/* ============================================================
   Calculator — shared component CSS
   Dùng cho .calc-widget, .calc-form, .calc-field, .calc-section
   + .casio (Casio FX-580VN keypad UI)
   ============================================================ */

/* ---------- Widget wrapper ---------- */

.calc-widget {
    background: var(--vjol-color-bg);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-lg);
    padding: clamp(var(--vjol-space-5), 3vw, var(--vjol-space-8));
    margin-block: var(--vjol-space-6) var(--vjol-space-10);
    box-shadow: var(--vjol-shadow-sm);
}

.calc-widget__missing {
    color: var(--vjol-color-danger);
    font-style: italic;
    margin: 0;
}

/* ---------- Form ---------- */

.calc-form__intro {
    margin: 0 0 var(--vjol-space-4);
    color: var(--vjol-color-text-muted);
    font-size: var(--vjol-fs-sm);
}
.calc-form__intro code {
    background: var(--vjol-color-surface-2);
    padding: 0.1em 0.35em;
    border-radius: var(--vjol-radius-sm);
    font-size: 0.95em;
}

/* ---------- Tabs (form mode switcher) ---------- */

.calc-tabs {
    display: flex;
    gap: var(--vjol-space-2);
    margin-bottom: var(--vjol-space-4);
    border-bottom: 1px solid var(--vjol-color-border);
}
.calc-tabs__tab {
    flex: 1;
    appearance: none;
    background: transparent;
    border: 0;
    border-bottom: 2px solid transparent;
    padding: var(--vjol-space-3) var(--vjol-space-4);
    font: inherit;
    font-weight: 500;
    color: var(--vjol-color-text-muted);
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
    margin-bottom: -1px;
}
.calc-tabs__tab:hover {
    color: var(--vjol-color-text);
}
.calc-tabs__tab.is-active {
    color: var(--vjol-color-primary);
    border-bottom-color: var(--vjol-color-primary);
}
.calc-tabs__tab:focus-visible {
    outline: 2px solid var(--vjol-color-primary);
    outline-offset: 2px;
    border-radius: var(--vjol-radius-sm);
}

.calc-form__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--vjol-space-4);
    margin-bottom: var(--vjol-space-5);
}

@media (min-width: 640px) {
    .calc-form__grid { grid-template-columns: repeat(2, 1fr); }
    .calc-form__grid--3 { grid-template-columns: repeat(3, 1fr); }
    .calc-form__grid--4 { grid-template-columns: repeat(4, 1fr); }
}

.calc-form__actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--vjol-space-3);
}

/* ---------- Full-width field (vd: input PT hoá học) ---------- */

.calc-field--full {
    grid-column: 1 / -1;
}

/* ---------- Breakdown table (khối lượng mol) ---------- */

.calc-breakdown {
    width: 100%;
    border-collapse: collapse;
    margin-top: var(--vjol-space-3);
    font-size: var(--vjol-fs-sm);
}
.calc-breakdown th,
.calc-breakdown td {
    padding: 6px 12px;
    border: 1px solid var(--vjol-color-border);
    text-align: right;
}
.calc-breakdown th { background: var(--vjol-color-surface-2); font-weight: 600; }
.calc-breakdown td:first-child,
.calc-breakdown th:first-child { text-align: left; font-family: ui-monospace, monospace; }

/* ---------- Chain reaction (chuỗi phản ứng) ---------- */

.chain-examples {
    display: flex;
    flex-wrap: wrap;
    gap: var(--vjol-space-2);
    align-items: center;
    margin: var(--vjol-space-3) 0;
    font-size: var(--vjol-fs-sm);
}
.chain-examples__label { color: var(--vjol-color-text-muted); }
.chain-examples__btn {
    appearance: none;
    background: var(--vjol-color-surface-2);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    padding: 4px 12px;
    font: inherit;
    font-size: var(--vjol-fs-sm);
    cursor: pointer;
    transition: background 0.15s;
}
.chain-examples__btn:hover { background: var(--vjol-color-border); }

