/* Layout: แถบหัวไล่สีน้ำเงินของโรงเรียน ตามด้วยสองคอลัมน์ ซ้ายคือฟอร์มและแผงตกแต่ง ขวาคือ QR ตัวอย่างที่ลอยตามจอ
   แล้วปิดด้วยทะเบียนลิงก์ของโรงเรียน บนมือถือเรียงเป็นคอลัมน์เดียว: ฟอร์ม, QR, ตกแต่ง, ทะเบียน */
:root{color-scheme:light;
  --bg:#EDF3FC; --bg2:#DCE9FA; --surface:#FFFFFF; --sunk:#F1F6FD;
  --ink:#14205C; --muted:#56628C; --line:#D4DFF2;
  --accent:#1546A0; --on-accent:#FFFFFF; --sky:#0A72BA; --mark:#F8E11A;
  --hero-a:#151B6E; --hero-b:#1546A0; --hero-c:#0E86B8; --on-hero:#FFFFFF;
  --btn-a:#16337F; --btn-b:#0E7FB4;
  --shadow:0 12px 32px rgba(21,52,128,.10);
  --bad:#B3261E; --ok:#17683A;
  --display:"Kanit","Sarabun","Noto Sans Thai",Tahoma,sans-serif;
  --body:"Sarabun","Noto Sans Thai",Tahoma,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,Menlo,Consolas,monospace;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#0A1024; --bg2:#0F1A3A; --surface:#141D3D; --sunk:#0E1631;
  --ink:#E9EEFC; --muted:#A0ABD2; --line:#2A3766;
  --accent:#8DB4FF; --on-accent:#0A1024; --sky:#62B8F2; --mark:#F8E11A;
  --hero-a:#10155A; --hero-b:#123C8C; --hero-c:#0B6E99; --on-hero:#FFFFFF;
  --btn-a:#2A56C4; --btn-b:#1196CF;
  --shadow:0 12px 32px rgba(0,0,0,.35);
  --bad:#FF8A80; --ok:#7BD79C; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0A1024; --bg2:#0F1A3A; --surface:#141D3D; --sunk:#0E1631;
  --ink:#E9EEFC; --muted:#A0ABD2; --line:#2A3766;
  --accent:#8DB4FF; --on-accent:#0A1024; --sky:#62B8F2; --mark:#F8E11A;
  --hero-a:#10155A; --hero-b:#123C8C; --hero-c:#0B6E99; --on-hero:#FFFFFF;
  --btn-a:#2A56C4; --btn-b:#1196CF;
  --shadow:0 12px 32px rgba(0,0,0,.35);
  --bad:#FF8A80; --ok:#7BD79C; color-scheme:dark}

*{box-sizing:border-box}
body{background:linear-gradient(180deg,var(--bg2),var(--bg) 420px) var(--bg);color:var(--ink);font-family:var(--body);font-size:17px;line-height:1.6}
.wrap{max-width:1120px;margin:0 auto;padding-inline:20px;padding-block:24px 56px;display:flex;flex-direction:column;gap:24px}
h1,h2,h3{font-family:var(--display);line-height:1.25;margin:0;text-wrap:balance}
h1{font-size:clamp(1.7rem,5vw,2.5rem);font-weight:600}
h2{font-size:1.2rem;font-weight:600}
h3{font-size:.98rem;font-weight:500;color:var(--sky)}
p{margin:0}
.mono{font-family:var(--mono);font-size:.88em;overflow-wrap:anywhere}
.muted{color:var(--muted)}
.small{font-size:.9rem}

/* หัวเว็บ */
.hero{background:linear-gradient(135deg,var(--hero-a),var(--hero-b) 55%,var(--hero-c));color:var(--on-hero);border-radius:28px;padding:clamp(20px,4vw,34px);display:flex;flex-direction:column;gap:20px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.hero::after{content:"";position:absolute;right:-90px;top:-120px;width:360px;height:360px;border-radius:50%;border:44px solid rgba(255,255,255,.07);pointer-events:none}
.brand{display:flex;gap:16px;align-items:center;position:relative;z-index:1}
.crest{background:#FFFFFF;border-radius:20px;padding:8px;width:84px;height:84px;flex:none;box-shadow:0 8px 20px rgba(0,0,0,.18)}
.crest img{display:block;width:100%;height:100%}
.brand .txt{display:flex;flex-direction:column;min-width:0}
.school{font-family:var(--display);font-weight:500;font-size:1.15rem;line-height:1.3}
.place{font-size:.88rem;opacity:.85;letter-spacing:.02em}
.hero h1{position:relative;z-index:1}
.hero .lead{max-width:58ch;opacity:.92;position:relative;z-index:1}
.chips{display:flex;gap:10px;flex-wrap:wrap;position:relative;z-index:1}
.chip{background:rgba(255,255,255,.13);border:1px solid rgba(255,255,255,.26);border-radius:14px;padding:8px 14px;font-size:.92rem;display:flex;gap:8px;align-items:center}
.chip i{width:8px;height:8px;border-radius:50%;background:var(--mark);flex:none}
@media (max-width:520px){.crest{width:64px;height:64px;border-radius:16px;padding:6px}.school{font-size:1rem}}

