/* ==========================================================
   Aqua Best - 2500 GPD Water Purifier page
   Self-contained stylesheet (only what this page needs)
   ========================================================== */

:root {
    --bg: #f6fafd;
    --surface: #ffffff;
    --alt: #e9f4fb;
    --text: #0e2342;
    --muted: #53647c;
    --line: #d5e3ee;
    --blue: #1a9be0;
    --navy: #0b2a5b;
    --gold: #b88e3a;
    --gold-text: #ffffff;
    --shadow: 0 10px 30px rgba(11, 42, 91, .08);
    --radius: 14px;
    --head: system-ui, -apple-system, "Segoe UI", Roboto, Arial, Helvetica, sans-serif;
    --body: system-ui, -apple-system, "Segoe UI", Roboto, Arial, Helvetica, sans-serif;
}

[data-theme="dark"] {
    --bg: #08131f;
    --surface: #0f2133;
    --alt: #0c1b2b;
    --text: #e8f1f8;
    --muted: #9fb3c6;
    --line: #1d3550;
    --blue: #4cb8f0;
    --navy: #0a2745;
    --gold: #d4ab55;
    --gold-text: #1a1305;
    --shadow: 0 10px 30px rgba(0, 0, 0, .4);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--body);
    background: var(--bg);
    color: var(--text);
    line-height: 1.65;
    transition: background .3s, color .3s;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

:focus-visible {
    outline: 3px solid var(--blue);
    outline-offset: 2px;
}

.wrap {
    width: min(1140px, 100% - 40px);
    margin-inline: auto;
}

.narrow {
    max-width: 760px;
}

h1,
h2,
h3 {
    font-family: var(--head);
    font-weight: 700;
    line-height: 1.2;
}

.center {
    text-align: center;
}

.center-sub {
    margin-inline: auto;
    text-align: center;
}

.small {
    color: var(--muted);
    font-size: .92rem;
}

/* ===== Header ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
}

.header-in {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    min-height: 76px;
}

.brand img {
    height: 56px;
    width: auto;
}

[data-theme="dark"] .brand img {
    background: #fff;
    border-radius: 10px;
    padding: 4px 8px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav a {
    padding: 8px 14px;
    border-radius: 999px;
    font-weight: 600;
    font-size: .95rem;
    color: var(--muted);
    transition: color .2s, background .2s;
}

.nav a:hover,
.nav a.active {
    color: var(--text);
    background: var(--alt);
}

.nav a.nav-cta {
    background: var(--gold);
    color: var(--gold-text);
    margin-inline: 4px;
}

.nav a.nav-cta:hover {
    filter: brightness(1.08);
}

.header-tools {
    display: flex;
    gap: 8px;
}

.icon-btn {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 1px solid var(--line);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
    display: grid;
    place-items: center;
}

.icon-btn:hover {
    background: var(--alt);
}

.i-sun {
    display: none;
}

[data-theme="dark"] .i-sun {
    display: block;
}

[data-theme="dark"] .i-moon {
    display: none;
}

.menu-btn {
    display: none;
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 13px 24px;
    border-radius: 10px;
    font-weight: 700;
    font-size: .95rem;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform .15s, filter .2s, background .2s;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background: var(--blue);
    color: #04121f;
}

.btn-ghost {
    border-color: var(--line);
    color: var(--text);
}

.btn-gold {
    background: var(--gold);
    color: var(--gold-text);
    padding: 10px 18px;
}

.btn-light {
    background: #fff;
    color: var(--navy);
}

.btn-row {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

/* ===== Hero ===== */
.pd-top {
    background: linear-gradient(120deg, #07203f, #0b2a5b 60%, #124a86);
    color: #fff;
    padding: 56px 0 60px;
}

.dom-top {
    padding: 64px 0;
}

.dom-hero {
    display: grid;
    grid-template-columns: 1.15fr .85fr;
    gap: 48px;
    align-items: center;
}

.dom-top h1 {
    font-size: clamp(2rem, 4.2vw, 3.1rem);
    margin-bottom: 14px;
}

.lead {
    font-size: 1.12rem;
    color: #d6e6f5;
    max-width: 52ch;
    margin-bottom: 26px;
}

.crumbs {
    font-size: .9rem;
    color: #b7c8db;
    font-weight: 600;
    margin-bottom: 24px;
}

.crumbs a:hover {
    color: #fff;
    text-decoration: underline;
}

.dom-top .btn-ghost {
    background: rgba(6, 22, 40, .55);
    border-color: rgba(255, 255, 255, .7);
    color: #fff;
}

.dom-top .btn-ghost:hover {
    background: #fff;
    color: #0b2a5b;
}

.dom-img {
    background: #fff;
    border-radius: 18px;
    padding: 24px;
    display: grid;
    place-items: center;
    box-shadow: 0 16px 40px rgba(0, 0, 0, .3);
}

.dom-img img {
    max-height: 340px;
    width: auto;
    max-width: 100%;
    object-fit: contain;
}

/* ===== Quick spec strip ===== */
.spec-strip {
    background: var(--surface);
    border-bottom: 1px solid var(--line);
}

