/* =========================================
   FUTUREVERSE SPACE CENTER
   EARTH SCIENCE
   earth-science.css
========================================= */


/* =========================================
   01. ROOT
========================================= */

:root {

    --earth-primary: #147d8f;
    --earth-secondary: #1e9fb3;
    --earth-accent: #49b6a8;

    --earth-dark: #102b35;
    --earth-text: #20343b;
    --earth-muted: #687c83;

    --earth-bg: #f4f9fa;
    --earth-card: #ffffff;
    --earth-border: rgba(20, 125, 143, 0.12);

    --earth-shadow:
        0 20px 55px rgba(20, 60, 75, 0.10);

    --earth-radius: 24px;
}


/* =========================================
   02. RESET
========================================= */

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

html {
    scroll-behavior: smooth;
}

body {

    font-family:
        "Segoe UI",
        Arial,
        sans-serif;

    background:
        var(--earth-bg);

    color:
        var(--earth-text);

    line-height: 1.7;

    overflow-x: hidden;

    transition:
        background 0.3s ease,
        color 0.3s ease;
}

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

button {
    font: inherit;
}

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


/* =========================================
   03. PAGE
========================================= */

.earth-science-page {
    width: 100%;
    min-height: 100vh;
}


/* =========================================
   04. HEADER
========================================= */

.earth-header {

    width: min(1180px, calc(100% - 40px));

    margin: 0 auto;

    min-height: 82px;

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 20px;
}


/* Brand */

.earth-brand {

    display: flex;

    align-items: center;

    gap: 12px;
}

.earth-brand-icon {

    width: 46px;
    height: 46px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 14px;

    background:
        linear-gradient(
            135deg,
            var(--earth-primary),
            var(--earth-accent)
        );

    color: #ffffff;

    font-size: 20px;

    box-shadow:
        0 10px 25px
        rgba(20, 125, 143, 0.22);
}

.earth-brand-text {

    display: flex;

    flex-direction: column;

    line-height: 1.2;
}

.earth-brand-text strong {

    font-size: 17px;

    color:
        var(--earth-dark);

    letter-spacing: -0.3px;
}

.earth-brand-text span {

    margin-top: 3px;

    font-size: 11px;

    color:
        var(--earth-muted);

    text-transform: uppercase;

    letter-spacing: 1.3px;
}


/* Back button */

.back-home-btn {

    display: inline-flex;

    align-items: center;

    justify-content: center;

    gap: 8px;

    min-height: 42px;

    padding: 0 17px;

    border-radius: 12px;

    border: 1px solid var(--earth-border);

    background:
        rgba(255, 255, 255, 0.8);

    color:
        var(--earth-dark);

    font-size: 13px;

    font-weight: 600;

    transition:
        transform 0.25s ease,
        background 0.25s ease,
        box-shadow 0.25s ease;
}

.back-home-btn:hover {

    transform: translateY(-2px);

    background: #ffffff;

    box-shadow:
        0 10px 25px
        rgba(20, 70, 80, 0.10);
}


/* =========================================
   05. HERO
========================================= */

.earth-hero {

    position: relative;

    width: min(1180px, calc(100% - 40px));

    min-height: 530px;

    margin: 18px auto 0;

    padding: 72px 70px;

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 50px;

    overflow: hidden;

    border-radius: 34px;

    background:

        radial-gradient(
            circle at 85% 50%,
            rgba(73, 182, 168, 0.30),
            transparent 30%
        ),

        radial-gradient(
            circle at 20% 20%,
            rgba(30, 159, 179, 0.18),
            transparent 32%
        ),

        linear-gradient(
            135deg,
            #102f39,
            #0d4550 55%,
            #126f78
        );

    color: #ffffff;

    box-shadow:
        0 30px 80px
        rgba(10, 70, 80, 0.18);
}


/* Decorative glow */

.earth-hero::before {

    content: "";

    position: absolute;

    width: 420px;
    height: 420px;

    right: -150px;
    top: -180px;

    border-radius: 50%;

    border:
        1px solid
        rgba(255, 255, 255, 0.10);

    box-shadow:
        0 0 0 70px rgba(255,255,255,0.025),
        0 0 0 140px rgba(255,255,255,0.018);

    pointer-events: none;
}

.earth-hero::after {

    content: "";

    position: absolute;

    width: 8px;
    height: 8px;

    left: 52%;
    top: 18%;

    border-radius: 50%;

    background: rgba(255,255,255,0.75);

    box-shadow:
        120px 90px 0 rgba(255,255,255,0.45),
        -190px 210px 0 rgba(255,255,255,0.35),
        250px -30px 0 rgba(255,255,255,0.30);
}


