:root {
            --bg-color: #090b10;
            --panel: #11151d;
            --panel-strong: #151b26;
            --field: #090d14;
            --field-raised: #0e1420;
            --text-primary: #f8fafc;
            --text-secondary: #9aa7b8;
            --text-muted: #687589;
            --accent: #19c6b3;
            --accent-hover: #5eead4;
            --accent-soft: rgba(25, 198, 179, 0.13);
            --amber: #f5b84b;
            --coral: #f07167;
            --border: rgba(148, 163, 184, 0.18);
            --border-strong: rgba(148, 163, 184, 0.28);
            --error: #fb7185;
            --error-soft: rgba(251, 113, 133, 0.12);
            --shadow: 0 30px 90px rgba(0, 0, 0, 0.42);
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            -webkit-tap-highlight-color: transparent;
        }

        body {
            background:
                linear-gradient(135deg, rgba(25, 198, 179, 0.16), transparent 34%),
                linear-gradient(315deg, rgba(240, 113, 103, 0.13), transparent 32%),
                linear-gradient(180deg, #10131b 0%, var(--bg-color) 64%);
            color: var(--text-primary);
            font-family: Inter, 'Segoe UI', system-ui, -apple-system, sans-serif;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 18px;
            padding-top: max(18px, env(safe-area-inset-top));
            padding-bottom: max(18px, env(safe-area-inset-bottom));
        }

        button,
        input,
        select {
            font: inherit;
        }

        .container {
            background:
                linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent 42%),
                var(--panel);
            border: 1px solid var(--border);
            border-radius: 8px;
            box-shadow: var(--shadow);
            width: 100%;
            max-width: 860px;
            overflow: hidden;
            position: relative;
        }

        .container::before {
            content: "";
            position: absolute;
            inset: 0 0 auto;
            height: 3px;
            background: linear-gradient(90deg, var(--accent), var(--amber), var(--coral));
        }

        header {
            align-items: flex-start;
            border-bottom: 1px solid var(--border);
            display: grid;
            grid-template-columns: auto minmax(0, 1fr) auto;
            justify-content: initial;
            gap: 1rem;
            padding: 1.35rem 1.5rem 1.1rem;
        }

        .back-btn {
            align-items: center;
            align-self: flex-start;
            background: var(--field-raised);
            border: 1px solid var(--border);
            border-radius: 8px;
            color: var(--text-secondary);
            display: inline-flex;
            height: 38px;
            justify-content: center;
            text-decoration: none;
            transition: background-color 0.18s, border-color 0.18s, color 0.18s;
            width: 38px;
        }

        .back-btn:hover,
        .back-btn:focus-visible {
            background: var(--accent-soft);
            border-color: rgba(94, 234, 212, 0.38);
            color: var(--accent-hover);
        }

        .back-btn:focus-visible {
            outline: 3px solid rgba(94, 234, 212, 0.28);
            outline-offset: 3px;
        }

        .back-btn svg {
            height: 18px;
            width: 18px;
        }

        h1 {
            color: var(--text-primary);
            font-size: 1.6rem;
            font-weight: 760;
            letter-spacing: 0;
            line-height: 1.12;
            margin-bottom: 0.38rem;
        }

        p.subtitle {
            color: var(--text-secondary);
            font-size: 0.9rem;
        }

        .status-line {
            align-items: center;
            color: var(--text-muted);
            display: flex;
            flex: 0 0 auto;
            font-size: 0.82rem;
            gap: 0.45rem;
            min-height: 1.25rem;
            padding-top: 0.15rem;
        }

        .status-dot {
            background: var(--accent);
            border-radius: 50%;
            box-shadow: 0 0 0 4px rgba(25, 198, 179, 0.12);
            height: 7px;
            width: 7px;
        }

        .status-line.error .status-dot {
            background: var(--error);
            box-shadow: 0 0 0 4px rgba(251, 113, 133, 0.12);
        }

        .workspace {
            display: grid;
            gap: 1rem;
            grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
            padding: 1.25rem;
        }

        .input-group {
            background:
                linear-gradient(180deg, rgba(255, 255, 255, 0.035), transparent),
                var(--panel-strong);
            border: 1px solid var(--border);
            border-radius: 8px;
            min-width: 0;
            padding: 1rem;
            position: relative;
        }

        label {
            align-items: center;
            color: var(--text-secondary);
            display: flex;
            font-size: 0.76rem;
            font-weight: 760;
            justify-content: space-between;
            letter-spacing: 0;
            margin-bottom: 0.8rem;
            text-transform: uppercase;
        }

        label span:last-child {
            color: var(--accent-hover);
            font-size: 0.72rem;
            text-transform: none;
        }

