:root {
    --paper: #f5efe4;
    --cream: #fcf8f2;
    --cloud: #eef4f3;
    --card: rgba(255, 252, 247, 0.9);
    --card-strong: rgba(255, 255, 255, 0.94);
    --berry: #b64b3e;
    --berry-deep: #8b342b;
    --moss: #6d7f6a;
    --ink: #201b17;
    --muted: #665d54;
    --line: rgba(32, 27, 23, 0.1);
    --line-strong: rgba(32, 27, 23, 0.16);
    --shadow-lg: 0 28px 60px rgba(77, 48, 34, 0.12);
    --shadow-md: 0 18px 36px rgba(77, 48, 34, 0.1);
    --radius-xl: 30px;
    --radius-lg: 24px;
    --radius-md: 18px;
    --radius-sm: 14px;
}

* {
    box-sizing: border-box;
}

[hidden] {
    display: none !important;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    font-family: "Avenir Next", "Segoe UI", "Trebuchet MS", sans-serif;
    background:
        radial-gradient(circle at top left, rgba(182, 75, 62, 0.08), transparent 28%),
        radial-gradient(circle at top right, rgba(109, 127, 106, 0.12), transparent 30%),
        linear-gradient(180deg, #f7f1e7 0%, #efe5d7 100%);
}

a {
    color: var(--berry-deep);
}

button,
input {
    font: inherit;
}

.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;
}

.page-glow {
    position: fixed;
    inset: 0;
    pointer-events: none;
    background:
        radial-gradient(circle at 15% 8%, rgba(255, 255, 255, 0.45), transparent 22%),
        radial-gradient(circle at 92% 18%, rgba(182, 75, 62, 0.08), transparent 24%),
        radial-gradient(circle at 8% 90%, rgba(109, 127, 106, 0.12), transparent 26%);
}

.topbar {
    position: sticky;
    top: 0;
    z-index: 30;
    backdrop-filter: blur(18px);
    background: rgba(247, 241, 231, 0.78);
    border-bottom: 1px solid rgba(32, 27, 23, 0.06);
}

.topbar-inner,
.app-shell {
    width: min(980px, calc(100% - 1.1rem));
    margin: 0 auto;
}

.letter-page .topbar-inner {
    width: min(1120px, calc(100% - 1.1rem));
}

.topbar-inner {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 0.5rem 1rem;
    align-items: center;
    padding: 0.95rem 0 0.9rem;
}

.topbar-copy {
    min-width: 0;
}

.brand-mark {
    margin: 0;
    font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
    font-size: clamp(1.2rem, 2.8vw, 1.6rem);
    font-weight: 700;
    letter-spacing: 0.01em;
}

.brand-link {
    color: inherit;
    text-decoration: none;
}

.brand-link:hover {
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 0.14em;
}

.brand-copy {
    margin: 0;
    color: var(--muted);
    font-size: 0.98rem;
}

.topbar-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-left: auto;
    min-height: 2.5rem;
    padding: 0.35rem 0.8rem;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.72);
    border: 1px solid rgba(32, 27, 23, 0.08);
    color: var(--berry-deep);
    text-decoration: none;
    font-weight: 700;
    box-shadow: var(--shadow-md);
}

.topbar-link:hover {
    transform: translateY(-1px);
}

.app-shell {
    padding: 1rem 0 2rem;
}

.search-panel,
.result-card {
    position: relative;
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, 0.75);
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-xl);
}

.search-panel {
    position: sticky;
    top: 4.85rem;
    z-index: 20;
    padding: 1rem;
    backdrop-filter: blur(14px);
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.78), rgba(238, 244, 243, 0.72)),
        var(--card);
}

.search-bar {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.7rem;
    align-items: center;
}

.search-field {
    display: block;
}

.search-field input {
    width: 100%;
    min-height: 3.6rem;
    border: 1px solid rgba(32, 27, 23, 0.12);
    border-radius: 22px;
    padding: 0 1.1rem;
    font-size: 1rem;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.88);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

.search-field input::placeholder {
    color: rgba(102, 93, 84, 0.8);
}

.search-field input:focus {
    outline: none;
    border-color: rgba(182, 75, 62, 0.45);
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.8),
        0 0 0 4px rgba(182, 75, 62, 0.12);
}

