:root {
  --gcse-ink: #102b35;
  --gcse-muted: #546975;
  --gcse-deep: #123b4a;
  --gcse-green: #087d62;
  --gcse-bright: #66e3a3;
  --gcse-mint: #e9fbf2;
  --gcse-sky: #eaf7fb;
  --gcse-border: #d8e7e5;
  --gcse-shadow: 0 18px 40px rgba(18, 59, 74, .10);
}

.gcse-landing { max-width: 1180px; margin: 0 auto; padding: clamp(1rem, 3vw, 2.25rem) 1rem clamp(3.75rem, 8vw, 6.5rem); color: var(--gcse-ink); }
.gcse-eyebrow { margin: 0 0 .65rem; color: var(--gcse-green); font-size: .76rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
.gcse-eyebrow--light { color: #a9f0cb; }
.gcse-hero { position: relative; display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(275px, .7fr); gap: clamp(2rem, 6vw, 6rem); overflow: hidden; align-items: center; padding: clamp(2rem, 6vw, 5.25rem); border-radius: 30px; color: #fff; background: radial-gradient(circle at 88% 15%, rgba(110, 234, 169, .28), transparent 20%), radial-gradient(circle at 15% 100%, rgba(53, 167, 218, .25), transparent 32%), linear-gradient(135deg, #123b4a 0%, #0d5960 55%, #087d62 100%); box-shadow: var(--gcse-shadow); }
.gcse-hero::after { position: absolute; right: -96px; bottom: -165px; width: 355px; height: 355px; border: 1px solid rgba(255,255,255,.18); border-radius: 50%; content: ''; }
.gcse-hero__copy, .gcse-start-card { position: relative; z-index: 1; }
.gcse-hero h1, .gcse-section h2, .gcse-membership h2, .gcse-demo-banner h2, .gcse-final-cta h2 { margin: 0; color: inherit; line-height: 1.08; }
.gcse-hero h1 { max-width: 690px; font-size: clamp(2.35rem, 5.4vw, 4.65rem); letter-spacing: -.045em; }
.gcse-hero__intro { max-width: 690px; margin: 1.3rem 0 0; color: rgba(255,255,255,.91); font-size: clamp(1rem, 1.7vw, 1.16rem); line-height: 1.68; }
.gcse-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.7rem; }
.gcse-button { display: inline-flex; min-height: 50px; align-items: center; justify-content: center; gap: .62rem; padding: .78rem 1.1rem; border: 1px solid transparent; border-radius: 12px; font-weight: 850; line-height: 1.2; text-align: center; text-decoration: none; transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease; }
.gcse-button:hover { transform: translateY(-2px); text-decoration: none; }
.gcse-button--primary { border-color: var(--gcse-bright); background: var(--gcse-bright); color: #08271e; box-shadow: 0 8px 18px rgba(0, 0, 0, .12); }
.gcse-button--primary:hover, .gcse-button--primary:focus-visible { background: #8beeb8; color: #08271e; }
.gcse-button--ghost { border-color: rgba(255,255,255,.65); background: rgba(255,255,255,.07); color: #fff; }
.gcse-button--ghost:hover, .gcse-button--ghost:focus-visible { border-color: #fff; background: rgba(255,255,255,.16); color: #fff; }
.gcse-button--dark { border-color: var(--gcse-deep); background: var(--gcse-deep); color: #fff; }
.gcse-button--dark:hover, .gcse-button--dark:focus-visible { background: #1d5261; color: #fff; }
.gcse-button:focus-visible, .gcse-start-card a:focus-visible, .gcse-faq-list summary:focus-visible { outline: 3px solid #f4cb5b; outline-offset: 4px; }
.gcse-hero__reassure { margin: .85rem 0 0; color: rgba(255,255,255,.8); font-size: .89rem; }
.gcse-hero__reassure i { color: var(--gcse-bright); }
.gcse-proof { display: flex; flex-wrap: wrap; gap: .6rem 1.05rem; margin: 1.75rem 0 0; padding: 0; list-style: none; }
.gcse-proof li { display: inline-flex; align-items: center; gap: .38rem; color: #e6fff1; font-size: .88rem; font-weight: 700; }
.gcse-proof i { color: var(--gcse-bright); }
.gcse-start-card { padding: clamp(1.35rem, 2.3vw, 1.8rem); border: 1px solid rgba(255,255,255,.32); border-radius: 20px; background: rgba(4, 35, 40, .33); box-shadow: 0 16px 28px rgba(0,0,0,.13); backdrop-filter: blur(8px); }
.gcse-start-card__spark { display: inline-grid; width: 42px; height: 42px; place-items: center; border-radius: 13px; background: #c5f9dc; color: #0b5a49; }
.gcse-start-card__eyebrow { margin: 1rem 0 .38rem; color: #b6f3d2; font-size: .72rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
.gcse-start-card h2 { color: #fff; font-size: clamp(1.45rem, 2.3vw, 1.9rem); line-height: 1.12; }
.gcse-start-card > p:not(.gcse-start-card__eyebrow):not(.gcse-start-card__member) { margin: .75rem 0 1.1rem; color: rgba(255,255,255,.84); line-height: 1.55; }
.gcse-start-card__demo { display: flex; align-items: center; justify-content: space-between; gap: .7rem; padding: .9rem 1rem; border-radius: 10px; background: #fff; color: #123b4a; font-weight: 850; text-decoration: none; }
.gcse-start-card__demo:hover { background: #dffdeb; color: #123b4a; text-decoration: none; }
.gcse-start-card__divider { height: 1px; margin: 1.1rem 0; background: rgba(255,255,255,.22); }
.gcse-start-card__member { margin: 0 0 .45rem; color: rgba(255,255,255,.8); font-size: .88rem; line-height: 1.48; }
.gcse-start-card__member strong { color: #fff; }
.gcse-text-link { color: #baf6d4; font-size: .92rem; font-weight: 800; text-decoration: none; }
.gcse-text-link:hover { color: #fff; text-decoration: underline; }

