:root {
    color-scheme: dark;
    --bg: #080a10;
    --panel: rgba(20, 28, 44, 0.88);
    --panel-strong: rgba(15, 20, 34, 0.99);
    --border: rgba(85, 128, 223, 0.22);
    --text: #e8eefc;
    --muted: #9aaccc;
    --accent: #58a6ff;
    --accent-soft: rgba(88, 166, 255, 0.14);
    --shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: radial-gradient(circle at top left, rgba(80, 153, 255, 0.14), transparent 20%),
                radial-gradient(circle at bottom right, rgba(75, 255, 255, 0.1), transparent 22%),
                linear-gradient(180deg, #05070e 0%, #0d1220 100%);
    color: var(--text);
}

button,
input[type="submit"],
button[type="submit"] {
    cursor: pointer;
    border: none;
    border-radius: 18px;
    transition: transform 0.22s ease, background-color 0.22s ease, box-shadow 0.22s ease;
}

button:hover,
input[type="submit"]:hover,
button[type="submit"]:hover {
    transform: translateY(-1px);
}

button:active,
input[type="submit"]:active,
button[type="submit"]:active {
    transform: translateY(0);
}

.app-shell {
    min-height: 100vh;
}

.page-shell {
    display: grid;
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 24px;
    padding: 24px;
}

.sidebar {
    position: sticky;
    top: 24px;
    align-self: start;
    background: linear-gradient(180deg, rgba(12, 24, 44, 0.98), rgba(12, 24, 44, 0.88));
    border: 1px solid rgba(95, 160, 255, 0.14);
    backdrop-filter: blur(18px);
    border-radius: 28px;
    padding: 26px 20px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.brand-block {
    display: flex;
    align-items: center;
    gap: 14px;
}

.brand-mark {
    width: 52px;
    height: 52px;
    border-radius: 18px;
    display: grid;
    place-items: center;
    background: rgba(88, 166, 255, 0.2);
    color: var(--accent);
    font-weight: 800;
    font-size: 1.3rem;
    box-shadow: inset 0 0 0 1px rgba(88, 166, 255, 0.15);
}

.brand-title {
    margin: 0;
    font-size: 1.12rem;
    font-weight: 700;
    color: #eef3ff;
}

.brand-subtitle {
    margin: 4px 0 0;
    font-size: 0.95rem;
    color: var(--muted);
    line-height: 1.5;
}

.sidebar-nav {
    display: grid;
    gap: 12px;
}

.nav-link {
    display: block;
    padding: 14px 18px;
    text-decoration: none;
    border-radius: 16px;
    color: var(--text);
    background: rgba(255, 255, 255, 0.02);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.03);
    transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
    background: rgba(88, 166, 255, 0.14);
    color: #d8e6ff;
}

.nav-link.active {
    color: #fff;
    background: linear-gradient(135deg, rgba(88, 166, 255, 0.22), rgba(56, 106, 208, 0.22));
    box-shadow: 0 20px 45px rgba(22, 49, 92, 0.28);
}

.sidebar-footer {
    padding: 18px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.03);
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.6;
}

.main-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    padding: 22px 24px;
    border-radius: 28px;
    background: var(--panel);
    border: 1px solid rgba(88, 166, 255, 0.12);
    box-shadow: var(--shadow);
}

.page-title {
    margin: 0;
    font-size: clamp(1.8rem, 2.4vw, 2.6rem);
    letter-spacing: -0.02em;
}

.page-description {
    margin: 10px 0 0;
    color: var(--muted);
    font-size: 0.99rem;
}

.content-area {
    display: grid;
    gap: 24px;
}

.glass-card,
.panel {
    background: rgba(16, 24, 40, 0.88);
    border: 1px solid rgba(127, 166, 255, 0.12);
    border-radius: 28px;
    box-shadow: var(--shadow);
    padding: 26px;
}

.glass-card:has(.progress-panel) {
    padding-top: 0;
    padding-bottom: 26px;
}

.progress-panel + .question-flow {
    padding-top: 20px;
}

.section-grid {
    display: grid;
    gap: 20px;
}

.cards-row {
    display: grid;
    gap: 20px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (max-width: 980px) {
    .page-shell {
        grid-template-columns: minmax(0, 1fr);
        padding: 18px;
    }

