/* 佐渡商事有限会社 コーポレートサイト
   依存ゼロ（素のHTML5+CSS）。 */

:root {
  --ink: #16181c;          /* 墨 */
  --ink-soft: #454a53;
  --ink-mute: #7c828d;
  --paper: #fcfbf8;        /* 和紙 */
  --paper-2: #f3f0ea;
  --paper-3: #eae5dc;
  --line: #e4dfd5;
  --line-soft: #efebe3;
  --accent: #1c3557;       /* 藍 */
  --accent-soft: #2f5583;
  --accent-2: #2f5583;
  --maxw: 1080px;
  --pad: clamp(22px, 5vw, 56px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
               "Hiragino Sans", "Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--pad); }

/* ---- ヘッダ ---- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(252, 251, 248, .88);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line-soft);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  min-height: 74px; gap: 16px;
}
.brand {
  font-size: 1.06rem; font-weight: 700; letter-spacing: .08em;
  text-decoration: none; color: var(--ink); line-height: 1.4;
}
.brand small {
  display: block; font-size: .58rem; font-weight: 500;
  color: var(--ink-mute); letter-spacing: .2em; margin-top: 2px;
}
.nav { display: flex; gap: clamp(14px, 3vw, 34px); }
.nav a {
  position: relative; color: var(--ink-soft); text-decoration: none;
  font-size: .87rem; letter-spacing: .04em; padding: 6px 0; transition: color .22s;
}
.nav a::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 0; height: 1px; background: var(--accent); transition: width .28s ease;
}
.nav a:hover, .nav a:focus-visible { color: var(--accent); }
.nav a:hover::after, .nav a:focus-visible::after { width: 100%; }
@media (max-width: 640px) { .nav { gap: 15px; } .nav a { font-size: .78rem; } }

/* ---- ヒーロー ---- */
.hero { padding: clamp(72px, 13vw, 148px) 0 clamp(60px, 10vw, 112px); }
.hero h1 {
  margin: 0 0 30px;
  font-size: clamp(1.8rem, 4.8vw, 3.05rem);
  line-height: 1.5; font-weight: 700; letter-spacing: .015em;
}
.hero h1 .accent { color: var(--accent); }
.hero p {
  margin: 0; max-width: 44em; color: var(--ink-soft);
  font-size: clamp(.94rem, 1.9vw, 1.02rem); line-height: 2.05;
}
.hero p + p { margin-top: 20px; }
.rule { width: 52px; height: 2px; background: var(--accent); margin: 0 0 30px; }

/* ---- セクション ---- */
section { padding: clamp(60px, 9vw, 104px) 0; }
section.alt { background: var(--paper-2); border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }
.sec-head { margin: 0 0 clamp(34px, 5vw, 52px); }
.sec-head h2 {
  margin: 0; font-size: clamp(1.32rem, 3vw, 1.72rem);
  letter-spacing: .06em; font-weight: 700;
}
.sec-head .en {
  display: block; font-size: .64rem; color: var(--accent-2);
  letter-spacing: .28em; margin-bottom: 10px; font-weight: 700;
}
.sec-head .sec-lead {
  margin: 20px 0 0; max-width: 50em;
  font-size: .92rem; color: var(--ink-soft); line-height: 2;
}

/* ---- 事業カード ---- */
.cards {
  display: grid; gap: 22px;
  grid-template-columns: repeat(auto-fit, minmax(430px, 1fr));
  align-items: stretch;            /* 各カードの高さを揃える */
}
@media (max-width: 920px) { .cards { grid-template-columns: 1fr; } }

.card {
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;   /* 実例ブロックを下端に揃えるため */
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px 30px 30px;
  transition: transform .28s ease, box-shadow .28s ease, border-color .28s ease;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 38px rgba(22, 24, 28, .08);
  border-color: var(--paper-3);
}
.card .num {
  position: absolute; top: 14px; right: 22px;
  font-size: 3.1rem; font-weight: 800; line-height: 1;
  color: rgba(28, 53, 87, .06); letter-spacing: 0;
  pointer-events: none; user-select: none;
}
.card h3 {
  position: relative; margin: 0 0 22px; padding-bottom: 16px;
  font-size: 1.08rem; font-weight: 700; color: var(--accent);
  letter-spacing: .04em; line-height: 1.6;
}
.card h3::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 30px; height: 2px; background: var(--accent);
}

