:root {
    /* 白色系主题配色 */
    --bg: #f4f7f6;
    --surface: #ffffff;
    --render-bg: #ffffff;
    --source-bg: #f8f9fa;
    --accent: #00a870; 
    --accent-dim: rgba(0, 168, 112, 0.08);
    --gold: #d49a00;
    --gold-dim: rgba(212, 154, 0, 0.08);
    --fg: #2c3e50;
    --fg-dim: #6c757d;
    --fg-muted: #868e96;
    --border: #e9ecef;
    
    /* 按钮色块区分 */
    --fn-bg: #e6fcf5;
    --fn-hover: #c3fae8;
    --op-bg: #fff9db;
    --op-hover: #ffec99;
    --nm-bg: #ffffff;
    --nm-hover: #f1f3f5;
    --err: #fa5252;
    
    --font-ui: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
    --font-mono: "SF Mono", "Cascadia Code", "Fira Code", Consolas, "Liberation Mono", Menlo, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-ui); background: var(--bg); color: var(--fg); min-height: 100vh; }

body::before {
    content: ''; position: fixed; inset: 0; pointer-events: none; z-index: 0;
    background: radial-gradient(ellipse at 15% 10%, rgba(0, 168, 112, 0.04) 0%, transparent 50%),
                radial-gradient(ellipse at 85% 90%, rgba(212, 154, 0, 0.03) 0%, transparent 45%);
}

/* 整体放大宽度 */
.app { position: relative; z-index: 1; max-width: 600px; margin: 0 auto; }

.render-zone {
    background: var(--render-bg); border: 1px solid var(--border); border-radius: 16px 16px 0 0;
    padding: 22px 24px 18px; min-height: 100px; position: relative; overflow: hidden;
}
.render-zone::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
    background: linear-gradient(90deg, transparent 5%, var(--accent) 50%, transparent 95%); opacity: 0.5;
}
.render-zone::after {
    content: ''; position: absolute; inset: 0; pointer-events: none;
    background-image: linear-gradient(rgba(0, 0, 0, 0.02) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(0, 0, 0, 0.02) 1px, transparent 1px);
    background-size: 24px 24px;
}

.ztag {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: 12px; font-weight: 600; color: var(--fg-muted); letter-spacing: 2px; text-transform: uppercase;
    position: relative; z-index: 1; margin-bottom: 8px;
}
.ztag .dot { width: 5px; height: 5px; border-radius: 50%; background: var(--accent); animation: pulse 2.5s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: 0.4; transform: scale(0.8); } 50% { opacity: 1; transform: scale(1.2); } }
.ztag .ico { font-size: 14px; line-height: 1; opacity: 0.8; }

.render-box {
    position: relative; z-index: 1; display: flex; align-items: center; justify-content: flex-end;
    min-height: 54px; overflow-x: auto; scrollbar-width: none; padding: 4px 0;
}
.render-box::-webkit-scrollbar { display: none; }
/* 渲染预览字体大幅度放大 */
.render-box .katex { font-size: 2.2rem; }
.ph { color: var(--fg-muted); font-size: 1rem; font-weight: 400; }

.input-zone {
    background: var(--source-bg); border-left: 1px solid var(--border); border-right: 1px solid var(--border);
    padding: 12px 20px 16px; position: relative;
}
.input-zone::before {
    content: ''; position: absolute; top: -5px; left: 50%; transform: translateX(-50%);
    border-left: 5px solid transparent; border-right: 5px solid transparent; border-top: 5px solid var(--border);
}

.input-row { display: flex; align-items: center; gap: 10px; }
.src-in {
    flex: 1; background: transparent; border: none; outline: none;
    color: var(--accent); font-family: var(--font-mono);
    /* 输入框字体放大 */
    font-size: 1.2rem; font-weight: 600; letter-spacing: 0.5px;
    caret-color: var(--accent); padding: 12px 0; scrollbar-width: none;
}
.src-in::-webkit-scrollbar { display: none; }
.src-in::placeholder { color: var(--fg-muted); opacity: 0.5; font-weight: 400; }

.eq-btn {
    /* 按钮放大 */
    width: 52px; height: 52px; border-radius: 14px; border: none; flex-shrink: 0;
    background: linear-gradient(135deg, var(--accent), #00cf8a);
    color: #ffffff; font-size: 1.6rem; font-weight: 700; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 14px rgba(0, 168, 112, 0.25); transition: all 0.15s;
}
.eq-btn:hover { box-shadow: 0 6px 20px rgba(0, 168, 112, 0.35); transform: translateY(-1px); }
.eq-btn:active { transform: translateY(0) scale(0.95); }

.res-line {
    display: flex; align-items: center; justify-content: flex-end; gap: 8px;
    min-height: 32px; padding-top: 4px; overflow-x: auto; scrollbar-width: none;
}
.res-line::-webkit-scrollbar { display: none; }
.res-eq { color: var(--fg-muted); font-family: var(--font-mono); font-size: 1.1rem; }
/* 结果字体放大 */
.res-val { font-family: var(--font-mono); font-size: 1.5rem; font-weight: 600; color: var(--gold); white-space: nowrap; }
.res-val.pop { animation: rpop 0.4s cubic-bezier(0.34, 1.56, 0.64, 1); }
@keyframes rpop { 0% { opacity: 0; transform: translateY(5px) scale(0.93); } 100% { opacity: 1; transform: none; } }
.res-err { color: var(--err); font-size: 0.9rem; }

