:root{--bg:#07111f;--panel:#0d1c2f;--line:rgba(92,199,255,.14);--text:#eef8ff;--muted:#9eb3c6;--cyan:#4de2ff;--green:#65efbd;--danger:#ff8aa5;--topbar-h:72px;--sidebar-w:310px}
*{box-sizing:border-box}html,body{margin:0;min-height:100%}body{color:var(--text);background:radial-gradient(circle at 10% 10%,rgba(77,226,255,.08),transparent 26%),radial-gradient(circle at 88% 18%,rgba(91,141,255,.10),transparent 28%),linear-gradient(180deg,#06101d,#081424 58%,#07111f);font-family:"Microsoft JhengHei","Noto Sans TC",system-ui,sans-serif}body::before{content:"";position:fixed;inset:0;pointer-events:none;opacity:.24;background-image:linear-gradient(rgba(77,226,255,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(77,226,255,.04) 1px,transparent 1px);background-size:38px 38px}button{font:inherit}
.topbar{position:sticky;top:0;z-index:100;height:var(--topbar-h);display:flex;align-items:center;gap:24px;padding:0 26px;border-bottom:1px solid var(--line);background:rgba(5,13,24,.94);backdrop-filter:blur(16px)}.brand{display:flex;align-items:center;gap:12px;min-width:280px}.brand-logo{width:40px;height:40px;display:grid;place-items:center;color:#04121d;font-weight:900;border-radius:12px;background:linear-gradient(135deg,var(--cyan),#b2f4ff)}.brand div{display:grid;gap:3px}.brand strong{font-size:1rem}.brand small{color:var(--muted);font-size:.72rem}.topnav{display:flex;gap:8px;margin-left:auto}.topnav-item{padding:10px 14px;color:#b7cada;border:1px solid transparent;border-radius:10px;background:transparent;cursor:pointer}.topnav-item:hover,.topnav-item.active{color:#fff;border-color:rgba(77,226,255,.14);background:rgba(77,226,255,.07)}.mobile-menu-btn{display:none;margin-left:auto;width:42px;height:42px;color:#fff;border:1px solid var(--line);border-radius:10px;background:rgba(255,255,255,.03);cursor:pointer}
.app-shell{position:relative;z-index:1;min-height:calc(100vh - var(--topbar-h));display:grid;grid-template-columns:var(--sidebar-w) minmax(0,1fr)}.sidebar{position:sticky;top:var(--topbar-h);height:calc(100vh - var(--topbar-h));overflow-y:auto;border-right:1px solid var(--line);background:rgba(8,20,35,.94)}.sidebar-head{position:sticky;top:0;z-index:3;padding:20px 18px 16px;border-bottom:1px solid var(--line);background:rgba(8,20,35,.98)}.sidebar-kicker{color:var(--cyan);font-size:.68rem;font-weight:800;letter-spacing:.12em}.sidebar h2{margin:6px 0 0;font-size:1rem}.sidebar-close{display:none}.accordion{padding:10px 10px 26px}.chapter{margin-bottom:6px;border:1px solid transparent;border-radius:12px;overflow:hidden}.chapter.open{border-color:rgba(77,226,255,.10);background:rgba(77,226,255,.025)}.chapter-button{width:100%;padding:13px 12px;display:grid;grid-template-columns:40px 1fr 20px;gap:8px;align-items:center;text-align:left;color:#d7e5ef;border:0;background:transparent;cursor:pointer}.chapter-button:hover{background:rgba(255,255,255,.025)}.chapter-no{color:var(--cyan);font-family:Consolas,monospace;font-size:.78rem;font-weight:900}.chapter-arrow{color:#7f9bb1;transition:transform .18s}.chapter.open .chapter-arrow{transform:rotate(90deg)}.submenu{display:none;padding:4px 8px 9px 48px}.chapter.open .submenu{display:block}.submenu button{width:100%;margin:2px 0;padding:9px 10px;text-align:left;color:#9fb5c7;border:0;border-left:2px solid transparent;border-radius:7px;background:transparent;cursor:pointer}.submenu button:hover,.submenu button.active{color:#fff;border-left-color:var(--cyan);background:rgba(77,226,255,.06)}
.content{padding:28px;min-width:0}.content-breadcrumb{max-width:1040px;margin:0 auto 12px;color:#7590a6;font-size:.78rem}.content-card{max-width:1040px;margin:0 auto;padding:34px 40px 54px;border:1px solid var(--line);border-radius:22px;background:linear-gradient(180deg,rgba(255,255,255,.018),transparent),rgba(10,24,41,.88);box-shadow:0 22px 65px rgba(0,0,0,.24)}.chapter-label{color:var(--cyan);font-size:.72rem;font-weight:900;letter-spacing:.15em}.content-heading h1{margin:8px 0 12px;font-size:clamp(2rem,4vw,3.2rem);letter-spacing:-.04em}.content-heading p{max-width:850px;margin:0;color:var(--muted);line-height:1.8}.lesson-content{margin-top:38px}.lesson-block{padding:26px 0;border-top:1px solid var(--line)}.lesson-block h2{margin:0 0 14px;font-size:1.28rem}.lesson-block p,.content-list{color:#c7d5df;line-height:1.85}pre{overflow-x:auto;margin:16px 0;padding:20px;border:1px solid rgba(77,226,255,.10);border-radius:14px;background:#06101b}code{font-family:Consolas,"Courier New",monospace}.notice{margin-top:14px;padding:14px 16px;color:#ffdce4;border-left:4px solid var(--danger);border-radius:10px;background:rgba(255,138,165,.08)}
.resource-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin-top:20px}.resource-card{min-height:175px;padding:20px;display:flex;flex-direction:column;align-items:flex-start;color:var(--text);text-decoration:none;border:1px solid var(--line);border-radius:16px;background:linear-gradient(145deg,rgba(77,226,255,.045),transparent 55%),rgba(7,18,31,.76);transition:.18s}.resource-card:hover{transform:translateY(-3px);border-color:rgba(77,226,255,.32)}.resource-card strong,.download-card strong{margin-top:12px;font-size:1.12rem}.resource-card p,.download-card p{margin:8px 0 0;color:var(--muted);line-height:1.7}.resource-link{margin-top:auto;padding-top:18px;color:var(--cyan);font-size:.82rem;font-weight:800}.resource-badge{display:inline-flex;padding:5px 8px;color:var(--cyan);font-size:.65rem;font-weight:900;letter-spacing:.12em;border:1px solid rgba(77,226,255,.16);border-radius:999px;background:rgba(77,226,255,.06)}.resource-badge.desktop{color:var(--green);border-color:rgba(101,239,189,.16);background:rgba(101,239,189,.06)}.download-card{margin-top:20px;padding:20px 22px;display:flex;align-items:center;justify-content:space-between;gap:22px;color:var(--text);text-decoration:none;border:1px solid var(--line);border-radius:16px;background:linear-gradient(135deg,rgba(101,239,189,.055),transparent 58%),rgba(7,18,31,.76);transition:.18s}.download-card:hover{transform:translateY(-2px);border-color:rgba(101,239,189,.30)}.download-card>div{display:flex;flex-direction:column;align-items:flex-start}.download-button{flex:0 0 auto;padding:11px 14px;color:#05141c;font-size:.84rem;font-weight:900;border-radius:10px;background:linear-gradient(135deg,var(--green),#b7f9df)}.sidebar-overlay{display:none}
@media(max-width:900px){.brand{min-width:0}.brand small{display:none}.topnav{display:none}.mobile-menu-btn{display:block}.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;top:var(--topbar-h);left:0;z-index:150;width:min(86vw,320px);height:calc(100vh - var(--topbar-h));transform:translateX(-105%);transition:transform .22s;box-shadow:18px 0 50px rgba(0,0,0,.28)}.sidebar.open{transform:translateX(0)}.sidebar-head{display:flex;align-items:center;justify-content:space-between}.sidebar-close{display:grid;place-items:center;width:36px;height:36px;color:#fff;font-size:1.4rem;border:1px solid var(--line);border-radius:9px;background:rgba(255,255,255,.03);cursor:pointer}.sidebar-overlay{position:fixed;inset:var(--topbar-h) 0 0;z-index:140;background:rgba(0,0,0,.46)}.sidebar-overlay.show{display:block}.content{padding:18px 14px 30px}.content-card{padding:26px 20px 42px;border-radius:18px}}
@media(max-width:680px){.resource-grid{grid-template-columns:1fr}.download-card{align-items:flex-start;flex-direction:column}.download-button{width:100%;text-align:center}}
@media(max-width:520px){:root{--topbar-h:64px}.topbar{padding:0 14px}.brand-logo{width:36px;height:36px}.brand strong{font-size:.92rem}.content-heading h1{font-size:2rem}.content-card{padding:22px 16px 36px}}