.gcse-section { margin-top: clamp(3.6rem, 8vw, 6.8rem); }
.gcse-section__heading { max-width: 760px; }
.gcse-section__heading--centred { margin-right: auto; margin-left: auto; text-align: center; }
.gcse-section__heading > p:last-child { margin: .82rem 0 0; color: var(--gcse-muted); line-height: 1.68; }
.gcse-section h2, .gcse-membership h2, .gcse-demo-banner h2 { color: var(--gcse-ink); font-size: clamp(1.9rem, 3.7vw, 3rem); letter-spacing: -.032em; }
.gcse-course-choice-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.15rem; margin-top: 2rem; }
.gcse-course-choice { display: grid; grid-template-columns: auto 1fr; gap: 0 1rem; padding: clamp(1.35rem, 3vw, 2rem); border: 1px solid var(--gcse-border); border-radius: 18px; background: #fff; box-shadow: 0 8px 24px rgba(18,59,74,.06); }
.gcse-course-choice--physics { border-top: 5px solid #1e9a76; }
.gcse-course-choice--combined { border-top: 5px solid #2f8db6; }
.gcse-course-choice__icon { display: grid; width: 44px; height: 44px; place-items: center; border-radius: 13px; background: var(--gcse-mint); color: var(--gcse-green); font-size: 1.15rem; }
.gcse-course-choice--combined .gcse-course-choice__icon { background: var(--gcse-sky); color: #2879a0; }
.gcse-course-choice__label { margin: .1rem 0 .25rem; color: var(--gcse-green); font-size: .72rem; font-weight: 850; letter-spacing: .09em; text-transform: uppercase; }
.gcse-course-choice--combined .gcse-course-choice__label { color: #2879a0; }
.gcse-course-choice h3 { margin: 0; font-size: 1.4rem; letter-spacing: -.02em; }
.gcse-course-choice h3 + p { margin: .35rem 0 0; color: var(--gcse-muted); font-size: .92rem; }
.gcse-course-choice__description { grid-column: 1 / -1; margin: 1.1rem 0 .85rem; color: #38515a; line-height: 1.58; }
.gcse-course-choice ul { display: grid; grid-column: 1 / -1; gap: .48rem; margin: 0; padding: 0; list-style: none; }
.gcse-course-choice li { color: #46606a; font-size: .9rem; }
.gcse-course-choice li i { margin-right: .45rem; color: var(--gcse-green); }

