:root{--bg:#f7f9fc;--surface:#fff;--text:#162033;--muted:#5d6879;--line:#e4e9f0;--primary:#315bea;--primary-dark:#2448c7;--soft:#eef3ff;--success:#147a4b;--shadow:0 12px 32px rgba(22,32,51,.08);--radius:16px}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
.container{width:min(1120px,calc(100% - 40px));margin:0 auto}
.narrow{width:min(820px,calc(100% - 40px))}
.site-header{position:relative;z-index:20;background:rgba(255,255,255,.94);border-bottom:1px solid var(--line);backdrop-filter:blur(12px)}
.nav{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{font-size:1.12rem;font-weight:800;letter-spacing:-.02em;color:var(--text)}
.nav nav{display:flex;align-items:center;gap:20px;flex-wrap:wrap}
.nav nav a{color:#465266;font-size:.94rem;font-weight:600}
.hero{padding:86px 0 70px;background:linear-gradient(180deg,#fff 0%,#f7f9fc 100%)}
.hero h1,.tool-hero h1{max-width:850px;margin:10px 0 18px;font-size:clamp(2.25rem,4.25vw,3.85rem);line-height:1.05;letter-spacing:-.045em}
.hero-copy{max-width:760px;color:var(--muted);font-size:1.08rem}
.eyebrow{margin:0;text-transform:uppercase;letter-spacing:.12em;font-size:.76rem;font-weight:800;color:var(--primary)}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}
.button{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:10px 17px;border-radius:10px;border:1px solid transparent;font:inherit;font-weight:750;cursor:pointer;text-decoration:none}
.button:hover{text-decoration:none;transform:translateY(-1px)}
.button.primary{background:var(--primary);color:#fff}.button.primary:hover{background:var(--primary-dark)}
.button.secondary{background:#fff;border-color:var(--line);color:var(--text)}
.section{padding:72px 0;scroll-margin-top:24px}.section.soft{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section-heading{max-width:780px;margin-bottom:30px}.section-heading h2{font-weight:750}.section-heading h2,.prose h2{margin:7px 0 10px;font-size:clamp(1.65rem,3vw,2.35rem);line-height:1.15;letter-spacing:-.025em}.section-heading p{color:var(--muted)}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.card,.tool-card,.info-box,.callout{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.card{padding:24px}.card .icon{display:inline-flex;align-items:center;justify-content:center;min-width:52px;height:34px;padding:0 10px;border-radius:8px;background:var(--soft);color:var(--primary);font-size:.78rem;font-weight:850}.card h3{margin:17px 0 8px;font-size:1.2rem}.card p{color:var(--muted)}.card a{font-weight:750}
.prose-grid{display:grid;grid-template-columns:1.4fr .8fr;gap:48px;align-items:start}.info-box{padding:24px}.info-box h3{margin-top:0}.info-box ul{padding-left:20px;margin-bottom:0}.prose{color:#303b4e}.prose h2{color:var(--text);margin-top:34px}.prose h2:first-child{margin-top:0}.prose p,.prose li{max-width:780px}.prose strong{color:var(--text)}
.tool-hero{padding:62px 0 34px;scroll-margin-top:24px;background:#fff;border-bottom:1px solid var(--line)}.tool-hero h1{font-size:clamp(2rem,4vw,3.35rem);max-width:800px;margin-bottom:10px}.tool-hero p:not(.eyebrow){color:var(--muted);font-size:1.05rem}
.tool-card{padding:24px}.dropzone{border:2px dashed #c9d2df;border-radius:14px;background:#fbfcfe;padding:48px 24px;text-align:center;transition:.15s ease}.dropzone:hover,.dropzone.dragging{border-color:var(--primary);background:#f5f7ff}.dropzone input[type=file]{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}.upload-icon{display:grid;place-items:center;width:48px;height:48px;margin:0 auto 14px;border-radius:50%;background:var(--soft);color:var(--primary);font-size:1.35rem;font-weight:800}.dropzone h2{margin:0 0 5px;font-size:1.35rem}.dropzone p{margin:6px 0;color:var(--muted)}.dropzone .small{margin-top:16px;font-size:.88rem}
.controls{display:flex;gap:14px;flex-wrap:wrap;align-items:center;margin-top:18px}.controls label{display:flex;gap:8px;align-items:center;font-weight:650}.controls input,.controls select{padding:9px 10px;border:1px solid var(--line);border-radius:9px;background:#fff;font:inherit}.controls p{margin:0}