.chain-steps {
    list-style: none;
    padding: 0; margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--vjol-space-3);
}
.chain-step {
    padding: var(--vjol-space-3);
    border-radius: var(--vjol-radius-md);
    border-left: 4px solid;
}
.chain-step--ok { background: #ecfdf5; border-color: #10b981; }
.chain-step--miss { background: #fef2f2; border-color: #ef4444; }
.chain-step__eq { margin-top: 6px; font-size: var(--vjol-fs-base); }
.chain-step__cond { font-size: var(--vjol-fs-sm); color: var(--vjol-color-text-muted); margin-top: 4px; }
.chain-step__warn { color: #991b1b; font-size: var(--vjol-fs-sm); margin-top: 6px; }

/* ---------- Electrochemical series (dãy điện hoá) ---------- */

.ec-compare {
    margin: var(--vjol-space-4) 0;
}
.ec-compare__box {
    padding: var(--vjol-space-4);
    border-radius: var(--vjol-radius-md);
    border-left: 4px solid;
}
.ec-compare__box.is-yes { background: #ecfdf5; border-color: #10b981; }
.ec-compare__box.is-no  { background: #fef2f2; border-color: #ef4444; }
.ec-compare__box p { margin: var(--vjol-space-2) 0 0; }
.ec-compare__warn { color: var(--vjol-color-text-muted); }

.ec-series-title {
    font-size: var(--vjol-fs-base);
    margin: var(--vjol-space-5) 0 var(--vjol-space-2);
}
.ec-series {
    list-style: none;
    padding: 0; margin: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 4px;
    font-size: var(--vjol-fs-sm);
}
.ec-series__item {
    display: flex;
    justify-content: space-between;
    padding: 6px 10px;
    background: var(--vjol-color-surface-2);
    border-radius: var(--vjol-radius-sm);
    border: 1px solid var(--vjol-color-border);
}
.ec-series__item.is-h {
    background: #fef3c7;
    border-color: #eab308;
    font-weight: 600;
}
.ec-series__e {
    color: var(--vjol-color-text-muted);
    font-family: ui-monospace, monospace;
}

/* ---------- Identification (nhận biết ion) ---------- */

.ident-wrap { margin: var(--vjol-space-4) 0; }
.ident-toolbar {
    display: flex; flex-wrap: wrap;
    gap: var(--vjol-space-3);
    align-items: center;
    margin-bottom: var(--vjol-space-4);
}
.ident-search input {
    min-width: 280px;
    padding: var(--vjol-space-2) var(--vjol-space-3);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    font: inherit;
}
.ident-filters { display: flex; gap: 4px; flex-wrap: wrap; }
.ident-filter {
    appearance: none;
    background: var(--vjol-color-surface-2);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    padding: 6px 12px;
    font: inherit;
    font-size: var(--vjol-fs-sm);
    cursor: pointer;
}
.ident-filter.is-active {
    background: var(--vjol-color-primary);
    color: #fff;
    border-color: var(--vjol-color-primary);
}

.ident-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 6px;
}
.ident-item {
    appearance: none;
    background: var(--vjol-color-bg);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    padding: var(--vjol-space-2) var(--vjol-space-3);
    text-align: left;
    cursor: pointer;
    font: inherit;
    display: flex; flex-direction: column; gap: 2px;
    transition: transform 0.1s, box-shadow 0.1s;
}
.ident-item:hover { transform: translateY(-2px); box-shadow: 0 4px 8px rgba(0,0,0,0.1); }
.ident-item__type { font-size: var(--vjol-fs-xs); color: var(--vjol-color-text-muted); }
.ident-item__name { font-weight: 600; font-size: var(--vjol-fs-base); }
.ident-item--cation  { border-left: 4px solid #ef4444; }
.ident-item--anion   { border-left: 4px solid #3b82f6; }
.ident-item--gas     { border-left: 4px solid #10b981; }
.ident-item--organic { border-left: 4px solid #a855f7; }

