:root {
    --bg: #dfe7ea;
    --bg-deep: #c9d5db;
    --surface: #f7fafb;
    --surface-2: #eef3f5;
    --ink: #142028;
    --ink-soft: #4a5c66;
    --line: #c5d2d8;
    --accent: #0b6b5c;
    --accent-hover: #085447;
    --accent-soft: #d7ebe6;
    --warn: #8a4b12;
    --shadow: 0 12px 32px rgba(20, 32, 40, 0.08);
    --radius: 14px;
    --font: "Manrope", "Segoe UI", sans-serif;
    --mono: "JetBrains Mono", ui-monospace, monospace;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    color-scheme: light;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: var(--font);
    color: var(--ink);
    background:
        radial-gradient(1200px 600px at 10% -10%, #edf6f4 0%, transparent 55%),
        radial-gradient(900px 500px at 100% 0%, #e4ecf1 0%, transparent 50%),
        linear-gradient(160deg, var(--bg) 0%, var(--bg-deep) 100%);
}

.page {
    width: min(1080px, calc(100% - 2rem));
    margin: 0 auto;
    padding: 2.25rem 0 3rem;
}

.hero {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.75rem;
}

.hero-mark {
    width: 3.25rem;
    height: 3.25rem;
    border-radius: 12px;
    display: grid;
    place-items: center;
    background: var(--accent);
    color: #f4fffc;
    font-family: var(--mono);
    font-size: 1.35rem;
    font-weight: 600;
    box-shadow: 0 8px 20px rgba(11, 107, 92, 0.28);
}

.hero-copy h1 {
    margin: 0;
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.15;
}

.hero-copy p {
    margin: 0.35rem 0 0;
    color: var(--ink-soft);
    font-size: 0.98rem;
    font-weight: 500;
}

.toolbar {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr)) auto;
    gap: 0.75rem 1rem;
    align-items: start;
    padding: 1.15rem 1.25rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.field {
    display: grid;
    grid-template-rows: auto auto auto;
    gap: 0.4rem;
    min-width: 0;
    align-content: start;
}

.field label,
.metric-label {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    color: var(--ink-soft);
    line-height: 1.2;
    min-height: 1.2em;
}

.hint {
    margin: 0;
    font-size: 0.72rem;
    line-height: 1.2;
    color: var(--ink-soft);
    min-height: 1.2em;
}

/* 无提示的字段也占同样高度，保证三列输入框基线一致 */
.toolbar .field:not(.field-naira)::after {
    content: "";
    min-height: 1.2em;
}

.input-shell {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    min-height: 2.75rem;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 10px;
    padding: 0 0.75rem;
    transition: border-color 160ms ease, box-shadow 160ms ease;
}

.input-shell:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(11, 107, 92, 0.16);
}

.affix {
    color: var(--accent);
    font-family: var(--mono);
    font-weight: 600;
    font-size: 0.95rem;
}

input[type="number"] {
    width: 100%;
    border: 0;
    outline: 0;
    background: transparent;
    padding: 0.72rem 0;
    font-family: var(--mono);
    font-size: 1rem;
    font-weight: 500;
    color: var(--ink);
    appearance: textfield;
    -moz-appearance: textfield;
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input::placeholder {
    color: #8aa0aa;
    font-family: var(--font);
    font-weight: 500;
}

.toolbar-actions {
    display: flex;
    align-items: center;
    /* 与 label + gap 对齐，使按钮与输入框同一行 */
    padding-top: calc(0.78rem * 1.2 + 0.4rem);
    height: auto;
}

.toolbar-actions .btn {
    min-height: 2.75rem;
}

.btn {
    border: 0;
    border-radius: 10px;
    font-family: var(--font);
    font-weight: 700;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background 160ms ease, color 160ms ease, transform 160ms ease;
}

.btn:active {
    transform: translateY(1px);
}

.btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.btn-ghost {
    background: var(--surface-2);
    color: var(--ink-soft);
    padding: 0.72rem 1rem;
    border: 1px solid var(--line);
}

.btn-ghost:hover {
    background: #e4ebef;
    color: var(--ink);
}

.btn-primary {
    background: var(--accent);
    color: #f4fffc;
    padding: 0.72rem 1rem;
    white-space: nowrap;
}

