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

:root {
    --navy: #0b2142;
    --blue: #0b5ed7;
    --blue-dark: #084aab;
    --blue-light: #eaf3ff;

    --green: #12a66a;
    --green-light: #eafaf3;

    --purple: #7157d9;
    --purple-light: #f1efff;

    --orange: #e68a19;
    --orange-light: #fff5e5;

    --text: #17243a;
    --text-soft: #5e6b80;
    --text-light: #7d899b;

    --border: #e2e8f0;
    --background: #f7faff;
    --white: #ffffff;

    --shadow-small:
        0 5px 18px rgba(18, 43, 78, 0.06);

    --shadow:
        0 14px 40px rgba(18, 43, 78, 0.08);

    --shadow-large:
        0 25px 70px rgba(18, 43, 78, 0.12);
}

html {
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    overflow-x: hidden;
    font-family: "Nunito Sans", sans-serif;
    color: var(--text);
    background: var(--white);
    line-height: 1.65;
}

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

button,
a {
    -webkit-tap-highlight-color: transparent;
}

/* =========================================================
   HERO
========================================================= */

.hero {
    position: relative;
    min-height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;

    background:
        radial-gradient(
            circle at 10% 20%,
            rgba(18, 166, 106, 0.12),
            transparent 28%
        ),
        radial-gradient(
            circle at 90% 15%,
            rgba(11, 94, 215, 0.16),
            transparent 30%
        ),
        linear-gradient(
            180deg,
            #ffffff 0%,
            #f5f9ff 100%
        );
}

.navbar {
    position: relative;
    z-index: 5;

    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
    padding: 24px 0;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 11px;

    font-family: "Sora", sans-serif;
    font-weight: 700;
    font-size: 1.15rem;
}

.brand img {
    width: 40px;
    height: 40px;
    object-fit: cover;
    border-radius: 11px;

    box-shadow:
        0 5px 15px rgba(11, 94, 215, 0.14);
}

.nav-button,
.primary-button,
.secondary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;

    min-height: 48px;
    padding: 0 22px;

    border-radius: 12px;

    font-size: 0.92rem;
    font-weight: 800;

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

.nav-button,
.primary-button {
    color: var(--white);
    background: var(--blue);
    box-shadow:
        0 8px 20px rgba(11, 94, 215, 0.18);
}

.nav-button:hover,
.primary-button:hover {
    transform: translateY(-2px);

    background: var(--blue-dark);

    box-shadow:
        0 12px 28px rgba(11, 94, 215, 0.25);
}

.secondary-button {
    border: 1px solid var(--border);
    background: var(--white);
    color: var(--text);
}

.secondary-button:hover {
    transform: translateY(-2px);

    border-color: #b8c8dc;

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

.hero-content {
    position: relative;
    z-index: 2;

    width: min(900px, calc(100% - 40px));
    margin: auto;
    padding: 60px 0 100px;

    text-align: center;
}

.hero-logo {
    margin-bottom: 25px;
}

.hero-logo img {
    width: 92px;
    height: 92px;
    object-fit: cover;
    border-radius: 25px;

    box-shadow:
        0 20px 45px rgba(11, 94, 215, 0.15);
}

.eyebrow {
    margin-bottom: 12px;

    font-family: "Sora", sans-serif;
    font-size: 0.72rem;
    font-weight: 800;

    letter-spacing: 0.15em;
    text-transform: uppercase;
}

.hero .eyebrow {
    color: var(--blue);
}

.hero h1,
.section h2,
.cta-section h2 {
    font-family: "Sora", sans-serif;
    line-height: 1.12;
    letter-spacing: -0.045em;
}

.hero h1 {
    max-width: 820px;
    margin: 0 auto 25px;

    font-size: clamp(3rem, 8vw, 6.3rem);
    font-weight: 800;
}

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

.hero-description {
    max-width: 690px;
    margin: 0 auto;

    color: var(--text-soft);
    font-size: clamp(1rem, 2vw, 1.18rem);
}

.hero-actions {
    margin-top: 34px;

    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.hero-highlights {
    width: min(650px, 100%);
    margin: 65px auto 0;

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

    border: 1px solid var(--border);
    border-radius: 18px;
    overflow: hidden;