        .input-wrapper {
            display: grid;
            gap: 0.7rem;
            grid-template-columns: minmax(0, 1fr) 112px;
        }

        input,
        select {
            background-color: var(--field);
            border: 1px solid var(--border);
            border-radius: 8px;
            color: var(--text-primary);
            outline: none;
            transition: border-color 0.18s, box-shadow 0.18s, background-color 0.18s;
        }

        input {
            font-family: 'Cascadia Mono', 'SFMono-Regular', Consolas, 'Courier New', monospace;
            font-size: 1.35rem;
            font-weight: 650;
            min-height: 58px;
            min-width: 0;
            padding: 0 0.9rem;
            width: 100%;
        }

        input::placeholder {
            color: rgba(154, 167, 184, 0.46);
        }

        input:focus,
        select:focus {
            border-color: rgba(94, 234, 212, 0.78);
            box-shadow: 0 0 0 3px rgba(25, 198, 179, 0.14);
        }

        input.invalid {
            background: var(--error-soft);
            border-color: rgba(251, 113, 133, 0.74);
            color: #fecdd3;
        }

        select {
            appearance: none;
            background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%239aa7b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
            background-position: right 12px center;
            background-repeat: no-repeat;
            background-size: 16px;
            cursor: pointer;
            font-size: 0.94rem;
            font-weight: 700;
            min-height: 58px;
            padding: 0 2rem 0 0.85rem;
        }

        select option {
            background-color: #111827;
            color: var(--text-primary);
        }

        .base-shortcuts {
            display: grid;
            gap: 0.45rem;
            grid-template-columns: repeat(4, minmax(0, 1fr));
            margin-top: 0.75rem;
        }

        .preset-btn {
            background: var(--field-raised);
            border: 1px solid var(--border);
            border-radius: 8px;
            color: var(--text-secondary);
            cursor: pointer;
            font-size: 0.72rem;
            font-weight: 760;
            min-height: 34px;
            transition: background-color 0.18s, border-color 0.18s, color 0.18s;
        }

        .preset-btn:hover,
        .preset-btn.active {
            background: var(--accent-soft);
            border-color: rgba(94, 234, 212, 0.38);
            color: var(--accent-hover);
        }

        .swap-container {
            align-items: center;
            display: flex;
            justify-content: center;
            padding-top: 2.25rem;
            z-index: 5;
        }

        .swap-btn,
        .copy-btn {
            align-items: center;
            border: none;
            cursor: pointer;
            display: flex;
            justify-content: center;
        }

        .swap-btn {
            background: linear-gradient(135deg, var(--accent), #2dd4bf);
            border-radius: 50%;
            box-shadow: 0 14px 30px rgba(25, 198, 179, 0.24);
            color: #04110f;
            height: 48px;
            transition: transform 0.24s, box-shadow 0.24s;
            width: 48px;
        }

        .swap-btn:hover {
            box-shadow: 0 18px 36px rgba(25, 198, 179, 0.32);
            transform: rotate(180deg) scale(1.04);
        }

        .swap-btn:focus-visible,
        .copy-btn:focus-visible,
        .preset-btn:focus-visible {
            outline: 3px solid rgba(94, 234, 212, 0.28);
            outline-offset: 3px;
        }

        .swap-btn svg {
            height: 19px;
            width: 19px;
        }

        .output-wrapper {
            position: relative;
        }

        .output-field {
            background:
                linear-gradient(180deg, rgba(25, 198, 179, 0.1), rgba(25, 198, 179, 0.05)),
                var(--field);
            border-color: rgba(94, 234, 212, 0.34);
            color: var(--accent-hover);
            cursor: pointer;
            padding-right: 3.2rem;
        }

        .copy-btn {
            background: rgba(248, 250, 252, 0.06);
            border: 1px solid var(--border);
            border-radius: 8px;
            color: var(--accent-hover);
            height: 38px;
            position: absolute;
            right: 10px;
            top: 10px;
            transition: background-color 0.18s, border-color 0.18s, color 0.18s;
            width: 38px;
        }

        .copy-btn:hover {
            background: var(--accent-soft);
            border-color: rgba(94, 234, 212, 0.42);
            color: #ffffff;
        }

        .copy-btn svg {
            height: 17px;
            width: 17px;
        }

        .toast {
            background-color: #f8fafc;
            border-radius: 999px;
            bottom: 20px;
            box-shadow: 0 18px 34px rgba(0, 0, 0, 0.32);
            color: #090b10;
            font-size: 0.85rem;
            font-weight: 720;
            left: 50%;
            opacity: 0;
            padding: 10px 18px;
            pointer-events: none;
            position: fixed;
            transform: translateX(-50%) translateY(20px);
            transition: all 0.3s ease;
            white-space: nowrap;
            z-index: 100;
        }

        .toast.show {
            opacity: 1;
            transform: translateX(-50%) translateY(0);
        }

        @media (max-width: 760px) {
            body {
                align-items: flex-start;
            }

            header {
                display: block;
                padding: 1.2rem 1rem 1rem;
            }

            .status-line {
                margin-top: 0.85rem;
            }

            .workspace {
                display: flex;
                flex-direction: column;
                gap: 0.85rem;
                padding: 1rem;
            }

            .swap-container {
                margin: -0.15rem 0;
                padding-top: 0;
            }

            .swap-btn {
                height: 42px;
                width: 42px;
            }

            .input-wrapper {
                grid-template-columns: minmax(0, 1fr) 104px;
            }

            input {
                font-size: 1.08rem;
                min-height: 52px;
            }

            select {
                font-size: 0.86rem;
                min-height: 52px;
            }

            h1 {
                font-size: 1.35rem;
            }

            .back-btn {
                display: none;
            }
        }

        @media (max-width: 420px) {
            body {
                padding-left: 12px;
                padding-right: 12px;
            }

            .input-wrapper {
                grid-template-columns: 1fr;
            }

            .base-shortcuts {
                grid-template-columns: repeat(2, minmax(0, 1fr));
            }

            .copy-btn {
                height: 34px;
                top: 9px;
                width: 34px;
            }
        }