.gcse-membership { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.1fr); gap: clamp(1.75rem, 6vw, 5.5rem); align-items: center; padding: clamp(1.5rem, 4.2vw, 3.6rem); border-radius: 24px; background: linear-gradient(135deg, #ebfbf3, #f7fcfa); }
.gcse-membership__intro > p:not(.gcse-eyebrow) { margin: 1rem 0 1.4rem; color: var(--gcse-muted); line-height: 1.67; }
.gcse-benefit-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .85rem; }
.gcse-benefit-grid article { min-height: 160px; padding: 1.1rem; border: 1px solid #d6ebe2; border-radius: 15px; background: #fff; }
.gcse-benefit-grid span { display: grid; width: 35px; height: 35px; place-items: center; border-radius: 10px; background: var(--gcse-mint); color: var(--gcse-green); }
.gcse-benefit-grid h3 { margin: .7rem 0 .35rem; font-size: 1rem; }
.gcse-benefit-grid p { margin: 0; color: var(--gcse-muted); font-size: .88rem; line-height: 1.5; }

.gcse-tool-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: .95rem; margin-top: 1.75rem; }
.gcse-tool-card { min-height: 224px; padding: 1.25rem; border: 1px solid var(--gcse-border); border-radius: 16px; background: #fff; transition: transform .18s ease, box-shadow .18s ease; }
.gcse-tool-card:hover { transform: translateY(-4px); box-shadow: 0 14px 28px rgba(18, 59, 74, .10); }
.gcse-tool-card__icon { display: inline-grid; width: 42px; height: 42px; place-items: center; border-radius: 12px; background: var(--gcse-mint); color: var(--gcse-green); font-size: 1.08rem; }
.gcse-tool-card:nth-child(2) .gcse-tool-card__icon, .gcse-tool-card:nth-child(5) .gcse-tool-card__icon { background: var(--gcse-sky); color: #2879a0; }
.gcse-tool-card:nth-child(3) .gcse-tool-card__icon { background: #f4efff; color: #7255b5; }
.gcse-tool-card h3 { margin: 1rem 0 .5rem; font-size: 1.04rem; }
.gcse-tool-card p { margin: 0; color: var(--gcse-muted); font-size: .91rem; line-height: 1.55; }

.gcse-demo-banner { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: 1.2rem 1.7rem; align-items: center; margin-top: clamp(3.6rem, 8vw, 6.8rem); padding: clamp(1.45rem, 3.5vw, 2.5rem); border: 1px solid #bfe9d0; border-radius: 20px; background: #e7fff1; }
.gcse-demo-banner__icon { display: grid; width: 54px; height: 54px; place-items: center; border-radius: 16px; background: #fff; color: var(--gcse-green); font-size: 1.35rem; box-shadow: 0 6px 16px rgba(8,125,98,.1); }
.gcse-demo-banner h2 { font-size: clamp(1.45rem, 2.7vw, 2.1rem); }
.gcse-demo-banner p:not(.gcse-eyebrow) { margin: .45rem 0 0; color: var(--gcse-muted); line-height: 1.55; }
.gcse-demo-banner .gcse-button--primary { align-self: center; }

.gcse-topic-courses { display: grid; gap: 1rem; margin-top: 1.8rem; }
.gcse-course-topics { padding: clamp(1.3rem, 3vw, 2rem); border: 1px solid var(--gcse-border); border-radius: 18px; background: #fff; }
.gcse-course-topics__heading { display: flex; justify-content: space-between; gap: 1.25rem; align-items: baseline; }
.gcse-course-topics h3 { margin: 0; font-size: 1.25rem; }
.gcse-course-topics__heading p { max-width: 620px; margin: 0; color: var(--gcse-muted); line-height: 1.5; text-align: right; }
.gcse-topic-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .7rem; margin: 1.3rem 0 0; padding: 0; list-style: none; }
.gcse-topic-grid li { display: flex; align-items: flex-start; gap: .55rem; padding: .85rem .8rem; border-radius: 10px; background: #f4faf8; font-size: .91rem; line-height: 1.3; }
.gcse-topic-grid i { margin-top: .25rem; color: var(--gcse-green); font-size: .45rem; }

