:root {
            --card-background: rgb(20, 20, 20);
            --text: #172033;
            --text-secondary: #667085;
            --border: #505050;
            --primary: #447fff;
            --primary-hover: #0b58ff;
            --success-background: #000000;
            --success-border: #505050;
            --warning-background: #ffe6e6;
            --warning-border: #f07272;
            --error-background: #fff0f0;
            --error-border: #e9a3a3;
            --shadow: 0 16px 40px rgba(23, 32, 51, 0.1);
            --radius: 18px;
        }

        * {
            box-sizing: border-box;
        }

        button,
        input,
        select {
            font: inherit;
        }

        .container {
            width: 100%;
            max-width: 760px;
        }

        .header {
            margin-bottom: 24px;
            text-align: center;
        }

        .header h1 {
            margin: 0 0 10px;
            font-size: clamp(2rem, 7vw, 3.4rem);
            line-height: 1.1;
        }

        .header p {
            max-width: 600px;
            margin: 0 auto;
            color: var(--text-secondary);
            font-size: 1.05rem;
            line-height: 1.6;
        }

        .card {
            padding: 28px;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            background: var(--card-background);
            box-shadow: var(--shadow);
        }

        .form-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
        }

        .form-group {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

        .form-group.full-width {
            grid-column: 1 / -1;
        }

        label {
            font-weight: 650;
        }

        select,
        input[type="time"] {
            width: 100%;
            min-height: 50px;
            padding: 12px 14px;
            border: 1px solid var(--border);
            border-radius: 12px;
            outline: none;
            color: var(--text);
            background: #000000;
            color: #ffffff;
            transition:
                border-color 0.2s,
                box-shadow 0.2s;
        }

        select:focus,
        input[type="time"]:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 4px rgba(56, 89, 233, 0.13);
        }

        .button-row {
            grid-column: 1 / -1;
            display: flex;
            gap: 12px;
            margin-top: 4px;
        }

        button {
            min-height: 50px;
            padding: 12px 20px;
            border: none;
            border-radius: 12px;
            cursor: pointer;
            font-weight: 700;
            transition:
                background-color 0.2s,
                transform 0.1s;
        }

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

        .primary-button {
            flex: 1;
            color: #ffffff;
            background: var(--primary);
        }

        .primary-button:hover {
            background: var(--primary-hover);
        }

        .secondary-button {
            border: 1px solid var(--border);
            color: var(--text);
            background: #ffffff;
        }

        .secondary-button:hover {
            background: #f7f8fc;
        }

        .notice {
            margin-top: 22px;
            padding: 14px 16px;
            border: 1px solid var(--warning-border);
            border-radius: 12px;
            color: #6c5011;
            background: var(--warning-background);
            font-size: 0.92rem;
            line-height: 1.5;
        }

        .result {
            display: none;
            margin-top: 24px;
            padding: 24px;
            border: 1px solid var(--success-border);
            border-radius: var(--radius);
            background: var(--success-background);
        }

        .result.visible {
            display: block;
        }

        .result-heading {
            margin: 0 0 18px;
            font-size: 1rem;
            color: var(--text-secondary);
            font-weight: 600;
        }

        .result-comparison {
            display: grid;
            grid-template-columns: 1fr auto 1fr;
            gap: 18px;
            align-items: center;
        }

        .time-card {
            min-width: 0;
        }

        .time-card.target {
            text-align: right;
        }

        .location-name {
            margin-bottom: 6px;
            color: var(--text-secondary);
            font-weight: 650;
        }

        .time-value {
            font-size: clamp(2rem, 8vw, 3.5rem);
            line-height: 1;
            font-weight: 800;
            letter-spacing: -0.04em;
        }

        .day-label {
            min-height: 24px;
            margin-top: 8px;
            color: var(--text-secondary);
            font-size: 0.92rem;
        }

        .arrow {
            color: var(--primary);
            font-size: 2rem;
            font-weight: 700;
        }

        .difference {
            margin-top: 20px;
            padding-top: 18px;
            border-top: 1px solid var(--success-border);
            text-align: center;
            font-weight: 650;
        }

        .error {
            display: none;
            margin-top: 20px;
            padding: 14px 16px;
            border: 1px solid var(--error-border);
            border-radius: 12px;
            color: #842525;
            background: var(--error-background);
            line-height: 1.5;
        }

        .error.visible {
            display: block;
        }

        .privacy {
            margin-top: 18px;
            text-align: center;
            color: var(--text-secondary);
            font-size: 0.85rem;
        }

        @media (max-width: 620px) {
            body {
                padding: 20px 12px;
            }

            .card {
                padding: 20px;
            }

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

            .form-group.full-width,
            .button-row {
                grid-column: auto;
            }

            .button-row {
                flex-direction: column;
            }

            .result-comparison {
                grid-template-columns: 1fr;
                text-align: center;
            }

            .time-card.target {
                text-align: center;
            }

            .arrow {
                transform: rotate(90deg);
            }
        }

        
.info-card {
    background-color: #1f1f1f;
    border: 1px solid #444;
    border-radius: 1rem;
    padding: 1.5rem;
    text-align: left;
    transition: 0.2s ease;

    margin: 20px;
    box-sizing: border-box;
}