    .sidebar {
        position: relative;
        top: 0;
    }
}

@media (max-width: 680px) {
    .cards-row {
        grid-template-columns: 1fr;
    }
}

.card-title {
    margin: 0 0 14px;
    font-size: 1.05rem;
}

.card-subtitle,
.hint-text,
.small-text {
    margin: 0;
    color: var(--muted);
    font-size: 0.96rem;
    line-height: 1.6;
}

.primary-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 14px 22px;
    background: linear-gradient(135deg, #58a6ff, #2f7cff);
    color: #f8fbff;
    font-weight: 700;
    letter-spacing: 0.01em;
    box-shadow: 0 20px 45px rgba(56, 106, 208, 0.28);
}

.secondary-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 18px;
    color: var(--text);
    background: rgba(255, 255, 255, 0.05);
}

.link-card {
    display: block;
    border-radius: 22px;
    padding: 22px 20px;
    text-decoration: none;
    color: var(--text);
    background: rgba(18, 28, 48, 0.95);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.22s ease, border-color 0.22s ease, background-color 0.22s ease;
}

.link-card:hover {
    transform: translateY(-2px);
    border-color: rgba(88, 166, 255, 0.28);
}

.topic-showcase {
    display: grid;
    gap: 32px;
}

.topics-intro {
    padding: 20px 24px;
    border-radius: 20px;
    background: rgba(88, 166, 255, 0.08);
    border: 1px solid rgba(88, 166, 255, 0.18);
    text-align: center;
}

.topics-intro p {
    margin: 0;
    color: var(--muted);
    font-size: 1.02rem;
}

.topics-intro strong {
    color: var(--accent);
    font-weight: 700;
}

.topics-grid {
    display: grid;
    gap: 16px;
    grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
}

.topic-card {
    display: grid;
    grid-template-columns: 60px 1fr 24px;
    align-items: center;
    gap: 20px;
    padding: 24px;
    border-radius: 24px;
    background: linear-gradient(135deg, rgba(20, 40, 70, 0.8), rgba(12, 24, 44, 0.9));
    border: 1px solid rgba(88, 166, 255, 0.14);
    text-decoration: none;
    color: var(--text);
    transition: all 0.24s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(88, 166, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

.topic-card:hover::before {
    left: 100%;
}

.topic-card:hover {
    transform: translateY(-4px);
    border-color: rgba(88, 166, 255, 0.28);
    background: linear-gradient(135deg, rgba(30, 50, 85, 0.9), rgba(15, 30, 55, 0.95));
    box-shadow: 0 20px 50px rgba(88, 166, 255, 0.15);
}

.topic-card-icon {
    font-size: 2.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    border-radius: 18px;
    background: rgba(88, 166, 255, 0.12);
    border: 1px solid rgba(88, 166, 255, 0.2);
    transition: all 0.24s ease;
}

.topic-card:hover .topic-card-icon {
    background: rgba(88, 166, 255, 0.22);
    transform: scale(1.1) rotate(5deg);
}

.topic-card-content {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.topic-card-title {
    margin: 0;
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.topic-card-desc {
    margin: 0;
    color: var(--muted);
    font-size: 0.96rem;
    line-height: 1.5;
}

.topic-card-arrow {
    font-size: 1.4rem;
    color: var(--accent);
    transition: transform 0.24s cubic-bezier(0.34, 1.56, 0.64, 1);
    opacity: 0.7;
}

.topic-card:hover .topic-card-arrow {
    transform: translateX(6px);
    opacity: 1;
}

.modes-showcase {
    display: grid;
    gap: 24px;
}

.modes-grid {
    display: grid;
    gap: 20px;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.mode-card {
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 28px 24px;
    border-radius: 24px;
    background: linear-gradient(135deg, rgba(30, 55, 90, 0.7), rgba(15, 30, 55, 0.85));
    border: 1px solid rgba(88, 166, 255, 0.15);
    transition: all 0.24s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
    overflow: hidden;
}

.mode-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(88, 166, 255, 0.08), transparent);
    transition: left 0.5s ease;
    pointer-events: none;
    opacity: 0;
}

