@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&display=swap");

:root {
  color-scheme: light only;
  --fg: #0a0a0a;
  --fg-muted: #4a4a4a;
  --fg-faint: #8a8a8a;
  --bg: #ffffff;
  --line: #0a0a0a;
  --line-soft: #d4d4d4;
  --surface: #f7f7f7;
  --font-mono: "IBM Plex Mono", ui-monospace, "Cascadia Code", "Cascadia Mono", Consolas, monospace;
  --font-ui: "IBM Plex Mono", ui-monospace, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", Meiryo, sans-serif;
}

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

html {
  scroll-padding-top: 64px;
}

html,
body {
  width: 100%;
  min-height: 100%;
}

body {
  font-size: 0.875rem;
  line-height: 1.55;
  font-family: var(--font-ui);
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--fg);
  background-color: var(--bg);
  word-break: auto-phrase;
  -webkit-font-smoothing: antialiased;
}

#wrapper {
  width: 100%;
  min-height: 100%;
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--line);
}

a {
  color: var(--fg);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
  transition: background-color 0.12s ease, color 0.12s ease;
}

a:hover {
  color: var(--bg);
  background-color: var(--fg);
  text-decoration: none;
}

::selection {
  color: var(--bg);
  background-color: var(--fg);
}

.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;
}

/* ヘッダー */
#header-flex {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  position: sticky;
  top: 0;
  z-index: 10;
  padding: 0.65rem 1rem 0.65rem clamp(0.75rem, 3vw, 1.25rem);
  background-color: var(--bg);
  background-color: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
}

#back {
  width: 1.5rem;
  flex-shrink: 0;
  line-height: 1;
}

#address {
  flex: 1;
  min-width: 0;
  line-height: 1.35;
}

a#backicon,
a.addressbar {
  color: var(--fg);
  text-decoration: none;
}

a#backicon:hover,
a.addressbar:hover {
  background-color: var(--fg);
  color: var(--bg);
}

.breadcrumb {
  list-style: none;
  display: flex;
  column-gap: 0;
  flex-wrap: wrap;
  align-items: center;
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
}

.breadcrumb li::before {
  content: "/";
  margin: 0 0.35em;
  color: var(--fg-faint);
  font-weight: 400;
  text-decoration: none;
  pointer-events: none;
}

.breadcrumb li:first-child::before {
  content: "~";
  margin-right: 0.5em;
  margin-left: 0;
  color: var(--fg-muted);
}

.breadcrumb li:last-child::after {
  content: none;
}

.breadcrumb li[aria-current="page"] {
  font-weight: 600;
}

.breadcrumb a {
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
  text-decoration-thickness: 1px;
}

/* メイン */
#main {
  width: min(92vw, 72ch);
  margin: 0 auto;
  margin-top: clamp(2.5rem, 6vw, 3.25rem);
  padding-bottom: clamp(3rem, 8vw, 4.5rem);
  flex: 1;
}

h1.title {
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.5vw, 1.2rem);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: lowercase;
  text-align: left;
  padding: 0 0 0.85rem;
  margin-bottom: 0.25rem;
  border-bottom: 1px solid var(--line);
}

h1.title::before {
  content: "$ ";
  font-weight: 500;
  color: var(--fg-muted);
  letter-spacing: 0;
}

#poster-filter-banner {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--fg-muted);
  margin: 1rem 0 1.25rem;
  padding: 0.5rem 0 0.65rem;
  border-bottom: 1px dashed var(--line-soft);
}

#poster-filter-banner a {
  margin-left: 0.35em;
}

/* 投稿フォーム */
#post-form {
  margin-top: 2rem;
  margin-bottom: 2.75rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line-soft);
}

#post-form h2,
#comments-section h2 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: 1rem;
}

#post-form h2::before,
#comments-section h2::before {
  content: "## ";
  font-weight: 500;
  color: var(--fg-faint);
}

