:root {
    --green-950: #063f20;
    --green-900: #075226;
    --green-800: #0b6b2f;
    --green-700: #0f8237;
    --green-600: #16a03f;
    --green-500: #38c746;
    --lime: #a6ee47;
    --yellow: #f3ff4d;
    --cream: #f7fff2;
    --text: #102416;
    --muted: #526157;
    --border: #cce7c6;
    --shadow: 0 18px 50px rgba(0, 0, 0, .16);
}

* {
    box-sizing: border-box
}

body {
    margin: 0;
    font-family: Inter, Arial, sans-serif;
    color: var(--text);
    background: linear-gradient(180deg, #f8fff4 0%, #ecfae8 100%)
}

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

.container {
    width: min(1180px, calc(100% - 36px));
    margin: auto
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: linear-gradient(90deg, var(--green-950), var(--green-700));
    border-bottom: 1px solid rgba(255, 255, 255, .15)
}

.nav-wrap {
    height: 86px;
    display: flex;
    align-items: center;
    gap: 28px
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #fff;
    min-width: 220px
}

.brand img {
    width: 80px;
    height: auto
}

.brand span {
    font-size: 26px;
    line-height: .85;
    font-weight: 900
}

.brand em {
    display: block;
    font-style: normal;
    color: #FFF
}

.main-nav {
    display: flex;
    gap: 24px;
    align-items: center;
    flex: 1;
    justify-content: center
}

.main-nav a {
    color: #fff;
    font-weight: 700;
    opacity: .92
}

.main-nav a.active,
.main-nav a:hover {
    border-bottom: 3px solid #fff;
    padding-bottom: 8px
}

.nav-actions {
    display: flex;
    gap: 14px
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    padding: 12px 22px;
    font-weight: 800;
    border: 0;
    cursor: pointer;
    transition: .2s ease
}

.btn:hover {
    transform: translateY(-1px)
}

.btn-outline {
    border: 2px solid #fff;
    color: #fff
}

.btn-light {
    background: var(--lime);
    color: #083c1d
}

.btn-primary {
    background: linear-gradient(180deg, var(--green-500), var(--green-700));
    color: #fff;
    box-shadow: 0 8px 18px rgba(22, 160, 63, .25);
    text-align: center;
}

.mobile-toggle {
    display: none;
    margin-left: auto;
    background: none;
    border: 0
}

.mobile-toggle span {
    display: block;
    width: 26px;
    height: 3px;
    background: #fff;
    margin: 5px;
    border-radius: 4px
}

.hero {
    position: relative;
    overflow: hidden;
    background: radial-gradient(circle at 70% 35%, #42bd3f 0%, #16803a 35%, #0b5c2c 70%, #06401f 100%);
    color: #fff
}

.hero:before {
    content: "2x+3=11  √25=5  a²+b²=c²  5x-2=13";
    position: absolute;
    inset: 80px 0 auto 35%;
    font-weight: 800;
    font-size: 32px;
    letter-spacing: 18px;
    line-height: 3;
    color: rgba(255, 255, 255, .09);
    transform: rotate(-8deg);
    white-space: pre-wrap
}

.hero-grid {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1.05fr;
    align-items: center;
    min-height: 455px
}

.eyebrow {
    display: inline-flex;
    background: rgba(255, 255, 255, .12);
    padding: 8px 12px;
    border-radius: 999px;
    font-weight: 800;
    margin-bottom: 18px
}

.hero h1 {
    font-size: clamp(44px, 6vw, 76px);
    line-height: .98;
    margin: 0 0 22px;
    text-shadow: 0 2px 8px rgba(0, 0, 0, .18)
}

.hero h1 span {
    color: var(--yellow)
}

.hero p {
    font-size: 20px;
    max-width: 560px;
    line-height: 1.45;
    margin: 0 0 28px
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px
}

.role-card {
    min-width: 230px;
    border-radius: 12px;
    padding: 16px 22px;
    display: block;
    box-shadow: var(--shadow)
}

.role-card strong {
    display: block;
    font-size: 18px
}

.role-card small {
    font-size: 13px
}

.role-teacher {
    background: linear-gradient(180deg, #86d930, #20a02f);
    color: #fff
}

.role-student {
    background: #fff;
    color: var(--green-800)
}

.hero-art {
    position: relative;
    text-align: right
}

.hero-art img {
    max-width: 100%;
    filter: drop-shadow(0 18px 30px rgba(0, 0, 0, .25))
}

.speech-bubble {
    position: absolute;
    right: 58px;
    top: 42px;
    background: #cbf68f;
    color: #0d4f24;
    padding: 18px 24px;
    border-radius: 28px;
    font-weight: 900;
    font-size: 20px;
    transform: rotate(3deg);
    z-index: 2;
    text-align: center;
}