/* Hero content */

.earth-hero-content {

    position: relative;

    z-index: 2;

    width: min(620px, 100%);
}

.earth-eyebrow {

    display: inline-block;

    margin-bottom: 14px;

    font-size: 11px;

    font-weight: 700;

    letter-spacing: 2.5px;

    color:
        #8ee4d6;
}

.earth-hero h1 {

    font-size:
        clamp(48px, 6vw, 82px);

    line-height: 0.98;

    letter-spacing: -3px;

    margin-bottom: 26px;

    font-weight: 800;
}

.earth-hero h1 span {

    display: block;

    color:
        #73d8cb;
}

.earth-hero p {

    max-width: 650px;

    color:
        rgba(255,255,255,0.78);

    font-size: 16px;

    line-height: 1.8;
}


/* Hero statistics */

.earth-hero-meta {

    display: flex;

    flex-wrap: wrap;

    gap: 28px;

    margin-top: 35px;
}

.earth-meta-item {

    display: flex;

    flex-direction: column;

    min-width: 110px;
}

.earth-meta-item strong {

    font-size: 23px;

    color: #ffffff;

    line-height: 1.2;
}

.earth-meta-item span {

    margin-top: 4px;

    font-size: 10px;

    color:
        rgba(255,255,255,0.58);

    text-transform: uppercase;

    letter-spacing: 0.7px;
}


/* =========================================
   06. CSS EARTH VISUAL
========================================= */

.earth-visual {

    position: relative;

    width: 360px;
    height: 360px;

    flex-shrink: 0;

    display: flex;

    align-items: center;
    justify-content: center;

    z-index: 2;
}

.earth-glow {

    position: absolute;

    width: 310px;
    height: 310px;

    border-radius: 50%;

    background:
        rgba(73, 182, 168, 0.20);

    filter: blur(35px);
}

.earth-orbit {

    position: absolute;

    width: 345px;
    height: 345px;

    border-radius: 50%;

    border:
        1px solid
        rgba(255,255,255,0.15);

    transform: rotate(-18deg);
}

.earth-planet {

    position: relative;

    width: 245px;
    height: 245px;

    overflow: hidden;

    border-radius: 50%;

    background:

        radial-gradient(
            circle at 32% 28%,
            #56c8d0 0%,
            #1b8eaa 38%,
            #125c7b 72%,
            #092f45 100%
        );

    box-shadow:

        inset -28px -20px 45px
        rgba(0,0,0,0.30),

        inset 18px 12px 35px
        rgba(255,255,255,0.12),

        0 0 0 10px
        rgba(255,255,255,0.05),

        0 25px 60px
        rgba(0,0,0,0.30);

    animation:
        earthFloat 7s ease-in-out infinite;
}


/* Earth land shapes */

.earth-land {

    position: absolute;

    background:
        #56a66c;

    opacity: 0.9;

    filter:
        drop-shadow(0 3px 4px rgba(0,0,0,0.12));
}

.land-one {

    width: 95px;
    height: 58px;

    left: 28px;
    top: 50px;

    border-radius:
        70% 30% 45% 55% /
        45% 50% 50% 55%;

    transform: rotate(-18deg);
}

.land-two {

    width: 62px;
    height: 100px;

    left: 108px;
    top: 76px;

    border-radius:
        40% 60% 35% 65% /
        35% 50% 50% 65%;

    transform: rotate(15deg);
}

.land-three {

    width: 70px;
    height: 42px;

    right: 18px;
    top: 125px;

    border-radius:
        50% 35% 55% 40%;

    transform: rotate(22deg);
}

.land-four {

    width: 55px;
    height: 75px;

    left: 54px;
    bottom: 17px;

    border-radius:
        55% 45% 40% 60%;

    transform: rotate(12deg);
}


/* Clouds */

.earth-cloud {

    position: absolute;

    height: 10px;

    border-radius: 20px;

    background:
        rgba(255,255,255,0.58);

    filter:
        blur(1px);

    transform: rotate(-12deg);
}

.cloud-one {

    width: 90px;

    top: 40px;
    right: 12px;
}

.cloud-two {

    width: 72px;

    left: 22px;
    bottom: 63px;

    transform: rotate(15deg);
}

.cloud-three {

    width: 105px;

    right: 32px;
    bottom: 42px;

    transform: rotate(-5deg);
}


@keyframes earthFloat {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}


/* =========================================
   07. DOCUMENTARY NAV
========================================= */

.earth-documentary-nav {

    width: min(1180px, calc(100% - 40px));

