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

:root {
    --bg: #f7f8fc;
    --card: #ffffff;
    --text: #171925;
    --muted: #74798c;
    --border: #e8e9f0;
    --primary: #6c4df6;
    --primary-dark: #5639dd;
    --sidebar: #ffffff;
    --shadow: 0 10px 30px rgba(20, 20, 40, 0.06);
}

body.dark {
    --bg: #11121a;
    --card: #191a24;
    --text: #f5f5f8;
    --muted: #9b9dab;
    --border: #2b2c37;
    --sidebar: #171820;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

body {
    font-family: "Inter", sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}


/* SIDEBAR */

.sidebar {
    width: 245px;
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;

    background: var(--sidebar);
    border-right: 1px solid var(--border);

    padding: 28px 18px;

    display: flex;
    flex-direction: column;
    z-index: 20;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;

    font-size: 22px;
    font-weight: 800;

    margin-bottom: 45px;
    padding-left: 10px;
}

.logo span span {
    color: var(--primary);
}

.logo-icon {
    width: 35px;
    height: 35px;

    display: grid;
    place-items: center;

    border-radius: 10px;

    color: white;
    background: var(--primary);
}

nav {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.nav-item {
    border: none;
    background: transparent;

    width: 100%;

    padding: 13px 14px;

    border-radius: 10px;

    color: var(--muted);

    display: flex;
    align-items: center;
    gap: 13px;

    font-size: 14px;
    font-weight: 600;

    cursor: pointer;

    transition: 0.2s;
}

.nav-item:hover {
    background: var(--bg);
    color: var(--text);
}

.nav-item.active {
    background: #eeeaff;
    color: var(--primary);
}

.sidebar-bottom {
    margin-top: auto;
}


/* MAIN */

.main {
    margin-left: 245px;
    min-height: 100vh;
}


/* TOPBAR */

.topbar {
    height: 75px;

    background: var(--card);
    border-bottom: 1px solid var(--border);

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

    padding: 0 40px;
}

.search {
    width: 350px;

    display: flex;
    align-items: center;
    gap: 10px;

    background: var(--bg);
    border: 1px solid var(--border);

    border-radius: 10px;

    padding: 10px 13px;

    color: var(--muted);
}

.search input {
    border: none;
    outline: none;
    background: transparent;

    width: 100%;

    color: var(--text);
}

.profile {
    display: flex;
    align-items: center;
    gap: 10px;
}

.profile small {
    display: block;
    color: var(--muted);
    margin-top: 3px;
}

.avatar {
    width: 40px;
    height: 40px;

    border-radius: 50%;

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

    display: grid;
    place-items: center;

    font-weight: 700;
}

.mobile-menu {
    display: none;
}


/* PAGE */

.page {
    display: none;
    padding: 38px 45px;
}

.page.active-page {
    display: block;
}

.welcome {
    display: flex;
    align-items: center;
    justify-content: space-between;

    margin-bottom: 30px;
}

.welcome h1 {
    font-size: 30px;
    margin: 5px 0;
}

.welcome p {
    color: var(--muted);
}


/* TEXT */

.eyebrow {
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 1.5px;
    color: var(--primary);
}


/* BUTTONS */

button {
    font-family: inherit;
}

.primary-btn {
    border: none;

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

    padding: 12px 18px;

    border-radius: 10px;

    font-weight: 700;

    cursor: pointer;

    transition: 0.2s;
}

.primary-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.text-btn {
    border: none;
    background: transparent;

    color: var(--primary);

    font-weight: 700;

    cursor: pointer;
}


/* STATS */

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 17px;

    margin-bottom: 25px;
}

.stat-card {
    background: var(--card);
    border: 1px solid var(--border);

    border-radius: 14px;

    padding: 20px;

    display: flex;
    align-items: center;
    gap: 13px;

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

.stat-card > div:nth-child(2) {
    flex: 1;
}

.stat-card span,
.stat-card small {
    display: block;
    color: var(--muted);
    font-size: 12px;
}

.stat-card strong {
    display: block;
    font-size: 20px;
    margin-top: 5px;
}