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

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

.hero-highlight {
    padding: 20px 15px;

    display: flex;
    flex-direction: column;
    gap: 3px;

    border-right: 1px solid var(--border);
}

.hero-highlight:last-child {
    border-right: 0;
}

.hero-highlight strong {
    color: var(--blue);

    font-family: "Sora", sans-serif;
    font-size: 1.35rem;
}

.hero-highlight span {
    color: var(--text-light);
    font-size: 0.78rem;
    font-weight: 700;
}

.hero-pattern {
    position: absolute;
    inset: 0;

    pointer-events: none;
    opacity: 0.07;
}

.hero-pattern span {
    position: absolute;

    color: var(--blue);
    font-family: "Sora", sans-serif;
    font-size: clamp(2rem, 6vw, 5rem);
    font-weight: 800;
}

.hero-pattern span:nth-child(1) {
    top: 18%;
    left: 6%;
}

.hero-pattern span:nth-child(2) {
    top: 35%;
    right: 8%;
}

.hero-pattern span:nth-child(3) {
    bottom: 20%;
    left: 10%;
}

.hero-pattern span:nth-child(4) {
    bottom: 15%;
    right: 12%;
}

.hero-pattern span:nth-child(5) {
    top: 15%;
    right: 28%;
}

.hero-pattern span:nth-child(6) {
    bottom: 25%;
    left: 30%;
}

/* =========================================================
   GENERAL SECTIONS
========================================================= */

.section {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
    padding: 105px 0;
}

.section-heading {
    max-width: 560px;
}

.section-heading.centered {
    max-width: 720px;
    margin: 0 auto 55px;
    text-align: center;
}

.section-heading .eyebrow {
    color: var(--blue);
}

.section h2,
.cta-section h2 {
    font-size: clamp(2.1rem, 5vw, 4rem);
}

.section h2 span,
.cta-section h2 span {
    color: var(--blue);
}

.section-heading > p:last-child {
    margin-top: 18px;
    color: var(--text-soft);
}

/* =========================================================
   INTRODUCTION
========================================================= */

.introduction {
    display: grid;
    grid-template-columns:
        minmax(0, 0.9fr)
        minmax(0, 1.1fr);

    gap: 80px;
    align-items: start;

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

.section-content {
    color: var(--text-soft);
    font-size: 1.05rem;
}

.section-content p + p {
    margin-top: 20px;
}

.learning-note {
    margin-top: 30px;
    padding: 20px;

    display: flex;
    gap: 15px;
    align-items: flex-start;

    border: 1px solid #d7eee4;
    border-radius: 16px;

    background: var(--green-light);
}

.learning-note-icon {
    width: 34px;
    height: 34px;
    flex-shrink: 0;

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

    border-radius: 50%;

    color: var(--white);
    background: var(--green);

    font-weight: 800;
}

.learning-note strong {
    display: block;
    margin-bottom: 4px;

    color: var(--text);

    font-family: "Sora", sans-serif;
    font-size: 0.9rem;
}

.learning-note p {
    font-size: 0.9rem;
}

/* =========================================================
   SUBJECTS
========================================================= */

.subjects-section {
    border-top: 1px solid var(--border);
    background: var(--background);
}

.subject-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}

.subject-card {
    position: relative;

    min-height: 300px;
    padding: 28px;

    display: flex;
    flex-direction: column;

    border: 1px solid var(--border);
    border-radius: 20px;

    background: var(--white);

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

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

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.subject-card::before {
    content: "";

    position: absolute;
    top: 0;
    left: 25px;
    right: 25px;

    height: 4px;

    border-radius: 0 0 5px 5px;

    background: var(--blue);
}

.subject-card.biology::before {
    background: var(--green);
}

.subject-card.chemistry::before {
    background: var(--blue);
}

.subject-card.physics::before {
    background: var(--purple);
}

.subject-card.mathematics::before {
    background: var(--orange);
}

.subject-top {
    margin-bottom: 35px;

    display: flex;
    align-items: center;
    justify-content: space-between;
}

.subject-icon {
    width: 46px;
    height: 46px;

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

    border-radius: 13px;

    color: var(--blue);
    background: var(--blue-light);

    font-family: "Sora", sans-serif;
    font-weight: 800;
}

.biology .subject-icon {
    color: var(--green);
    background: var(--green-light);
}

.physics .subject-icon {
    color: var(--purple);
    background: var(--purple-light);
}

