:root {
    --app-bg: #f5f7fb;
    --app-card: #ffffff;
    --app-border: #dfe5ef;
    --app-text: #1f2937;
    --app-muted: #6b7280;
    --app-primary: #315efb;
    --app-primary-dark: #173bbd;
}

html,
body {
    min-height: 100%;
}

body {
    background: var(--app-bg);
    color: var(--app-text);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", "Microsoft JhengHei", Arial, sans-serif;
}

.app-navbar {
    background: linear-gradient(135deg, var(--app-primary), var(--app-primary-dark));
    box-shadow: 0 10px 24px rgba(17, 24, 39, 0.16);
}

.lang-select {
    min-width: 150px;
}

.hero-card,
.tool-card,
.info-card {
    background: var(--app-card);
    border: 1px solid var(--app-border);
    border-radius: 18px;
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.06);
}

.hero-card {
    padding: 22px;
}

.tool-card {
    overflow: hidden;
}

.info-card {
    padding: 18px;
}

.tool-card-header {
    min-height: 86px;
    padding: 16px;
    border-bottom: 1px solid var(--app-border);
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
}

.CodeMirror {
    height: 560px;
    font-family: Consolas, Monaco, "Courier New", monospace;
    font-size: 14px;
    line-height: 1.55;
}

.json-editor-box {
    height: 560px;
}

.jsoneditor {
    border: 0 !important;
}

.jsoneditor-menu {
    background: var(--app-primary) !important;
    border-bottom: 1px solid var(--app-primary) !important;
}

.alert {
    border-radius: 14px;
}

.feature-list {
    padding-left: 1.1rem;
}

.app-footer {
    background: #ffffff;
    border-top: 1px solid var(--app-border);
}

.btn {
    border-radius: 10px;
}

.btn-group-sm > .btn {
    border-radius: 9px;
}

@media (max-width: 1199.98px) {
    .CodeMirror,
    .json-editor-box {
        height: 460px;
    }
}

@media (max-width: 575.98px) {
    .hero-card {
        padding: 16px;
    }

    .tool-card-header {
        min-height: auto;
        padding: 14px;
    }

    .tool-card-header > div,
    .tool-card-header > button,
    .tool-card-header .btn-group {
        width: 100%;
    }

    .tool-card-header .btn,
    .tool-card-header .btn-group .btn {
        width: 100%;
    }

    .tool-card-header .btn-group {
        display: grid;
        grid-template-columns: 1fr 1fr;
    }

    .CodeMirror,
    .json-editor-box {
        height: 380px;
    }

    .navbar-brand {
        font-size: 1rem;
    }

    .lang-select {
        min-width: 118px;
    }
}