.stat-icon {
    width: 42px;
    height: 42px;

    display: grid;
    place-items: center;

    border-radius: 11px;

    font-weight: 800;
}

.purple {
    background: #eeeaff;
    color: #6c4df6;
}

.blue {
    background: #e7f3ff;
    color: #2888e8;
}

.orange {
    background: #fff0dd;
    color: #ef922c;
}

.green {
    background: #e5f8ee;
    color: #25a867;
}

.positive {
    color: #20a362 !important;
}


/* CARDS */

.card {
    background: var(--card);
    border: 1px solid var(--border);

    border-radius: 15px;

    padding: 24px;

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

.dashboard-grid {
    display: grid;
    grid-template-columns: 1.3fr 1fr;
    gap: 20px;
}

.card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;

    margin-bottom: 22px;
}

.card-header h2 {
    margin-top: 5px;
    font-size: 19px;
}

.ai-badge {
    background: #eeeaff;
    color: var(--primary);

    padding: 7px 10px;

    border-radius: 8px;

    font-size: 12px;
    font-weight: 800;
}


/* AI SUGGESTIONS */

.suggestions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;

    margin-bottom: 20px;
}

.suggestions button,
.chat-suggestions button {
    border: 1px solid var(--border);
    background: var(--bg);

    color: var(--text);

    padding: 13px;

    border-radius: 9px;

    text-align: left;

    cursor: pointer;

    transition: 0.2s;
}

.suggestions button:hover,
.chat-suggestions button:hover {
    border-color: var(--primary);
    transform: translateY(-1px);
}

.mini-chat {
    display: flex;

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

    border-radius: 10px;

    overflow: hidden;
}

.mini-chat input {
    flex: 1;

    border: none;
    outline: none;

    padding: 14px;

    background: transparent;

    color: var(--text);
}

.mini-chat button {
    width: 48px;

    border: none;

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

    font-size: 20px;

    cursor: pointer;
}


/* TASKS */

.task-list {
    display: flex;
    flex-direction: column;
    gap: 13px;
}

.task {
    display: flex;
    align-items: center;
    gap: 12px;

    cursor: pointer;
}

.task input {
    width: 17px;
    height: 17px;

    accent-color: var(--primary);
}

.task span {
    flex: 1;
}

.task strong,
.task small {
    display: block;
}

.task small {
    color: var(--muted);
    margin-top: 3px;
}

.task input:checked + span {
    text-decoration: line-through;
    opacity: 0.5;
}

.add-task {
    width: 100%;

    margin-top: 18px;

    padding: 10px;

    background: transparent;

    border: 1px dashed var(--border);

    color: var(--primary);

    border-radius: 9px;

    cursor: pointer;
}


/* SUBJECTS */

.section-title {
    display: flex;
    align-items: center;
    justify-content: space-between;

    margin: 35px 0 17px;
}

.section-title h2 {
    margin-top: 4px;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.subject-card {
    background: var(--card);

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

    border-radius: 14px;

    padding: 20px;
}

.subject-icon {
    width: 42px;
    height: 42px;

    display: grid;
    place-items: center;

    border-radius: 11px;

    margin-bottom: 17px;

    font-weight: 800;
}

.maths .subject-icon {
    background: #eeeaff;
    color: #6c4df6;
}

.physics .subject-icon {
    background: #e7f3ff;
    color: #2888e8;
}

.chemistry .subject-icon {
    background: #fff0dd;
    color: #ef922c;
}

.coding .subject-icon {
    background: #e5f8ee;
    color: #25a867;
}

.subject-card h3 {
    margin-bottom: 5px;
}

.subject-card p,
.subject-card small {
    color: var(--muted);
    font-size: 12px;
}

.progress {
    height: 6px;

    background: var(--bg);

    border-radius: 20px;

    overflow: hidden;

    margin: 17px 0 8px;
}

.progress span {
    height: 100%;
    display: block;

    background: var(--primary);
}


/* PAGE HEADINGS */

.page-heading {
    margin-bottom: 30px;
}

.page-heading h1 {
    font-size: 31px;
    margin: 5px 0;
}

.page-heading p:last-child {
    color: var(--muted);
}


/* CHAT */

.chat-container {
    max-width: 900px;

    margin: auto;

    background: var(--card);