    margin: 26px auto 0;

    padding: 12px;

    display: flex;

    gap: 8px;

    overflow-x: auto;

    scrollbar-width: none;

    background:
        rgba(255,255,255,0.92);

    border:
        1px solid
        var(--earth-border);

    border-radius: 18px;

    box-shadow:
        0 10px 35px
        rgba(20,60,75,0.06);

    position: sticky;

    top: 12px;

    z-index: 50;
}

.earth-documentary-nav::-webkit-scrollbar {
    display: none;
}

.earth-documentary-nav a {

    flex-shrink: 0;

    padding: 9px 14px;

    border-radius: 10px;

    font-size: 12px;

    font-weight: 600;

    color:
        var(--earth-muted);

    transition:
        background 0.2s ease,
        color 0.2s ease;
}

.earth-documentary-nav a:hover {

    color:
        var(--earth-primary);

    background:
        rgba(20,125,143,0.08);
}

.earth-documentary-nav a.active {

    color:
        var(--earth-primary);

    background:
        rgba(20, 125, 143, 0.10);
}


/* =========================================
   08. GENERAL SECTIONS
========================================= */

.earth-section {

    width: min(1100px, calc(100% - 40px));

    margin: 110px auto 0;
}

.section-heading {

    max-width: 760px;

    margin-bottom: 42px;
}

.section-heading > span {

    display: inline-block;

    margin-bottom: 10px;

    color:
        var(--earth-primary);

    font-size: 11px;

    font-weight: 800;

    letter-spacing: 2px;
}

.section-heading h2 {

    margin-bottom: 14px;

    color:
        var(--earth-dark);

    font-size:
        clamp(30px, 4vw, 46px);

    line-height: 1.1;

    letter-spacing: -1.5px;
}

.section-heading p {

    color:
        var(--earth-muted);

    font-size: 15px;

    line-height: 1.8;
}


/* =========================================
   09. OVERVIEW
========================================= */

.overview-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 18px;
}

.overview-card {

    padding: 28px 24px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius:
        var(--earth-radius);

    box-shadow:
        var(--earth-shadow);

    transition:
        transform 0.25s ease,
        box-shadow 0.25s ease;
}

.overview-card:hover {

    transform:
        translateY(-5px);

    box-shadow:
        0 25px 55px
        rgba(20,60,75,0.13);
}

.overview-icon {

    width: 48px;
    height: 48px;

    margin-bottom: 20px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 14px;

    background:
        rgba(20,125,143,0.09);

    color:
        var(--earth-primary);

    font-size: 19px;
}

.overview-card h3 {

    margin-bottom: 9px;

    font-size: 18px;

    color:
        var(--earth-dark);
}

.overview-card p {

    color:
        var(--earth-muted);

    font-size: 13px;

    line-height: 1.75;
}


/* Fact box */

.earth-fact-box {

    margin-top: 24px;

    padding: 34px;

    border-radius: 24px;

    background:

        linear-gradient(
            135deg,
            rgba(20,125,143,0.08),
            rgba(73,182,168,0.08)
        );

    border:
        1px solid
        rgba(20,125,143,0.12);
}

.earth-fact-box > span {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.8px;

    color:
        var(--earth-primary);
}

.earth-fact-box h3 {

    margin: 8px 0;

    font-size: 22px;

    color:
        var(--earth-dark);
}

.earth-fact-box p {

    max-width: 800px;

    color:
        var(--earth-muted);

    font-size: 14px;
}


/* =========================================
   10. EARTH INTERIOR
========================================= */

.interior-layout {

    display: grid;

    grid-template-columns:
        0.9fr 1.1fr;

    align-items: center;

    gap: 70px;
}


/* Cross section */

.earth-cross-section {

    position: relative;

    width: 360px;
    height: 360px;

    margin: auto;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 50%;

    background:
        #879aa0;

    box-shadow:
        0 25px 60px
        rgba(30,60,70,0.15);
}

.earth-cross-section > div {

    position: absolute;

    border-radius: 50%;

    display: flex;

    align-items: center;
    justify-content: center;

    text-align: center;

    font-size: 11px;

    font-weight: 700;

    color: #ffffff;
}

.mantle {

    width: 330px;
    height: 330px;

    background:
        #b85f48;
}

.outer-core {

    width: 205px;
    height: 205px;

    background:
        #d89148;
}

.inner-core {

    width: 110px;
    height: 110px;

    background:
        #e9bd67;

    color:
        #5a3a12 !important;
}

.crust {

    width: 360px;
    height: 360px;

    border:
        8px solid
        #617a72;

