@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&display=swap');

/* Global surface + layout */
.app-shell {
    font-family: 'Space Grotesk', 'Inter', system-ui, sans-serif;
    background: radial-gradient(circle at 15% 20%, rgba(0, 255, 55, 0.12), transparent 24%),
        radial-gradient(circle at 82% 10%, rgba(0, 132, 255, 0.12), transparent 24%),
        radial-gradient(circle at 35% 82%, rgba(255, 145, 0, 0.1), transparent 26%),
        var(--background-dark, #0f1218);
    color: #e9edf5;
    min-height: 100vh;
}

.app-shell a {
    color: inherit;
}

.page-shell {
    padding: clamp(1.5rem, 2vw + 1rem, 3rem) 0 3.5rem;
}

.section-shell {
    margin-bottom: clamp(1.75rem, 4vw, 3.5rem);
    position: relative;
}

.surface-card {
    background: color-mix(in srgb, var(--surface-dark, #131925), rgba(255, 255, 255, 0.04));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 22px;
    padding: clamp(1.3rem, 1vw + 1rem, 1.9rem);
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.surface-card::before {
    content: "";
    position: absolute;
    inset: -20% auto auto -20%;
    width: 240px;
    height: 240px;
    background: radial-gradient(circle, rgba(0, 255, 55, 0.08) 0%, transparent 60%);
    filter: blur(40px);
    opacity: 0.8;
    pointer-events: none;
}

.glassy-nav {
    background: var(--surface-dark, #1c2430);
    background: color-mix(in srgb, var(--surface-dark, #1c2430), rgba(255, 255, 255, 0.03));
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.glassy-nav .navbar-brand {
    letter-spacing: 0.02em;
}

.glassy-nav .nav-link {
    border-radius: 10px;
    padding: 0.45rem 0.8rem;
}

.glassy-nav .nav-link:hover,
.glassy-nav .nav-link:focus-visible {
    background: rgba(255, 255, 255, 0.08);
    color: var(--highlight-text);
}

.navbar-collapse {
    transition: transform 0.2s ease, opacity 0.2s ease;
}

@media (max-width: 991px) {
    .navbar-collapse {
        background: color-mix(in srgb, var(--surface-dark, #161b24), rgba(255, 255, 255, 0.03));
        border: 1px solid rgba(255, 255, 255, 0.08);
        border-radius: 14px;
        padding: 0.75rem 1rem;
        margin-top: 0.75rem;
    }
}

.hero {
    display: grid;
    gap: 1rem;
    grid-template-columns: 1fr;
    padding: clamp(1.5rem, 2vw + 1rem, 2.5rem);
    background: var(--surface-dark, #161b24);
    background: linear-gradient(135deg, rgba(0, 255, 55, 0.08), transparent 45%),
        linear-gradient(320deg, rgba(0, 132, 255, 0.08), transparent 55%),
        color-mix(in srgb, var(--surface-dark, #161b24), rgba(255, 255, 255, 0.03));
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 18px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.45);
}

.hero h1 {
    font-size: clamp(1.8rem, 1.2rem + 2vw, 2.8rem);
    margin-bottom: 0.35rem;
}

.hero p {
    color: #cdd5e0;
    max-width: 74ch;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
    margin-top: 1rem;
}

.btn-edit {
    padding: 0.46rem 1rem !important;
    border-radius: 12px !important;
    font-weight: 600;
    line-height: 1.1;
    border-color: var(--highlight-text) !important;
    color: var(--highlight-text) !important;
    box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.08);
}
.btn-edit:hover,
.btn-edit:focus-visible {
    background: rgba(0, 255, 55, 0.08) !important;
    color: #fff !important;
    border-color: var(--highlight-text) !important;
}

.eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.8rem;
    color: var(--highlight-hover-text);
    margin-bottom: 0.35rem;
}

@media (min-width: 992px) {
    .hero {
        grid-template-columns: 1.2fr 0.8fr;
        align-items: center;
    }
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
}

.content-grid.tasks-grid {
    grid-template-columns: 1fr;
}

@media (min-width: 992px) {
    .content-grid.tasks-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