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

    border-radius: 15px;

    min-height: 580px;

    display: flex;
    flex-direction: column;
}

.chat-messages {
    flex: 1;

    padding: 25px;

    overflow-y: auto;
}

.message {
    display: flex;
    gap: 12px;

    margin-bottom: 25px;
}

.message-avatar {
    width: 36px;
    height: 36px;

    flex-shrink: 0;

    border-radius: 10px;

    display: grid;
    place-items: center;

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

    font-weight: 800;
}

.message-content {
    max-width: 80%;
}

.message-content strong {
    display: block;
    margin-bottom: 7px;
}

.message-content p {
    color: var(--muted);
    line-height: 1.7;
}

.user-message {
    justify-content: flex-end;
}

.user-message .message-avatar {
    order: 2;

    background: #222331;
}

.user-message .message-content {
    background: var(--primary);
    color: white;

    padding: 13px 16px;

    border-radius: 13px;
}

.user-message .message-content p {
    color: white;
}

.chat-suggestions {
    display: flex;
    gap: 8px;

    padding: 0 25px 15px;
}

.chat-suggestions button {
    text-align: center;
    font-size: 12px;
}

.chat-input {
    display: flex;

    margin: 0 20px 20px;

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

    border-radius: 11px;

    overflow: hidden;
}

.chat-input input {
    flex: 1;

    border: none;
    outline: none;

    padding: 16px;

    background: transparent;

    color: var(--text);
}

.chat-input button {
    width: 55px;

    border: none;

    background: var(--primary);

    color: white;

    font-size: 20px;

    cursor: pointer;
}


/* SUBJECT PAGE */

.all-subjects {
    display: grid;
    grid-template-columns: 1fr 1fr;

    gap: 18px;
}

.large-subject {
    display: flex;
    align-items: center;
    gap: 16px;

    background: var(--card);

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

    padding: 22px;

    border-radius: 14px;
}

.large-subject > div:nth-child(2) {
    flex: 1;
}

.large-subject p {
    color: var(--muted);
    margin-top: 5px;
}

.large-icon {
    width: 52px;
    height: 52px;

    display: grid;
    place-items: center;

    border-radius: 13px;

    background: #eeeaff;
    color: var(--primary);

    font-size: 20px;
    font-weight: 800;
}

.large-subject button {
    border: none;

    background: var(--bg);

    color: var(--primary);

    padding: 9px 12px;

    border-radius: 8px;

    cursor: pointer;

    font-weight: 700;
}


/* NOTES */

.notes-toolbar {
    display: flex;
    gap: 10px;

    margin-bottom: 20px;
}

.notes-toolbar input {
    flex: 1;

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

    background: var(--card);

    color: var(--text);

    padding: 13px;

    border-radius: 10px;

    outline: none;
}

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

    gap: 18px;
}

.note-card {
    background: var(--card);

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

    border-radius: 14px;

    padding: 22px;
}

.note-card span {
    color: var(--primary);

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1px;
}

.note-card h3 {
    margin: 10px 0;
}

.note-card p {
    color: var(--muted);

    line-height: 1.6;

    font-size: 13px;

    margin-bottom: 17px;
}

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


/* QUIZ */

.quiz-card {
    max-width: 750px;

    margin: 50px auto;

    background: var(--card);

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

    border-radius: 16px;

    padding: 30px;

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

.quiz-top {
    display: flex;
    justify-content: space-between;

    color: var(--muted);

    font-size: 12px;

    margin-bottom: 15px;
}

.quiz-top span {
    color: var(--primary);

    font-weight: 800;
}

.quiz-progress {
    height: 6px;

    background: var(--bg);

    border-radius: 10px;

    overflow: hidden;

    margin-bottom: 35px;
}

.quiz-progress span {
    display: block;

    height: 100%;

    width: 20%;

    background: var(--primary);
}

.quiz-card h2 {
    margin-bottom: 25px;

    line-height: 1.5;
}

.answers {
    display: grid;
    grid-template-columns: 1fr 1fr;

    gap: 12px;
}

.answers button {
    padding: 15px;

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

    background: var(--bg);

    color: var(--text);

    border-radius: 10px;

    cursor: pointer;

    text-align: left;
}

.answers button:hover {
    border-color: var(--primary);
}

.quiz-result {
    margin-top: 20px;

    font-weight: 700;
}


/* PROGRESS */

.progress-dashboard {
    display: grid;

    grid-template-columns: 2fr 1fr 1fr;

    gap: 18px;

    margin-bottom: 20px;
}

.progress-card {
    background: var(--card);

