:root{color-scheme:dark;--bg:#090e18;--panel:#0f1622;--border:#232e3d;--text:#e4ecee;--muted:#7d8c9d;--green:#90e6bd;--mint:#42c990;--curve:#a7bcff;--red:#ed8e98;font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;font-synthesis:none}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text)}button,input{font:inherit}button{cursor:pointer;touch-action:manipulation}button:focus-visible,a:focus-visible{outline:2px solid var(--green);outline-offset:4px}button{transition:background .18s,border-color .18s,transform .18s}button:active{transform:translateY(1px)}button:disabled{cursor:wait;opacity:.65}a{color:inherit;text-decoration:none}button[hidden],[hidden]{display:none!important}
.topbar{height:90px;border-bottom:1px solid #1b2432;padding:0 4%;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:13px;font-size:23px;font-weight:750;letter-spacing:3px}.brand-symbol{color:var(--green);font:italic 46px Georgia,serif;border-right:1px solid var(--border);padding-right:17px}.brand small{display:block;font-size:8px;letter-spacing:2.6px;font-weight:500;color:var(--muted);margin-top:5px}.top-right{display:flex;align-items:center;gap:25px}.mode-tag{font-size:12px;color:#a3b3c1;display:flex;align-items:center;gap:9px}.small-dot{display:inline-block;width:6px;height:6px;background:var(--mint);border-radius:50%;box-shadow:0 0 10px #42c99030}.icon-button{width:33px;height:33px;border:1px solid var(--border);border-radius:50%;color:var(--muted);background:transparent;font-size:17px}.icon-button:hover{color:var(--green);border-color:var(--green)}
.workspace{max-width:1600px;margin:auto;display:grid;grid-template-columns:260px minmax(300px,1fr) 200px;gap:42px;padding:40px 4% 32px;align-items:start}.eyebrow{font-size:10px;letter-spacing:1.8px;color:var(--muted);font-weight:600}.level-intro{padding:8px 0 28px}.level-intro h1{font-size:42px;letter-spacing:2px;font-weight:650;margin:16px 0 12px}.level-intro h1 span,.mission h2 span{color:var(--green)}.level-intro>p{font-size:13px;color:var(--muted);margin:0}.level-meta{display:flex;justify-content:space-between;font-size:10px;color:#a4b0bd;margin-top:25px}.level-meta>span:first-child{background:#192b26;color:#83c7aa;padding:5px 9px;border-radius:4px}.level-meta>span:last-child{align-self:center;font-family:monospace;letter-spacing:1px}.meta-slash{color:#475465;margin:0 6px}
.expression-panel{border:1px solid var(--border);background:linear-gradient(140deg,#111b28,#0d141f);border-radius:14px;padding:17px;box-shadow:0 12px 40px #00000018}.panel-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}.panel-heading h2{font-size:12px;margin:0;font-weight:500;color:#b7c6d1}.panel-heading>span{font-size:10px;color:var(--muted)}.expression-field{display:flex;gap:10px;align-items:center;background:#090f18;border:1px solid #2e4250;border-radius:8px;padding:0 12px;height:54px}.expression-field:focus-within{border-color:#71bb99;box-shadow:0 0 0 3px #71bb9910}.expression-field label{font:italic 24px Georgia,serif;color:var(--green);white-space:nowrap}.expression-field label span{font-style:normal;font-size:18px;margin-left:3px}.expression-field input{color:var(--text);width:100%;min-width:0;border:0;outline:0;background:transparent;font:20px "Cambria Math",Georgia,serif;height:100%}.expression-field input::placeholder{font:12px "Microsoft YaHei",sans-serif;color:#4f6072}.input-feedback{font-size:10px;color:var(--muted);min-height:38px;padding:10px 0;line-height:1.6}.input-feedback.error{color:var(--red)}.keypad{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}.keypad button{height:37px;border-radius:6px;border:1px solid #293442;background:#17202d;color:#d7e0e9;font:19px Georgia,serif}.keypad button:hover{background:#29374a;border-color:#61768b}.keypad .operator{background:#121c2a;color:#98adbf}.keypad .variable{color:var(--green);background:#172c29;font-style:italic;border-color:#2c5043}.keypad .clear{font:11px "Segoe UI",sans-serif;color:#d28a92;background:#281b24;border-color:#55303a}.keypad .utility{font-size:18px;color:#b0becb}.editor-tools{display:flex;align-items:center;gap:6px;margin:11px 