/* 主要項目 */
.card > ul { margin: 0; padding: 0; list-style: none; }
.card > ul > li {
  position: relative; padding-left: 1.15em; margin-bottom: 11px;
  font-size: .91rem; color: var(--ink-soft); line-height: 1.75;
}
.card > ul > li:last-child { margin-bottom: 0; }
.card > ul > li::before {
  content: ""; position: absolute; left: 0; top: .66em;
  width: 6px; height: 6px; border-radius: 50%;
  background: transparent; border: 1.5px solid var(--accent-2);
}
@media (min-width: 921px) { .card > ul > li { white-space: nowrap; } }

/* ---- 実例（チップ表示で主要項目と明確に区別） ---- */
.case { margin-top: auto; padding-top: 20px; border-top: 1px solid var(--line-soft); }
.card > ul { margin-bottom: 24px; }   /* 実例ブロックとの最低限の間隔 */
.case-label {
  display: block; margin-bottom: 13px;
  font-size: .58rem; font-weight: 700; letter-spacing: .26em;
  color: var(--ink-mute);
}
.case-list {
  margin: 0; padding: 0; list-style: none;
  display: flex; flex-wrap: wrap; gap: 8px;
}
.case-list li {
  padding: 5px 12px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 100px;
  font-size: .77rem; line-height: 1.7; color: var(--ink-soft);
  white-space: nowrap;
}

/* ---- 会社概要 ---- */
.profile { width: 100%; border-collapse: collapse; max-width: 780px; }
.profile th, .profile td {
  text-align: left; padding: 20px 10px; border-bottom: 1px solid var(--line);
  font-size: .92rem; vertical-align: top; line-height: 1.85;
}
.profile tr:first-child th, .profile tr:first-child td { border-top: 1px solid var(--line); }
.profile th { width: 28%; min-width: 7em; font-weight: 700; color: var(--ink); letter-spacing: .04em; }
.profile td { color: var(--ink-soft); }
@media (max-width: 560px) {
  .profile th, .profile td { display: block; width: 100%; border-bottom: none; padding: 3px 0; }
  .profile tr:first-child th { border-top: none; }
  .profile th { padding-top: 18px; color: var(--accent); font-size: .74rem; letter-spacing: .12em; }
  .profile tr { display: block; border-bottom: 1px solid var(--line); padding-bottom: 14px; }
}

/* ---- お問い合わせ ---- */
.contact-box {
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  padding: clamp(30px, 5vw, 52px); max-width: 720px;
}
.contact-box > p { margin: 0 0 28px; color: var(--ink-soft); font-size: .93rem; }
.btn {
  display: inline-block; background: var(--accent); color: #fff;
  text-decoration: none; padding: 15px 42px; border: none; border-radius: 8px;
  font-size: .94rem; font-weight: 700; letter-spacing: .06em; cursor: pointer;
  transition: background .22s, transform .22s, box-shadow .22s;
  font-family: inherit;
}
.btn:hover, .btn:focus-visible {
  background: var(--accent-2); transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(28, 53, 87, .22);
}
.btn:disabled { opacity: .55; cursor: not-allowed; transform: none; box-shadow: none; }

/* ---- フォーム ---- */
.field { margin-bottom: 22px; }
.field label {
  display: block; margin-bottom: 8px;
  font-size: .82rem; font-weight: 700; color: var(--ink); letter-spacing: .05em;
}
.field .req {
  display: inline-block; margin-left: 8px; padding: 1px 7px;
  background: var(--accent); color: #fff; border-radius: 3px;
  font-size: .6rem; font-weight: 700; letter-spacing: .08em; vertical-align: 2px;
}
.field input, .field textarea {
  width: 100%; padding: 13px 15px;
  background: var(--paper); border: 1px solid var(--line); border-radius: 8px;
  font-size: .93rem; font-family: inherit; color: var(--ink); line-height: 1.7;
  transition: border-color .2s, box-shadow .2s, background .2s;
}
.field input:focus, .field textarea:focus {
  outline: none; background: #fff;
  border-color: var(--accent-2); box-shadow: 0 0 0 3px rgba(47, 85, 131, .12);
}
.field textarea { min-height: 150px; resize: vertical; }
.form-note { margin: 0 0 26px; font-size: .78rem; color: var(--ink-mute); line-height: 1.85; }
.form-msg { margin-top: 20px; font-size: .88rem; line-height: 1.8; display: none; }
.form-msg.ok { display: block; color: #1d6b3f; }
.form-msg.ng { display: block; color: #a33227; }

/* ---- フッタ ---- */
.site-footer {
  border-top: 1px solid var(--line); padding: 40px 0;
  font-size: .76rem; color: var(--ink-mute); letter-spacing: .04em;
}
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 10px; justify-content: space-between; }