.gcse-section--how { padding: clamp(1.5rem, 4vw, 3rem); border: 1px solid var(--gcse-border); border-radius: 20px; }
.gcse-steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.25rem; margin: 1.8rem 0 0; padding: 0; list-style: none; }
.gcse-steps li { display: flex; gap: .85rem; }
.gcse-steps > li > span { display: inline-grid; width: 33px; height: 33px; flex: 0 0 auto; place-items: center; border-radius: 50%; background: var(--gcse-deep); color: #fff; font-size: .9rem; font-weight: 850; }
.gcse-steps h3 { margin: .25rem 0 .35rem; font-size: 1.04rem; }
.gcse-steps p { margin: 0; color: var(--gcse-muted); line-height: 1.55; }
.gcse-faq-list { display: grid; gap: .75rem; margin-top: 1.5rem; }
.gcse-faq-list details { padding: 1rem 1.15rem; border: 1px solid var(--gcse-border); border-radius: 12px; background: #fff; }
.gcse-faq-list summary { cursor: pointer; color: var(--gcse-ink); font-weight: 800; }
.gcse-faq-list p { margin: .85rem 1.4rem 0 0; color: var(--gcse-muted); line-height: 1.65; }
.gcse-final-cta { display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; margin-top: clamp(3.6rem, 8vw, 6.8rem); padding: clamp(1.7rem, 4vw, 3.2rem); border-radius: 24px; background: var(--gcse-deep); color: #fff; }
.gcse-final-cta h2 { max-width: 685px; color: #fff; font-size: clamp(1.8rem, 3.4vw, 2.8rem); letter-spacing: -.03em; }
.gcse-final-cta > div > p:last-child { max-width: 690px; margin: .75rem 0 0; color: #d1e9e3; line-height: 1.55; }
.gcse-final-cta .gcse-eyebrow { color: #9fe9c0; }
.gcse-final-cta__actions { display: flex; flex-wrap: wrap; gap: .7rem; justify-content: flex-end; }

@media (max-width: 1040px) { .gcse-tool-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); } .gcse-demo-banner { grid-template-columns: auto 1fr; } .gcse-demo-banner .gcse-button { grid-column: 2; justify-self: start; } .gcse-topic-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
@media (max-width: 780px) { .gcse-hero, .gcse-membership { grid-template-columns: 1fr; } .gcse-start-card { max-width: 550px; } .gcse-course-choice-grid, .gcse-steps { grid-template-columns: 1fr; } .gcse-topic-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .gcse-final-cta { align-items: flex-start; flex-direction: column; } .gcse-final-cta__actions { justify-content: flex-start; } }
@media (max-width: 560px) { .gcse-landing { padding-right: .75rem; padding-left: .75rem; } .gcse-hero { padding: 1.7rem 1.35rem; border-radius: 22px; } .gcse-hero h1 { font-size: clamp(2.15rem, 12vw, 3.1rem); } .gcse-actions, .gcse-actions .gcse-button { width: 100%; } .gcse-proof { display: grid; } .gcse-membership { padding: 1.35rem; } .gcse-benefit-grid { grid-template-columns: 1fr; } .gcse-tool-grid { grid-template-columns: 1fr; } .gcse-tool-card { min-height: auto; } .gcse-demo-banner { grid-template-columns: 1fr; } .gcse-demo-banner .gcse-button { grid-column: auto; justify-self: stretch; } .gcse-course-topics__heading { display: block; } .gcse-course-topics__heading p { margin-top: .5rem; text-align: left; } .gcse-topic-grid { grid-template-columns: 1fr; } .gcse-final-cta__actions, .gcse-final-cta__actions .gcse-button { width: 100%; } }