    background:
        transparent;

    z-index: 5;

    justify-content:
        flex-start !important;

    align-items:
        flex-start !important;

    padding:
        34px 0 0 18px;

    color:
        #ffffff;
}


/* Interior content */

.interior-content {

    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 16px;
}

.science-block {

    padding: 24px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius: 18px;

    box-shadow:
        0 15px 35px
        rgba(20,60,75,0.07);
}

.science-block h3 {

    margin-bottom: 8px;

    color:
        var(--earth-dark);

    font-size: 17px;
}

.science-block p {

    color:
        var(--earth-muted);

    font-size: 13px;
    line-height: 1.7;
}


/* Science note */

.science-note {

    margin-top: 28px;

    display: flex;

    gap: 16px;

    padding: 22px 25px;

    border-radius: 18px;

    background:
        rgba(20,125,143,0.06);

    border:
        1px solid
        rgba(20,125,143,0.10);
}

.science-note > i {

    color:
        var(--earth-primary);

    font-size: 21px;

    margin-top: 4px;
}

.science-note strong {

    color:
        var(--earth-dark);

    font-size: 14px;
}

.science-note p {

    margin-top: 4px;

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   11. TECTONICS
========================================= */

.tectonic-process-grid {

    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 18px;
}

.tectonic-card {

    position: relative;

    padding: 32px 27px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius: 22px;

    box-shadow:
        var(--earth-shadow);

    overflow: hidden;
}

.tectonic-number {

    position: absolute;

    right: 22px;
    top: 18px;

    font-size: 44px;

    font-weight: 800;

    color:
        rgba(20,125,143,0.07);
}

.tectonic-card h3 {

    margin-bottom: 12px;

    color:
        var(--earth-dark);

    font-size: 20px;
}

.tectonic-card p {

    color:
        var(--earth-muted);

    font-size: 14px;
    line-height: 1.8;
}

.tectonics-fact {

    margin-top: 24px;

    display: flex;

    gap: 20px;

    align-items: center;

    padding: 28px;

    border-radius: 22px;

    background:
        linear-gradient(
            135deg,
            #e9f7f6,
            #edf8fb
        );
}

.tectonics-fact-icon {

    width: 54px;
    height: 54px;

    flex-shrink: 0;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 15px;

    background:
        #ffffff;

    color:
        var(--earth-primary);

    box-shadow:
        0 10px 25px
        rgba(20,80,90,0.08);
}

.tectonics-fact span {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.5px;

    color:
        var(--earth-primary);
}

.tectonics-fact h3 {

    margin: 3px 0;

    font-size: 21px;

    color:
        var(--earth-dark);
}

.tectonics-fact p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   12. LANDFORMS
========================================= */

.landforms-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 18px;
}

.landform-card {

    padding: 28px 24px;

    background:
        var(--earth-card);

    border-radius: 22px;

    border:
        1px solid
        var(--earth-border);

    box-shadow:
        var(--earth-shadow);

    transition:
        transform 0.25s ease;
}

.landform-card:hover {

    transform:
        translateY(-5px);
}

.landform-icon {

    width: 50px;
    height: 50px;

    margin-bottom: 20px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 15px;

    background:
        rgba(73,182,168,0.10);

    color:
        var(--earth-accent);

    font-size: 20px;
}

.landform-card h3 {

    margin-bottom: 9px;

    font-size: 18px;

    color:
        var(--earth-dark);
}

.landform-card p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   13. ATMOSPHERE
========================================= */

.atmosphere-layers {

    display: flex;

    flex-direction: column;

    gap: 12px;
}

.atmosphere-layer {

    display: grid;

    grid-template-columns:
        55px 1fr;

    align-items: center;

    gap: 20px;

    padding: 23px 28px;

    border-radius: 18px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    box-shadow:
        0 12px 30px
        rgba(20,60,75,0.06);

    transition:
        transform 0.2s ease;
}

.atmosphere-layer:hover {

    transform:
        translateX(5px);
}

.layer-number {

    width: 42px;
    height: 42px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 12px;

    background:
        rgba(20,125,143,0.08);

    color:
        var(--earth-primary);

    font-size: 12px;

    font-weight: 800;
}

.atmosphere-layer h3 {

    margin-bottom: 4px;

    color:
        var(--earth-dark);

    font-size: 18px;
}

.atmosphere-layer p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   14. WEATHER
========================================= */

.weather-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 18px;
}

.weather-card {

    padding: 30px 25px;

    border-radius: 22px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    box-shadow:
        var(--earth-shadow);
}