0 16px}.editor-tools button{width:31px;height:26px;background:transparent;border:1px solid var(--border);border-radius:5px;color:var(--muted)}.editor-tools span{margin-left:auto;font-size:9px;color:#718194}.editor-tools kbd{font:9px monospace;padding:2px 4px;border:1px solid #354252;border-radius:3px;color:#9babbc}.submit-button{display:flex;align-items:center;justify-content:space-between;width:100%;height:45px;border-radius:8px;border:1px solid #8cddaf;background:var(--green);color:#123b2b;font-size:13px;font-weight:750;padding:0 15px}.submit-button>span{font-size:22px;font-weight:400}.submit-button:hover{background:#adf2ce;box-shadow:0 0 20px #90e6bd16}.hint-button{border:0;background:transparent;color:var(--muted);font-size:11px;width:100%;display:flex;gap:8px;align-items:center;padding:18px 3px}.hint-button>span:first-child{color:var(--green);font-size:16px}.hint-arrow{margin-left:auto}.hint-button:hover{color:var(--green)}.hint-text{font-size:12px;line-height:1.9;color:#a5b5c1;margin:0;padding:12px;border-left:2px solid #557f68;background:#111e1c}
.board-top{display:flex;align-items:center;justify-content:space-between;min-height:67px;padding-bottom:20px}.board-top .eyebrow{font-size:9px;letter-spacing:1.6px}.board-top h2{font-size:14px;font-weight:450;letter-spacing:1px;margin:8px 0 0;color:#bdc9d2}.reset-button{font-size:20px;color:#899bae;display:flex;gap:7px;align-items:center;border:0;background:transparent}.reset-button span{font-size:11px}.reset-button:hover{color:var(--green)}.board-wrap{aspect-ratio:1;position:relative;background:#0b101c;border:1px solid #273140;border-radius:14px;overflow:hidden;box-shadow:0 14px 70px #00000025}canvas{display:block;width:100%;height:100%}.board-badge{position:absolute;bottom:18px;left:50%;transform:translateX(-50%);white-space:nowrap;border:1px solid #303a48;background:#101825dd;border-radius:30px;padding:9px 14px;font-size:10px;color:#9cabbc;display:flex;gap:8px;align-items:center;pointer-events:none;max-width:90%}.axis-label{position:absolute;font:italic 16px Georgia,serif;color:#b2bfce;pointer-events:none}.x-label{right:10px;top:calc(50% - 25px)}.y-label{left:calc(50% + 13px);top:9px}.board-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:15px;font-size:10px;color:var(--muted)}.legend{display:flex;gap:18px}.legend>span{display:flex;align-items:center;gap:7px}.legend i{display:inline-block;width:8px;height:8px;border-radius:2px}.green-swatch{background:#42c990;border:1px solid #90e6bd}.legend .curve-swatch{width:13px;height:2px;background:var(--curve)}.range-note{font-family:monospace;color:#607287}.result{margin-top:24px;display:flex;gap:13px;align-items:center;background:#111a26;border:1px solid #233040;border-radius:10px;padding:15px 18px;min-height:75px}.result-icon{font-size:22px;color:var(--curve);border:1px solid #35445a;border-radius:50%;height:33px;width:33px;display:grid;place-items:center;flex-shrink:0}.result strong{font-size:12px;font-weight:500;color:#c3cfd9}.result p{font-size:10px;color:var(--muted);margin:6px 0 0;line-height:1.6}.result.success{background:#12271f;border-color:#315c48}.result.success .result-icon{border-color:#42795b;color:var(--green)}.result.success strong{color:var(--green)}.result.failure{border-color:#603540;background:#251820}.result.failure .result-icon{color:var(--red);border-color:#603540}.result.failure strong{color:var(--red)}
.right-panel{padding-top:6px}.level-pill{display:inline-flex;gap:12px;align-items:center;font-size:9px;letter-spacing:2px;color:#8caf9c;background:#14261f;border:1px solid #294437;border-radius:30px;padding:10px 15px}.level-pill strong{font:18px Georgia,serif;color:var(--green)}.mission{margin-top:47px}.mission h2{font-size:25px;font-weight:500;line-height:1.7;letter-spacing:1px;margin:12px 0 15px}.mission>p{font-size:12px;color:var(--muted);line-height:1.9;margin:0}.target-progress{display:flex;align-items:center;gap:9px;padding:14px 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border);margin-top:23px;font-size:11px;color:#b0c0cd}.target-icon{font-size:21px;color:var(--mint)}.target-progress