* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --background: #08090c;
    --panel: #101218;
    --panel-hover: #151821;
    --border: #242832;
    --text: #f4f7fb;
    --muted: #8b93a3;
    --accent: #6d7cff;
    --accent-hover: #8290ff;
    --success: #35d39a;
}

body {
    min-height: 100vh;

    background:
        radial-gradient(
            circle at 50% -20%,
            rgba(109, 124, 255, 0.18),
            transparent 40%
        ),
        var(--background);

    color: var(--text);

    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;
}


/* ---------- HEADER ---------- */

header {
    width: 100%;
    padding: 28px 6%;

    border-bottom: 1px solid var(--border);

    display: flex;
    align-items: center;
    justify-content: space-between;

    background: rgba(8, 9, 12, 0.72);

    backdrop-filter: blur(14px);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-mark {
    width: 34px;
    height: 34px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 10px;

    background:
        linear-gradient(
            135deg,
            var(--accent),
            #9b6dff
        );

    font-weight: 800;
}

header h1 {
    font-size: 19px;
    font-weight: 650;
    letter-spacing: -0.4px;
}

header p {
    color: var(--muted);
    font-size: 13px;
}


/* ---------- NAVIGATION ---------- */

.tool-nav {
    display: flex;
    gap: 8px;

    padding: 14px 6%;

    border-bottom: 1px solid var(--border);

    background: rgba(8, 9, 12, 0.72);
}

.tool-tab {
    border: 1px solid transparent;

    background: transparent;

    color: var(--muted);

    padding: 9px 15px;

    border-radius: 9px;

    font-size: 13px;
    font-weight: 600;

    cursor: pointer;

    transition:
        background 0.2s ease,
        color 0.2s ease,
        border-color 0.2s ease;
}

.tool-tab:hover {
    background: var(--panel-hover);
    color: var(--text);
}

.tool-tab.active {
    background: var(--panel);
    border-color: var(--border);
    color: var(--text);
}


/* ---------- MAIN ---------- */

main {
    width: min(1400px, 88%);

    margin: 70px auto;
}

.hero {
    margin-bottom: 35px;
}

.hero h2 {
    font-size: clamp(32px, 5vw, 52px);

    letter-spacing: -2px;

    line-height: 1.05;
}

.hero span {
    background:
        linear-gradient(
            90deg,
            #ffffff,
            #8793ff
        );

    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    margin-top: 15px;

    color: var(--muted);

    font-size: 16px;
}


/* ---------- EDITORS ---------- */

.editor-container {
    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 18px;
}

.editor {
    background: rgba(16, 18, 24, 0.86);

    border: 1px solid var(--border);

    border-radius: 16px;

    overflow: hidden;

    box-shadow:
        0 20px 60px rgba(0, 0, 0, 0.25);

    transition:
        border-color 0.2s ease,
        transform 0.2s ease;
}

.editor:focus-within {
    border-color: rgba(109, 124, 255, 0.6);
}

.editor-header {
    height: 48px;

    padding: 0 16px;

    display: flex;
    align-items: center;
    justify-content: space-between;

    border-bottom: 1px solid var(--border);
}

.editor-header span:first-child {
    color: var(--text);

    font-size: 13px;
    font-weight: 600;
}

.status {
    color: var(--success);

    font-size: 12px;
}

textarea {
    width: 100%;

    height: 420px;

    padding: 20px;

    resize: vertical;

    border: none;
    outline: none;

    background: transparent;

    color: #dce2ed;

    font-family:
        "JetBrains Mono",
        "Cascadia Code",
        Consolas,
        monospace;

    font-size: 14px;

    line-height: 1.7;
}

textarea::placeholder {
    color: #555d6d;
}


/* ---------- CONTROLS ---------- */

.controls {
    display: flex;

    align-items: center;
    justify-content: space-between;

    margin-top: 20px;
}

.button-group {
    display: flex;

    gap: 10px;
}

button {
    border: 1px solid var(--border);

    background: var(--panel);

    color: var(--text);

    padding: 11px 18px;

    border-radius: 10px;

    font-size: 13px;
    font-weight: 600;