.feature-strip {
    position: relative;
    z-index: 4
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    background: rgba(255, 255, 255, .96);
    border: 1px solid var(--border);
    border-radius: 18px;
    padding: 24px;
    box-shadow: var(--shadow)
}

.feature-grid article {
    padding: 0 22px;
    border-right: 1px solid var(--border)
}

.feature-grid article:last-child {
    border-right: 0
}

.feature-grid span {
    font-size: 42px
}

.feature-grid h3 {
    color: var(--green-800);
    margin: 6px 0
}

.feature-grid p {
    margin: 0;
    color: #203327;
    line-height: 1.45
}

.dashboard-preview {
    padding: 34px 0 24px
}

.app-grid {
    display: grid;
    grid-template-columns: 1.45fr 1fr .95fr .95fr;
    gap: 14px
}

.panel {
    background: rgba(255, 255, 255, .93);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 18px;
    box-shadow: 0 10px 30px rgba(14, 88, 31, .08)
}

.panel h2 {
    margin: 0 0 14px;
    color: var(--green-800)
}

.fake-app {
    display: grid;
    grid-template-columns: 115px 1fr 105px;
    gap: 14px
}

.fake-app aside {
    background: linear-gradient(180deg, var(--green-900), #1f7b38);
    border-radius: 10px;
    padding: 12px
}

.fake-app aside a {
    display: block;
    color: #fff;
    font-size: 13px;
    padding: 9px;
    border-radius: 8px
}

.fake-app aside a.active {
    background: rgba(255, 255, 255, .14)
}

.fake-form,
.stats-card,
.problem-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px
}

.fake-form form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px
}

.fake-form h3 {
    margin: 0 0 10px
}

.fake-form label {
    display: grid;
    gap: 4px;
    font-size: 12px;
    font-weight: 800
}

.fake-form input,
.fake-form select,
.answer-row input {
    border: 1px solid #d7e6d5;
    border-radius: 8px;
    padding: 11px;
    background: #fbfffa
}

.fake-form button {
    grid-column: 1/-1
}

.form-message {
    margin: 8px 0 0;
    color: var(--green-700);
    font-weight: 800
}

.stats-card {
    display: grid;
    gap: 3px;
    align-content: start
}

.stats-card strong {
    font-size: 22px
}

.stats-card span {
    font-size: 12px;
    border-bottom: 1px solid #e5f0e3;
    padding-bottom: 10px
}

.problem-card {
    position: relative;
    overflow: hidden;
    min-height: 250px
}

.points {
    text-align: right;
    color: var(--green-800)
}

.equation {
    font-size: 34px;
    font-weight: 900;
    text-align: center;
    margin: 22px 0
}

.answer-row {
    display: flex;
    gap: 10px;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 900
}

.answer-row input {
    width: 72px;
    text-align: center;
    font-size: 22px;
    font-weight: 900;
    color: var(--green-800)
}

.answer-status {
    margin-top: 20px;
    font-size: 13px
}

.progress {
    height: 9px;
    background: #d9ded8;
    border-radius: 999px;
    overflow: hidden
}

.progress span {
    display: block;
    height: 100%;
    background: var(--green-500)
}

.problem-card img {
    position: absolute;
    left: -10px;
    bottom: -10px;
    width: 115px
}

.leader-list {
    list-style: none;
    padding: 0;
    margin: 0
}

.leader-list li {
    display: flex;
    justify-content: space-between;
    padding: 13px 0;
    border-bottom: 1px solid #e4efe1
}

.game-panel img {
    width: 100%;
    border-radius: 10px;
    display: block
}

.game-panel .btn {
    width: 100%;
    margin-top: 8px
}

.trust-bar {
    padding: 18px 0 36px
}

.trust-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: linear-gradient(90deg, var(--green-950), var(--green-800));
    border-radius: 14px;
    color: #fff;
    overflow: hidden
}

.trust-grid span {
    padding: 22px;
    text-align: center;
    font-weight: 800;
    border-right: 1px solid rgba(255, 255, 255, .18)
}

.site-footer {
    background: #053a1c;
    color: #dff6df;
    padding: 42px 0 18px
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.4fr;
    gap: 28px
}

.footer-brand {
    font-size: 28px;
    font-weight: 900;
    color: #fff
}

.site-footer h4 {
    margin: 0 0 12px;
    color: #fff
}

.site-footer a {
    display: block;
    margin: 8px 0;
    color: #dff6df
}

.copyright {
    border-top: 1px solid rgba(255, 255, 255, .14);
    margin-top: 28px;
    padding-top: 18px;
    text-align: center;
    color: #a9c9ad
}