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

    border-radius: 14px;

    padding: 25px;
}

.progress-card span,
.progress-card p {
    color: var(--muted);

    font-size: 13px;
}

.progress-card strong {
    display: block;

    font-size: 30px;

    margin: 10px 0;
}

.big-progress {
    height: 8px;

    background: var(--bg);

    border-radius: 20px;

    margin-top: 17px;

    overflow: hidden;
}

.big-progress span {
    display: block;

    height: 100%;

    background: var(--primary);
}

.study-chart {
    height: 350px;
}

.bars {
    height: 250px;

    display: flex;

    align-items: end;

    justify-content: space-around;

    gap: 20px;

    padding: 20px;
}

.bars div {
    height: 100%;

    flex: 1;

    display: flex;
    flex-direction: column;
    justify-content: end;
    align-items: center;
}

.bars span {
    width: 45px;

    max-width: 100%;

    background: var(--primary);

    border-radius: 7px 7px 0 0;
}

.bars small {
    margin-top: 8px;

    color: var(--muted);
}


/* MOBILE */

@media (max-width: 1100px) {

    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .subjects-grid {
        grid-template-columns: 1fr 1fr;
    }

    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .notes-grid {
        grid-template-columns: 1fr 1fr;
    }

    .progress-dashboard {
        grid-template-columns: 1fr 1fr;
    }

    .progress-card.big {
        grid-column: span 2;
    }
}


@media (max-width: 750px) {

    .sidebar {
        transform: translateX(-100%);
        transition: 0.3s;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main {
        margin-left: 0;
    }

    .topbar {
        padding: 0 18px;
        gap: 10px;
    }

    .mobile-menu {
        display: block;

        border: none;
        background: transparent;

        color: var(--text);

        font-size: 22px;
    }

    .search {
        width: auto;
        flex: 1;
    }

    .profile > div:last-child {
        display: none;
    }

    .page {
        padding: 25px 17px;
    }

    .welcome {
        flex-direction: column;
        align-items: flex-start;
        gap: 18px;
    }

    .welcome h1 {
        font-size: 25px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .subjects-grid {
        grid-template-columns: 1fr;
    }

    .suggestions {
        grid-template-columns: 1fr;
    }

    .all-subjects {
        grid-template-columns: 1fr;
    }

    .notes-grid {
        grid-template-columns: 1fr;
    }

    .progress-dashboard {
        grid-template-columns: 1fr;
    }

    .progress-card.big {
        grid-column: auto;
    }

    .chat-suggestions {
        overflow-x: auto;
    }

    .chat-suggestions button {
        white-space: nowrap;
    }

    .answers {
        grid-template-columns: 1fr;
    }

    .large-subject {
        flex-wrap: wrap;
    }
}

html {
    scroll-behavior: smooth;
}

body {
    background: #f7f8fc;
    color: #171925;
    line-height: 1.5;
}

img {
    max-width: 100%;
    display: block;
}

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

button,
input {
    font: inherit;
}

.navbar {
    max-width: 1240px;
    margin: 0 auto;
    padding: 20px 32px 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    line-height: 1;
    color: #171925;
}

.brand-text {
    font-size: 2.1rem;
}

.brand .brand-icon {
    width: 32px;
    height: 32px;
    border-radius: 10px;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #7458ff, #5f3fe7);
    color: white;
    font-size: 1.2rem;
    box-shadow: 0 8px 18px rgba(108, 77, 246, 0.25);
}

.brand-text span {
    color: #6c4df6;
}

.brand-domain {
    display: inline-flex;
    align-items: center;
    padding: 6px 10px;
    border-radius: 999px;
    background: rgba(108, 77, 246, 0.08);
    color: #5b46dd;
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: lowercase;
}

.desktop-nav {
    display: flex;
    align-items: center;
    gap: 24px;
    margin-left: auto;
    margin-right: 10px;
    color: #374151;
    font-weight: 600;
}

.desktop-nav a {
    position: relative;
    font-size: 1.06rem;
    color: #1f2937;
}

.desktop-nav a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 100%;
    height: 2px;
    background: #6c4df6;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.2s ease;
}

