--transition-fast), visibility var(--transition-fast);
    }

    .site-nav.is-open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .site-nav__link {
        display: flex;
        align-items: center;
        min-height: 48px;
        padding: var(--space-3) var(--space-6);
        font-size: var(--text-sm);
        border-bottom: 1px solid var(--color-border);
    }

    .site-nav .site-nav__link:last-child {
        border-bottom: none;
    }

    .site-nav__link--active {
        color: var(--color-ink);
        background-color: var(--color-paper-warm);
    }

    .hero {
        padding: var(--space-12) 0 var(--space-6);
    }

    .hero__title {
        font-size: var(--text-4xl);
    }

    .search-input {
        font-size: var(--text-base);
        padding: var(--space-4) var(--space-5);
        padding-left: var(--space-10);
    }

    .person-header__name {
        font-size: var(--text-3xl);
        overflow-wrap: anywhere;
    }

    .person-bio {
        font-size: var(--text-base);
        text-align: left;
    }

    /* Touch targets — 44x44 minimum */
    .filter-chip {
        min-height: 44px;
        padding: var(--space-3) var(--space-4);
    }

    .citation-block__tab {
        min-height: 44px;
        padding: var(--space-3) var(--space-4);
    }

    .citation-block__btn {
        min-height: 44px;
        padding: var(--space-3) var(--space-5);
    }

    .browse-search__input {
        min-height: 44px;
    }

    .entry-card__name {
        overflow-wrap: anywhere;
    }

    .author-portrait {
        float: none;
        margin: 0 auto var(--space-6);
    }

    .libri-hero {
        padding: var(--space-12) 0 var(--space-8);
    }

    .libri-hero__text .hero__title,
    .libri-hero__text .hero__subtitle {
        text-align: center;
    }

    .libri-hero__byline {
        text-align: center;
    }

    .libri-hero__cta {
        display: block;
        text-align: center;
    }

    .libri-stats__grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-6);
    }

    .libri-stats__item dd {
        font-size: var(--text-2xl);
    }

    .libri-order__row {
        grid-template-columns: 1fr;
        gap: var(--space-5);
    }

    .libri-order__row .form-group {
        margin-bottom: var(--space-5);
    }

    main {
        padding: var(--space-10) 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-3);
    }

    .hero__title {
        font-size: var(--text-3xl);
    }

    .filter-chips {
        gap: var(--space-2);
    }

    .citation-block {
        padding: var(--space-4);
    }

    .citation-block__actions {
        flex-direction: column;
    }

    .person-list__item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-1);
    }

    .back-to-top {
        bottom: var(--space-4);
        right: var(--space-4);
        box-shadow: var(--shadow-md);
    }
}

/* Tap (active) feedback — applies to all viewports */
.filter-chip:active {
    background-color: var(--color-paper-warm);
}

.filter-chip--active:active {
    background-color: var(--color-ink-light);
}

.citation-block__tab:active {
    background-color: rgba(0, 0, 0, 0.06);
}

.nav-toggle:active {
    background-color: var(--color-paper-warm);
}

/* Touch devices — nullify sticky hover states that linger after tap */
@media (hover: none) {
    .field-nav__link:hover {
        background-color: #fff;
        color: var(--color-ink-light);
        border-color: var(--color-border);
    }

    .filter-chip:hover {
        background-color: #fff;
        border-color: var(--color-border-dark);
        color: var(--color-ink-light);
    }

    .filter-chip--active:hover {
        background-color: var(--color-ink);
        border-color: var(--color-ink);
        color: #fff;
    }

    .citation-block__tab:hover {
        background-color: transparent;
        color: var(--color-ink-muted);
    }

    .citation-block__tab--active:hover {
        color: var(--color-accent);
        background-color: #fff;
    }

    .citation-block__btn:hover {
        background-color: transparent;
        color: var(--color-accent);
    }

    .browse-all-link:hover {
        background-color: transparent;
        color: var(--color-accent);
    }

    .back-to-top:hover {
        transform: none;
        background-color: var(--color-ink);
    }

    .result-item:hover {
        background-color: transparent;
        margin: 0;
        padding-left: 0;
        padding-right: 0;
    }

    .form-submit:hover {
        background-color: var(--color-ink);
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    html {
        scroll-behavior: auto;
    }

    .loading-state__spinner {
        animation: none;
        border-top-color: var(--color-accent);
    }

    .back-to-top:hover {
        transform: none;
    }
}