/* ==========================================================
   Kurashi Supporter - base.css
   共通スタイル
   ========================================================== */

:root {
  --color-text: #2b3a42;
  --color-text-sub: #5a6b73;
  --color-bg: #ffffff;
  --color-bg-soft: #f4f8f9;
  --color-primary: #1f7a8c;
  --color-primary-dark: #16606f;
  --color-border: #d9e2e6;
  --color-accent-bg: #e8f3f5;
  --radius: 8px;
  --font-body: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic",
    "Noto Sans JP", sans-serif;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  font-size: 16px;
}

h1, h2, h3, h4 {
  line-height: 1.5;
  color: var(--color-text);
}

h1 { font-size: 1.7rem; }
h2 { font-size: 1.35rem; margin-top: 3rem; }
h3 { font-size: 1.1rem; }

@media (min-width: 768px) {
  h1 { font-size: 2.1rem; }
  h2 { font-size: 1.55rem; }
}

p {
  margin: 1em 0;
}

a {
  color: var(--color-primary);
}

a:hover {
  color: var(--color-primary-dark);
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  width: min(100% - 32px, 1120px);
  margin-inline: auto;
}

.container--narrow {
  width: min(100% - 32px, 760px);
  margin-inline: auto;
}

/* ---------- Header ---------- */

.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}

.site-header__brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
  text-decoration: none;
}

.site-header__brand:hover {
  color: var(--color-primary-dark);
}

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

.site-footer {
  margin-top: 5rem;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-soft);
  font-size: 0.9rem;
}

.site-footer__inner {
  padding: 2.5rem 0 2rem;
}

.site-footer__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding: 0;
  margin: 0 0 1.5rem;
  list-style: none;
}

.site-footer__nav a {
  color: var(--color-text-sub);
  text-decoration: none;
}

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

.site-footer__copyright {
  color: var(--color-text-sub);
  margin: 0;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-block;
  padding: 0.9em 2.2em;
  border: none;
  border-radius: var(--radius);
  background: var(--color-primary);
  color: #ffffff;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  text-decoration: none;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.btn:hover {
  background: var(--color-primary-dark);
  color: #ffffff;
}

.btn--secondary {
  background: var(--color-bg);
  color: var(--color-primary-dark);
  border: 1px solid var(--color-primary);
}

.btn--secondary:hover {
  background: var(--color-accent-bg);
  color: var(--color-primary-dark);
}

.btn:disabled {
  background: #b9c6cb;
  cursor: not-allowed;
}

/* ---------- 汎用 ---------- */

.section {
  margin-top: 4rem;
}

.text-sub {
  color: var(--color-text-sub);
}

.note {
  font-size: 0.85rem;
  color: var(--color-text-sub);
}

.page-body {
  padding-top: 2.5rem;
}

.page-body h1 {
  margin-bottom: 1.5rem;
}