strong{margin-left:auto;font:13px monospace;color:var(--green)}.mission .boundary-note{font-size:10px;line-height:1.9;margin-top:15px;color:#677b8e}.record-card{margin-top:45px;border-radius:10px;background:linear-gradient(130deg,#15211e,#101920);border:1px solid #283a34;padding:19px 16px}.record-card .eyebrow{font-size:8px;letter-spacing:1.3px}.record-card>div{display:flex;align-items:baseline;gap:10px;margin-top:10px}.record-card strong{font:38px Georgia,serif;color:#bce2cd}.record-card>div>span{font-size:10px;color:#7c9b8b}.record-card p{font-size:10px;color:#759083;line-height:1.9;margin:12px 0 0;overflow-wrap:anywhere}.side-footer{font-size:10px;display:flex;gap:8px;align-items:center;color:#607382;margin-top:36px}.side-footer .small-dot{background:#476154;box-shadow:none}.page-footer{max-width:1600px;margin:auto;padding:22px 4%;border-top:1px solid #19232f;display:flex;justify-content:space-between;font-size:10px;color:#526779;letter-spacing:.5px}.footer-dot{padding:0 9px}
dialog{width:min(480px,calc(100% - 32px));border:1px solid #364754;border-radius:18px;background:#111b27;color:var(--text);padding:28px;box-shadow:0 30px 120px #0009}dialog::backdrop{background:#030813c9;backdrop-filter:blur(5px)}.dialog-heading{display:flex;align-items:center;justify-content:space-between}dialog h2{font-size:24px;font-weight:550;margin:18px 0}dialog p,dialog li{font-size:12px;line-height:1.9;color:#9fafbf}dialog ul{padding-left:18px;margin-bottom:25px}dialog li{margin-bottom:8px}
@media(min-width:1600px){.workspace{gap:55px;grid-template-columns:280px minmax(300px,1fr) 210px;padding-top:46px}.keypad button{height:42px}}
@media(max-width:1150px){.workspace{grid-template-columns:235px minmax(300px,1fr);gap:28px;padding:28px 3%}.right-panel{grid-column:1/-1;display:flex;gap:25px;align-items:center;border-top:1px solid var(--border);padding-top:22px}.right-panel .level-pill,.side-footer{display:none}.mission{margin:0;flex:1;display:grid;grid-template-columns:1fr 1fr;gap:5px 25px}.mission>.eyebrow{grid-column:1}.mission h2{font-size:16px;grid-column:1;grid-row:2;margin:0}.mission h2 br{display:none}.mission>p:not(.boundary-note){grid-column:1;grid-row:3;font-size:10px}.target-progress{grid-column:2;grid-row:1/3;margin:0}.mission .boundary-note{grid-column:2;grid-row:3;margin:0}.record-card{width:190px;margin:0;padding:12px}.record-card strong{font-size:26px}.record-card p{margin-top:6px;font-size:9px}.board-top h2{font-size:13px}}
@media(max-width:680px){.topbar{height:68px;padding:0 20px}.brand{font-size:18px;gap:10px}.brand-symbol{font-size:34px;padding-right:12px}.brand small{font-size:6px}.top-right{gap:16px}.mode-tag{font-size:10px}.workspace{padding:22px 16px;grid-template-columns:1fr;gap:22px}.left-panel{display:contents}.level-intro{grid-row:1;padding:0;position:relative}.level-intro .eyebrow{font-size:8px}.level-intro h1{font-size:28px;display:inline-block;margin:9px 0 5px}.level-intro>p{font-size:11px}.level-meta{position:absolute;right:0;top:16px;margin:0;gap:15px}.board-section{grid-row:2}.board-top{display:none}.board-wrap{border-radius:12px}.board-badge{bottom:12px;font-size:9px;padding:7px 10px}.board-bottom{margin-top:10px;font-size:9px}.result{margin-top:14px;padding:12px;min-height:64px}.result strong{font-size:11px}.result p{font-size:10px}.expression-panel{grid-row:3;padding:16px}.panel-heading{margin-bottom:12px}.expression-field{height:49px}.keypad{gap:7px}.keypad button{height:40px}.input-feedback{min-height:31px;padding:7px 0}.editor-tools{margin:10px 0 12px}.hint-button{grid-row:4;padding:0 5px}.hint-text{grid-row:5}.right-panel{grid-row:6;grid-column:1;align-items:start;gap:16px;padding-top:18px}.mission{display:block}.mission>.eyebrow{font-size:9px}.mission h2{margin:8px 0;font-size:16px;line-height:1.6}.mission>p:not(.boundary-note){font-size:10px}.target-progress{margin-top:12px;padding:10px 0}.mission .boundary-note{margin-top:8px}.record-card{width:125px;flex-shrink:0;padding:12px}.record-card .eyebrow{font-size:7px;letter-spacing:.7px}.record-card p{line-height:1.8}.page-footer{font-size:9px;padding:18px 16px}.page-footer>span:last-child{display:none}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