.desktop-nav a:hover::after,
.desktop-nav a:focus-visible::after {
    transform: scaleX(1);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.login-btn,
.nav-cta,
.primary-btn,
.secondary-btn,
.price-btn,
.header-button,
.modal button {
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

.login-btn {
    background: transparent;
    color: #171925;
    font-weight: 700;
    padding: 10px 16px;
    border-radius: 10px;
    border: 1px solid rgba(23, 25, 37, 0.15);
}

.login-btn:hover {
    background: #f3f4f6;
}

.nav-cta,
.primary-btn,
.price-btn.primary {
    background: linear-gradient(135deg, #7d5cff, #6443ef);
    color: white;
    font-weight: 700;
    box-shadow: 0 16px 30px rgba(108, 77, 246, 0.2);
}

.nav-cta,
.primary-btn {
    padding: 13px 20px;
    border-radius: 12px;
}

.nav-cta:hover,
.primary-btn:hover,
.price-btn.primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 18px 34px rgba(108, 77, 246, 0.28);
}

.menu-btn {
    display: none;
    width: 42px;
    height: 42px;
    border: 1px solid rgba(23, 25, 37, 0.12);
    background: white;
    border-radius: 10px;
    font-size: 1.6rem;
    color: #171925;
}

.mobile-nav {
    display: none;
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 22px 18px;
    flex-direction: column;
    gap: 12px;
    color: #171925;
    font-weight: 700;
}

.mobile-nav.active {
    display: flex;
}

.mobile-nav a,
.mobile-nav button {
    background: transparent;
    border: none;
    text-align: left;
    font-size: 1.15rem;
    padding: 8px 0;
    color: #171925;
}

.mobile-nav button {
    width: max-content;
    background: #fff;
    border: 1px solid rgba(23, 25, 37, 0.12);
    padding: 10px 14px;
    border-radius: 10px;
}

main {
    max-width: 1240px;
    margin: 0 auto;
    padding: 18px 32px 30px;
}

.hero {
    display: grid;
    grid-template-columns: 1.08fr 0.92fr;
    align-items: center;
    gap: 32px;
    padding: 24px 0 12px;
}

.hero-content {
    max-width: 660px;
}

.announcement {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(108, 77, 246, 0.12);
    color: #272b36;
    border-radius: 999px;
    padding: 8px 16px;
    font-weight: 700;
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}

.announcement span:first-child {
    color: #6c4df6;
}

.announcement .arrow {
    color: #6c4df6;
    font-size: 1.3rem;
}

.hero h1 {
    font-size: clamp(3.1rem, 5vw, 5.1rem);
    line-height: 0.95;
    letter-spacing: -0.06em;
    margin: 0 0 18px;
    font-weight: 900;
}

.hero h1 span {
    display: block;
    color: #171925;
}

.hero-text {
    max-width: 640px;
    font-size: 1.25rem;
    line-height: 1.6;
    color: #4b5563;
    margin-bottom: 28px;
}

.hero-buttons {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
    margin-bottom: 26px;
}

.primary-btn.large {
    padding: 16px 24px;
    font-size: 1.05rem;
}

.secondary-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 13px 18px;
    color: #3b5fd9;
    font-weight: 700;
}

.secondary-btn span {
    font-size: 1.1rem;
}

.hero-trust {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-top: 10px;
}

.avatars {
    display: flex;
    align-items: center;
    padding-left: 8px;
}

.avatars span {
    width: 34px;
    height: 34px;
    display: grid;
    place-items: center;
    margin-left: -8px;
    border-radius: 50%;
    background: linear-gradient(135deg, #c4b5fd, #7c3aed);
    color: white;
    font-size: 0.82rem;
    font-weight: 800;
    border: 2px solid #f7f8fc;
}

.avatars span:first-child {
    margin-left: 0;
}

.hero-trust strong {
    display: block;
    font-size: 1.05rem;
}

.hero-trust small {
    display: block;
    color: #6b7280;
    margin-top: 4px;
}

.hero-preview {
    position: relative;
    min-height: 460px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.glow {
    position: absolute;
    inset: 20% 10% 10% 14%;
    background: radial-gradient(circle, rgba(108,77,246,0.18), rgba(108,77,246,0) 60%);
    filter: blur(20px);
}