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

.scenarios-head {
    margin: 0 0 0.9rem;
}

.scenarios-head h2 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.scenarios-head p {
    margin: 0.3rem 0 0;
    color: var(--ink-soft);
    font-size: 0.9rem;
}

.scenario-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.scenario {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1fr) auto;
    gap: 1rem;
    align-items: start;
    padding: 1rem 1.15rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 6px 18px rgba(20, 32, 40, 0.05);
    animation: rise 320ms cubic-bezier(0.16, 1, 0.3, 1) both;
}

.scenario:nth-child(2) {
    animation-delay: 40ms;
}

.scenario:nth-child(3) {
    animation-delay: 80ms;
}

.scenario-index {
    align-self: end;
    margin-bottom: 0;
    /* 与输入框垂直居中：label 行 + gap */
    margin-top: calc(0.78rem * 1.2 + 0.4rem);
    height: 2.75rem;
    display: grid;
    place-items: center;
    font-family: var(--mono);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--accent-soft);
    border-radius: 8px;
    padding: 0 0.55rem;
    box-sizing: border-box;
}

.scenario .field {
    /* 场景内不要底部占位，避免把结果行顶歪 */
    grid-template-rows: auto auto;
}

.scenario .field::after {
    content: none;
    display: none;
}

.metric {
    display: grid;
    grid-template-rows: auto auto;
    gap: 0.4rem;
    min-width: 0;
    align-content: start;
}

.metric-label {
    line-height: 1.2;
    min-height: 1.2em;
}

.metric-value {
    display: flex;
    align-items: center;
    min-height: 2.75rem;
    padding: 0 0.75rem;
    font-family: var(--mono);
    font-size: 1.15rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--ink);
    line-height: 1.2;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 10px;
    transition: color 180ms ease, background 180ms ease, border-color 180ms ease;
    box-sizing: border-box;
}

.settlement-result {
    color: var(--accent);
    background: var(--accent-soft);
    border-color: transparent;
}

.difference {
    color: #a33b2d;
    background: #f8e8e5;
    border-color: transparent;
}

.metric-value.is-updating {
    filter: brightness(0.97);
}

.difference.is-updating {
    background: #f3d9d4;
}

.scenario .copy-btn {
    margin-top: calc(0.78rem * 1.2 + 0.4rem);
    min-height: 2.75rem;
    align-self: start;
}

.foot {
    margin-top: 1.5rem;
    color: var(--ink-soft);
    font-size: 0.78rem;
    line-height: 1.55;
}

.foot p {
    margin: 0;
    max-width: 70ch;
}

.toast {
    position: fixed;
    top: 1.25rem;
    right: 1.25rem;
    background: var(--ink);
    color: #f4fffc;
    padding: 0.75rem 1rem;
    border-radius: 10px;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: 0 10px 28px rgba(20, 32, 40, 0.22);
    opacity: 0;
    transform: translateY(-8px);
    pointer-events: none;
    transition: opacity 180ms ease, transform 180ms ease;
    z-index: 20;
}

.toast.is-visible {
    opacity: 1;
    transform: translateY(0);
}

@keyframes rise {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 900px) {
    .toolbar {
        grid-template-columns: 1fr 1fr;
    }

    .toolbar-actions {
        grid-column: 1 / -1;
        justify-content: stretch;
        padding-top: 0;
    }

    .toolbar-actions .btn {
        width: 100%;
    }

    .scenario {
        grid-template-columns: auto 1fr 1fr;
    }

    .scenario-index {
        margin-top: calc(0.78rem * 1.2 + 0.4rem);
        align-self: start;
    }

    .scenario .copy-btn {
        grid-column: 1 / -1;
        margin-top: 0;
        width: 100%;
    }
}

@media (max-width: 640px) {
    .page {
        width: min(100% - 1.25rem, 1080px);
        padding-top: 1.4rem;
    }

    .hero {
        align-items: flex-start;
    }

    .hero-copy h1 {
        font-size: 1.45rem;
    }

    .toolbar,
    .scenario {
        grid-template-columns: 1fr;
    }

    .scenario-index {
        width: fit-content;
        margin-top: 0;
        height: auto;
        padding: 0.45rem 0.55rem;
    }

    .scenario .copy-btn {
        margin-top: 0;
    }

    .metric-value {
        font-size: 1.35rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .scenario,
    .btn,
    .toast,
    .metric-value,
    .input-shell {
        animation: none;
        transition: none;
    }
}