.weather-card > i {

    margin-bottom: 20px;

    font-size: 25px;

    color:
        var(--earth-primary);
}

.weather-card h3 {

    margin-bottom: 9px;

    font-size: 18px;

    color:
        var(--earth-dark);
}

.weather-card p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   15. WATER CYCLE
========================================= */

.water-cycle {

    display: flex;

    align-items: stretch;

    justify-content: center;

    gap: 10px;
}

.water-step {

    flex: 1;

    min-width: 0;

    padding: 28px 20px;

    text-align: center;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius: 20px;

    box-shadow:
        var(--earth-shadow);
}

.water-step > span {

    display: block;

    margin-bottom: 12px;

    color:
        var(--earth-primary);

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.5px;
}

.water-step > i {

    margin-bottom: 15px;

    font-size: 24px;

    color:
        var(--earth-secondary);
}

.water-step h3 {

    margin-bottom: 8px;

    font-size: 17px;

    color:
        var(--earth-dark);
}

.water-step p {

    color:
        var(--earth-muted);

    font-size: 12px;

    line-height: 1.7;
}

.water-arrow {

    align-self: center;

    color:
        var(--earth-accent);

    font-size: 14px;
}

.water-fact {

    margin-top: 24px;

    padding: 24px 28px;

    border-radius: 18px;

    background:
        rgba(20,125,143,0.06);

    border:
        1px solid
        rgba(20,125,143,0.10);
}

.water-fact strong {

    display: block;

    margin-bottom: 5px;

    color:
        var(--earth-dark);

    font-size: 15px;
}

.water-fact p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   16. OCEANS
========================================= */

.ocean-feature {

    display: grid;

    grid-template-columns:
        0.9fr 1.1fr;

    overflow: hidden;

    border-radius: 28px;

    background:
        linear-gradient(
            135deg,
            #0d4f67,
            #116e7f,
            #15928f
        );

    color: #ffffff;

    box-shadow:
        0 25px 65px
        rgba(15,80,95,0.18);
}

.ocean-visual {

    position: relative;

    min-height: 330px;

    display: flex;

    align-items: center;
    justify-content: center;

    overflow: hidden;

    background:
        radial-gradient(
            circle at 50% 45%,
            rgba(111,224,214,0.25),
            transparent 40%
        );
}

.ocean-visual > i {

    position: relative;

    z-index: 3;

    font-size: 80px;

    color:
        rgba(255,255,255,0.92);
}

.ocean-wave {

    position: absolute;

    width: 480px;
    height: 180px;

    border-radius: 50%;

    border-top:
        2px solid
        rgba(255,255,255,0.22);

    transform: rotate(-10deg);
}

.wave-one {
    top: 40px;
}

.wave-two {
    top: 105px;
}

.wave-three {
    top: 170px;
}

.ocean-content {

    padding: 52px 48px;
}

.ocean-content > span {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 2px;

    color:
        #8ce5dc;
}

.ocean-content h3 {

    margin: 12px 0 16px;

    font-size:
        clamp(26px, 3vw, 38px);

    line-height: 1.15;
}

.ocean-content p {

    color:
        rgba(255,255,255,0.72);

    font-size: 14px;
}

.ocean-stats {

    display: flex;

    gap: 35px;

    margin-top: 30px;
}

.ocean-stats div {

    display: flex;

    flex-direction: column;
}

.ocean-stats strong {

    font-size: 24px;
}

.ocean-stats span {

    margin-top: 3px;

    color:
        rgba(255,255,255,0.58);

    font-size: 10px;

    text-transform: uppercase;

    letter-spacing: 0.7px;
}


/* =========================================
   17. CLIMATE
========================================= */

.climate-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 18px;
}

.climate-card {

    padding: 30px 25px;

    border-radius: 22px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    box-shadow:
        var(--earth-shadow);
}

.climate-card > i {

    margin-bottom: 20px;

    font-size: 24px;

    color:
        var(--earth-primary);
}

.climate-card h3 {

    margin-bottom: 9px;

    color:
        var(--earth-dark);

    font-size: 18px;
}

.climate-card p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   18. ECOSYSTEMS
========================================= */

.ecosystem-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 18px;
}

.ecosystem-card {

    padding: 28px 24px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius: 22px;

    box-shadow:
        var(--earth-shadow);
}

.ecosystem-icon {

    width: 50px;
    height: 50px;

    margin-bottom: 20px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 15px;

    background:
        rgba(73,182,168,0.10);

    color:
        var(--earth-accent);

    font-size: 20px;
}

.ecosystem-card h3 {

    margin-bottom: 9px;

    color:
        var(--earth-dark);

    font-size: 18px;
}

.ecosystem-card p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* =========================================
   19. EARTH FROM SPACE
========================================= */