.status{margin-top:16px;color:var(--muted);min-height:24px}.result{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:24px;margin-top:22px;padding-top:22px;border-top:1px solid var(--line)}.preview-wrap{display:flex;align-items:center;justify-content:center;min-height:280px;padding:18px;background:#f4f6f9;border-radius:12px;overflow:hidden}.preview-wrap img{display:block;max-width:100%;max-height:520px;object-fit:contain}.result-info{display:flex;flex-direction:column;justify-content:center}.result-info h3{margin:0 0 5px;overflow-wrap:anywhere}.result-info p{color:var(--muted)}.result-info .button{margin-top:8px}.result-info .button+.button{margin-top:10px}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;padding-left:0}.steps>div{padding:24px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}.steps span{display:grid;place-items:center;width:32px;height:32px;border-radius:50%;background:var(--soft);color:var(--primary);font-weight:800}.steps h3{margin:16px 0 6px}.steps p{margin:0;color:var(--muted)}.faq{border-top:1px solid var(--line);padding:18px 0}.faq:last-child{border-bottom:1px solid var(--line)}.faq h3{margin:0 0 6px;font-size:1.05rem}.contact-email{display:inline-flex;align-items:center;gap:10px;margin:6px 0 34px;padding:14px 18px;border:1px solid #dbe3f0;border-radius:12px;background:#fff;box-shadow:0 8px 22px rgba(22,32,51,.06);font-size:1.05rem;font-weight:750}.email-box{display:inline-block;margin-top:8px;padding:12px 15px;border:1px solid var(--line);border-radius:10px;background:#fff}
.footer{padding:42px 0 28px;background:#111827;color:#cbd3df}.footer a{color:#e8edf5}.footer-grid{display:grid;grid-template-columns:1fr auto;gap:28px}.footer-grid p{margin:6px 0 0;color:#9da8b8}.footer-grid>div:last-child{display:flex;gap:18px;flex-wrap:wrap;align-items:flex-start}.copyright{margin-top:28px;padding-top:20px;border-top:1px solid rgba(255,255,255,.12);font-size:.88rem;color:#8f9bad}
@media(max-width:900px){.cards{grid-template-columns:repeat(2,1fr)}.steps{grid-template-columns:1fr}.prose-grid{grid-template-columns:1fr;gap:28px}.result{grid-template-columns:1fr}.result-info{display:grid;grid-template-columns:1fr 1fr;gap:10px;align-items:center}.result-info h3,.result-info p{grid-column:1/-1}.result-info .button{margin:0}}
@media(max-width:650px){.container,.narrow{width:min(100% - 28px,1120px)}.nav{align-items:flex-start;padding:15px 0;flex-direction:column;gap:10px}.nav nav{gap:12px}.hero{padding:56px 0 48px}.hero h1{font-size:2.25rem}.section{padding:52px 0}.cards{grid-template-columns:1fr}.footer-grid{grid-template-columns:1fr}.result-info{display:flex}.result-info .button{width:100%}.dropzone{padding:34px 16px}}

/* V6.2 polish */
.site-header{min-height:70px}
.page-hero{padding:72px 0 58px;background:#fff;border-bottom:1px solid var(--line)}
.page-hero h1{max-width:880px;margin:10px 0 16px;font-size:clamp(2.25rem,4.25vw,3.75rem);line-height:1.06;letter-spacing:-.045em}
.page-hero p:not(.eyebrow){max-width:780px;color:var(--muted);font-size:1.06rem}
.search-panel{margin-top:30px;max-width:820px}
.search-box{display:flex;gap:10px;align-items:center;padding:8px 10px 8px 16px;background:#fff;border:1px solid #dbe2ec;border-radius:14px;box-shadow:0 10px 30px rgba(22,32,51,.07)}
.search-box input{flex:1;min-width:0;border:0;outline:0;background:transparent;font:inherit;font-size:1rem;color:var(--text)}
.search-box button{border:0;cursor:pointer}
.search-results{display:none;margin-top:10px;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 16px 36px rgba(22,32,51,.1);overflow:hidden}
.search-results.show{display:block}
.search-result{display:block;padding:14px 16px;border-bottom:1px solid var(--line);color:var(--text)}
.search-result:last-child{border-bottom:0}.search-result:hover{background:#f7f9fc;text-decoration:none}
.search-result strong{display:block;font-size:1rem}.search-result span{display:block;color:var(--muted);font-size:.9rem;margin-top:2px}.search-empty{padding:16px;color:var(--muted)}
.tool-groups{display:grid;gap:46px}.tool-group h2{margin:0 0 18px;font-size:1.65rem;letter-spacing:-.025em}.tool-group .cards{margin:0}
.related{margin-top:36px;padding-top:30px;border-top:1px solid var(--line)}
.guide-meta{color:var(--muted);font-size:.92rem}.guide-toc{padding:22px 24px;margin:24px 0;background:#fff;border:1px solid var(--line);border-radius:14px}.guide-toc strong{display:block;margin-bottom:8px}.guide-toc ul{margin:0;padding-left:20px}