.toolbar {
    background: var(--surface); border: 1px solid var(--border); border-top: none;
    padding: 8px 16px; display: flex; gap: 8px; align-items: center;
}
.tbtn {
    /* 顶部工具栏按钮放大 */
    padding: 8px 14px; border-radius: 8px; border: 1px solid var(--border);
    background: var(--nm-bg); color: var(--fg-muted);
    font-size: 0.9rem; font-weight: 600; cursor: pointer; transition: all 0.12s; letter-spacing: 0.5px;
}
.tbtn:hover { background: var(--nm-hover); color: var(--fg); }
.tbtn:active { transform: scale(0.95); }
.tbtn.on { border-color: rgba(0, 168, 112, 0.4); color: var(--accent); background: var(--accent-dim); }
.tbtn.on:hover { border-color: rgba(0, 168, 112, 0.6); }
.tbtn.rad-on { border-color: rgba(212, 154, 0, 0.4); color: var(--gold); background: var(--gold-dim); }
.tbtn.rad-on:hover { border-color: rgba(212, 154, 0, 0.6); }
.tbtn.dng { color: var(--err); border-color: rgba(250, 82, 82, 0.2); }
.tbtn.dng:hover { background: rgba(250, 82, 82, 0.08); }
.tsp { flex: 1; }

.panel {
    background: var(--source-bg); border-left: 1px solid var(--border); border-right: 1px solid var(--border);
    padding: 12px 14px 16px;
}
/* 键盘间距加大 */
.pg { display: grid; grid-template-columns: repeat(7, 1fr); gap: 8px; }
.psp { height: 4px; border-radius: 2px; background: var(--border); opacity: 0.6; }

.pb {
    /* 键盘高度加大，增加浅色模式下的微阴影让按钮更立体 */
    height: 48px; border-radius: 10px; border: 1px solid var(--border);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.02);
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    transition: all 0.12s; position: relative; overflow: hidden;
}
.pb:active { transform: scale(0.92); box-shadow: none; }
.pb .katex { font-size: 1rem; pointer-events: none; } /* 符号字号放大 */

.pb.fn { background: var(--fn-bg); color: var(--accent); border-color: transparent; }
.pb.fn:hover { background: var(--fn-hover); transform: translateY(-1px); }
.pb.fn .katex { color: var(--accent) !important; }

.pb.op { background: var(--op-bg); color: var(--gold); border-color: transparent; }
.pb.op:hover { background: var(--op-hover); transform: translateY(-1px); }
.pb.op .katex { color: var(--gold) !important; }

/* 数字键盘字号加大 */
.pb.nm { background: var(--nm-bg); color: var(--fg); font-family: var(--font-mono); font-size: 1.25rem; font-weight: 600; }
.pb.nm:hover { background: var(--nm-hover); transform: translateY(-1px); }

.ripple {
    position: absolute; border-radius: 50%; background: rgba(0, 0, 0, 0.06);
    transform: scale(0); animation: rip 0.45s ease-out forwards; pointer-events: none;
}
@keyframes rip { to { transform: scale(3.5); opacity: 0; } }

.ex-zone {
    background: var(--surface); border: 1px solid var(--border); border-top: none;
    border-radius: 0 0 16px 16px; padding: 16px 20px 32px;
}
.ex-cat {
    font-size: 12px; font-weight: 600; color: var(--fg-muted); letter-spacing: 1.5px;
    text-transform: uppercase; padding: 14px 4px 8px; opacity: 0.8;
}
.ex-cat:first-child { padding-top: 4px; }
.ex-list { display: flex; flex-direction: column; gap: 8px; }

.ex-card {
    /* 列表卡片放大 */
    padding: 12px 14px; background: var(--nm-bg); border: 1px solid var(--border);
    border-radius: 12px; cursor: pointer; transition: all 0.15s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.015);
}
.ex-card:hover { border-color: rgba(0, 168, 112, 0.4); background: var(--nm-hover); transform: translateX(3px); box-shadow: 0 4px 8px rgba(0,0,0,0.03); }
.ex-card:active { transform: translateX(1px) scale(0.98); }

.ex-top { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.ex-desc { font-size: 0.95rem; color: var(--fg-dim); width: 100%; margin-bottom: 6px; font-weight: 400; }
.ex-src {
    font-family: var(--font-mono); font-size: 0.95rem; font-weight: 600;
    color: var(--accent); padding: 4px 8px;
    background: rgba(0, 168, 112, 0.08); border-radius: 6px; border-left: 3px solid rgba(0, 168, 112, 0.6);
    white-space: nowrap; flex-shrink: 0;
}
.ex-arr { color: var(--border); font-size: 0.8rem; flex-shrink: 0; }
.ex-ktx { display: flex; align-items: center; flex: 1; min-width: 0; overflow: hidden; }
.ex-ktx .katex { font-size: 1.1rem; }
.ex-rv {
    font-family: var(--font-mono); font-size: 1.05rem; font-weight: 600;
    color: var(--gold); white-space: nowrap; flex-shrink: 0;
}

/* 针对手机端也同步放大 */
@media (max-width: 480px) {
    .pb { height: 42px; }
    .pb .katex { font-size: 0.9rem; }
    .pb.nm { font-size: 1.1rem; }
    .render-box .katex { font-size: 1.8rem; }
    .ex-src { font-size: 0.85rem; padding: 3px 6px; }
    .ex-ktx .katex { font-size: 1rem; }
    .ex-rv { font-size: 0.95rem; }
    .input-zone { padding: 10px 14px 12px; }
    .eq-btn { width: 44px; height: 44px; font-size: 1.3rem; }
}

@media(prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; } }

/* =========================================
   从 HTML 中提取的布局类
   ========================================= */
.layout-wrapper {
    display: flex;
    min-height: 100vh;
    background-color: var(--bg);
}

.calculator-container {
    margin-left: 240px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.main-content {
    padding: 40px;
    flex: 1;
}

.page-title {
    margin-bottom: 30px;
    color: var(--fg);
    font-size: 2.2rem;
    font-weight: bold;
}