/* ===== 歷屆試題 ===== */
.exam-title-row{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:16px}
.exam-title-row h2{margin:0}.exam-title-row>span{color:#7893aa;font-size:.72rem;padding:5px 9px;border:1px solid var(--line);border-radius:999px}
.exam-list{display:grid;gap:18px}.exam-card{padding:22px;border:1px solid rgba(77,226,255,.14);border-radius:16px;background:linear-gradient(145deg,rgba(77,226,255,.025),transparent 42%),rgba(5,15,27,.68)}
.exam-meta{display:flex;align-items:center;flex-wrap:wrap;gap:8px 10px;margin-bottom:16px;color:#8da6ba;font-size:.74rem}.exam-id{padding:4px 8px;color:#06131d;background:var(--cyan);border-radius:7px;font-family:Consolas,monospace;font-weight:900}.exam-unit{margin-left:auto;color:#86dff1}
.exam-question{white-space:pre-wrap;color:#eff8ff;line-height:1.78;font-size:.98rem;font-family:"Microsoft JhengHei","Noto Sans TC",system-ui,sans-serif}
.exam-options{display:grid;gap:9px;margin-top:18px}.exam-option{display:grid;grid-template-columns:32px minmax(0,1fr);gap:10px;align-items:start;padding:11px 12px;border:1px solid rgba(255,255,255,.055);border-radius:10px;background:rgba(255,255,255,.018)}.exam-option b{width:26px;height:26px;display:grid;place-items:center;border-radius:7px;color:var(--cyan);background:rgba(77,226,255,.08)}.exam-option span{white-space:pre-wrap;color:#c6d6e2;line-height:1.62;overflow-wrap:anywhere}
.exam-answer{margin-top:16px;border-top:1px solid rgba(77,226,255,.10);padding-top:13px}.exam-answer summary{width:max-content;color:#9ddff0;cursor:pointer;font-weight:700;font-size:.84rem}.exam-answer div{margin-top:10px;padding:10px 12px;border-left:3px solid var(--green);border-radius:8px;background:rgba(101,239,189,.06);color:#c9f5e4}.exam-answer strong{color:var(--green);font-size:1.08rem}
.exam-empty{padding:18px;text-align:center;color:#9eb3c6;border:1px dashed rgba(158,179,198,.23);border-radius:12px;background:rgba(255,255,255,.018)}.exam-only-block{border-top:0;padding-top:0}
@media(max-width:680px){.exam-card{padding:16px}.exam-unit{width:100%;margin-left:0}.exam-question{font-size:.94rem}.exam-option{grid-template-columns:28px minmax(0,1fr);padding:10px}.exam-title-row{align-items:flex-start;flex-direction:column}}