.mathematics .subject-icon {
    color: var(--orange);
    background: var(--orange-light);
}

.subject-number {
    color: #a2adbd;

    font-family: "Sora", sans-serif;
    font-size: 0.75rem;
    font-weight: 800;
}

.subject-card h3 {
    margin-bottom: 10px;

    font-family: "Sora", sans-serif;
    font-size: 1.3rem;
}

.subject-card p {
    color: var(--text-soft);
    font-size: 0.92rem;
}

.subject-tag {
    margin-top: auto;
    padding-top: 25px;

    color: var(--text-light);

    font-size: 0.75rem;
    font-weight: 800;
}

/* =========================================================
   LEVELS
========================================================= */

.levels-section {
    display: grid;
    grid-template-columns:
        minmax(0, 0.8fr)
        minmax(0, 1.2fr);

    gap: 80px;

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

.levels-content {
    color: var(--text-soft);
    font-size: 1.05rem;
}

.level-list {
    margin-top: 30px;

    display: grid;
    gap: 12px;
}

.level-item {
    padding: 17px 20px;

    display: flex;
    align-items: center;
    gap: 16px;

    border: 1px solid var(--border);
    border-radius: 15px;

    background: var(--white);

    transition:
        transform 0.2s ease,
        border-color 0.2s ease;
}

.level-item:hover {
    transform: translateX(4px);
    border-color: #b9cbe2;
}

.level-marker {
    width: 36px;
    height: 36px;
    flex-shrink: 0;

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

    border-radius: 10px;

    color: var(--blue);
    background: var(--blue-light);

    font-family: "Sora", sans-serif;
    font-size: 0.7rem;
    font-weight: 800;
}

.level-item strong {
    display: block;

    color: var(--text);

    font-family: "Sora", sans-serif;
    font-size: 0.92rem;
}

.level-item span {
    display: block;

    color: var(--text-light);
    font-size: 0.86rem;
}

/* =========================================================
   HOW IT WORKS
========================================================= */

.how-section {
    border-top: 1px solid var(--border);
}

.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}

.step {
    position: relative;

    padding: 30px;

    border: 1px solid var(--border);
    border-radius: 20px;

    background: var(--white);

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

.step:not(:last-child)::after {
    content: "→";

    position: absolute;
    top: 40px;
    right: -18px;
    z-index: 2;

    width: 36px;
    height: 36px;

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

    border: 1px solid var(--border);
    border-radius: 50%;

    color: var(--blue);
    background: var(--white);

    font-weight: 800;
}

.step-number {
    width: 44px;
    height: 44px;
    margin-bottom: 30px;

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

    border-radius: 12px;

    color: var(--white);
    background: var(--blue);

    font-family: "Sora", sans-serif;
    font-weight: 800;

    box-shadow:
        0 8px 18px rgba(11, 94, 215, 0.18);
}

.step h3 {
    margin-bottom: 10px;

    font-family: "Sora", sans-serif;
}

.step p {
    color: var(--text-soft);
}

/* =========================================================
   FEATURES
========================================================= */

.features-section {
    border-top: 1px solid var(--border);
    background: var(--background);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
}

.feature-card {
    min-height: 210px;
    padding: 30px;

    border: 1px solid var(--border);
    border-radius: 20px;

    background: var(--white);

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

.feature-icon {
    width: 42px;
    height: 42px;
    margin-bottom: 25px;

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

    border-radius: 11px;

    color: var(--blue);
    background: var(--blue-light);

    font-family: "Sora", sans-serif;
    font-size: 0.9rem;
    font-weight: 800;
}

.feature-card h3 {
    margin-bottom: 9px;

    font-family: "Sora", sans-serif;
}

.feature-card p {
    color: var(--text-soft);
}

/* =========================================================
   ASSESSMENT
========================================================= */

.assessment-section {
    border-top: 1px solid var(--border);
}

.assessment-box {
    display: grid;
    grid-template-columns:
        minmax(0, 0.8fr)
        minmax(0, 1.2fr);

    gap: 80px;

    padding: 55px;

    border-radius: 28px;

    background:
        linear-gradient(
            135deg,
            #edf5ff,
            #f4fbf8
        );

    border: 1px solid #dce8f4;
}

.assessment-text {
    color: var(--text-soft);
}

.assessment-text p + p {
    margin-top: 20px;
}

.assessment-points {
    margin-top: 25px;

    display: flex;
    flex-wrap: wrap;
    gap: 9px;
}

.assessment-points span {
    padding: 8px 12px;

    border-radius: 999px;

    color: #176b4c;
    background: #dff5eb;

    font-size: 0.78rem;
    font-weight: 800;
}

/* =========================================================
   CALL TO ACTION
========================================================= */

