/* ============ Root Variables ============ */
:root{
  --ink:#16211C;
  --ink-soft:#4A564E;
  --paper:#F2F4F1;
  --paper-raised:#FFFFFF;
  --line:#D8DDD4;
  --line-strong:#B9C1B4;

  --tool-1:#2F5DE3; /* Image Size Control */
  --tool-2:#7C3AED; /* Image to PDF */
  --tool-3:#12946B; /* PDF Size Control */
  --tool-4:#D97A0B; /* PDF User Password */
  --tool-5:#DC3E42; /* PDF to Image */

  --font-display:'Space Grotesk', sans-serif;
  --font-body:'IBM Plex Sans', sans-serif;

  --radius:10px;
  --shell-max:1400px;
  --rail-w:180px;
}

/* ============ Resets & Typography ============ */
*{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  line-height:1.5;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{ font-family:var(--font-display); margin:0; color:var(--ink); }
p{ margin:0; }
button{ font-family:inherit; cursor:pointer; }
a{ color:inherit; }
img{ max-width:100%; display:block; }

:focus-visible{
  outline:2px solid var(--tool-1);
  outline-offset:2px;
}

.hidden{ display:none !important; }

.visually-hidden-input{
  position:absolute;
  width:1px; height:1px;
  padding:0; margin:-1px;
  overflow:hidden;
  clip:rect(0,0,0,0);
  white-space:nowrap;
  border:0;
}

/* ============ Header ============ */
.site-header{
  border-bottom:1px solid var(--line);
  background:var(--paper-raised);
}
.site-header-inner{
  max-width:var(--shell-max);
  margin:0 auto;
  padding:16px 24px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  text-decoration:none;
}
.brand-mark{
  font-family:var(--font-display);
  font-weight:700;
  font-size:22px;
  letter-spacing:-0.02em;
}
.brand-mark span{ color:var(--tool-1); }
.nav-link{
  text-decoration:none;
  font-weight:500;
  font-size:15px;
  color:var(--ink-soft);
  padding:8px 12px;
  border-radius:6px;
}
.nav-link:hover{ color:var(--ink); background:var(--paper); }
.header-right{
  display:flex;
  align-items:center;
  gap:14px;
  font-size:14px;
  color:var(--ink-soft);
}
.theme-toggle{
  width:34px; height:34px;
  border-radius:50%;
  border:1px solid var(--line);
  background:var(--paper);
  display:flex; align-items:center; justify-content:center;
  font-size:16px;
  color:var(--ink);
}
.theme-toggle:hover{ border-color:var(--line-strong); }

/* ============ Desktop 100% Zoom Shell Grid ============ */
.app-shell{
  max-width:var(--shell-max);
  width:100%;
  margin:0 auto;
  display:grid;
  grid-template-columns: var(--rail-w) 1fr var(--rail-w);
  gap:20px;
  padding:20px 24px;
  align-items:start;
}
.ad-rail{
  width:100%;
  min-height:600px;
  border:1px dashed var(--line-strong);
  border-radius:var(--radius);
  background:var(--paper-raised);
  display:flex;
  align-items:center;
  justify-content:center;
  color:var(--ink-soft);
  font-size:13px;
  letter-spacing:0.02em;
  position:sticky;
  top:20px;
}
.ad-bottom{
  grid-column:1 / -1;
  border:1px dashed var(--line-strong);
  border-radius:var(--radius);
  background:var(--paper-raised);
  min-height:90px;
  display:flex;
  align-items:center;
  justify-content:center;
  color:var(--ink-soft);
  font-size:13px;
}
.main-content{ min-width:0; }

/* ============ Footer ============ */
.site-footer{
  border-top:1px solid var(--line);
  background:var(--paper-raised);
  margin-top:12px;
}
.site-footer-inner{
  max-width:var(--shell-max);
  margin:0 auto;
  padding:22px 24px;
  display:flex;
  flex-wrap:wrap;
  gap:16px;
  align-items:center;
  justify-content:space-between;
}
.footer-links{
  display:flex;
  gap:24px;
  flex-wrap:wrap;
}
.footer-link{
  display:flex;
  align-items:center;
  gap:6px;
  font-size:14px;
  text-decoration:none;
  color:var(--ink-soft);
  background:none;
  border:none;
  padding:0;
}
.footer-link:hover{ color:var(--ink); }
.footer-copy{
  font-size:13px;
  color:var(--ink-soft);
  width:100%;
  text-align:center;
  padding-top:10px;
  border-top:1px solid var(--line);
}