    cursor: pointer;

    transition:
        background 0.2s ease,
        border-color 0.2s ease,
        transform 0.15s ease;
}

button:hover {
    background: var(--panel-hover);

    border-color: #353b49;
}

button:active {
    transform: translateY(1px);
}

.primary {
    border-color: transparent;

    background:
        linear-gradient(
            135deg,
            var(--accent),
            #8b6dff
        );

    box-shadow:
        0 8px 25px rgba(109, 124, 255, 0.2);
}

.primary:hover {
    background:
        linear-gradient(
            135deg,
            var(--accent-hover),
            #997eff
        );
}


/* ---------- DIAGNOSTICS ---------- */

.diagnostics {
    display: flex;

    align-items: center;

    gap: 0;

    margin-top: 14px;

    background: rgba(16, 18, 24, 0.75);

    border: 1px solid var(--border);

    border-radius: 12px;

    overflow: hidden;
}

.diagnostic-item {
    display: flex;

    align-items: center;

    gap: 8px;

    padding: 12px 18px;

    border-right: 1px solid var(--border);
}

.diagnostic-item:last-child {
    border-right: none;
}

.diagnostic-label {
    color: #666f80;

    font-size: 10px;

    font-weight: 700;

    letter-spacing: 0.8px;
}

.diagnostic-value {
    color: var(--text);

    font-size: 12px;

    font-family:
        "JetBrains Mono",
        "Cascadia Code",
        Consolas,
        monospace;
}

.diagnostic-valid {
    color: var(--success);
}

.diagnostic-invalid {
    color: #ff6b7a;
}


/* ---------- ERROR PANEL ---------- */

.error-panel {
    display: none;

    margin: 0 14px 14px;

    padding: 12px 14px;

    border: 1px solid rgba(255, 90, 110, 0.3);

    border-radius: 10px;

    background: rgba(255, 70, 90, 0.06);
}

.error-title {
    display: flex;

    align-items: center;

    gap: 7px;

    color: #ff7180;

    font-size: 12px;

    font-weight: 700;
}

.error-message {
    margin-top: 6px;

    color: #aeb5c2;

    font-size: 12px;

    font-family:
        "JetBrains Mono",
        "Cascadia Code",
        Consolas,
        monospace;

    line-height: 1.5;
}


/* ---------- SUCCESS PANEL ---------- */

.success-panel {
    display: none;

    margin: 0 14px 14px;

    padding: 12px 14px;

    border: 1px solid rgba(53, 211, 154, 0.3);

    border-radius: 10px;

    background: rgba(53, 211, 154, 0.06);
}

.success-title {
    display: flex;

    align-items: center;

    gap: 7px;

    color: var(--success);

    font-size: 12px;

    font-weight: 700;
}

.success-message {
    margin-top: 6px;

    color: #aeb5c2;

    font-size: 12px;

    font-family:
        "JetBrains Mono",
        "Cascadia Code",
        Consolas,
        monospace;

    line-height: 1.5;
}


/* ---------- CSV TOOL ---------- */

.csv-tool {
    display: none;
}


/* ---------- RESPONSIVE ---------- */

@media (max-width: 900px) {

    main {
        width: 92%;

        margin: 45px auto;
    }

    .editor-container {
        grid-template-columns: 1fr;
    }

    textarea {
        height: 320px;
    }

    .controls {
        flex-direction: column;

        align-items: stretch;

        gap: 12px;
    }

    .button-group {
        width: 100%;
    }

    button {
        flex: 1;
    }
}


@media (max-width: 700px) {

    .diagnostics {
        flex-wrap: wrap;
    }

    .diagnostic-item {
        flex: 1;

        min-width: 50%;
    }
}


@media (max-width: 520px) {

    header {
        padding: 22px 5%;
    }

    .tool-nav {
        padding: 12px 5%;
    }

    main {
        width: 94%;
    }

    .hero h2 {
        font-size: 34px;
    }

    .diagnostic-item {
        min-width: 100%;
    }

    .button-group {
        flex-wrap: wrap;
    }

    button {
        min-width: 45%;
    }
}