.ident-detail {
    margin-top: var(--vjol-space-4);
    padding: var(--vjol-space-4);
    background: var(--vjol-color-surface-2);
    border-radius: var(--vjol-radius-md);
}
.ident-detail__head { margin-bottom: var(--vjol-space-3); }
.ident-detail__type { color: var(--vjol-color-text-muted); font-size: var(--vjol-fs-sm); }
.ident-detail__name { font-size: var(--vjol-fs-2xl); margin: 4px 0 0; }
.ident-detail__table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--vjol-fs-sm);
}
.ident-detail__table th,
.ident-detail__table td {
    padding: 8px 12px;
    text-align: left;
    border-bottom: 1px solid var(--vjol-color-border);
    vertical-align: top;
}
.ident-detail__table th { background: var(--vjol-color-bg); font-weight: 600; }
.ident-eq {
    margin-top: 4px;
    color: var(--vjol-color-text-muted);
    font-family: ui-monospace, monospace;
    font-size: 0.9em;
}

/* ---------- Isomer counter ---------- */

.iso-result {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--vjol-space-2) var(--vjol-space-4);
    margin-top: var(--vjol-space-3);
    font-size: var(--vjol-fs-sm);
}
.iso-result dt { color: var(--vjol-color-text-muted); }
.iso-result dd { margin: 0; }
.iso-examples {
    list-style: none;
    padding: 0; margin: var(--vjol-space-2) 0 0;
    display: flex; flex-direction: column;
    gap: 4px;
}
.iso-examples li {
    padding: 4px 10px;
    background: var(--vjol-color-bg);
    border-radius: var(--vjol-radius-sm);
    border: 1px solid var(--vjol-color-border);
    font-family: ui-monospace, monospace;
    font-size: 0.9em;
}

/* ---------- Hess law (nhiệt phản ứng) ---------- */

.hess-side {
    margin-bottom: var(--vjol-space-4);
}
.hess-side__title {
    font-size: var(--vjol-fs-base);
    margin: 0 0 var(--vjol-space-2);
    color: var(--vjol-color-text);
}
.hess-rows {
    display: flex; flex-direction: column;
    gap: var(--vjol-space-2);
    margin-bottom: var(--vjol-space-2);
}
.hess-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr auto;
    gap: var(--vjol-space-2);
    align-items: stretch;
}
.hess-row select,
.hess-row input {
    padding: var(--vjol-space-2);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-sm);
    font: inherit;
    font-size: var(--vjol-fs-sm);
    min-width: 0;
}
.hess-row__del {
    background: transparent;
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-sm);
    width: 36px;
    cursor: pointer;
    font-size: 20px;
    color: var(--vjol-color-danger);
}
.hess-row__del:hover { background: var(--vjol-color-surface-2); }
.hess-add {
    font-size: var(--vjol-fs-sm) !important;
    padding: var(--vjol-space-2) var(--vjol-space-3) !important;
}

@media (max-width: 600px) {
    .hess-row { grid-template-columns: 1fr 1fr auto; grid-template-rows: auto auto; }
    .hess-row select { grid-column: 1 / -1; }
}

/* ---------- Hybrid / Lewis chips ---------- */

.hybrid-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
}
.hybrid-chip {
    appearance: none;
    background: var(--vjol-color-surface-2);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    padding: 4px 10px;
    font: inherit;
    font-size: var(--vjol-fs-sm);
    cursor: pointer;
    transition: background 0.15s;
}
.hybrid-chip:hover {
    background: var(--vjol-color-primary);
    color: #fff;
    border-color: var(--vjol-color-primary);
}

/* ---------- IUPAC lookup table ---------- */

.iupac-table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--vjol-fs-sm);
    margin-top: var(--vjol-space-2);
}
.iupac-table th,
.iupac-table td {
    padding: 6px 10px;
    text-align: left;
    border-bottom: 1px solid var(--vjol-color-border);
    vertical-align: top;
}
.iupac-table th { background: var(--vjol-color-surface-2); font-weight: 600; }
.iupac-table small { color: var(--vjol-color-text-muted); }
.iupac-cat {
    display: inline-block;
    padding: 2px 8px;
    border-radius: var(--vjol-radius-sm);
    font-size: var(--vjol-fs-xs);
    white-space: nowrap;
}
.iupac-cat--alkane   { background: #e0e7ff; color: #3730a3; }
.iupac-cat--alkene   { background: #d1fae5; color: #065f46; }
.iupac-cat--alkyne   { background: #cffafe; color: #155e75; }
.iupac-cat--alcohol  { background: #fef3c7; color: #854d0e; }
.iupac-cat--acid     { background: #fee2e2; color: #991b1b; }
.iupac-cat--aldehyde { background: #ffedd5; color: #9a3412; }
.iupac-cat--ketone   { background: #fae8ff; color: #6b21a8; }
.iupac-cat--ester    { background: #ede9fe; color: #5b21b6; }
.iupac-cat--amine    { background: #fce7f3; color: #9d174d; }