/* ============ Home Hero ============ */
.hero{
  text-align:center;
  padding:40px 12px 32px;
}
.hero h1{
  font-size:clamp(28px, 3.4vw, 42px);
  line-height:1.15;
  letter-spacing:-0.01em;
}
.hero h1 em{
  font-style:normal;
  color:var(--tool-1);
}
.hero p{
  margin-top:12px;
  color:var(--ink-soft);
  font-size:16px;
}

/* ============ Home 5-Card Horizontal Grid ============ */
.tools-grid{
  display:grid;
  grid-template-columns:repeat(5, 1fr);
  gap:15px;
  margin-bottom:20px;
}
.tool-card{
  background:var(--paper-raised);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:18px 16px 20px;
  display:flex;
  flex-direction:column;
  gap:12px;
  text-align:left;
  min-width:0;
}
.tool-tab{
  font-family:var(--font-display);
  font-size:12px;
  font-weight:600;
  color:var(--ink-soft);
  border:1px solid var(--line);
  width:fit-content;
  padding:2px 8px;
  border-radius:20px;
}
.tool-icon{
  width:40px; height:40px;
  border-radius:8px;
  display:flex; align-items:center; justify-content:center;
  font-size:18px;
  color:#fff;
  flex-shrink:0;
}
.tool-card h3{
  font-size:16px;
  font-weight:600;
}
.tool-card p{
  font-size:13.5px;
  color:var(--ink-soft);
  flex:1;
}
.tool-btn{
  border:none;
  border-radius:7px;
  padding:10px 14px;
  font-size:14px;
  font-weight:600;
  color:#fff;
  display:flex;
  align-items:center;
  justify-content:center;
  gap:6px;
  width:100%;
}
.tool-btn:hover{ filter:brightness(1.08); }

.card-1 .tool-icon, .card-1 .tool-btn{ background:var(--tool-1); }
.card-2 .tool-icon, .card-2 .tool-btn{ background:var(--tool-2); }
.card-3 .tool-icon, .card-3 .tool-btn{ background:var(--tool-3); }
.card-4 .tool-icon, .card-4 .tool-btn{ background:var(--tool-4); }
.card-5 .tool-icon, .card-5 .tool-btn{ background:var(--tool-5); }
/* ============ Tool View Shell ============ */
.tool-view-inner{
  display:flex;
  flex-direction:column;
  gap:20px;
  padding-bottom:20px;
}
.tool-back{
  align-self:flex-start;
  border:none;
  background:none;
  color:var(--ink-soft);
  font-size:14px;
  font-weight:500;
  padding:6px 0;
}
.tool-back:hover{ color:var(--ink); }

.tool-view-header{
  display:flex;
  align-items:center;
  gap:14px;
  padding:18px 20px;
  background:var(--paper-raised);
  border:1px solid var(--line);
  border-radius:var(--radius);
}
.tool-view-header .tool-icon{
  width:44px; height:44px;
  border-radius:10px;
  font-size:20px;
}
.tool-view-header h2{
  font-size:19px;
  margin-bottom:2px;
}
.tool-view-header p{
  font-size:13.5px;
  color:var(--ink-soft);
}

.tool-panel{
  background:var(--paper-raised);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:24px;
  display:flex;
  flex-direction:column;
  gap:18px;
}

