/* Musuhi - Photo Backup — Official site styles (JA)
   Calm, honest, indie-developer Mac-app aesthetic.
   White cards on a soft blue-grey page, steel-blue accent. */

:root {
  --bg: #f4f6f9;
  --card: #ffffff;
  --fg: #1c2330;
  --fg-muted: #56607a;
  --fg-faint: #8a93a6;
  --rule: #e4e8ef;
  --rule-strong: #d2d8e2;

  --brand: #4a7bb5;
  --brand-hover: #3a6499;
  --brand-tint: #ebf2fa;
  --brand-tint-rule: #d6e4f4;

  --link: #3a6499;
  --link-hover: #2c4f7d;
  --code-bg: #eef1f6;

  --max-width: 720px;
  --radius: 12px;
  --radius-sm: 8px;
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP",
    "Yu Gothic", "Meiryo", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  font-feature-settings: "palt" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ----- Layout ----- */

.page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 28px 24px 96px;
}

@media (max-width: 540px) {
  .page {
    padding: 20px 18px 72px;
  }
}

/* ----- Top bar ----- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0 18px;
  margin-bottom: 40px;
  border-bottom: 1px solid var(--rule);
  font-size: 14px;
}

.topbar .brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: 0.01em;
}

.topbar .brand .mark {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  flex: none;
  display: block;
  object-fit: cover;
}

.topbar nav {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}

.topbar nav a {
  color: var(--fg-muted);
  text-decoration: none;
}

.topbar nav a:hover {
  color: var(--brand);
}

/* ----- Typography ----- */

h1, h2, h3 {
  font-weight: 600;
  color: var(--fg);
  letter-spacing: 0.005em;
}

h1 {
  font-size: 30px;
  line-height: 1.5;
  margin: 0 0 16px;
  letter-spacing: 0.01em;
}

h2 {
  font-size: 20px;
  line-height: 1.5;
  margin: 0 0 18px;
}

h3 {
  font-size: 16px;
  line-height: 1.55;
  margin: 28px 0 8px;
}

p {
  margin: 0 0 16px;
  color: var(--fg);
  text-wrap: pretty;
}

p.lede {
  font-size: 17px;
  color: var(--fg-muted);
  margin-bottom: 28px;
}

a {
  color: var(--link);
  text-underline-offset: 2px;
}

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

ul, ol {
  margin: 0 0 16px;
  padding-left: 1.4em;
}

li {
  margin-bottom: 6px;
}

li::marker {
  color: var(--brand);
}

strong {
  font-weight: 600;
}

code, kbd {
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 0.88em;
  background: var(--code-bg);
  padding: 1px 5px;
  border-radius: 3px;
  color: var(--fg);
}

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 44px 0;
}

/* ----- Section rhythm ----- */

.section {
  margin: 64px 0 0;
}

.section > h2 {
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand);
  margin: 0 0 10px;
}

/* Sub-document pages (privacy/support) keep simple stacked headings */

.doc h2 {
  font-size: 19px;
  margin: 52px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}

.doc h3 {
  font-size: 15px;
  margin: 28px 0 8px;
  color: var(--fg);
}

/* ----- Hero ----- */

.hero {
  text-align: center;
  padding: 8px 0 8px;
}

.hero .app-icon {
  margin: 0 auto 24px;
}

.hero .lede {
  max-width: 32em;
  margin-left: auto;
  margin-right: auto;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 26px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn-primary {
  background: var(--brand);
  color: #fff;
}

.btn-primary:hover {
  background: var(--brand-hover);
  color: #fff;
}

.btn-secondary {
  background: var(--card);
  color: var(--brand-hover);
  border-color: var(--brand-tint-rule);
}

.btn-secondary:hover {
  background: var(--brand-tint);
  color: var(--brand-hover);
}

.hero .hint {
  font-size: 13px;
  color: var(--fg-faint);
  margin: 16px 0 0;
}

/* ----- App icon ----- */

.app-icon {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  display: block;
  object-fit: cover;
  box-shadow: 0 8px 22px rgba(74, 123, 181, 0.28);
}

/* ----- Trust grid ----- */

.trust {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 4px 0 0;
}

.trust-item {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.trust-item .t {
  font-weight: 600;
  margin: 0 0 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.trust-item .t::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--brand);
  flex: none;
}

.trust-item .d {
  margin: 0;
  font-size: 14px;
  color: var(--fg-muted);
  line-height: 1.7;
}

@media (max-width: 540px) {
  .trust {
    grid-template-columns: 1fr;
  }
}

/* ----- Definition-style features ----- */

.features {
  margin: 0;
  padding: 0;
  list-style: none;
}

.features li {
  padding: 16px 0;
  border-top: 1px solid var(--rule);
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 20px;
  margin: 0;
}

.features li:last-child {
  border-bottom: 1px solid var(--rule);
}

.features .term {
  color: var(--fg);
  font-weight: 600;
}

.features .desc {
  color: var(--fg-muted);
  font-size: 15px;
}

@media (max-width: 540px) {
  .features li {
    grid-template-columns: 1fr;
    gap: 3px;
    padding: 14px 0;
  }
}

/* ----- Premium block ----- */

.premium {
  background: var(--brand-tint);
  border: 1px solid var(--brand-tint-rule);
  border-radius: var(--radius);
  padding: 28px 28px 24px;
}