/* ---------- Lewis dot ASCII art ---------- */

.lewis-art {
    background: #0f172a;
    color: #e2e8f0;
    padding: var(--vjol-space-4);
    border-radius: var(--vjol-radius-md);
    font-family: ui-monospace, monospace;
    font-size: var(--vjol-fs-base);
    line-height: 1.5;
    white-space: pre;
    overflow-x: auto;
    margin: 0;
}

/* ---------- Đếm ngày: tool tổng /dem-ngay-online/ ---------- */

.calc-options {
    display: flex;
    flex-wrap: wrap;
    gap: var(--vjol-space-3);
    margin: var(--vjol-space-3) 0;
}
.calc-checkbox {
    display: flex; align-items: center; gap: 6px;
    font-size: var(--vjol-fs-sm);
    cursor: pointer;
}
.calc-field__hint {
    font-size: var(--vjol-fs-xs);
    color: var(--vjol-color-text-muted);
    padding: 0 var(--vjol-space-3);
}

.dn-quick {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
    margin-top: var(--vjol-space-4);
    padding-top: var(--vjol-space-3);
    border-top: 1px dashed var(--vjol-color-border);
    font-size: var(--vjol-fs-sm);
}
.dn-quick__label { color: var(--vjol-color-text-muted); }
.dn-quick__btn {
    appearance: none;
    background: var(--vjol-color-surface-2);
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-md);
    padding: 4px 12px;
    font: inherit; font-size: var(--vjol-fs-sm);
    cursor: pointer;
}
.dn-quick__btn:hover { background: var(--vjol-color-border); }

.dn-result {
    padding: var(--vjol-space-5);
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-radius: var(--vjol-radius-lg);
    text-align: center;
}
.dn-result__title {
    background: #fff;
    padding: var(--vjol-space-2) var(--vjol-space-4);
    border-radius: 999px;
    color: var(--vjol-color-text-muted);
    font-size: var(--vjol-fs-sm);
    margin: 0 auto var(--vjol-space-3);
    display: inline-block;
}
.dn-result__big {
    font-size: clamp(2rem, 6vw, 3rem);
    font-weight: 800;
    color: #1e3a8a;
    margin: var(--vjol-space-2) 0;
}
.dn-chips {
    display: flex; flex-wrap: wrap;
    gap: 6px; justify-content: center;
    margin: var(--vjol-space-3) 0;
}
.dn-chip {
    background: #fff;
    padding: 4px 14px;
    border-radius: 999px;
    font-size: var(--vjol-fs-sm);
    color: var(--vjol-color-text);
}
.dn-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--vjol-space-2);
    margin: var(--vjol-space-3) 0;
}
.dn-card {
    background: #fff;
    padding: var(--vjol-space-3);
    border-radius: var(--vjol-radius-md);
}
.dn-card__val { font-size: clamp(1.5rem, 4vw, 2rem); font-weight: 700; color: #1e3a8a; }
.dn-card__lbl { font-size: var(--vjol-fs-xs); color: var(--vjol-color-text-muted); letter-spacing: 0.05em; }

.dn-progress { margin: var(--vjol-space-3) 0; }
.dn-progress__bar { background: rgba(255,255,255,0.5); border-radius: 999px; height: 8px; overflow: hidden; }
.dn-progress__fill { background: linear-gradient(90deg, #1e3a8a 0%, #f59e0b 100%); height: 100%; transition: width 0.5s; }
.dn-progress__text { font-size: var(--vjol-fs-sm); color: var(--vjol-color-text-muted); margin: 6px 0 0; }