@media(max-width:680px){.board-top{display:flex;min-height:0;padding-bottom:10px;justify-content:flex-end}.board-top>div{display:none}.reset-button{font-size:17px}.keypad button{height:44px}}

/* Desktop campaign: chapters, free level selection and persistent progress. */
.topbar{height:76px}
.campaign-bar{max-width:1600px;margin:auto;padding:14px 4%;display:flex;align-items:center;justify-content:space-between;gap:24px;border-bottom:1px solid #1b2432}
.difficulty-tabs{display:flex;gap:8px}
.difficulty-tabs button{display:flex;align-items:center;gap:14px;color:#8c9eaf;background:transparent;border:1px solid transparent;border-radius:7px;padding:9px 16px;font-size:12px}
.difficulty-tabs button small{font-size:9px;color:#5b7484;letter-spacing:.5px}
.difficulty-tabs button.active{border-color:#325a47;background:#14251e;color:var(--green)}
.difficulty-tabs button.active small{color:#83b397}
.difficulty-tabs button:hover{background:#172330;border-color:#364b5d}
.campaign-actions{display:flex;align-items:center;gap:23px;font-size:11px;color:#7b90a0}
.campaign-actions button{background:#14202d;border:1px solid #2e4050;border-radius:7px;color:#b9cbd5;padding:9px 14px;font-size:11px}
.campaign-actions button:hover{border-color:var(--green);color:var(--green)}
.workspace{padding-top:28px;gap:32px}
.level-intro h1{font-size:32px;letter-spacing:1px;line-height:1.5;margin-top:12px}
.level-intro h1 #level-title{color:var(--text)}
.level-intro>p{line-height:1.8;min-height:24px;font-size:12px}
.level-intro{padding-bottom:22px}
.level-meta{margin-top:18px}
.board-section{width:100%;max-width:min(100%,max(360px,calc(100dvh - 435px)));justify-self:center}
.board-top{min-height:57px;padding-bottom:16px}
.legend .red-swatch{background:#b85c68;border:1px solid #e18e96}
.result{margin-top:18px;min-height:69px;padding:13px 15px}
.level-navigation{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:15px}
.level-navigation button{font-size:11px;background:#121e2b;border:1px solid #2a3a49;color:#9eafbc;border-radius:6px;padding:8px 12px}
.level-navigation button:hover{border-color:#82cba2;color:var(--green)}
.level-navigation button:disabled{cursor:default;opacity:.35}
.level-navigation button.ready{color:var(--green);background:#163025;border-color:#3e6c50}
.level-navigation>span{font-size:10px;color:#71879b}
.level-pill{gap:8px;letter-spacing:1px;padding:9px 12px}
.level-pill #completed-badge{font-size:8px;letter-spacing:0;color:#98cdb0}
.mission{margin-top:28px}
.mission h2{font-size:23px;margin-top:10px;margin-bottom:12px}
.mission #mission-heading{color:var(--text)}
.mission>p{font-size:11px}
.target-progress{margin-top:18px;padding:11px 0}
.red-progress{margin-top:0;border-top:0}
.red-progress .target-icon{color:#b97079}
.red-progress strong{color:#9b8390;font-size:11px}
.red-progress.collision strong{color:#ffa0ad}
.mission .boundary-note{font-size:10px;margin-top:12px}
.chapter-map{margin-top:25px}
.chapter-map>div:first-child{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.chapter-map .eyebrow{font-size:9px;letter-spacing:1px}
#chapter-progress{font:10px monospace;color:#739483}
.level-shortcuts{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}
.level-shortcuts button{position:relative;height:30px;border:1px solid #2a3644;border-radius:5px;background:#111b26;color:#8da0b2;font:11px monospace}
.level-shortcuts button:hover{border-color:#92caad;color:var(--green)}
.level-shortcuts button.completed{background:#162b22;border-color:#2c5040;color:#8acfa8}
.level-shortcuts button.completed::after{content:'';position:absolute;right:3px;top:3px;width:3px;height:3px;border-radius:50%;background:var(--green)}
.level-shortcuts button.current{border-color:var(--green);color:var(--green);box-shadow:0 0 0 1px #90e6bd20}
.record-card{margin-top:25px;padding:15px}
.record-card strong{font-size:32px}
.side-footer{margin-top:22px;font-size:9px}
.hint-text ol{margin:0;padding-left:16px}