.quick-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    grid-auto-rows: minmax(0, 1fr);
}

.quick-card {
    background: linear-gradient(145deg, rgba(15, 21, 32, 0.96), rgba(21, 29, 42, 0.96));
    border: 1px solid rgba(255, 255, 255, 0.06);
    min-height: 210px;
    box-shadow: 0 18px 38px rgba(0, 0, 0, 0.45);
    position: relative;
    overflow: hidden;
}

.quick-card::before {
    content: "";
    position: absolute;
    inset: -30%;
    background: radial-gradient(circle at 18% 18%, rgba(0, 255, 55, 0.14), transparent 45%),
        radial-gradient(circle at 80% 0%, rgba(0, 132, 255, 0.16), transparent 40%);
    opacity: 0;
    transition: opacity 0.25s ease, transform 0.25s ease;
    pointer-events: none;
    filter: blur(6px);
}

.card.quick-card:hover {
    transform: translateY(-6px);
    border-color: rgba(0, 255, 140, 0.4);
    box-shadow: 0 22px 46px rgba(0, 0, 0, 0.55), 0 0 28px rgba(0, 255, 140, 0.12);
    background: linear-gradient(145deg, rgba(16, 26, 40, 0.98), rgba(24, 32, 46, 0.96));
}

.card.quick-card:hover::before {
    opacity: 1;
    transform: scale(1.05);
}

.quick-card-body {
    position: relative;
    height: 100%;
    display: grid;
    grid-template-rows: auto 1fr auto;
    gap: 1rem;
}

.quick-card .card-title {
    color: #f5f7ff;
}

.quick-card .card-text {
    color: #cdd5e0;
}

.quick-card .meta-pill {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.1);
}

.icon-badge {
    width: 46px;
    height: 46px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    background: rgba(0, 255, 55, 0.15);
    color: #9af5b9;
    border: 1px solid rgba(0, 255, 55, 0.18);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.04);
}

.quick-card__cta {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: #6cf19d;
    font-weight: 600;
    letter-spacing: 0.01em;
    transition: color 0.2s ease, transform 0.2s ease;
}

.card.quick-card:hover .quick-card__cta {
    color: #9ae6ff;
    transform: translateX(4px);
}

@media (max-width: 576px) {
    .quick-grid {
        grid-template-columns: 1fr;
    }
}

.content-grid .card {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.grid-balanced {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1rem;
}

.grid-dense {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.75rem;
}

.split-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.25rem;
    align-items: start;
}

.action-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
    gap: 0.75rem;
}

.filters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.75rem;
}

.card-link,
.list-tile {
    display: block;
    text-decoration: none;
    color: inherit;
}

.card {
    background: color-mix(in srgb, var(--surface-dark, #111724), rgba(255, 255, 255, 0.03));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
    position: relative;
    overflow: hidden;
}

.task-card {
    min-height: 240px;
    gap: 0.75rem;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.task-card .card-top {
    min-height: 32px;
}

.task-card .math-content {
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    overflow: hidden;
    min-height: 110px;
}

.task-question {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-4px);
    border-color: rgba(0, 255, 55, 0.45);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.45), 0 0 20px rgba(0, 255, 55, 0.08);
    background: color-mix(in srgb, var(--surface-dark, #0f1520), rgba(0, 255, 55, 0.02));
}

.card-header,
.card-footer {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.06);
}

.list-tile {
    padding: 1rem 1.25rem;
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 12px;
    background: var(--surface-dark, #161b24);
    background: color-mix(in srgb, var(--surface-dark, #161b24), rgba(255, 255, 255, 0.02));
    transition: transform 0.2s ease, border-color 0.2s ease;
    box-shadow: 0 10px 26px rgba(0, 0, 0, 0.3);
}

.list-tile:hover {
    transform: translateY(-2px);
    border-color: rgba(0, 255, 55, 0.4);
}

.tile-title {
    color: #f0f4ff;
}

.meta-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.8rem;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.04);
    color: #d6e4ff;
    font-size: 0.9rem;
    letter-spacing: 0.01em;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.section-header p {
    color: #b5bdc9;
    margin-bottom: 0;
}