/* โครง */
.work{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);grid-template-areas:"form prev" "deco prev";gap:24px;align-items:start}
.a-form{grid-area:form}.a-deco{grid-area:deco}.a-prev{grid-area:prev;position:sticky;top:calc(env(safe-area-inset-top,0px) + 16px)}
@media (max-width:860px){.work{grid-template-columns:minmax(0,1fr);grid-template-areas:"form" "prev" "deco"}.a-prev{position:static}}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:22px;padding:clamp(18px,3vw,26px);display:flex;flex-direction:column;gap:18px;min-width:0;box-shadow:var(--shadow)}
.ptitle{display:flex;gap:12px;align-items:center}
.ico{width:38px;height:38px;border-radius:12px;background:linear-gradient(135deg,var(--btn-a),var(--btn-b));display:grid;place-items:center;flex:none}
.ico svg{width:20px;height:20px;stroke:#FFFFFF;fill:none;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.ptitle .sp{margin-left:auto}

/* ฟอร์ม */
form{display:flex;flex-direction:column;gap:16px}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
label,.lab{font-weight:600;font-size:.95rem}
label .opt{font-weight:400;color:var(--muted)}
input[type=text],input[type=url],input[type=search]{font:inherit;color:var(--ink);background:var(--sunk);border:1px solid var(--line);border-radius:12px;padding:11px 14px;width:100%;min-width:0}
input.mono{font-family:var(--mono);font-size:.95rem}
input::placeholder{color:var(--muted);opacity:.75}
:focus-visible{outline:3px solid var(--sky);outline-offset:2px}
.hint{font-size:.88rem;color:var(--muted)}
.codebox{display:flex;align-items:stretch}
.codebox span{display:flex;align-items:center;padding:0 14px;background:var(--line);border-radius:12px 0 0 12px;font-family:var(--mono);color:var(--muted)}
.codebox input{border-radius:0 12px 12px 0}
.check{display:flex;gap:8px;align-items:center;font-weight:500}
.check input{width:18px;height:18px;accent-color:var(--accent)}

button{font:inherit;cursor:pointer;border-radius:12px;border:1px solid var(--line);background:var(--surface);color:var(--ink);padding:9px 15px;font-weight:500}
button:hover{border-color:var(--sky)}
button.primary,button.solid{background:linear-gradient(90deg,var(--btn-a),var(--btn-b));color:#FFFFFF;border:0}
button.primary{font-family:var(--display);font-weight:500;font-size:1.08rem;padding:14px 18px;border-radius:14px;box-shadow:0 8px 18px rgba(21,70,160,.25)}
button.primary:hover,button.solid:hover{filter:brightness(1.1)}
button.danger{color:var(--bad)}
button:disabled{opacity:.5;cursor:not-allowed}
.msg{font-size:.95rem;min-height:1.5em}
.msg.bad{color:var(--bad)} .msg.ok{color:var(--ok)}
.tag{font-family:var(--display);font-weight:500;font-size:.78rem;background:var(--mark);color:#14205C;border-radius:8px;padding:2px 9px}

/* QR ตัวอย่าง */
.qrframe{background:var(--sunk);border:1px solid var(--line);border-radius:18px;padding:16px;display:grid;place-items:center}
.qrframe canvas{display:block;width:100%;max-width:300px;height:auto;box-shadow:0 6px 18px rgba(21,52,128,.16)}
.row{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.row input{flex:1 1 180px}
.row.stretch button{flex:1 1 180px}

/* แผงตกแต่ง */
.group{display:flex;flex-direction:column;gap:12px;padding-top:16px;border-top:1px solid var(--line)}
.seg{display:grid;grid-template-columns:repeat(auto-fit,minmax(64px,1fr));gap:6px}
.seg button{background:var(--sunk);font-size:.92rem;padding:9px 6px}
.seg button[aria-pressed=true]{background:var(--accent);color:var(--on-accent);border-color:var(--accent)}
.two{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:14px}
.colors{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px}
.color{display:flex;gap:10px;align-items:center;font-weight:500;font-size:.93rem}
input[type=color]{width:46px;height:38px;padding:3px;border:1px solid var(--line);border-radius:10px;background:var(--sunk);cursor:pointer;flex:none}
input[type=range]{width:100%;accent-color:var(--accent)}
input[type=file]{font:inherit;font-size:.9rem;color:var(--muted);max-width:100%}
.presets{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:8px}
.presets button{display:flex;gap:8px;align-items:center;justify-content:flex-start;font-size:.92rem;background:var(--sunk);text-align:left}
.presets .sw{width:22px;height:22px;border-radius:7px;flex:none;border:1px solid var(--line)}