.source-link {
    min-height: 3.2rem;
    border: 0;
    border-radius: 18px;
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
}

.source-link:hover,
.result-toggle:hover,
.search-clear-button:hover {
    transform: translateY(-1px);
}

.results-shell {
    margin-top: 1rem;
}

.results-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 0.8rem;
    padding: 0.2rem 0.2rem 0.8rem;
}

.results-label,
.result-code,
.detail-label {
    margin: 0 0 0.3rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.75rem;
    color: var(--berry-deep);
}

.results-toolbar h1,
.result-title,
.detail-block h3 {
    margin: 0;
    font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
    line-height: 1.06;
}

.results-toolbar h1 {
    font-size: clamp(1.7rem, 4vw, 2.4rem);
}

.results-hint {
    margin: 0.45rem 0 0;
    color: var(--muted);
    line-height: 1.55;
    max-width: 42rem;
}

.results-list {
    display: grid;
    gap: 0.85rem;
}

.result-card {
    overflow: hidden;
    cursor: pointer;
}

.result-shell {
    padding: 1rem 1rem 0.95rem;
    user-select: text;
}

.result-header {
    display: flex;
    gap: 0.8rem;
    justify-content: space-between;
    align-items: start;
}

.result-title {
    font-size: clamp(1.2rem, 3vw, 1.6rem);
}

.result-meta,
.tag-list,
.detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.result-meta {
    margin: 0.8rem 0 0.7rem;
}

.meta-chip,
.tag {
    display: inline-flex;
    align-items: center;
    min-height: 2rem;
    padding: 0.35rem 0.7rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.8);
    color: var(--muted);
    font-size: 0.92rem;
}

.result-summary,
.detail-block p,
.detail-list li {
    margin: 0;
    color: var(--ink);
    line-height: 1.68;
}

mark {
    background: rgba(255, 218, 119, 0.6);
    color: inherit;
    padding: 0 0.12rem;
    border-radius: 0.2rem;
}

.result-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.8rem;
    margin-top: 0.9rem;
}

.result-prompt {
    color: var(--muted);
    font-size: 0.94rem;
}

.result-action {
    min-height: 2.75rem;
    border: 0;
    border-radius: 999px;
    padding: 0.6rem 0.95rem;
    cursor: pointer;
    background: rgba(182, 75, 62, 0.1);
    color: var(--berry-deep);
    font-weight: 600;
}

.result-action:hover {
    background: rgba(182, 75, 62, 0.16);
}

.search-clear-button {
    min-height: 3.2rem;
    padding: 0.75rem 1rem;
}

.detail-panel {
    border-top: 1px solid rgba(32, 27, 23, 0.08);
    padding: 0.95rem 1rem 1rem;
    background:
        linear-gradient(180deg, rgba(238, 244, 243, 0.4), rgba(255, 255, 255, 0));
}

.detail-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.5fr) minmax(220px, 0.9fr);
    gap: 1rem;
}

.detail-block {
    display: grid;
    gap: 0.7rem;
}

.detail-lead {
    color: var(--muted);
}

.detail-list {
    margin: 0;
    padding-left: 1.1rem;
    color: var(--muted);
}

.detail-list li + li {
    margin-top: 0.45rem;
}

.source-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.source-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.8rem;
    padding: 0.65rem 0.95rem;
    text-decoration: none;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 241, 231, 0.9));
    color: var(--berry-deep);
    box-shadow: var(--shadow-md);
}

.letter-shell {
    width: min(860px, calc(100% - 1.1rem));
    margin: 0 auto;
    padding: 1rem 0 2.4rem;
}

.letter-card {
    position: relative;
    background: var(--card-strong);
    border: 1px solid rgba(255, 255, 255, 0.8);
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-xl);
    padding: 1.5rem 1.35rem 1.6rem;
}

.letter-body {
    max-width: 44rem;
    margin: 0 auto;
}

.letter-kicker {
    margin: 0 0 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.74rem;
    color: var(--berry-deep);
}

.letter-date,
.letter-salute {
    margin: 0;
    color: var(--muted);
}

.letter-date {
    font-size: 0.95rem;
}

.letter-salute {
    margin-top: 0.9rem;
    font-weight: 600;
}

.letter-card h1,
.letter-card h2 {
    margin: 0;
    font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
    line-height: 1.08;
}

