:root {
  --white: #fff; --gray-25: #d8d8d8; --light-blue: #b4c1c3; --cool-gray: #747678;
  --light-red: #ff3034; --red: #d31316; --dark-red: #b41312; --medium-blue: #405356;
  --navy: #1b373d; --shadow: 0 18px 50px rgb(11 55 61 / 18%);
}
* { box-sizing: border-box; }
body {
  min-width: 700px; min-height: 100vh; margin: 0;
  background: radial-gradient(circle at 12% 18%, rgb(255 255 255 / 10%) 0 3px, transparent 4px), linear-gradient(145deg, var(--navy), var(--medium-blue));
  background-size: 36px 36px, auto; color: var(--navy); font-family: "Trebuchet MS", "Segoe UI", sans-serif;
}
button, input { font: inherit; } button { cursor: pointer; }
.app-shell { width: min(100%, 1180px); min-height: 100vh; margin: 0 auto; background: #f4f6f6; box-shadow: 0 0 80px rgb(0 0 0 / 30%); }
.topbar { min-height: 108px; padding: 24px 42px; display: flex; align-items: center; gap: 22px; background: var(--navy); color: var(--white); }
.topbar h1, .topbar p, h2, p { margin: 0; } .topbar h1 { font-size: 2rem; letter-spacing: -.05em; }
.brand-icon { width: 48px; height: 54px; padding: 6px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 4px; border: 2px solid var(--light-blue); border-radius: 11px; }
.brand-icon span { border-radius: 3px; background: var(--light-blue); }
.brand-icon .brand-display { grid-column: 1 / -1; display: grid; place-items: center; background: var(--white); color: var(--red); font-size: .66rem; font-weight: 900; letter-spacing: -.04em; }
.eyebrow { margin-bottom: 4px; color: var(--light-blue); font-size: .74rem; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
.eyebrow.dark { color: var(--red); } .hidden { display: none !important; }
.header-meta { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.score-pill { padding: 10px 18px; border: 2px solid var(--light-blue); border-radius: 999px; font-weight: 800; }
.version-badge { padding: 6px 10px; border: 1px solid rgb(180 193 195 / 60%); border-radius: 8px; color: var(--light-blue); font-family: Consolas, "Courier New", monospace; font-size: .68rem; font-weight: 700; letter-spacing: .02em; white-space: nowrap; }
.icon-button { width: 52px; height: 52px; border: 2px solid var(--light-blue); border-radius: 50%; background: transparent; color: var(--white); font-size: 1.7rem; }
.icon-button:hover { background: var(--medium-blue); }
.screen { display: none; padding: 38px 42px 48px; } .screen.active { display: block; }
.hero { min-height: 190px; padding: 34px 38px; display: flex; align-items: center; justify-content: space-between; overflow: hidden; border-radius: 28px; background: var(--white); box-shadow: var(--shadow); }
.hero h2, .section-heading h2, .game-heading h2, .quiz-meta h2, .result-card h2 { margin-bottom: 10px; font-size: clamp(2rem, 4vw, 3.4rem); line-height: 1; letter-spacing: -.055em; }
.hero p:not(.eyebrow), .section-heading p:not(.eyebrow), .result-card p { color: var(--cool-gray); font-size: 1.1rem; }
.hero-calculator { width: 168px; margin: -10px 24px -45px 30px; padding: 14px; flex: 0 0 auto; border: 5px solid var(--navy); border-radius: 25px; background: var(--red); box-shadow: 10px 12px 0 var(--light-blue); transform: rotate(7deg); }
.calculator-display { height: 45px; margin-bottom: 11px; padding: 8px; border-radius: 9px; background: var(--white); color: var(--navy); text-align: right; font-size: 1.15rem; font-weight: 900; }
.calculator-keys { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.calculator-keys span { height: 26px; display: grid; place-items: center; border-radius: 6px; background: var(--white); color: var(--navy); font-size: .72rem; font-weight: 900; }
.calculator-keys .calculator-accent { background: var(--navy); color: var(--white); }
.level-grid { margin-top: 26px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.level-card { min-height: 150px; padding: 24px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 18px; border: 2px solid transparent; border-radius: 24px; background: var(--white); color: var(--navy); text-align: left; box-shadow: 0 8px 25px rgb(11 55 61 / 10%); transition: .18s ease; }
.level-card:hover, .level-card:focus-visible { border-color: var(--red); transform: translateY(-3px); }
.level-card.featured { grid-column: 1 / -1; background: var(--red); color: var(--white); }
.level-card.featured:hover, .level-card.featured:focus-visible { border-color: var(--dark-red); background: var(--dark-red); }
.level-number { width: 64px; height: 64px; display: grid; place-items: center; border-radius: 18px; background: var(--navy); color: var(--white); font-size: 2rem; font-weight: 900; }
.featured .level-number { background: var(--white); color: var(--red); }
.level-copy { display: grid; gap: 7px; } .level-copy strong { font-size: 1.45rem; }
.level-copy small { color: var(--cool-gray); font-size: .95rem; line-height: 1.4; } .featured .level-copy small { color: var(--gray-25); }
.card-arrow { font-size: 2rem; font-weight: 900; }
.section-heading { margin-bottom: 28px; }
.table-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.table-button { min-height: 124px; border: 0; border-radius: 24px; background: var(--white); color: var(--navy); box-shadow: 0 8px 22px rgb(11 55 61 / 12%); font-size: 2rem; font-weight: 900; }