.premium-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 6px;
}

.premium-head h2 {
  margin: 0;
  border: none;
  padding: 0;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 11px;
  border-radius: 999px;
  background: var(--brand);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.premium > p.intro {
  color: var(--fg-muted);
  font-size: 15px;
  margin-bottom: 20px;
}

.premium-list {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.premium-list li {
  background: var(--card);
  border: 1px solid var(--brand-tint-rule);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  margin: 0;
}

.premium-list .pt {
  font-weight: 600;
  display: block;
  margin-bottom: 2px;
}

.premium-list .pd {
  font-size: 13.5px;
  color: var(--fg-muted);
  line-height: 1.65;
}

.premium .buy-note {
  margin: 0;
  font-size: 13.5px;
  color: var(--fg-muted);
  padding-top: 16px;
  border-top: 1px solid var(--brand-tint-rule);
}

@media (max-width: 540px) {
  .premium {
    padding: 22px 20px 20px;
  }
  .premium-list {
    grid-template-columns: 1fr;
  }
}

/* ----- Steps (how to use) ----- */

.steps {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.steps li {
  counter-increment: step;
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  padding: 16px 18px 16px 58px;
  position: relative;
  margin: 0;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 15px;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  background: var(--brand-tint);
  color: var(--brand-hover);
  border: 1px solid var(--brand-tint-rule);
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.steps .st {
  font-weight: 600;
  display: block;
  margin-bottom: 2px;
}

.steps .sd {
  font-size: 14px;
  color: var(--fg-muted);
  line-height: 1.7;
}

/* ----- Story ----- */

.story {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 26px 28px;
  color: var(--fg-muted);
}

.story p {
  color: var(--fg-muted);
}

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

/* ----- Spec list (recommended env) ----- */

.spec {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.spec li {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.spec .k {
  color: var(--fg-muted);
  font-size: 14px;
}

.spec .v {
  color: var(--fg);
  font-size: 14px;
}

@media (max-width: 540px) {
  .spec li {
    grid-template-columns: 1fr;
    gap: 2px;
  }
}

/* ----- Before-use compact notice ----- */

.notice {
  margin: 0;
  padding: 20px 22px;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  background: var(--card);
}

.notice h3 {
  margin: 0 0 10px;
  font-size: 15px;
  color: var(--fg);
  font-weight: 600;
}

.notice ul {
  margin: 0;
  padding-left: 1.2em;
}

.notice li {
  color: var(--fg-muted);
  font-size: 14px;
  margin-bottom: 5px;
}

.notice .more {
  margin: 12px 0 0;
  font-size: 13.5px;
}

/* ----- Privacy summary callout on home ----- */

.callout {
  background: var(--brand-tint);
  border: 1px solid var(--brand-tint-rule);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.callout ul {
  margin: 0;
  padding-left: 1.2em;
}

.callout li {
  color: var(--fg);
  font-size: 14.5px;
  margin-bottom: 6px;
}

.callout li:last-child {
  margin-bottom: 0;
}

/* ----- FAQ ----- */

.faq {
  margin: 0;
}

.faq details {
  border-top: 1px solid var(--rule);
  padding: 16px 0;
}

.faq details:last-of-type {
  border-bottom: 1px solid var(--rule);
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--fg);
  list-style: none;
  position: relative;
  padding-right: 28px;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: -2px;
  color: var(--brand);
  font-weight: 400;
  font-size: 20px;
  line-height: 1.4;
}

.faq details[open] summary::after {
  content: "−";
}

.faq .answer {
  margin-top: 12px;
  color: var(--fg-muted);
  font-size: 15px;
}

.faq .answer p:last-child {
  margin-bottom: 0;
}

/* ----- Inline contact card ----- */

.contact-card {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.contact-card p:last-child {
  margin-bottom: 0;
}

.contact-card a {
  font-weight: 600;
}

/* ----- Footer ----- */

.footer {
  margin-top: 80px;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  color: var(--fg-faint);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
}

.footer nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

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

.footer a:hover {
  color: var(--brand);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ----- Optional step ----- */

.steps li.step-optional {
  border-color: var(--rule-strong);
  border-style: dashed;
  background: transparent;
}

.steps li.step-optional::before {
  background: var(--bg);
  color: var(--fg-faint);
  border-color: var(--rule-strong);
  font-weight: 600;
}

.steps li.step-optional .st {
  color: var(--fg-muted);
}

.steps li.step-optional .sd {
  color: var(--fg-faint);
}

.step-opt-badge {
  display: inline-flex;
  align-items: center;
  padding: 1px 7px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.04em;
  border: 1px solid var(--rule-strong);
  color: var(--fg-faint);
  margin-left: 5px;
  vertical-align: middle;
}

/* ----- Small utility ----- */

.muted { color: var(--fg-muted); }
.small { font-size: 13px; }
.mono { font-family: "SF Mono", "Menlo", monospace; }
.meta {
  color: var(--fg-faint);
  font-size: 13px;
  margin: 0 0 28px;
}

/* ----- Language switcher (dropdown, top bar) ----- */

.topbar nav select.lang-select {
  font: inherit;
  font-size: 13px;
  color: var(--fg-muted);
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 5px 10px;
  line-height: 1.4;
  min-width: 96px;
  cursor: pointer;
}

.topbar nav select.lang-select:hover,
.topbar nav select.lang-select:focus {
  border-color: var(--brand-tint-rule);
  color: var(--brand);
  outline: none;
}

/* --- legal footer --- */
.legal {
  margin-top: 80px;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
}
.legal p {
  margin: 0 0 6px;
  line-height: 1.7;
}