.ai-window {
    position: relative;
    width: min(100%, 520px);
    background: rgba(255,255,255,0.82);
    border: 1px solid rgba(23,25,37,0.08);
    border-radius: 22px;
    box-shadow: 0 32px 60px rgba(17, 24, 39, 0.12);
    backdrop-filter: blur(8px);
    overflow: hidden;
}

.window-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 20px;
    border-bottom: 1px solid rgba(23,25,37,0.08);
    background: rgba(255,255,255,0.85);
}

.window-title {
    display: flex;
    align-items: center;
    gap: 12px;
}

.ai-logo {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #7d5cff, #6443ef);
    color: white;
    font-size: 0.95rem;
}

.window-title strong {
    display: block;
    font-size: 1rem;
}

.window-title small {
    display: block;
    color: #6b7280;
}

.window-dots {
    display: flex;
    gap: 8px;
}

.window-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #d1d5db;
}

.window-dots span:first-child { background: #fbbf24; }
.window-dots span:nth-child(2) { background: #34d399; }
.window-dots span:nth-child(3) { background: #f87171; }

.chat-preview {
    padding: 18px 18px 8px;
    background: rgba(247,248,252,0.75);
}

.preview-message {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 18px;
}

.preview-message.ai {
    color: #1f2937;
}

.preview-message.user {
    justify-content: flex-end;
}

.preview-message.user p {
    background: #f0ebff;
    color: #1f2937;
    border-radius: 14px 14px 14px 4px;
    padding: 12px 14px;
    max-width: 320px;
}

.small-ai {
    width: 26px;
    height: 26px;
    border-radius: 7px;
    background: linear-gradient(135deg, #7d5cff, #6443ef);
    color: white;
    display: grid;
    place-items: center;
    font-size: 0.8rem;
    flex-shrink: 0;
}

.preview-message small {
    display: block;
    color: #6b7280;
    font-size: 0.72rem;
    margin-bottom: 6px;
}

.preview-message p {
    font-size: 0.98rem;
    line-height: 1.5;
    color: #374151;
}

.formula {
    display: inline-block;
    margin: 10px 0;
    background: rgba(108, 77, 246, 0.08);
    border: 1px solid rgba(108, 77, 246, 0.16);
    color: #5b44d1;
    font-weight: 800;
    border-radius: 10px;
    padding: 8px 12px;
}

.preview-input {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin: 0 18px 18px;
    padding: 12px 14px;
    border: 1px solid rgba(23,25,37,0.08);
    background: #fff;
    border-radius: 12px;
    color: #9ca3af;
}

.preview-input button {
    width: 30px;
    height: 30px;
    border: none;
    border-radius: 8px;
    background: linear-gradient(135deg, #7d5cff, #6443ef);
    color: white;
    font-weight: 800;
}

.trust-section {
    padding: 46px 0 18px;
}

.trust-section > p {
    text-align: center;
    color: #5b6477;
    letter-spacing: 0.18em;
    font-size: 0.86rem;
    font-weight: 800;
    margin-bottom: 22px;
}

.subject-logos {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 18px 26px;
    color: #1f2937;
    font-size: 1.08rem;
    font-weight: 700;
}

.section {
    padding: 72px 0 12px;
}

.section-heading {
    max-width: 700px;
    margin-bottom: 28px;
}

.section-heading.center {
    text-align: center;
    max-width: 760px;
    margin: 0 auto 28px;
}

.section-label {
    display: inline-block;
    color: #6c4df6;
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.section-heading h2,
.final-cta h2 {
    font-size: clamp(2.2rem, 3vw, 3.2rem);
    line-height: 1.05;
    letter-spacing: -0.06em;
    margin-bottom: 10px;
}

.section-heading p,
.final-cta p,
.testimonial-section p {
    color: #576074;
    font-size: 1.06rem;
    line-height: 1.7;
}

.features-grid {
    display: grid;
    grid-template-columns: 1.3fr 1fr 1fr;
    gap: 24px;
}

.feature-card {
    background: rgba(255,255,255,0.9);
    border: 1px solid rgba(23,25,37,0.08);
    border-radius: 22px;
    padding: 28px 24px;
    box-shadow: 0 10px 24px rgba(17,24,39,0.04);
}