.table-button:hover, .table-button:focus-visible { background: var(--red); color: var(--white); }
.table-button small { display: block; margin-top: 5px; color: var(--cool-gray); font-size: .72rem; text-transform: uppercase; letter-spacing: .1em; }
.table-button:hover small, .table-button:focus-visible small { color: var(--gray-25); }
.game-heading, .quiz-meta { margin-bottom: 18px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.progress-track { height: 10px; margin-bottom: 24px; overflow: hidden; border-radius: 99px; background: var(--gray-25); }
.progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--red); transition: width .2s ease; }
.primary-button, .secondary-button { min-height: 54px; padding: 0 24px; border: 0; border-radius: 15px; font-weight: 900; }
.primary-button { background: var(--red); color: var(--white); } .primary-button:hover { background: var(--dark-red); }
.secondary-button { border: 2px solid var(--light-blue); background: var(--white); color: var(--navy); }
.sums-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.sum-row { min-height: 76px; padding: 10px 16px 10px 24px; display: flex; align-items: center; gap: 16px; border: 2px solid transparent; border-radius: 18px; background: var(--white); box-shadow: 0 5px 16px rgb(11 55 61 / 8%); }
.sum-row label { flex: 1; font-size: 1.45rem; font-weight: 900; }
.sum-row input { width: 105px; height: 52px; border: 2px solid var(--light-blue); border-radius: 12px; color: var(--navy); text-align: center; font-size: 1.35rem; font-weight: 900; }
.sum-row input[readonly] { border-color: transparent; background: var(--gray-25); cursor: not-allowed; }
.sum-row.correct { border-color: var(--medium-blue); background: #e8f1f0; } .sum-row.incorrect { border-color: var(--red); background: #fff0f0; }
.sum-status { width: 22px; font-weight: 900; }
.quiz-meta strong { padding: 10px 15px; border-radius: 12px; background: var(--navy); color: var(--white); }
.quiz-card { padding: 35px; border-radius: 28px; background: var(--white); text-align: center; box-shadow: var(--shadow); }
.quiz-prompt { color: var(--cool-gray); font-weight: 800; }
.big-sum { margin: 18px 0; color: var(--navy); font-size: clamp(4rem, 9vw, 7rem); font-weight: 900; line-height: 1; letter-spacing: -.07em; }
.answer-display { width: min(100%, 430px); min-height: 72px; margin: 0 auto; padding: 14px; display: grid; place-items: center; border: 3px solid var(--red); border-radius: 18px; color: var(--navy); font-size: 2rem; font-weight: 900; }
.answer-display.empty { border-color: var(--light-blue); color: var(--cool-gray); font-size: 1rem; }
.feedback { min-height: 28px; margin-top: 14px; font-size: 1.15rem; font-weight: 900; } .feedback.good { color: var(--medium-blue); } .feedback.bad { color: var(--red); }
.keypad { width: min(100%, 620px); margin: 22px auto 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.keypad button { min-height: 65px; border: 0; border-radius: 16px; background: var(--white); color: var(--navy); font-size: 1.55rem; font-weight: 900; box-shadow: 0 4px 12px rgb(11 55 61 / 12%); }
.keypad button:hover { background: var(--gray-25); } .keypad .key-clear { color: var(--red); font-size: 1rem; }
.keypad .key-submit { background: var(--red); color: var(--white); font-size: 1rem; } .keypad .key-submit:hover { background: var(--dark-red); }
.result-card { max-width: 700px; margin: 30px auto; padding: 50px; border-radius: 30px; background: var(--white); text-align: center; box-shadow: var(--shadow); }
.result-badge { width: 90px; height: 90px; margin: 0 auto 24px; display: grid; place-items: center; border-radius: 50%; background: var(--red); color: var(--white); font-size: 3rem; font-weight: 900; }
.result-score { margin: 22px 0 8px !important; color: var(--navy) !important; font-size: 2rem !important; font-weight: 900; }
.mail-status { min-height: 22px; margin-top: 10px !important; font-size: .88rem !important; font-weight: 800; }
.mail-status.sent { color: var(--medium-blue) !important; }
.mail-status.failed { color: var(--red) !important; }
.result-review { margin-top: 28px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; text-align: left; }
.review-row { padding: 13px 15px; display: grid; grid-template-columns: auto 1fr; gap: 3px 10px; border: 2px solid var(--light-blue); border-radius: 14px; background: #f4f6f6; }
.review-row.incorrect { border-color: var(--red); background: #fff0f0; }
.review-row span:last-child { grid-column: 2; color: var(--cool-gray); font-size: .82rem; }
.review-status { grid-row: 1 / 3; align-self: center; color: var(--medium-blue); font-size: 1.35rem; font-weight: 900; }
.review-row.incorrect .review-status { color: var(--red); }
.result-actions { margin-top: 30px; display: flex; justify-content: center; gap: 12px; }
:focus-visible { outline: 4px solid var(--light-red); outline-offset: 3px; }
@media (max-width: 900px) { .screen { padding: 28px; } .topbar { padding: 22px 28px; } .table-grid { gap: 12px; } .table-button { min-height: 105px; } }