/* ============================================
   許彧銘 作品集 — 共用設計系統
   溫潤編輯誌風格 (Editorial / Warm Paper)
   ============================================ */

:root{
  --paper:#f6f1e7;
  --paper-2:#efe7d6;
  --paper-3:#e8dec8;
  --ink:#1d1a15;
  --ink-soft:#5b5346;
  --ink-faint:#8a8170;
  --accent:#bf3f26;
  --accent-deep:#8f2d18;
  --line:rgba(29,26,21,0.14);
  --line-soft:rgba(29,26,21,0.08);
  --serif:"Noto Serif TC","Fraunces",serif;
  --display:"Fraunces","Noto Serif TC",serif;
  --sans:"Noto Sans TC",sans-serif;
  --mono:"Space Mono",monospace;
  --maxw:1180px;
}

*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-weight:300;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
  position:relative;
}
/* 紙張顆粒紋理 */
body::before{
  content:"";
  position:fixed;inset:0;
  pointer-events:none;z-index:9999;
  opacity:0.04;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
::selection{background:var(--accent);color:var(--paper);}

a{color:inherit;}
img{max-width:100%;display:block;}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 40px;}

/* ── 導覽列 ── */
nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  display:flex;align-items:center;justify-content:space-between;
  padding:22px 40px;
  transition:background .4s ease, border-color .4s ease, padding .4s ease;
  border-bottom:1px solid transparent;
}
nav.scrolled{
  background:rgba(246,241,231,0.82);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line-soft);
  padding:14px 40px;
}
.brand{font-family:var(--serif);font-weight:700;font-size:1.15rem;letter-spacing:.04em;text-decoration:none;}
.brand .dot{color:var(--accent);}
.nav-links{display:flex;gap:34px;align-items:center;}
.nav-links a{
  font-family:var(--mono);font-size:.74rem;letter-spacing:.12em;
  text-transform:uppercase;color:var(--ink-soft);text-decoration:none;
  position:relative;transition:color .3s;
}
.nav-links a::after{
  content:"";position:absolute;left:0;bottom:-4px;width:0;height:1px;
  background:var(--accent);transition:width .35s ease;
}
.nav-links a:hover{color:var(--accent);}
.nav-links a:hover::after{width:100%;}
.nav-links a.active{color:var(--accent);}

/* ── 區段標題 ── */
.section-head{
  display:flex;align-items:baseline;gap:20px;margin-bottom:56px;
}
.section-head .num{font-family:var(--mono);font-size:.8rem;color:var(--accent);letter-spacing:.1em;}
.section-head h2{
  font-family:var(--serif);font-weight:500;font-size:clamp(1.7rem,4vw,2.7rem);
  letter-spacing:.02em;
}
.section-head .rule{flex:1;height:1px;background:var(--line);align-self:center;}

/* ── 通用按鈕 ── */
.btn{
  display:inline-flex;align-items:center;gap:12px;
  font-family:var(--mono);font-size:.8rem;letter-spacing:.08em;
  text-decoration:none;cursor:pointer;border:none;
  transition:gap .3s, background .3s, color .3s, opacity .3s;
}
.btn-primary{
  background:var(--accent);color:var(--paper);
  padding:16px 30px;border-radius:6px;
}
.btn-primary:hover{background:var(--accent-deep);gap:18px;}
.btn-ghost{
  color:var(--ink);border:1px solid var(--line);
  padding:15px 28px;border-radius:6px;
}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);gap:18px;}
.btn .ar{transition:transform .3s;}
.btn:hover .ar{transform:translateX(3px);}

/* ── 進場動畫 ── */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .9s cubic-bezier(.16,1,.3,1),transform .9s cubic-bezier(.16,1,.3,1);}
.reveal.in{opacity:1;transform:none;}
.hero-anim{opacity:0;transform:translateY(34px);animation:rise 1.1s cubic-bezier(.16,1,.3,1) forwards;}
.d1{animation-delay:.1s;}.d2{animation-delay:.26s;}.d3{animation-delay:.42s;}.d4{animation-delay:.58s;}.d5{animation-delay:.74s;}
@keyframes rise{to{opacity:1;transform:none;}}

/* ── 頁尾 ── */
footer{
  padding:110px 0 56px;border-top:1px solid var(--line);
  background:linear-gradient(180deg,transparent,rgba(29,26,21,0.03));
  margin-top:120px;
}
.contact-big{
  font-family:var(--display);font-weight:300;
  font-size:clamp(2.2rem,7vw,5rem);line-height:1.05;letter-spacing:-.01em;margin-bottom:42px;
}
.contact-big em{font-style:italic;color:var(--accent);}
.contact-links{display:flex;flex-wrap:wrap;gap:14px 44px;margin-bottom:72px;}
.contact-links a{
  font-family:var(--serif);font-size:1.2rem;color:var(--ink);text-decoration:none;
  display:flex;align-items:center;gap:12px;transition:color .3s,gap .3s;
}
.contact-links a .ar{color:var(--accent);transition:transform .3s;}
.contact-links a:hover{color:var(--accent);gap:18px;}
.contact-links a:hover .ar{transform:translateX(4px);}
.foot-base{display:flex;justify-content:space-between;flex-wrap:wrap;gap:14px;
  font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;color:var(--ink-faint);}

/* ── RWD ── */
@media(max-width:860px){
  .wrap{padding:0 24px;}
  nav{padding:18px 24px;}nav.scrolled{padding:12px 24px;}
  .nav-links{gap:20px;}
}
@media(max-width:560px){
  .nav-links a:not(.cta){display:none;}
}