.form-row {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 1rem;
}

label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-muted);
}

input[type="text"],
textarea {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 0.5rem 0.55rem;
  background: var(--bg);
  color: var(--fg);
  appearance: none;
  resize: vertical;
  line-height: 1.45;
}

input[type="text"]::placeholder,
textarea::placeholder {
  color: var(--fg-faint);
  opacity: 1;
}

input[type="text"]:focus,
textarea:focus {
  outline: 1px solid var(--fg);
  outline-offset: 1px;
}

textarea {
  min-height: 7rem;
  tab-size: 2;
}

.char-count {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--fg-faint);
  text-align: right;
  letter-spacing: 0.02em;
}

.char-count.warn {
  color: var(--fg);
  font-weight: 600;
}

.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1rem;
  align-items: center;
}

.btn {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 0.35rem 0.75rem;
  transition: background-color 0.12s ease, color 0.12s ease;
  background: var(--bg);
  color: var(--fg);
}

.btn:hover:not(:disabled) {
  background: var(--fg);
  color: var(--bg);
}

.btn-primary {
  background: var(--fg);
  color: var(--bg);
}

.btn-primary:hover:not(:disabled) {
  background: var(--bg);
  color: var(--fg);
}

.btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

#preview-panel {
  display: none;
  margin-bottom: 1rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--line-soft);
  background: var(--surface);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
}

#preview-panel.is-visible {
  display: block;
}

#form-status {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  margin-top: 0.65rem;
  min-height: 1.35em;
  color: var(--fg-muted);
}

#form-status.ok {
  color: var(--fg-muted);
}

#form-status.err {
  color: var(--fg);
  font-weight: 600;
}

.cf-turnstile {
  margin-top: 0.75rem;
  transform: scale(0.9);
  transform-origin: left center;
}

/* コメント一覧 */
#comments-section {
  border-top: 1px solid var(--line-soft);
  padding-top: 1.75rem;
}

.guestbook-entry {
  margin-bottom: 0;
  padding: 1.15rem 0 1.15rem 0.85rem;
  border-bottom: 1px solid var(--line-soft);
  border-left: 2px solid var(--line-soft);
}

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

.guestbook-entry header {
  margin-bottom: 0.45rem;
}

.guestbook-head {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--fg);
}

.guestbook-head a {
  text-decoration: none;
}

.guestbook-head a:hover {
  text-decoration: underline;
}

.guestbook-head .p-author {
  font-weight: 600;
}

.guestbook-body {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.65;
  white-space: pre-wrap;
  word-break: break-word;
  margin-top: 0.5rem;
  color: var(--fg);
}

.guestbook-stats {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--fg-faint);
  margin-top: 0.45rem;
  letter-spacing: 0.02em;
}

.reply-row {
  margin-top: 0.65rem;
}

.ref-link--stale {
  opacity: 0.4;
}

#loading {
  font-family: var(--font-mono);
  color: var(--fg-faint);
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
}

#no-comments {
  font-family: var(--font-mono);
  color: var(--fg-faint);
  font-size: 0.8125rem;
  display: none;
}

/* フッター */
#main-footer {
  width: min(92vw, 72ch);
  margin: 0 auto;
  padding: 1.25rem 0 2.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--fg-faint);
  border-top: 1px solid var(--line-soft);
}

#main-footer a {
  color: var(--fg-muted);
  text-decoration: none;
}

#main-footer a:hover {
  color: var(--bg);
  background: var(--fg);
}

#main-footer a.feed-link {
  display: inline-block;
  margin-left: 0.65em;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.6875rem;
}

/* レスポンシブ */
@media screen and (width <= 768px) {
  #header-flex {
    padding-left: 0.65rem;
    padding-right: 0.65rem;
  }
}

@media screen and (width <= 576px) {
  #wrapper {
    border-left-width: 1px;
  }

  body {
    font-size: 0.8125rem;
  }

  #main {
    margin-top: 1.75rem;
  }

  #back {
    width: 0;
    overflow: hidden;
    margin: 0;
    padding: 0;
  }
}