/* Shared orbital identity, with a quiet star field for the optional night palette. */
.logo,.auth-logo{width:44px!important;height:44px!important;min-width:44px;padding:0!important;background:transparent!important;box-shadow:none!important;border-radius:12px;display:grid;place-items:center}.logo::before,.logo::after{display:none!important}.logo img,.auth-logo img{width:44px;height:44px;display:block;border-radius:12px}
:root[data-theme="starry"]{color-scheme:dark;--accent:#b7acff;--accent-rgb:183,172,255;--accent-dark:#9489e0;--accent-ink:#ded8ff;--secondary:#f0c77d;--secondary-rgb:240,199,125;--bg:#090f24;--text:#edf0ff;--ink:#edf0ff;--muted:#b0bad7;--line:rgba(190,200,245,.19);--panel:rgba(18,27,52,.97);--panel-solid:#141e39;--surface:#141e39;--soft:rgba(183,172,255,.12);--accent-soft:#202c4c;--shadow:0 25px 70px rgba(0,0,0,.32)}
:root[data-theme="starry"] body{background:radial-gradient(ellipse at 15% 0%,#30345d88,transparent 40rem),radial-gradient(ellipse at 85% 35%,#28255266,transparent 40rem),#090f24;background-size:auto;background-attachment:fixed}
:root[data-theme="starry"] body::before{opacity:.7;background-image:radial-gradient(circle at 15px 21px,#f8f4da 0 1px,transparent 1.4px),radial-gradient(circle at 83px 61px,#c3cbff 0 .7px,transparent 1.2px),radial-gradient(circle at 151px 127px,#e5d5ff 0 1px,transparent 1.5px);background-size:223px 211px,179px 173px,317px 293px;pointer-events:none}
:root[data-theme="starry"] :is(.auth-tabs,.auth-language,.sidebar,.user-sidebar,.question-card,.concept-card,.unit-card,.topic-button,.how-card,.data-card,.concept-orbit,.daily-challenge,.daily-choice,.account-nav-button,.user-shell,.world-card,.field-card,.theme-card,.app-sidebar,.placement-test,.knowledge-tree,.tree-toolbar,.tree-root,.tree-topic,.tree-unit>details>summary,.tree-course>details>summary,.search-wrap,.example,.secondary,.back-control,.browse-mode-switch,.field input,.field select,.field textarea,.compact-select,.lesson-video,.result,.math-calculator){background:var(--panel-solid);color:var(--text);border-color:var(--line)}
:root[data-theme="starry"] :is(input,select,textarea,.daily-level-row select,.math-calculator input,.calculator-keys button,.calculator-mode button){background:#101a32;color:var(--text);border-color:var(--line)}
:root[data-theme="starry"] :is(.primary,.auth-submit,.admin-primary,.calculator-equals){background:linear-gradient(135deg,#b7acff,#9489e0);color:#10162b}
:root[data-theme="starry"] :is(.subject.active,.account-nav-button[aria-current="page"],.account-nav-button[aria-pressed="true"],.study-option.selected,.user-tab.active){background:var(--soft);color:var(--accent-ink);border-color:var(--accent)}
:root[data-theme="starry"] :is(.demo-pill,.role-chip,.stat-chip,.daily-badge,.tree-node-icon,.tree-leaf-dot,.course-kicker,.unit-code){color:var(--accent-ink)}
:root[data-theme="starry"] .daily-choice.correct,:root[data-theme="starry"] .daily-answer.success{background:#123a30;color:#b9f0d2;border-color:#5ba782}
:root[data-theme="starry"] .daily-choice.incorrect,:root[data-theme="starry"] .daily-answer.review{background:#3b2635;color:#ffd2d5;border-color:#c38794}
:root[data-theme="starry"] .daily-meta>.daily-done{background:#123a30;color:#b9f0d2}
:root[data-theme="starry"] .field-photo-link{background:#0b1329}
:root[data-theme="starry"] .browse-mode-switch .browse-mode-toggle[aria-pressed="true"]{color:var(--accent-ink)}
:root[data-theme="starry"] .theme-preview{background:radial-gradient(circle at 18% 25%,#fff 0 1px,transparent 2px),radial-gradient(circle at 80% 65%,#f0c77d 0 1px,transparent 2px),var(--preview-bg)}
:root[data-theme="starry"] .theme-state,:root[data-theme="starry"] .theme-card.selected{color:var(--accent-ink)}
/* Solar-system edition. Decorative planets stay separate from button labels. */
.solar-hero,.solar-backdrop{display:none}
:root[data-theme="starry"] .photo-composition{display:none}