.spec-strip-in {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
}

.spec-strip-in>div {
    padding: 26px 16px;
    text-align: center;
    border-right: 1px solid var(--line);
}

.spec-strip-in>div:last-child {
    border-right: 0;
}

.spec-strip-in strong {
    display: block;
    font-family: var(--head);
    font-size: 1.9rem;
    color: var(--blue);
    line-height: 1.1;
}

.spec-strip-in span {
    color: var(--muted);
    font-size: .88rem;
    font-weight: 600;
}

/* ===== Sections ===== */
.section {
    padding: 80px 0;
}

.section.alt {
    background: var(--alt);
}

.eyebrow {
    text-transform: uppercase;
    letter-spacing: .16em;
    font-size: .78rem;
    font-weight: 700;
    color: var(--gold);
    margin-bottom: 12px;
}

.sec-title {
    font-size: clamp(1.7rem, 3.2vw, 2.4rem);
    margin-bottom: 10px;
}

.sec-sub {
    color: var(--muted);
    margin-bottom: 36px;
    max-width: 60ch;
}

.about-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.body-p {
    color: var(--muted);
    margin-top: 14px;
    max-width: 58ch;
}

.mini-h {
    font-size: 1.25rem;
    margin-top: 26px;
}

/* ===== Checklist card ===== */
.checklist-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 26px;
}

.checklist-card h3 {
    font-size: 1.2rem;
    margin-bottom: 14px;
}

.checklist {
    list-style: none;
    display: grid;
    gap: 10px;
}

.checklist li {
    padding-left: 28px;
    position: relative;
    font-weight: 600;
}

.checklist li::before {
    content: "";
    position: absolute;
    left: 4px;
    top: .45em;
    width: 7px;
    height: 12px;
    border: solid var(--gold);
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.checklist.two-col {
    grid-template-columns: 1fr 1fr;
    gap: 10px 22px;
}

/* ===== Step cards ===== */
.step-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
    margin-top: 36px;
}

.step-grid.three-col {
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
}

.step-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    transition: transform .2s, box-shadow .2s;
}

.step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.sn {
    font-family: var(--head);
    font-size: 2.2rem;
    line-height: 1;
    color: var(--gold);
    font-weight: 700;
    display: block;
    margin-bottom: 8px;
}

.step-card h3 {
    font-size: 1.08rem;
    margin-bottom: 8px;
    color: var(--blue);
}

.step-card p {
    color: var(--muted);
    font-size: .92rem;
}

/* ===== Spec table ===== */
.spec-table {
    width: 100%;
    border-collapse: collapse;
}

.spec-table th,
.spec-table td {
    text-align: left;
    padding: 11px 0;
    border-bottom: 1px solid var(--line);
    font-size: .95rem;
}

.spec-table th {
    font-weight: 700;
    color: var(--muted);
    width: 45%;
}

.spec-table td {
    font-weight: 600;
}

.spec-table tr:last-child th,
.spec-table tr:last-child td {
    border-bottom: 0;
}

/* ===== Benefits ===== */
.benefits {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 16px;
    margin-top: 32px;
}

.benefits.three {
    grid-template-columns: repeat(3, 1fr);
}

.benefit {
    background: var(--surface);
    border: 1px solid var(--line);
    border-top: 3px solid var(--gold);
    border-radius: var(--radius);
    padding: 22px;
}

.benefit h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
}

.benefit p {
    color: var(--muted);
    font-size: .92rem;
}

/* ===== CTA ===== */
.cta {
    background: var(--navy);
    color: #fff;
    padding: 56px 0;
}

.cta-in {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: space-between;
    align-items: center;
}

.cta h2 {
    font-size: 2rem;
    margin-bottom: 4px;
}

.cta p {
    color: #b9cde3;
}

/* ===== FAQ ===== */
details {
    border-bottom: 1px solid var(--line);
    padding: 18px 0;
}

summary {
    cursor: pointer;
    font-weight: 700;
    list-style: none;
    display: flex;
    justify-content: space-between;
    gap: 16px;
}

summary::after {
    content: "+";
    font-size: 1.4rem;
    line-height: 1;
    color: var(--blue);
}

details[open] summary::after {
    content: "\2212";
}

details p {
    color: var(--muted);
    margin-top: 10px;
}

/* ===== Footer ===== */
.site-footer {
    background: #051a33;
    color: #b7c8db;
    padding-top: 64px;
}

.f-grid {
    display: grid;
    grid-template-columns: 1.2fr .7fr 1.7fr 1.2fr;
    gap: 44px;
}

.f-logo {
    display: inline-block;
    background: #fff;
    border-radius: 12px;
    padding: 8px 14px;
    margin-bottom: 18px;
}

.f-logo img {
    height: 52px;
    width: auto;
}

.f-brand p {
    font-size: .94rem;
    max-width: 34ch;
}

.f-col h4 {
    font-family: var(--head);
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: 18px;
    padding-bottom: 10px;
    position: relative;
}

.f-col h4::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 34px;
    height: 2px;
    background: var(--gold);
}