/* ============ Upload Box ============ */
.upload-box{
  border:2px dashed var(--line-strong);
  border-radius:var(--radius);
  background:var(--paper);
  padding:36px 20px;
  text-align:center;
  cursor:pointer;
  transition:border-color .15s ease, background .15s ease;
}
.upload-box:hover,
.upload-box:focus-visible{
  border-color:var(--tool-1);
  background:#EDF1FF;
}
.upload-box.dragover{
  border-color:var(--tool-1);
  background:#EDF1FF;
}
.upload-icon{
  font-size:30px;
  margin-bottom:10px;
}
.upload-title{
  font-size:15px;
  font-weight:600;
  color:var(--ink);
  margin-bottom:6px;
}
.upload-sub{
  font-size:12.5px;
  color:var(--ink-soft);
}
.file-name-display{
  text-align:center;
  margin-top:-6px;
}

/* ============ Format Row ============ */
.format-row{
  display:flex;
  gap:10px;
  flex-wrap:wrap;
}
.format-btn{
  border:1px solid var(--line);
  background:var(--paper-raised);
  color:var(--ink-soft);
  font-size:13.5px;
  font-weight:600;
  padding:8px 18px;
  border-radius:7px;
}
.format-btn:hover{ border-color:var(--line-strong); }
.format-btn.active{
  border-color:var(--tool-1);
  color:#fff;
  background:var(--tool-1);
}

/* ============ Size Row ============ */
.size-row{
  display:flex;
  align-items:center;
  gap:10px;
  flex-wrap:wrap;
}
.size-label{
  font-size:13px;
  font-weight:600;
  color:var(--ink-soft);
  white-space:nowrap;
}
.size-input{
  width:90px;
  padding:9px 10px;
  border:1px solid var(--line);
  border-radius:7px;
  font-size:14px;
  font-family:inherit;
  color:var(--ink);
  background:var(--paper-raised);
}
.size-input:focus{ border-color:var(--tool-1); }

.unit-group{
  display:flex;
  border:1px solid var(--line);
  border-radius:7px;
  overflow:hidden;
}
.unit-btn{
  border:none;
  background:var(--paper-raised);
  color:var(--ink-soft);
  font-size:13px;
  font-weight:600;
  padding:9px 14px;
  border-right:1px solid var(--line);
}
.unit-btn:last-child{ border-right:none; }
.unit-btn.active{
  background:var(--tool-1);
  color:#fff;
}

.action-btn{
  border:none;
  border-radius:7px;
  padding:11px 20px;
  font-size:14px;
  font-weight:600;
  color:#fff;
  background:var(--tool-1);
  white-space:nowrap;
}
.action-btn:hover{ filter:brightness(1.08); }
.action-btn:disabled{
  opacity:0.5;
  cursor:not-allowed;
  filter:none;
}
.action-btn.full-width{ width:100%; }

.card-1.action-btn, .action-btn.card-1{ background:var(--tool-1); }
.card-2.action-btn, .action-btn.card-2{ background:var(--tool-2); }
.card-3.action-btn, .action-btn.card-3{ background:var(--tool-3); }
.card-4.action-btn, .action-btn.card-4{ background:var(--tool-4); }
.card-5.action-btn, .action-btn.card-5{ background:var(--tool-5); }

/* ============ Slider Row ============ */
.slider-row{ display:flex; flex-direction:column; gap:6px; }
.quality-slider{
  width:100%;
  accent-color:var(--tool-1);
  height:6px;
  cursor:pointer;
}
.slider-scale{
  display:flex;
  justify-content:space-between;
  font-size:12px;
  color:var(--ink-soft);
}
.slider-caption{
  font-size:12.5px;
  color:var(--ink-soft);
  text-align:center;
}

/* ============ Password Fields ============ */
.password-fields{
  display:flex;
  flex-direction:column;
  gap:8px;
}
.field-label{
  font-size:13px;
  font-weight:600;
  color:var(--ink-soft);
}
.text-input{
  padding:10px 12px;
  border:1px solid var(--line);
  border-radius:7px;
  font-size:14px;
  font-family:inherit;
  color:var(--ink);
  background:var(--paper-raised);
}
.text-input:focus{ border-color:var(--tool-1); }
.field-error{
  font-size:12.5px;
  color:var(--tool-5);
  margin-top:-4px;
}