.letter-card h1 {
    font-size: clamp(2rem, 5vw, 3rem);
}

.letter-intro,
.letter-card p,
.letter-card li {
    color: var(--ink);
    line-height: 1.72;
}

.letter-intro {
    margin: 0.9rem 0 0;
    font-size: 1.03rem;
}

.letter-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
    gap: 0.9rem;
    margin-top: 1.2rem;
}

.summary-card,
.callout-card,
.qa-card,
.timeline-step {
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.72);
    box-shadow: var(--shadow-md);
}

.summary-card {
    display: grid;
    align-content: start;
    gap: 0.35rem;
    min-height: 9.25rem;
    padding: 1rem 1rem 1.05rem;
    border: 1px solid rgba(182, 75, 62, 0.16);
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 241, 231, 0.9));
    box-shadow: 0 18px 34px rgba(77, 48, 34, 0.08);
}

.summary-label {
    margin: 0 0 0.35rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.72rem;
    color: var(--berry-deep);
}

.summary-value {
    margin: 0;
    line-height: 1.5;
    color: var(--ink);
    font-size: 0.98rem;
}

.letter-sections {
    display: grid;
    gap: 1.1rem;
    margin-top: 1.4rem;
}

.letter-section {
    padding-top: 1.05rem;
    border-top: 1px solid var(--line);
}

.letter-section h2 {
    font-size: 1.45rem;
    margin-bottom: 0.55rem;
}

.letter-section p {
    margin: 0.6rem 0 0;
}

.letter-section ul {
    margin: 0.7rem 0 0;
    padding-left: 1.1rem;
}

.callout-grid,
.qa-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.8rem;
    margin-top: 0.95rem;
}

.callout-card,
.qa-card {
    padding: 0.95rem 1rem;
}

.callout-card h3,
.qa-card h3 {
    margin: 0;
    font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
    font-size: 1.14rem;
    line-height: 1.14;
}

.callout-card p,
.qa-card p {
    margin: 0.55rem 0 0;
    color: var(--muted);
    line-height: 1.62;
}

.timeline {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0.8rem;
    margin-top: 0.95rem;
}

.timeline-step {
    padding: 0.95rem 1rem;
}

.timeline-time {
    display: block;
    margin: 0 0 0.35rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.72rem;
    color: var(--berry-deep);
}

.timeline-step strong {
    display: block;
    line-height: 1.35;
}

.timeline-step p {
    margin: 0.5rem 0 0;
    color: var(--muted);
    line-height: 1.58;
}

.letter-diagram {
    margin: 0.85rem 0 0;
    padding: 0.95rem 1rem;
    overflow-x: auto;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(32, 27, 23, 0.04);
    color: var(--ink);
    font: 0.92rem/1.55 "SFMono-Regular", "Cascadia Mono", "Liberation Mono", monospace;
}

.letter-ending {
    margin-top: 1.35rem;
    padding-top: 1.05rem;
    border-top: 1px solid var(--line);
}

.letter-updated {
    margin-top: 0.75rem;
    color: var(--muted);
    font-size: 0.94rem;
}

.letter-close {
    margin-top: 0.8rem;
    color: var(--muted);
}

@media (max-width: 900px) {
    .detail-grid {
        grid-template-columns: 1fr;
    }

    .timeline,
    .callout-grid,
    .qa-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 700px) {
    .topbar-inner,
    .app-shell,
    .letter-shell {
        width: min(100%, calc(100% - 0.85rem));
    }

    .topbar-inner {
        padding: 0.8rem 0 0.82rem;
    }

    .search-panel {
        top: 4.6rem;
        padding: 0.85rem;
        border-radius: 24px;
    }

    .results-toolbar {
        padding-inline: 0.05rem;
    }

    .topbar-link {
        min-height: 2.3rem;
        padding-inline: 0.72rem;
    }

    .letter-card {
        padding: 1.15rem 0.95rem 1.2rem;
        border-radius: 24px;
    }

    .letter-overview,
    .timeline,
    .callout-grid,
    .qa-grid {
        grid-template-columns: 1fr;
    }

    .detail-panel {
        padding-left: 0.9rem;
        padding-right: 0.9rem;
    }

    .result-footer {
        align-items: start;
        flex-direction: column;
    }
}