.cta-section {
    position: relative;
    overflow: hidden;

    padding: 120px 20px;

    text-align: center;

    color: var(--white);

    background:
        radial-gradient(
            circle at 20% 30%,
            rgba(28, 117, 228, 0.3),
            transparent 30%
        ),
        radial-gradient(
            circle at 80% 70%,
            rgba(18, 166, 106, 0.2),
            transparent 30%
        ),
        var(--navy);
}

.cta-content {
    position: relative;
    z-index: 2;

    width: min(760px, 100%);
    margin: 0 auto;
}

.cta-section .eyebrow {
    color: #72b7ff;
}

.cta-section h2 span {
    color: #72b7ff;
}

.cta-section p {
    max-width: 600px;
    margin: 22px auto 0;

    color: #c3d0e1;
}

.cta-section .primary-button {
    margin-top: 32px;

    color: var(--navy);
    background: var(--white);

    box-shadow: none;
}

.cta-section .primary-button:hover {
    background: #edf5ff;
}

/* =========================================================
   FOOTER
========================================================= */

.footer {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;

    padding: 45px 0 30px;
}

.footer-main {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.footer-main > p {
    color: var(--text-light);
}

.footer-links {
    margin-top: 30px;

    display: flex;
    flex-wrap: wrap;
    gap: 22px;

    color: var(--text-soft);
    font-size: 0.9rem;
}

.footer-links a {
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--blue);
}

.copyright {
    margin-top: 25px;
    padding-top: 25px;

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

    color: #98a3b3;
    font-size: 0.8rem;
}

/* =========================================================
   TABLET
========================================================= */

@media (max-width: 1000px) {
    .subject-grid,
    .steps {
        grid-template-columns: repeat(2, 1fr);
    }

    .introduction,
    .levels-section,
    .assessment-box {
        grid-template-columns: 1fr;
        gap: 45px;
    }

    .assessment-box {
        padding: 45px;
    }

    .step:not(:last-child)::after {
        display: none;
    }
}

/* =========================================================
   MOBILE
========================================================= */

@media (max-width: 600px) {
    .navbar {
        width: min(100% - 28px, 1180px);
        padding: 18px 0;
    }

    .brand {
        font-size: 1rem;
    }

    .brand img {
        width: 36px;
        height: 36px;
    }

    .nav-button {
        min-height: 42px;
        padding: 0 15px;
        font-size: 0.82rem;
    }

    .hero-content {
        width: min(100% - 28px, 900px);
        padding: 50px 0 70px;
    }

    .hero-logo img {
        width: 72px;
        height: 72px;
        border-radius: 20px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .primary-button,
    .secondary-button {
        width: 100%;
    }

    .hero-highlights {
        margin-top: 45px;
    }

    .hero-highlight {
        padding: 15px 8px;
    }

    .hero-highlight strong {
        font-size: 1.05rem;
    }

    .hero-highlight span {
        font-size: 0.68rem;
    }

    .hero-pattern span:nth-child(1),
    .hero-pattern span:nth-child(4) {
        display: none;
    }

    .section {
        width: min(100% - 28px, 1180px);
        padding: 75px 0;
    }

    .subject-grid,
    .steps,
    .feature-grid {
        grid-template-columns: 1fr;
    }

    .subject-card {
        min-height: 270px;
    }

    .subject-card,
    .feature-card,
    .step {
        padding: 24px;
    }

    .subject-top {
        margin-bottom: 28px;
    }

    .learning-note {
        padding: 17px;
    }

    .level-item {
        align-items: flex-start;
    }

    .assessment-box {
        padding: 28px;
    }

    .assessment-points {
        flex-direction: column;
        align-items: flex-start;
    }

    .cta-section {
        padding: 90px 14px;
    }

    .footer {
        width: min(100% - 28px, 1180px);
    }

    .footer-main {
        align-items: flex-start;
        flex-direction: column;
    }
}