.btn {
    border-radius: 12px;
    min-height: 44px;
    font-weight: 700;
    letter-spacing: 0.01em;
    padding: 0.65rem 1.1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.45rem;
    border-width: 1px;
    line-height: 1.1;
    transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
    text-decoration: none !important;
}

.btn:focus-visible {
    outline: none;
    box-shadow: 0 0 0 2px rgba(0, 255, 140, 0.35), 0 0 0 4px rgba(0, 132, 255, 0.25);
}

.btn:active {
    transform: translateY(1px);
}

.btn-primary {
    background: linear-gradient(135deg, rgba(0, 255, 55, 0.92), rgba(0, 132, 255, 0.82));
    border: 1px solid rgba(0, 255, 55, 0.6);
    color: #060a11;
    box-shadow: 0 12px 30px rgba(0, 255, 55, 0.18);
}

.btn-primary:hover,
.btn-primary:focus-visible {
    color: #03070d;
    border-color: rgba(0, 255, 140, 0.75);
    box-shadow: 0 16px 34px rgba(0, 255, 55, 0.26);
    background: linear-gradient(135deg, rgba(0, 255, 110, 0.98), rgba(0, 152, 255, 0.9));
}

.btn-outline-light {
    border-color: rgba(255, 255, 255, 0.28);
    color: #f3f6ff;
    background: rgba(255, 255, 255, 0.03);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.04);
}

.btn-outline-light:hover,
.btn-outline-light:focus-visible {
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    border-color: rgba(255, 255, 255, 0.45);
    box-shadow: 0 10px 26px rgba(0, 0, 0, 0.35);
}

.btn-danger {
    background: linear-gradient(135deg, #ff4d6d, #ff6b6b);
    border: 1px solid rgba(255, 109, 128, 0.7);
    color: #fff;
    box-shadow: 0 12px 28px rgba(255, 77, 109, 0.25);
}

.btn-danger:hover,
.btn-danger:focus-visible {
    background: linear-gradient(135deg, #ff5e7b, #ff7a7a);
    border-color: rgba(255, 109, 128, 0.9);
    box-shadow: 0 16px 32px rgba(255, 77, 109, 0.3);
}

.btn-secondary,
.btn-outline-secondary {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.16);
    color: #e8ecf5;
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.04);
}

.btn-outline-secondary {
    background: transparent;
}

.btn-secondary:hover,
.btn-secondary:focus-visible,
.btn-outline-secondary:hover,
.btn-outline-secondary:focus-visible {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.3);
    color: #fff;
}

.badge {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: #e5e7eb;
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.35rem 0.7rem;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.04);
    color: #cbd5e5;
    font-size: 0.9rem;
}

.form-shell {
    display: grid;
    gap: 1rem;
}

.form-shell label {
    color: #e6ebf5;
    font-weight: 600;
}

.dropdown-menu {
    background: color-mix(in srgb, var(--surface-dark, #161b24), rgba(255, 255, 255, 0.05));
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: #e9edf5;
}

.dropdown-item {
    color: #e9edf5;
}

.dropdown-item:hover,
.dropdown-item:focus {
    background: rgba(0, 255, 55, 0.12);
    color: #fff;
}

.page-footer {
    color: #a8b3c4;
    padding: 2rem 0 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    margin-top: 3rem;
    text-align: center;
}

.breadcrumb {
    gap: 0.35rem;
    flex-wrap: wrap;
}

.breadcrumb-item + .breadcrumb-item::before {
    color: rgba(255, 255, 255, 0.35);
}

.task-card .math-content {
    margin-top: 0.5rem;
}

.pagination {
    justify-content: center;
    gap: 0.4rem;
}

.pagination .page-link {
    border-radius: 10px;
    border-color: rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.04);
    color: #d9e2f2;
}

.pagination .page-link:hover {
    border-color: rgba(0, 255, 55, 0.5);
    color: var(--highlight-text);
}

@media (max-width: 768px) {
    .hero {
        padding: 1.25rem;
    }

    .hero-actions {
        width: 100%;
    }

    .section-header {
        align-items: flex-start;
    }

    .action-grid {
        grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    }
}