/* Shared look for inner pages (V1.27) — loaded after each page's own <style> */
@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@600;700;800;900&display=swap');
:root{--primary:#3355e8;--blue:#3355e8;--ink:#1b2559;--bg:#f4f7ff;--border:#e1e7f7;--soft:#e8eeff}
html body{font-family:'Nunito','Segoe UI',system-ui,'PingFang SC','Microsoft YaHei',Arial,sans-serif;background:#f4f7ff;color:#1b2559;-webkit-font-smoothing:antialiased}
html body header{background:rgba(255,255,255,.93);backdrop-filter:blur(10px);border-bottom:1px solid #e1e7f7;box-shadow:0 6px 18px rgba(27,37,89,.05);position:sticky;top:0;z-index:20}
html body header:before{content:"";display:block;position:absolute;left:0;right:0;top:0;height:4px;background:linear-gradient(90deg,#3355e8,#14b8a6,#ffc53d)}
html body header .brand,html body header>b,html body header .top>b{font-weight:900;letter-spacing:-.3px;color:#1b2559}
html body header .brand:before,html body header>b:before,html body header .top>b:before{content:"S";display:inline-grid;place-items:center;width:30px;height:30px;margin-right:9px;border-radius:10px;color:#fff;font-size:12px;font-weight:900;vertical-align:middle;background:linear-gradient(135deg,#3355e8,#14b8a6)}
html body .nav a,html body header nav a{border-radius:999px;font-weight:800}
html body .nav a.active,html body header nav a.active{color:#3355e8;background:#e8eeff;border-bottom-color:transparent}
html body .btn,html body .back,html body button.back{border-radius:999px;font-family:inherit;font-weight:850}
html body .btn:not(.secondary):not(.ghost),html body .primary{background:#3355e8;color:#fff;box-shadow:0 6px 14px rgba(51,85,232,.25)}
html body .btn.secondary,html body .secondary{background:#eaf0ff;color:#1b2559;box-shadow:none}
html body .card,html body .box,html body .panel,html body section.card{border-radius:22px;border-color:#e1e7f7;box-shadow:0 8px 22px rgba(27,37,89,.06)}
html body .hero.card{background:linear-gradient(135deg,#eef3ff,#e3f8f4);border:1px solid #dbe5ff}
html body h1,html body h2,html body h3{letter-spacing:-.4px}
html body input,html body select,html body textarea{font-family:inherit;border-radius:12px}
html body .nav a,html body header nav a{color:#3a4770}html body .nav a.active,html body header nav a.active{color:#3355e8}
html body .step.active{background:#3355e8;border-color:#3355e8}
@media(max-width:600px){html body header .brand:before,html body header>b:before,html body header .top>b:before{display:none}}
@media(max-width:600px){html body header .brand,html body header>b,html body header .top>b{font-size:15px}html body header .top{gap:8px}html body header .chapter-select{max-width:46vw;min-width:0}html body header .top-right{min-width:0;gap:6px}}