.space-observation-grid {

    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 18px;
}

.observation-card {

    padding: 30px;

    background:
        var(--earth-card);

    border:
        1px solid
        var(--earth-border);

    border-radius: 22px;

    box-shadow:
        var(--earth-shadow);
}

.observation-card > i {

    margin-bottom: 20px;

    font-size: 25px;

    color:
        var(--earth-primary);
}

.observation-card h3 {

    margin-bottom: 9px;

    color:
        var(--earth-dark);

    font-size: 19px;
}

.observation-card p {

    color:
        var(--earth-muted);

    font-size: 13px;
}


/* Observation banner */

.earth-observation-banner {

    margin-top: 24px;

    display: flex;

    align-items: center;

    gap: 20px;

    padding: 30px;

    border-radius: 24px;

    background:
        linear-gradient(
            135deg,
            #102f39,
            #126d76
        );

    color: #ffffff;

    box-shadow:
        0 20px 55px
        rgba(10,70,80,0.15);
}

.observation-banner-icon {

    width: 58px;
    height: 58px;

    flex-shrink: 0;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 17px;

    background:
        rgba(255,255,255,0.10);

    color:
        #8ce5dc;

    font-size: 23px;
}

.earth-observation-banner span {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.8px;

    color:
        #8ce5dc;
}

.earth-observation-banner h3 {

    margin: 3px 0 5px;

    font-size: 23px;
}

.earth-observation-banner p {

    max-width: 760px;

    color:
        rgba(255,255,255,0.68);

    font-size: 13px;
}


/* =========================================
   20. CONNECTION
========================================= */

.earth-connection {

    width: min(1100px, calc(100% - 40px));

    margin: 110px auto 0;

    padding: 48px;

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 35px;

    border-radius: 28px;

    background:
        linear-gradient(
            135deg,
            rgba(20,125,143,0.09),
            rgba(73,182,168,0.10)
        );

    border:
        1px solid
        rgba(20,125,143,0.12);
}

.connection-content {

    max-width: 620px;
}

.connection-content > span {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 2px;

    color:
        var(--earth-primary);
}

.connection-content h2 {

    margin: 8px 0 10px;

    color:
        var(--earth-dark);

    font-size:
        clamp(25px, 3vw, 36px);

    line-height: 1.2;
}

.connection-content p {

    color:
        var(--earth-muted);

    font-size: 13px;
}

.connection-actions {

    display: flex;

    flex-wrap: wrap;

    gap: 9px;

    justify-content: flex-end;
}

.connection-btn {

    display: inline-flex;

    align-items: center;

    gap: 8px;

    padding: 11px 15px;

    border-radius: 12px;

    background:
        #ffffff;

    border:
        1px solid
        var(--earth-border);

    color:
        var(--earth-dark);

    font-size: 12px;

    font-weight: 700;

    transition:
        transform 0.2s ease,
        box-shadow 0.2s ease;
}

.connection-btn:hover {

    transform:
        translateY(-2px);

    box-shadow:
        0 10px 25px
        rgba(20,60,75,0.10);
}


/* =========================================
   21. FOOTER
========================================= */

.earth-footer {

    width: min(1180px, calc(100% - 40px));

    margin: 100px auto 0;

    padding: 35px 0 40px;

    border-top:
        1px solid
        var(--earth-border);
}

.earth-footer-brand {

    display: flex;

    align-items: center;

    gap: 11px;

    margin-bottom: 22px;
}

.footer-earth-icon {

    width: 38px;
    height: 38px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 11px;

    background:
        rgba(20,125,143,0.09);

    color:
        var(--earth-primary);
}

.earth-footer-brand > div:last-child {

    display: flex;

    flex-direction: column;

    line-height: 1.2;
}

.earth-footer-brand strong {

    color:
        var(--earth-dark);

    font-size: 15px;
}

.earth-footer-brand span {

    margin-top: 3px;

    color:
        var(--earth-muted);

    font-size: 9px;

    text-transform: uppercase;

    letter-spacing: 1.2px;
}

.earth-footer-links {

    display: flex;

    flex-wrap: wrap;

    gap: 18px;

    margin-bottom: 22px;
}

.earth-footer-links a {

    color:
        var(--earth-muted);

    font-size: 12px;

    transition:
        color 0.2s ease;
}

.earth-footer-links a:hover {

    color:
        var(--earth-primary);
}

.earth-footer-copy {

    color:
        var(--earth-muted);

    font-size: 11px;
}


/* =========================================
   22. DARK MODE
========================================= */

body[data-theme="dark"] {

    --earth-bg: #08191f;
    --earth-card: #10282f;