:root[data-theme="starry"] .solar-hero{display:block;position:relative;min-width:0;width:100%;max-width:530px;min-height:310px;align-self:center;isolation:isolate;border:1px solid var(--line);border-radius:34px;background:radial-gradient(ellipse at center,#26345c88,transparent 70%),#0c142b;overflow:hidden}
.solar-hero img{width:100%;height:auto;display:block;position:relative;z-index:1}.solar-hero-label{position:absolute;bottom:19px;left:24px;color:#c8d0ef;font-size:9px;letter-spacing:.18em;z-index:2}.solar-hero-orbit{position:absolute;width:110%;height:72%;border:1px solid #b5c2ee14;border-radius:50%;left:-5%;top:15%;transform:rotate(-18deg)}
:root[data-theme="starry"] .solar-backdrop{display:block;position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden;opacity:.45}.solar-backdrop-sun{position:absolute;left:-170px;top:10vh;width:280px;height:280px;border-radius:50%;background:radial-gradient(circle at 65% 40%,#ffe9ac,#d58b45 65%,#6f382b);box-shadow:0 0 80px 20px #e3a35130}.solar-backdrop-ring{position:absolute;left:-280px;top:7vh;width:900px;height:480px;border:1px solid #edc88422;border-radius:50%;transform:rotate(-35deg);box-shadow:0 0 0 70px #0000,0 0 0 71px #b1bcee14,0 0 0 130px #0000,0 0 0 131px #b1bcee0d}.solar-backdrop-saturn{position:absolute;right:-35px;top:49vh;opacity:.7}.solar-backdrop-neptune{position:absolute;left:3vw;bottom:9vh;opacity:.55}
:root[data-theme="starry"] button[data-planet]{background-image:var(--planet-image)!important;background-repeat:no-repeat!important;background-size:30px 30px!important;background-position:12px center!important;padding-left:51px!important;position:relative;border-color:var(--line);transition:border-color .18s ease,box-shadow .18s ease}
:root[data-theme="starry"] button[data-planet]:hover:not(:disabled){border-color:var(--planet-glow);box-shadow:0 0 19px -10px var(--planet-glow)}
:root[data-theme="starry"] .app-sidebar button[data-planet]::before{content:none!important}
:root[data-theme="starry"] .subject[data-planet]{min-height:54px;text-align:left}
:root[data-theme="starry"] :is(.lang-btn,.browse-mode-toggle,.sidebar-close,#calculatorClose,.calculator-keys button,.calculator-mode button)[data-planet]{background-size:15px 15px!important;background-position:right 3px bottom 3px!important;padding-left:10px!important}
:root[data-theme="starry"] :is(.daily-choice,.study-option,.tree-topic,.unit-card,.topic-button)[data-planet]{background-position:right 10px top 10px!important;background-size:22px 22px!important;padding-left:initial!important;padding-right:40px!important}
:root[data-theme="starry"] .theme-card[data-planet]{background-size:24px 24px!important;background-position:right 10px top 10px!important;padding-left:0!important}
:root[data-theme="starry"] :is(.primary,.auth-submit,.admin-primary,.calculator-equals)[data-planet]{background-color:#b7acff;color:#10162b}
.theme-card[data-theme-choice="starry"] .theme-preview{background-image:url("images/solar/solar-scene.svg");background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#090f24}
.theme-card[data-theme-choice="starry"] .theme-preview>*{opacity:.15}
@media(max-width:760px){:root[data-theme="starry"] .solar-hero{min-height:0;margin:0 auto;max-width:460px}.solar-backdrop-sun{width:160px;height:160px;left:-115px}.solar-backdrop-saturn{width:120px;height:120px;right:-60px;opacity:.3}.solar-backdrop-neptune{display:none}.solar-hero-label{bottom:12px;font-size:8px}}
@media(prefers-reduced-motion:reduce){:root[data-theme="starry"] button[data-planet]{transition:none}}
/* Black labels on the English / Chinese controls in the solar theme. */
:root[data-theme="starry"] :is(.lang-btn,.auth-language button,[data-preference-language]){color:#000!important;background-color:#f3efff!important;border-color:#c4bbea}
:root[data-theme="starry"] :is(.lang-btn.active,.auth-language button.active,[data-preference-language][aria-pressed="true"]){color:#000!important;background-color:#b7acff!important}