.mode-card:hover::before {
    left: 100%;
    opacity: 1;
}

.mode-card:hover {
    transform: translateY(-6px);
    border-color: rgba(88, 166, 255, 0.28);
    background: linear-gradient(135deg, rgba(40, 65, 105, 0.85), rgba(20, 35, 65, 0.95));
    box-shadow: 0 24px 60px rgba(88, 166, 255, 0.12);
}

.mode-icon {
    font-size: 2.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 70px;
    height: 70px;
    border-radius: 20px;
    background: rgba(88, 166, 255, 0.14);
    border: 1px solid rgba(88, 166, 255, 0.22);
    transition: all 0.24s ease;
}

.mode-card:hover .mode-icon {
    background: rgba(88, 166, 255, 0.24);
    transform: scale(1.15) rotate(-8deg);
}

.mode-content {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.mode-content h4 {
    margin: 0;
    font-size: 1.18rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.mode-content p {
    margin: 0;
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.5;
}

.mode-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 20px;
    border-radius: 16px;
    background: rgba(88, 166, 255, 0.18);
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    border: 1px solid rgba(88, 166, 255, 0.24);
    transition: all 0.2s ease;
    align-self: flex-start;
    cursor: pointer;
}

.mode-button:hover {
    background: rgba(88, 166, 255, 0.28);
    border-color: rgba(88, 166, 255, 0.4);
    transform: translateX(4px);
}

.themes-section {
    display: grid;
    gap: 16px;
}

.themes-list {
    display: grid;
    gap: 12px;
}

.theme-item {
    display: grid;
    grid-template-columns: 44px 1fr 20px;
    align-items: center;
    gap: 16px;
    padding: 16px 18px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(88, 166, 255, 0.12);
    text-decoration: none;
    color: var(--text);
    transition: all 0.2s ease;
}

.theme-item:hover {
    background: rgba(88, 166, 255, 0.12);
    border-color: rgba(88, 166, 255, 0.24);
    transform: translateX(6px);
}

.theme-item-icon {
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: rgba(88, 166, 255, 0.1);
}

.theme-item-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.theme-item-name {
    margin: 0;
    font-size: 0.98rem;
    font-weight: 600;
    color: var(--text);
}

.theme-item-arrow {
    font-size: 1.2rem;
    color: var(--accent);
    opacity: 0.6;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.theme-item:hover .theme-item-arrow {
    transform: translateX(4px);
    opacity: 1;
}

.modules-section {
    display: grid;
    gap: 16px;
}

.modules-grid {
    display: grid;
    gap: 20px;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
}

.module-card {
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 28px 24px;
    border-radius: 24px;
    background: linear-gradient(135deg, rgba(30, 55, 90, 0.7), rgba(15, 30, 55, 0.85));
    border: 1px solid rgba(88, 166, 255, 0.15);
    transition: all 0.24s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
    overflow: hidden;
}

.module-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(88, 166, 255, 0.08), transparent);
    transition: left 0.5s ease;
    pointer-events: none;
    opacity: 0;
}

.module-card:hover::before {
    left: 100%;
    opacity: 1;
}

.module-card:hover {
    transform: translateY(-6px);
    border-color: rgba(88, 166, 255, 0.28);
    background: linear-gradient(135deg, rgba(40, 65, 105, 0.85), rgba(20, 35, 65, 0.95));
    box-shadow: 0 24px 60px rgba(88, 166, 255, 0.12);
}

.module-icon {
    font-size: 2.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 70px;
    height: 70px;
    border-radius: 20px;
    background: rgba(88, 166, 255, 0.14);
    border: 1px solid rgba(88, 166, 255, 0.22);
    transition: all 0.24s ease;
}

.module-card:hover .module-icon {
    background: rgba(88, 166, 255, 0.24);
    transform: scale(1.15) rotate(-8deg);
}

.module-content {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.module-content h4 {
    margin: 0;
    font-size: 1.18rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.module-content p {
    margin: 0;
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.5;
}

.module-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 20px;
    border-radius: 16px;
    background: rgba(88, 166, 255, 0.18);
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    border: 1px solid rgba(88, 166, 255, 0.24);
    transition: all 0.2s ease;
    align-self: flex-start;
    cursor: pointer;
}