    --earth-dark: #f1fbfc;
    --earth-text: #e0edef;
    --earth-muted: #91aeb4;

    --earth-border:
        rgba(130,220,215,0.10);

    --earth-shadow:
        0 20px 55px
        rgba(0,0,0,0.22);
}

body[data-theme="dark"] .earth-brand-text strong {
    color: #f1fbfc;
}

body[data-theme="dark"] .back-home-btn {

    background:
        rgba(255,255,255,0.05);

    color:
        #eaf8f9;
}

body[data-theme="dark"] .back-home-btn:hover {

    background:
        rgba(255,255,255,0.09);
}

body[data-theme="dark"] .earth-documentary-nav {

    background:
        rgba(16,40,47,0.94);
}

body[data-theme="dark"] .earth-documentary-nav a:hover {

    background:
        rgba(130,220,215,0.08);
}

body[data-theme="dark"] .earth-fact-box {

    background:
        rgba(73,182,168,0.06);
}

body[data-theme="dark"] .tectonics-fact {

    background:
        rgba(73,182,168,0.07);
}

body[data-theme="dark"] .tectonics-fact-icon {

    background:
        #10282f;
}

body[data-theme="dark"] .science-note,
body[data-theme="dark"] .water-fact {

    background:
        rgba(73,182,168,0.06);
}

body[data-theme="dark"] .connection-btn {

    background:
        #10282f;

    color:
        #eaf8f9;
}

body[data-theme="dark"] .earth-footer {

    border-color:
        rgba(130,220,215,0.10);
}


/* =========================================
   23. TABLET
========================================= */

@media (max-width: 1000px) {

    .earth-hero {

        padding: 60px 45px;
    }

    .earth-visual {

        width: 300px;
        height: 300px;
    }

    .earth-planet {

        width: 205px;
        height: 205px;
    }

    .earth-orbit {

        width: 285px;
        height: 285px;
    }

    .overview-grid,
    .landforms-grid,
    .weather-grid,
    .climate-grid,
    .ecosystem-grid {

        grid-template-columns:
            repeat(2, 1fr);
    }

    .interior-layout {

        gap: 35px;
    }

    .water-cycle {

        flex-wrap: wrap;
    }

    .water-step {

        flex:
            1 1 40%;
    }

    .water-arrow {

        display: none;
    }

    .earth-connection {

        flex-direction: column;

        align-items: flex-start;
    }

    .connection-actions {

        justify-content: flex-start;
    }
}


/* =========================================
   24. MOBILE
========================================= */

@media (max-width: 700px) {

    .earth-header {

        width:
            calc(100% - 28px);

        min-height: 70px;
    }

    .earth-brand-icon {

        width: 40px;
        height: 40px;

        font-size: 17px;
    }

    .earth-brand-text strong {

        font-size: 15px;
    }

    .earth-brand-text span {

        font-size: 9px;
    }

    .back-home-btn {

        min-height: 38px;

        padding: 0 12px;

        font-size: 11px;
    }


    /* Hero */

    .earth-hero {

        width:
            calc(100% - 28px);

        min-height:
            auto;

        margin-top: 10px;

        padding:
            45px 25px 35px;

        flex-direction: column;

        align-items: flex-start;

        border-radius: 26px;

        gap: 20px;
    }

    .earth-hero h1 {

        font-size:
            clamp(43px, 14vw, 65px);

        letter-spacing:
            -2.5px;

        margin-bottom: 20px;
    }

    .earth-hero p {

        font-size: 13px;

        line-height: 1.75;
    }

    .earth-hero-meta {

        gap: 20px;

        margin-top: 25px;
    }

    .earth-meta-item {

        min-width:
            calc(33.333% - 15px);
    }

    .earth-meta-item strong {

        font-size: 18px;
    }

    .earth-meta-item span {

        font-size: 8px;

        line-height: 1.4;
    }


    /* Earth visual */

    .earth-visual {

        width: 270px;
        height: 270px;

        align-self: center;

        margin-top: 5px;
    }

    .earth-planet {

        width: 185px;
        height: 185px;
    }

    .earth-orbit {

        width: 255px;
        height: 255px;
    }

    .earth-glow {

        width: 230px;
        height: 230px;
    }


    /* Navigation */

    .earth-documentary-nav {

        width:
            calc(100% - 28px);

        margin-top: 16px;

        padding: 9px;

        top: 8px;

