:root {
    color: #303038;
    background: #ffffff;
    font-family: Arial, Helvetica, sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: #ffffff;
}

.quadric-page {
    width: min(1500px, 100%);
    margin: 0 auto;
    padding: 12px 20px 24px;
}

.quadric-header {
    padding: 2px 0 8px;
    text-align: center;
}

.quadric-header h1 {
    margin: 0;
    color: #33323d;
    font-size: clamp(1.55rem, 2.2vw, 2.15rem);
    font-weight: 500;
    letter-spacing: 0.01em;
}

.quadric-header p {
    margin: 4px 0 0;
    color: #777681;
    font-size: 0.92rem;
}

.quadric-layout {
    display: grid;
    grid-template-columns: minmax(0, 3fr) minmax(260px, 1fr);
    gap: 22px;
    align-items: start;
}

.visualization-column {
    min-width: 0;
}

.surface-shell {
    height: clamp(430px, 55vh, 580px);
    min-height: 430px;
    border: 1px solid #ececf0;
    border-radius: 8px;
    overflow: hidden;
}

.surface-graph {
    width: 100%;
    height: 100%;
    min-height: 100%;
}

.level-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    margin-top: 10px;
}

.level-graph {
    height: clamp(185px, 24vh, 230px);
    border: 1px solid #ececf0;
    border-radius: 7px;
    overflow: hidden;
}

.control-column {
    min-width: 0;
}

.control-panel {
    position: sticky;
    top: 18px;
    padding: 24px 22px 22px;
    border: 1px solid #e5e5ea;
    border-radius: 9px;
    background: #fbfbfc;
    box-shadow: 0 4px 18px rgba(45, 43, 60, 0.055);
}

.control-equation {
    margin-bottom: 10px;
    color: #363441;
    font-family: Georgia, "Times New Roman", serif;
    font-size: 1.38rem;
    text-align: center;
}

#parameter-description {
    margin-bottom: 28px;
    text-align: center;
}

.parameter-value {
    color: #555064;
    font-size: 1.08rem;
    font-weight: 600;
}

.parameter-family {
    margin-top: 3px;
    color: #777381;
    font-size: 0.88rem;
}

.control-label {
    display: block;
    margin-bottom: 13px;
    color: #4c4958;
    font-size: 0.92rem;
    font-weight: 600;
}

.important-cases {
    display: grid;
    gap: 8px;
    margin-top: 34px;
    padding-top: 16px;
    border-top: 1px solid #e4e3e8;
}

.important-cases div {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    color: #4b4855;
    font-size: 0.82rem;
}

.important-cases small {
    color: #85818c;
    text-align: right;
}

.control-note {
    margin: 22px 0 0;
    color: #77747e;
    font-size: 0.8rem;
    line-height: 1.45;
}

@media (max-width: 820px) {
    .quadric-page {
        padding: 10px 10px 22px;
    }

    .quadric-layout {
        grid-template-columns: 1fr;
    }

    .control-column {
        grid-row: 1;
    }

    .control-panel {
        position: static;
    }

    .level-grid {
        grid-template-columns: 1fr;
    }

    .level-graph {
        height: 250px;
    }
}