.f-col>a {
    display: block;
    color: #b7c8db;
    font-size: .94rem;
    padding: 5px 0;
    transition: color .2s, padding-left .2s;
}

.f-col>a:hover {
    color: #fff;
    padding-left: 4px;
}

/* Products list in footer: two columns */
.f-links {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0 24px;
}

.f-links a {
    display: block;
    color: #b7c8db;
    font-size: .94rem;
    padding: 5px 0;
    transition: color .2s, padding-left .2s;
}

.f-links a:hover {
    color: #fff;
    padding-left: 4px;
}

.f-contact .row {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    font-size: .92rem;
    margin-bottom: 14px;
    color: #b7c8db;
}

.f-contact a.row:hover {
    color: #fff;
}

.f-bottom {
    margin-top: 52px;
    border-top: 1px solid rgba(255, 255, 255, .1);
}

.f-bottom-in {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 24px;
    justify-content: space-between;
    padding: 20px 0;
    font-size: .85rem;
}

.f-legal {
    display: flex;
    gap: 20px;
}

.f-legal a:hover {
    color: #fff;
}

/* ===== Floating WhatsApp ===== */
.wa-float {
    position: fixed;
    right: 22px;
    bottom: calc(22px + env(safe-area-inset-bottom, 0px));
    z-index: 60;
    width: 58px;
    height: 58px;
    border-radius: 50%;
    background: #25d366;
    display: grid;
    place-items: center;
    box-shadow: 0 8px 22px rgba(0, 0, 0, .28);
    transition: transform .2s;
}

.wa-float:hover {
    transform: scale(1.08);
}

.wa-float::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: #25d366;
    z-index: -1;
    animation: waPulse 2.4s ease-out infinite;
}

.wa-tip {
    position: absolute;
    right: 70px;
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--line);
    padding: 7px 12px;
    border-radius: 8px;
    font-size: .85rem;
    font-weight: 700;
    white-space: nowrap;
    box-shadow: var(--shadow);
    opacity: 0;
    transform: translateX(6px);
    pointer-events: none;
    transition: opacity .2s, transform .2s;
}

.wa-float:hover .wa-tip,
.wa-float:focus-visible .wa-tip {
    opacity: 1;
    transform: none;
}

@keyframes waPulse {
    0% {
        transform: scale(1);
        opacity: .55;
    }

    100% {
        transform: scale(1.7);
        opacity: 0;
    }
}

/* ===== Responsive ===== */
@media (max-width: 1000px) {

    .step-grid,
    .step-grid.three-col {
        grid-template-columns: 1fr 1fr;
    }

    .benefits,
    .benefits.three {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 960px) {
    .about-split {
        grid-template-columns: 1fr;
        gap: 36px;
    }

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

    .f-range {
        grid-column: 1 / -1;
        order: 5;
    }

    .spec-strip-in {
        grid-template-columns: 1fr 1fr;
    }

    .spec-strip-in>div:nth-child(2) {
        border-right: 0;
    }

    .spec-strip-in>div:nth-child(-n+2) {
        border-bottom: 1px solid var(--line);
    }

    .menu-btn {
        display: grid;
    }

    .nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--surface);
        border-bottom: 1px solid var(--line);
        flex-direction: column;
        align-items: stretch;
        padding: 12px 20px 20px;
        display: none;
    }

    .nav.open {
        display: flex;
    }

    .nav a {
        padding: 12px 14px;
    }

    .nav a.nav-cta {
        text-align: center;
        margin: 6px 0;
    }
}

@media (max-width: 860px) {
    .dom-hero {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 560px) {
    .section {
        padding: 56px 0;
    }

    .step-grid,
    .step-grid.three-col,
    .benefits,
    .benefits.three {
        grid-template-columns: 1fr;
    }

    .checklist.two-col {
        grid-template-columns: 1fr;
    }

    .f-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .f-bottom-in {
        flex-direction: column;
    }

    .wa-float {
        right: 16px;
        width: 54px;
        height: 54px;
    }

    .wa-tip {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        scroll-behavior: auto !important;
    }

    .wa-float::before {
        animation: none;
        display: none;
    }
}

/* ===== Inline link inside body text ===== */
.inline-link {
    color: var(--blue);
    font-weight: 700;
}

.inline-link:hover {
    text-decoration: underline;
}

/* ===== Five step cards: three on top, two centred below ===== */
.step-grid {
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
}

.step-grid .step-card {
    grid-column: span 2;
}

.step-grid .step-card:nth-child(4) {
    grid-column: 2 / span 2;
}

.step-grid .step-card:nth-child(5) {
    grid-column: 4 / span 2;
}

@media (max-width: 1000px) {
    .step-grid {
        grid-template-columns: 1fr 1fr;
    }

    .step-grid .step-card,
    .step-grid .step-card:nth-child(4),
    .step-grid .step-card:nth-child(5) {
        grid-column: auto;
    }

    .step-grid .step-card:last-child {
        grid-column: 1 / -1;
    }
}

@media (max-width: 560px) {
    .step-grid {
        grid-template-columns: 1fr;
    }

    .step-grid .step-card:last-child {
        grid-column: auto;
    }
}