        border-radius: 14px;
    }

    .earth-documentary-nav a {

        padding:
            8px 11px;

        font-size: 10px;
    }


    /* Sections */

    .earth-section {

        width:
            calc(100% - 28px);

        margin-top: 75px;
    }

    .section-heading {

        margin-bottom: 28px;
    }

    .section-heading > span {

        font-size: 9px;

        letter-spacing: 1.5px;
    }

    .section-heading h2 {

        font-size:
            clamp(27px, 8vw, 36px);

        letter-spacing: -1px;
    }

    .section-heading p {

        font-size: 13px;
    }


    /* Cards */

    .overview-grid,
    .landforms-grid,
    .weather-grid,
    .climate-grid,
    .ecosystem-grid {

        grid-template-columns:
            1fr;
    }

    .overview-card,
    .landform-card,
    .weather-card,
    .climate-card,
    .ecosystem-card {

        padding:
            24px 21px;
    }


    /* Interior */

    .interior-layout {

        grid-template-columns:
            1fr;

        gap: 35px;
    }

    .earth-cross-section {

        width: 280px;
        height: 280px;
    }

    .mantle {

        width: 255px;
        height: 255px;
    }

    .outer-core {

        width: 160px;
        height: 160px;
    }

    .inner-core {

        width: 85px;
        height: 85px;
    }

    .crust {

        width: 280px;
        height: 280px;

        border-width: 6px;

        padding:
            27px 0 0 13px;
    }

    .interior-content {

        grid-template-columns:
            1fr;
    }

    .science-note {

        padding: 19px;

        gap: 12px;
    }


    /* Tectonics */

    .tectonic-process-grid {

        grid-template-columns:
            1fr;
    }

    .tectonics-fact {

        padding: 22px;

        align-items:
            flex-start;
    }

    .tectonics-fact h3 {

        font-size: 18px;
    }


    /* Atmosphere */

    .atmosphere-layer {

        grid-template-columns:
            45px 1fr;

        gap: 14px;

        padding:
            20px 18px;
    }

    .layer-number {

        width: 36px;
        height: 36px;
    }


    /* Water */

    .water-cycle {

        flex-direction:
            column;
    }

    .water-step {

        flex:
            none;

        width: 100%;

        padding:
            24px 20px;
    }


    /* Ocean */

    .ocean-feature {

        grid-template-columns:
            1fr;
    }

    .ocean-visual {

        min-height: 230px;
    }

    .ocean-visual > i {

        font-size: 60px;
    }

    .ocean-content {

        padding:
            35px 25px;
    }

    .ocean-stats {

        gap: 25px;
    }


    /* Space observation */

    .space-observation-grid {

        grid-template-columns:
            1fr;
    }

    .earth-observation-banner {

        align-items:
            flex-start;

        padding:
            23px 20px;
    }

    .earth-observation-banner h3 {

        font-size: 19px;
    }


    /* Connection */

    .earth-connection {

        width:
            calc(100% - 28px);

        margin-top: 75px;

        padding:
            30px 22px;

        border-radius: 23px;
    }

    .connection-actions {

        width: 100%;

        flex-direction:
            column;
    }

    .connection-btn {

        width: 100%;

        justify-content:
            center;
    }


    /* Footer */

    .earth-footer {

        width:
            calc(100% - 28px);

        margin-top: 75px;

        padding-bottom: 30px;
    }

    .earth-footer-links {

        gap:
            13px 18px;
    }

}


/* =========================================
   25. SMALL MOBILE
========================================= */

@media (max-width: 430px) {

    .earth-header {

        gap: 8px;
    }

    .back-home-btn {

        padding:
            0 10px;

        font-size: 10px;
    }

    .earth-hero {

        padding:
            38px 20px 28px;
    }

    .earth-hero-meta {

        width: 100%;

        justify-content:
            space-between;
    }

    .earth-meta-item {

        min-width:
            0;

        flex:
            1;
    }

    .earth-visual {

        width: 240px;
        height: 240px;
    }

    .earth-planet {

        width: 165px;
        height: 165px;
    }

    .earth-orbit {

        width: 225px;
        height: 225px;
    }

    .earth-glow {

        width: 205px;
        height: 205px;
    }

    .earth-cross-section {

        width: 250px;
        height: 250px;
    }

    .mantle {

        width: 227px;
        height: 227px;
    }

    .outer-core {

        width: 140px;
        height: 140px;
    }

    .inner-core {

        width: 75px;
        height: 75px;
    }

    .crust {

        width: 250px;
        height: 250px;
    }

    .earth-observation-banner {

        flex-direction:
            column;
    }

}