.module-button:hover {
    background: rgba(88, 166, 255, 0.28);
    border-color: rgba(88, 166, 255, 0.4);
    transform: translateX(4px);
}

@media (max-width: 780px) {
    .modes-grid {
        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    }
    
    .mode-card {
        padding: 20px;
    }
    
    .mode-icon {
        width: 60px;
        height: 60px;
        font-size: 2.2rem;
    }
    
    .topics-grid {
        grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
        gap: 12px;
    }
    
    .topic-card {
        grid-template-columns: 52px 1fr 20px;
        gap: 16px;
        padding: 16px;
    }
    
    .topic-card-icon {
        width: 52px;
        height: 52px;
        font-size: 1.8rem;
    }
}

@media (max-width: 520px) {
    .modes-grid {
        grid-template-columns: 1fr;
    }
    
    .topics-grid {
        grid-template-columns: 1fr;
    }
    
    .topic-card {
        grid-template-columns: 48px 1fr 18px;
        gap: 14px;
        padding: 14px;
    }
    
    .topic-card-icon {
        width: 48px;
        height: 48px;
        font-size: 1.6rem;
    }
    
    .topic-card-title {
        font-size: 1.05rem;
    }
}

.theme-grid,
.results-list {
    display: grid;
    gap: 18px;
}

.question-flow {
    display: grid;
    gap: 22px;
    margin-top: 12px;
}

.question-card {
    padding: 24px;
    border-radius: 24px;
    background: rgba(18, 28, 50, 0.95);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: border-color 0.2s ease, transform 0.2s ease;
}

.question-card:hover {
    transform: translateY(-2px);
    border-color: rgba(88, 166, 255, 0.18);
}

.question-meta {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 18px;
    color: var(--muted);
}

.question-card h2,
.question-card h3,
.glass-card h3 {
    margin: 0 0 16px;
    font-size: 1.08rem;
}

.answers {
    display: grid;
    gap: 12px;
}

.answer-option {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 16px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: background-color 0.2s ease, border-color 0.2s ease;
}

.answer-option:hover {
    background: rgba(88, 166, 255, 0.1);
    border-color: rgba(88, 166, 255, 0.14);
}

.answer-option input {
    accent-color: #58a6ff;
    width: 18px;
    height: 18px;
}

.progress-panel {
    display: grid;
    gap: 10px;
    padding: 18px 20px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.06);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(8px);
}

.progress-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
}

.progress-fill {
    height: 10px;
    width: 0;
    border-radius: 999px;
    background: linear-gradient(90deg, #69b7ff, #2e78ff);
    transition: width 0.3s ease;
}

.progress-track {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 999px;
    overflow: hidden;
}

.mistake-card {
    border: 1px solid rgba(88, 166, 255, 0.12);
    background: rgba(11, 17, 28, 0.96);
    border-radius: 22px;
    overflow: hidden;
}

.mistake-card summary {
    padding: 20px;
    cursor: pointer;
    list-style: none;
    font-size: 1rem;
    color: var(--text);
}

.mistake-card[open] summary {
    background: rgba(88, 166, 255, 0.08);
}

.mistake-card div {
    padding: 0 20px 20px;
    color: var(--muted);
    line-height: 1.75;
}

.footer-note,
.note-card {
    color: var(--muted);
}

.login-shell,
.error-shell {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
}

.login-card,
.error-card {
    width: min(100%, 520px);
    padding: 34px;
    border-radius: 28px;
    border: 1px solid rgba(88, 166, 255, 0.12);
    background: rgba(12, 20, 34, 0.95);
    box-shadow: var(--shadow);
}

.login-card h1,
.error-card h1 {
    margin: 0 0 12px;
    font-size: clamp(2rem, 2.6vw, 2.7rem);
}

.login-card p,
.error-card p {
    color: var(--muted);
    margin: 0 0 24px;
    line-height: 1.7;
}

@media (max-width: 680px) {
    .topbar,
    .glass-card,
    .sidebar,
    .login-card,
    .error-card {
        border-radius: 22px;
    }
}

.sidebar-footer .sidebar-meme {
    width: 160px !important;
    height: 160px !important;
    object-fit: cover !important;

    display: block !important;

    margin: 0 auto 12px auto !important;

    border-radius: 14px !important;
}