.dn-cals { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: var(--vjol-space-3); margin: var(--vjol-space-3) 0; }
.dn-cal { background: #fff; padding: var(--vjol-space-3); border-radius: var(--vjol-radius-md); }
.dn-cal__head { font-weight: 600; margin-bottom: 6px; }
.dn-cal__week { display: grid; grid-template-columns: repeat(7, 1fr); gap: 2px; font-size: var(--vjol-fs-xs); color: var(--vjol-color-text-muted); margin-bottom: 4px; }
.dn-cal__week span { text-align: center; padding: 2px; }
.dn-cal__grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 2px; }
.dn-cal__day { aspect-ratio: 1; display: flex; align-items: center; justify-content: center; font-size: var(--vjol-fs-sm); border-radius: 4px; }
.dn-cal__empty { aspect-ratio: 1; }
.dn-cal__day.is-in { background: #fef3c7; }
.dn-cal__day.is-start { background: #1e3a8a; color: #fff; font-weight: 600; }
.dn-cal__day.is-end { background: #f59e0b; color: #fff; font-weight: 600; }

.dn-copy { margin-top: var(--vjol-space-3); }

/* ---------- "Còn bao nhiêu ngày nữa đến X?" pages ---------- */

.cbn { margin: var(--vjol-space-4) 0; }
.cbn-loading { color: var(--vjol-color-text-muted); text-align: center; padding: var(--vjol-space-6); }
.cbn__box {
    background: #fff;
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-lg);
    padding: var(--vjol-space-5);
    text-align: center;
    box-shadow: var(--vjol-shadow-sm);
}
.cbn__head { font-size: var(--vjol-fs-base); margin: 0 0 var(--vjol-space-3); color: var(--vjol-color-text); }
.cbn__cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--vjol-space-2); margin: var(--vjol-space-3) 0; }
.cbn__card { background: #eff6ff; padding: var(--vjol-space-4) var(--vjol-space-2); border-radius: var(--vjol-radius-md); }
.cbn__num { font-size: clamp(1.5rem, 5vw, 2.5rem); font-weight: 800; color: #1e3a8a; line-height: 1; }
.cbn__lbl { font-size: var(--vjol-fs-xs); color: var(--vjol-color-text-muted); letter-spacing: 0.08em; margin-top: 4px; }

.cbn__progress { margin: var(--vjol-space-4) 0; }
.cbn__bar { background: #f3f4f6; border-radius: 999px; height: 8px; overflow: hidden; }
.cbn__fill { background: linear-gradient(90deg, #1e3a8a 0%, #f59e0b 100%); height: 100%; transition: width 0.5s; }
.cbn__pct { font-size: var(--vjol-fs-sm); color: var(--vjol-color-text-muted); margin: 6px 0 0; }

.cbn__info {
    margin-top: var(--vjol-space-4);
    background: #fff;
    border: 1px solid var(--vjol-color-border);
    border-radius: var(--vjol-radius-lg);
    padding: var(--vjol-space-5);
}
.cbn__info-title { margin: 0 0 var(--vjol-space-3); font-size: var(--vjol-fs-xl); }
.cbn__info-grid {
    display: grid;
    grid-template-columns: max-content 1fr;
    gap: var(--vjol-space-2) var(--vjol-space-4);
    margin: 0;
}
.cbn__info-grid dt {
    background: var(--vjol-color-surface-2);
    padding: 6px 12px;
    border-radius: var(--vjol-radius-sm);
    color: var(--vjol-color-text-muted);
    font-size: var(--vjol-fs-sm);
}
.cbn__info-grid dd { margin: 0; padding: 6px 0; font-weight: 500; }
.cbn__error { color: var(--vjol-color-danger); font-style: italic; padding: var(--vjol-space-4); }

/* ---------- Kỷ niệm milestone ---------- */

.ky-milestone {
    margin-top: var(--vjol-space-3);
    padding: var(--vjol-space-2) var(--vjol-space-3);
    background: #fef3c7;
    border-left: 3px solid #f59e0b;
    border-radius: var(--vjol-radius-sm);
    font-size: var(--vjol-fs-sm);
}