/* ============ Download / Print Buttons ============ */
.download-btn{
  border:none;
  border-radius:7px;
  padding:11px 20px;
  font-size:14px;
  font-weight:600;
  color:#fff;
  background:var(--ink);
  width:100%;
}
.download-btn:hover{ filter:brightness(1.15); }
.download-btn:disabled{
  opacity:0.5;
  cursor:not-allowed;
  filter:none;
}
.print-btn{
  border:1px solid var(--line);
  border-radius:7px;
  padding:11px 20px;
  font-size:14px;
  font-weight:600;
  color:var(--ink);
  background:var(--paper-raised);
  width:100%;
}
.print-btn:hover{ border-color:var(--line-strong); }

/* ============ Result Card ============ */
.result-card{
  display:flex;
  gap:16px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px;
  background:var(--paper);
  align-items:center;
}
.result-thumb{
  width:70px;
  height:70px;
  flex-shrink:0;
  border-radius:8px;
  background:var(--paper-raised);
  border:1px solid var(--line);
  display:flex;
  align-items:center;
  justify-content:center;
  overflow:hidden;
}
.result-thumb img{
  width:100%;
  height:100%;
  object-fit:cover;
}
.result-thumb-placeholder{ font-size:26px; }
.result-info{
  flex:1;
  display:flex;
  flex-direction:column;
  gap:6px;
  min-width:0;
}
.result-title{
  font-size:15px;
  font-weight:600;
}
.result-meta{
  font-size:13px;
  color:var(--ink-soft);
}
.result-actions{
  display:flex;
  gap:10px;
  margin-top:6px;
  flex-wrap:wrap;
}
.result-actions .download-btn,
.result-actions .print-btn{ width:auto; flex:1; }

/* ============ Modals ============ */
.modal-overlay{
  position:fixed;
  inset:0;
  background:rgba(22,33,28,0.55);
  display:flex;
  align-items:flex-start;
  justify-content:center;
  padding:40px 16px;
  z-index:1000;
  overflow-y:auto;
}
.modal-box{
  background:var(--paper-raised);
  border-radius:var(--radius);
  max-width:700px;
  width:100%;
  padding:32px 28px 28px;
  position:relative;
}
.modal-close{
  position:absolute;
  top:16px; right:16px;
  width:32px; height:32px;
  border:1px solid var(--line);
  border-radius:50%;
  background:var(--paper);
  font-size:16px;
  display:flex; align-items:center; justify-content:center;
}
.modal-close:hover{ border-color:var(--line-strong); }
.modal-box h2{
  font-size:22px;
  margin-bottom:4px;
  padding-right:36px;
}
.modal-eff-date{
  font-size:13px;
  color:var(--ink-soft);
  margin-bottom:18px;
}
.modal-body{
  max-height:60vh;
  overflow-y:auto;
  padding-right:6px;
}
.modal-point{ margin-bottom:16px; }
.modal-point h4{
  font-size:15px;
  margin-bottom:4px;
}
.modal-point p{
  font-size:14px;
  color:var(--ink-soft);
  line-height:1.6;
}
.modal-point a{ color:var(--tool-1); }

/* ============ Dark Theme ============ */
body.theme-dark{
  --ink:#EDF1EC;
  --ink-soft:#A7B3A2;
  --paper:#12160F;
  --paper-raised:#1B211A;
  --line:#2B332A;
  --line-strong:#3C463A;
}
body.theme-dark .upload-box:hover,
body.theme-dark .upload-box:focus-visible,
body.theme-dark .upload-box.dragover{
  background:#1A2340;
}

/* ============ Responsive ============ */
@media (max-width:980px){
  .tools-grid{ grid-template-columns:repeat(2, 1fr); }
}
@media (max-width:860px){
  .app-shell{ grid-template-columns:1fr; }
  .ad-rail{ display:none; }
}
@media (max-width:520px){
  .tools-grid{ grid-template-columns:1fr; }
  .site-header-inner{ padding:14px 16px; }
  .app-shell{ padding:14px 16px; }
  .size-row{ flex-direction:column; align-items:stretch; }
  .size-row .action-btn{ width:100%; }
  .result-card{ flex-direction:column; text-align:center; }
  .result-actions{ justify-content:center; }
}