.page-hero {
    background: linear-gradient(135deg, var(--green-900), var(--green-600));
    color: #fff;
    padding: 76px 0
}

.page-hero h1 {
    font-size: 54px;
    margin: 0 0 10px
}

.page-hero p {
    font-size: 20px;
    max-width: 720px
}

.content-section {
    padding: 42px 0
}

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

.content-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    box-shadow: 0 10px 30px rgba(14, 88, 31, .08)
}

@media(max-width:1000px) {
    .nav-actions {
        display: none
    }

    .main-nav {
        display: none;
        position: absolute;
        left: 18px;
        right: 18px;
        top: 86px;
        background: var(--green-900);
        border-radius: 14px;
        padding: 18px;
        flex-direction: column
    }

    .main-nav.open {
        display: flex
    }

    .mobile-toggle {
        display: block
    }

    .hero-grid,
    .app-grid {
        grid-template-columns: 1fr
    }

    .hero-art {
        text-align: center
    }

    .feature-grid {
        grid-template-columns: 1fr 1fr
    }

    .feature-grid article {
        border-right: 0;
        border-bottom: 1px solid var(--border);
        padding: 18px
    }

    .footer-grid,
    .trust-grid,
    .two-col {
        grid-template-columns: 1fr 1fr
    }

    .fake-app {
        grid-template-columns: 1fr
    }

    .fake-app aside {
        display: flex;
        overflow: auto
    }

    .stats-card {
        grid-template-columns: repeat(3, 1fr)
    }
}

@media(max-width:640px) {
    .container {
        width: min(100% - 24px, 1180px)
    }

    .nav-wrap {
        height: 76px
    }

    .brand {
        min-width: 0
    }

    .brand span {
        font-size: 22px
    }

    .hero-grid {
        min-height: auto;
        padding: 48px 0 20px
    }

    .hero p {
        font-size: 17px
    }

    .role-card {
        width: 100%
    }

    .feature-grid,
    .footer-grid,
    .trust-grid,
    .two-col {
        grid-template-columns: 1fr
    }

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

    .speech-bubble {
        right: 10px;
        top: 8px;
        font-size: 15px
    }

    .page-hero h1 {
        font-size: 42px
    }
}

.feature-cards {
    padding: 25px 0;
    background: #f5f7f6;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.feature-card {
    background: #fff;
    border-radius: 14px;
    overflow: hidden;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.06);
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    position: relative;
  padding: 0 0 35px;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.feature-card img {
    width: 100%;
    height: auto;
}

.feature-content {
    padding: 18px;
    text-align: center;
}

.feature-content h3 {
    margin-bottom: 8px;
    color: #1e7d3a;
}

.feature-content p {
    font-size: 14px;
    color: #555;
    margin: 0 0 15px;
}
.feature-content .btn.btn-primary {
  position: absolute;
  bottom: 10px;
  left: 10px;
  right: 10px;
}

.how-it-works {
    padding: 70px 0;
    background: linear-gradient(180deg, #f7fff7 0%, #ffffff 100%);
}

.section-heading {
    text-align: center;
    max-width: 720px;
    margin: 0 auto 40px;
}

.section-heading span {
    display: inline-block;
    color: #16a34a;
    font-weight: 700;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: .06em;
    font-size: 13px;
}

.section-heading h2 {
    font-size: 38px;
    color: #063f1f;
    margin-bottom: 12px;
}

.section-heading p {
    color: #4b5563;
    font-size: 17px;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
}

.step-card {
    position: relative;
    background: #ffffff;
    border: 1px solid rgba(22, 163, 74, .16);
    border-radius: 22px;
    padding: 34px 24px 28px;
    box-shadow: 0 12px 30px rgba(0, 80, 30, .08);
    text-align: center;
}

.step-number {
    width: 58px;
    height: 58px;
    margin: 0 auto 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, #16a34a, #84cc16);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    font-weight: 800;
    box-shadow: 0 8px 18px rgba(22, 163, 74, .25);
}

.step-card h3 {
    color: #075c2c;
    font-size: 21px;
    margin-bottom: 10px;
}

.step-card p {
    color: #4b5563;
    font-size: 15px;
    line-height: 1.55;
}

@media (max-width: 1024px) {
    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .steps-grid {
        grid-template-columns: 1fr;
    }

    .section-heading h2 {
        font-size: 30px;
    }
}


/* 📱 Responsive */
@media (max-width: 1024px) {
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .feature-grid {
        grid-template-columns: 1fr;
    }
}