.hint-text li{margin:0 0 8px;overflow-wrap:anywhere}
.hint-text li:last-child{margin-bottom:0}
#use-reference{margin-top:12px;border:1px solid #3d6952;background:#182e23;color:var(--green);border-radius:5px;font-size:10px;padding:8px 11px}
.campaign-dialog{width:min(800px,calc(100% - 50px));max-height:calc(100dvh - 64px);padding:30px;overflow:auto}
.campaign-dialog h2{font-size:28px;margin-top:14px}
.campaign-dialog .difficulty-tabs{border-bottom:1px solid #2a3744;padding-bottom:12px}
.campaign-dialog #menu-description{font-size:11px;margin:16px 0 20px}
.campaign-grid{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:12px}
.level-card{min-height:155px;padding:16px 12px;background:#111c2a;border:1px solid #2b3b4a;border-radius:9px;text-align:left;display:flex;flex-direction:column;align-items:start;color:#c4d1dc}
.level-card:hover{background:#192b35;border-color:#78b994;transform:translateY(-2px)}
.level-card .card-number{font:23px Georgia,serif;color:#7891a6;margin-bottom:15px}
.level-card strong{font-size:12px;font-weight:550;line-height:1.6;margin-bottom:6px}
.level-card small{font-size:9px;color:#6f879a;line-height:1.6}
.level-card .card-state{font-size:9px;color:#627b8f;margin-top:auto;padding-top:12px}
.level-card.completed{background:#15271f;border-color:#2e5140}
.level-card.completed .card-state,.level-card.completed .card-number{color:#8acda5}
.level-card.current{border-color:var(--green)}
.menu-footer{display:flex;justify-content:space-between;gap:15px;margin-top:22px;color:#718d81;font-size:10px}
@media(max-width:1150px){.board-section{max-width:100%}.right-panel{flex-wrap:wrap}.chapter-map{width:180px;margin-top:0}.mission{margin-top:0}.red-progress{grid-column:2;grid-row:3}.mission .boundary-note{grid-row:4}.right-panel .record-card{margin-top:0}.campaign-grid{gap:8px}}

.campaign-actions #custom-button.active{border-color:#90e6bd;color:var(--green);background:#163025}
.custom-toolbar{max-width:1472px;margin:18px auto 0;padding:18px 22px;background:#101d28;border:1px solid #345044;border-radius:12px;width:92%}
.custom-toolbar button,#custom-new,.saved-custom-row button{border:1px solid #354a5a;background:#16232e;color:#b5c9d7;padding:8px 12px;border-radius:6px;font-size:11px}
.custom-toolbar button:hover,#custom-new:hover,.saved-custom-row button:hover{border-color:var(--green);color:var(--green)}
.custom-toolbar button:disabled{opacity:.4;cursor:default}
.custom-tools,.custom-coordinate,.custom-management{display:flex;gap:9px;align-items:center;flex-wrap:wrap}
.custom-tools [data-brush="green"].active{background:#193a2a;color:#90e6bd;border-color:#75c99a}
.custom-tools [data-brush="red"].active{background:#3a202b;color:#f4a2ad;border-color:#c77c88}
.custom-tools [data-brush="erase"].active{background:#2b3744;color:#e0eaf1;border-color:#acbcc8}
.custom-coordinate{margin-top:12px;color:#8da6b8;font-size:11px}
.custom-coordinate label{display:flex;align-items:center;gap:7px}
.custom-toolbar input{background:#0a1420;border:1px solid #334957;border-radius:5px;color:#d9e8ed;padding:7px 9px;font-size:12px}
.custom-coordinate input{width:65px}
#cell-position{margin-left:8px;color:#6e91a5;font:11px monospace}
.custom-management{margin-top:14px;padding-top:14px;border-top:1px solid #283b46}
.custom-management label{color:#8da6b8;font-size:11px;display:flex;gap:8px;align-items:center;margin-right:auto}
#custom-name{width:155px}
.custom-toolbar .custom-primary{background:#90e6bd;color:#163526;border-color:#90e6bd;font-weight:600}
#custom-status{margin:12px 0 0;color:#a2c4b2;font-size:11px;line-height:1.8}
canvas.editing{cursor:crosshair;touch-action:none}
.saved-custom-row{display:flex;align-items:center;gap:8px;padding:15px 0;border-bottom:1px solid #2b3e49}
.saved-custom-row>div{flex:1;min-width:0}
.saved-custom-row strong{display:block;color:#c7dfd3;font-size:13px;overflow-wrap:anywhere}
.saved-custom-row small{display:block;margin-top:7px;font-size:10px;color:#799787}
.saved-custom-row .delete-custom{color:#c18b95}
#custom-saved-list{max-height:50vh;overflow:auto;margin-top:12px}