.callout{padding:20px 22px;margin:28px 0}.prose table{width:100%;border-collapse:collapse;margin:22px 0;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}.prose th,.prose td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--line);vertical-align:top}.prose th{background:#f7f9fc;font-weight:750}.prose tr:last-child td{border-bottom:0}
.preview-empty{display:grid;place-items:center;min-height:280px;text-align:center;color:var(--muted)}.preview-empty strong{display:block;color:var(--text);margin-bottom:4px}
@media(max-width:650px){.page-hero{padding:54px 0 46px}.page-hero h1{font-size:2.25rem}.search-box{padding-left:12px}.search-box .button{min-height:42px;padding:8px 12px}.tool-group h2{font-size:1.45rem}.prose table{font-size:.92rem;display:block;overflow-x:auto}}

/* V6.3 state fixes */
.result[hidden]{display:none !important}
.preview-wrap img[hidden]{display:none !important}
.preview-empty span{display:block;color:var(--muted)}

/* V6.3 visual refinement */
:root{--bg:#f7f7f4;--surface:#fff;--text:#182235;--muted:#596477;--line:#e2e5e8;--primary:#2f5bea;--primary-dark:#2349c8;--soft:#eef3ff;--warm:#fbfaf7;--cyan:#4aa6b8;--shadow:0 12px 30px rgba(24,34,53,.07);--radius:16px}
body{background:var(--bg)}
.hero{padding:78px 0 76px;background:linear-gradient(180deg,#fff 0%,#f7f7f4 100%)}
.hero-grid{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(360px,.72fr);gap:64px;align-items:center}
.hero-content{min-width:0}
.hero h1{max-width:760px;margin:12px 0 18px;font-size:clamp(2.75rem,4.1vw,3.55rem);line-height:1.06;letter-spacing:-.042em;font-weight:700}
.hero-copy{max-width:700px;font-size:1.04rem;line-height:1.7}
.hero-visual{position:relative;min-height:330px;display:flex;align-items:center;justify-content:center;gap:18px;padding:34px;border:1px solid #e1e4e5;border-radius:24px;background:linear-gradient(145deg,#fff 0%,#f4f5f2 100%);box-shadow:0 18px 48px rgba(24,34,53,.09);overflow:hidden}
.hero-visual:before,.hero-visual:after{content:"";position:absolute;border-radius:50%;filter:blur(1px);opacity:.7}
.hero-visual:before{width:150px;height:150px;right:-55px;top:-55px;background:#e8f5f5}
.hero-visual:after{width:130px;height:130px;left:-55px;bottom:-55px;background:#edf1ff}
.format-card{position:relative;z-index:1;width:145px;padding:12px;border:1px solid #e0e4e8;border-radius:18px;background:rgba(255,255,255,.96);box-shadow:0 12px 26px rgba(24,34,53,.08);transform:rotate(-2deg)}
.target-format{transform:rotate(2deg)}
.photo-swatch{height:132px;border-radius:12px;overflow:hidden;position:relative}
.photo-swatch:before,.photo-swatch:after{content:"";position:absolute}
.swatch-one{background:linear-gradient(155deg,#cbd7ec 0%,#879fc2 48%,#405779 49%,#2f3c51 100%)}
.swatch-one:before{width:80px;height:80px;border-radius:50%;background:#e8d7b6;left:48px;top:22px;opacity:.9}
.swatch-one:after{width:180px;height:70px;background:#2d3b4d;left:-12px;bottom:-26px;transform:rotate(-12deg)}
.swatch-two{background:linear-gradient(155deg,#dce9df 0%,#94b8a0 48%,#526d5a 49%,#33483c 100%)}
.swatch-two:before{width:80px;height:80px;border-radius:50%;background:#f0dfbd;left:46px;top:22px;opacity:.92}
.swatch-two:after{width:180px;height:70px;background:#405b4a;left:-12px;bottom:-26px;transform:rotate(-12deg)}
.format-card span{display:inline-block;margin-top:10px;font-size:.92rem;font-weight:850;letter-spacing:.04em}
.format-card small{float:right;margin-top:10px;color:var(--muted);font-size:.72rem}
.convert-arrow{position:relative;z-index:2;width:42px;height:42px;display:grid;place-items:center;border-radius:50%;background:#fff;border:1px solid #dfe4ea;color:var(--primary);font-size:1.35rem;font-weight:800;box-shadow:0 8px 18px rgba(24,34,53,.08)}
.visual-note{position:absolute;z-index:2;left:50%;bottom:16px;transform:translateX(-50%);padding:6px 10px;border-radius:999px;background:rgba(255,255,255,.88);border:1px solid #e2e5e8;color:var(--muted);font-size:.76rem;white-space:nowrap}
.card .icon{background:#f1f4f1;color:#2f5d68;border:1px solid #e0e7e4}
@media(max-width:900px){.hero-grid{grid-template-columns:1fr;gap:36px}.hero-visual{max-width:650px;justify-self:center;width:100%}}
@media(max-width:650px){.hero{padding:56px 0 50px}.hero h1{font-size:2.35rem;line-height:1.08}.hero-visual{min-height:270px;padding:26px 16px;gap:10px}.format-card{width:122px}.photo-swatch{height:108px}.convert-arrow{width:36px;height:36px}.visual-note{bottom:10px}.hero-actions .button{width:100%}}