/* เปิดลิงก์สั้น */
.open{border-left:8px solid var(--mark)}
.open a.go{display:inline-block;background:linear-gradient(90deg,var(--btn-a),var(--btn-b));color:#FFFFFF;font-family:var(--display);font-weight:500;text-decoration:none;padding:13px 22px;border-radius:14px;align-self:flex-start}

/* ทะเบียนลิงก์ */
ul.links{list-style:none;margin:0;padding:0;display:flex;flex-direction:column}
ul.links li{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:6px 16px;padding:14px 0;border-top:1px solid var(--line);align-items:center}
ul.links .info{min-width:0;display:flex;flex-direction:column;gap:2px}
ul.links .name{font-weight:600}
ul.links .code{font-family:var(--mono);color:var(--sky);font-weight:500}
ul.links .dest{color:var(--muted)}
ul.links .acts{display:flex;gap:6px;flex-wrap:wrap}
ul.links .acts button{font-size:.88rem;padding:6px 11px;border-radius:10px}
ul.links li.editing{grid-template-columns:minmax(0,1fr)}
ul.links .editor{display:flex;flex-direction:column;gap:10px}
@media (max-width:600px){ul.links li{grid-template-columns:minmax(0,1fr)}}
.empty{border:1px dashed var(--line);border-radius:14px;padding:22px;color:var(--muted)}
@media (prefers-reduced-motion:no-preference){button{transition:filter .15s,border-color .15s}}

/* แถบหัว: ปุ่มออกจากระบบ */
.brand .side{margin-left:auto;display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:flex-end}
.ghost{background:rgba(255,255,255,.13);border:1px solid rgba(255,255,255,.3);color:#FFFFFF;font-size:.92rem;padding:8px 14px}
.ghost:hover{background:rgba(255,255,255,.22);border-color:#FFFFFF}
.clicks{font-family:var(--display);font-weight:500;font-size:.8rem;background:var(--sunk);border:1px solid var(--line);border-radius:8px;padding:1px 8px;margin-left:8px;white-space:nowrap}

/* หน้าเข้าสู่ระบบ */
body.auth{min-height:100vh;min-height:100dvh;display:grid;place-items:center;padding:20px}
.authcard{width:100%;max-width:940px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);background:var(--surface);border:1px solid var(--line);border-radius:28px;overflow:hidden;box-shadow:var(--shadow)}
.authside{background:linear-gradient(150deg,var(--hero-a),var(--hero-b) 55%,var(--hero-c));color:var(--on-hero);padding:clamp(24px,4vw,40px);display:flex;flex-direction:column;gap:18px;position:relative;overflow:hidden}
.authside::after{content:"";position:absolute;right:-110px;bottom:-130px;width:340px;height:340px;border-radius:50%;border:44px solid rgba(255,255,255,.07)}
.authside h1{font-size:clamp(1.6rem,4vw,2.2rem)}
.authside .chips{flex-direction:column;align-items:flex-start}
.authform{padding:clamp(24px,4vw,40px);display:flex;flex-direction:column;gap:18px;justify-content:center}
.authform .eyebrow{font-family:var(--display);font-weight:500;font-size:.85rem;letter-spacing:.08em;color:var(--sky)}
.authform input[type=password]{font:inherit;color:var(--ink);background:var(--sunk);border:1px solid var(--line);border-radius:12px;padding:12px 14px;width:100%}
.authform .foot{font-size:.85rem;color:var(--muted);text-align:center}
.err{background:var(--sunk);border:1px solid var(--bad);color:var(--bad);border-radius:12px;padding:10px 14px;font-size:.95rem}
@media (max-width:760px){.authcard{grid-template-columns:minmax(0,1fr)}}

a.ghost{display:inline-block;text-decoration:none;border-radius:12px;font-weight:500}
.back{color:var(--sky);font-weight:500;text-align:center}
.notice{background:var(--sunk);border:1px solid var(--line);border-left:5px solid var(--mark);border-radius:12px;padding:10px 14px;font-size:.95rem}
textarea{font:inherit;color:var(--ink);background:var(--sunk);border:1px solid var(--line);border-radius:12px;padding:11px 14px;width:100%;min-height:92px;resize:vertical}
.panel input[type=password]{font:inherit;color:var(--ink);background:var(--sunk);border:1px solid var(--line);border-radius:12px;padding:11px 14px;width:100%}