/* ===== 模擬試題：沿用歷屆試題版型，僅以識別色區分 ===== */
.exam-card.mock-card {
  border-color: rgba(101, 239, 189, 0.16);
}
.exam-id.mock-id {
  background: linear-gradient(135deg, #65efbd, #b7f9df);
  color: #04151b;
}


/* ===== 教學內容補充 ===== */
.lesson-block h3 {
  margin: 28px 0 12px;
  color: #e7f5ff;
  font-size: 1.08rem;
}

.content-list {
  color: #c7d5df;
  line-height: 1.85;
}

.tutorial-img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 18px 0 34px;
  border: 1px solid rgba(77, 226, 255, 0.16);
  border-radius: 12px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.22);
}


/* ===== 第二層教材目錄：例如 4.5 常見問題 ===== */
.submenu-group{
  margin:2px 0;
}

.submenu .submenu-group-button{
  display:grid;
  grid-template-columns:minmax(0,1fr) 18px;
  gap:8px;
  align-items:center;
}

.submenu-group-arrow{
  color:#7895aa;
  font-size:.72rem;
  transition:transform .18s ease;
}

.submenu-group.open > .submenu-group-button .submenu-group-arrow{
  transform:rotate(90deg);
}

.submenu-children{
  display:none;
  margin:2px 0 5px 12px;
  padding-left:10px;
  border-left:1px solid rgba(77,226,255,.12);
}

.submenu-group.open > .submenu-children{
  display:block;
}

.submenu-children button{
  font-size:.92rem;
  padding-top:8px;
  padding-bottom:8px;
}


/* ===== 運算子教學表格 ===== */
.table-wrap{
  width:100%;
  overflow-x:auto;
  margin:18px 0 8px;
  border:1px solid rgba(77,226,255,.12);
  border-radius:14px;
  background:rgba(5,15,27,.45);
}

.operator-table{
  width:100%;
  min-width:760px;
  border-collapse:collapse;
  color:#cbd9e4;
  line-height:1.55;
}

.operator-table th,
.operator-table td{
  padding:12px 14px;
  text-align:left;
  vertical-align:top;
  border-right:1px solid rgba(77,226,255,.08);
  border-bottom:1px solid rgba(77,226,255,.08);
}

.operator-table th:last-child,
.operator-table td:last-child{
  border-right:0;
}

.operator-table tbody tr:last-child td{
  border-bottom:0;
}

.operator-table thead th{
  position:sticky;
  top:0;
  color:#eaf8ff;
  font-size:.84rem;
  white-space:nowrap;
  background:#0a1a2b;
}

.operator-table tbody tr:hover{
  background:rgba(77,226,255,.035);
}

.operator-table code{
  color:#aeeeff;
  white-space:nowrap;
}

.precedence-table td:first-child{
  color:var(--cyan);
  font-weight:800;
  white-space:nowrap;
}