.large-feature {
    grid-column: 1 / span 2;
    display: grid;
    grid-template-columns: 1fr 0.8fr;
    gap: 22px;
    align-items: center;
}

.feature-icon {
    width: 54px;
    height: 54px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    font-size: 1.8rem;
    margin-bottom: 20px;
}

.purple-icon { background: #efe9ff; color: #6848ef; }
.blue-icon { background: #eaf4ff; color: #2c7ef5; }
.orange-icon { background: #fff2e6; color: #f59e0b; }
.green-icon { background: #eafaf0; color: #2ea869; }

.feature-content span,
.feature-card span {
    display: inline-block;
    color: #6c4df6;
    font-size: 0.74rem;
    font-weight: 800;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin-bottom: 10px;
}

.feature-card h3 {
    font-size: clamp(1.5rem, 2vw, 2.1rem);
    line-height: 1.15;
    letter-spacing: -0.04em;
    margin-bottom: 10px;
}

.feature-card p {
    color: #586274;
    line-height: 1.7;
}

.feature-content a {
    display: inline-block;
    margin-top: 14px;
    color: #5a46ec;
    font-weight: 800;
}

.mini-ai-card {
    background: #f7f6ff;
    border: 1px solid rgba(108, 77, 246, 0.08);
    border-radius: 18px;
    padding: 18px;
}

.mini-ai-header {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #5b46dd;
    font-weight: 800;
    margin-bottom: 12px;
}

.mini-ai-response {
    margin-top: 12px;
    background: rgba(255,255,255,0.9);
    border: 1px solid rgba(108, 77, 246, 0.08);
    border-radius: 12px;
    padding: 12px 14px;
    color: #485265;
}

.how-section {
    padding-top: 78px;
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
    margin-top: 36px;
}

.step {
    background: rgba(255,255,255,0.9);
    border: 1px solid rgba(23,25,37,0.08);
    border-radius: 20px;
    padding: 24px;
    position: relative;
    box-shadow: 0 8px 18px rgba(17,24,39,0.03);
}

.step-number {
    font-size: 0.8rem;
    font-weight: 800;
    color: #6c4df6;
    letter-spacing: 0.18em;
    margin-bottom: 18px;
}

.step-line {
    position: absolute;
    right: -18px;
    top: 50%;
    width: 36px;
    height: 2px;
    background: rgba(108,77,246,0.2);
}

.step h3 {
    margin-bottom: 10px;
    font-size: 1.8rem;
    letter-spacing: -0.04em;
}

.step p {
    color: #586274;
    line-height: 1.7;
}

.subjects-showcase {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.subject-item {
    background: rgba(255,255,255,0.9);
    border: 1px solid rgba(23,25,37,0.08);
    border-radius: 18px;
    padding: 22px 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    box-shadow: 0 10px 22px rgba(17,24,39,0.04);
}

.subject-item div {
    width: 48px;
    height: 48px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    background: #efe9ff;
    color: #6c4df6;
    font-size: 1.5rem;
}

.subject-item span {
    font-size: 1.3rem;
    font-weight: 800;
}

.subject-item small {
    color: #586274;
}

.testimonial-section {
    padding: 80px 0 20px;
    text-align: center;
}

.quote-mark {
    font-size: 5rem;
    line-height: 1;
    color: #6c4df6;
    opacity: 0.35;
    margin-bottom: -10px;
}

.testimonial-section blockquote {
    max-width: 760px;
    margin: 0 auto 14px;
    font-size: clamp(2rem, 4vw, 3.2rem);
    line-height: 1.12;
    letter-spacing: -0.06em;
    font-weight: 800;
}

.pricing-section {
    padding-top: 80px;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px;
    max-width: 760px;
    margin: 0 auto;
}

.price-card {
    background: rgba(255,255,255,0.9);
    border: 1px solid rgba(23,25,37,0.08);
    border-radius: 22px;
    padding: 28px 24px;
    box-shadow: 0 12px 28px rgba(17,24,39,0.04);
}

.price-card.featured {
    background: linear-gradient(180deg, rgba(108,77,246,0.08), rgba(255,255,255,1));
    border-color: rgba(108,77,246,0.18);
    position: relative;
}

.popular {
    position: absolute;
    top: 18px;
    right: 18px;
    background: rgba(108,77,246,0.1);
    color: #5e47d8;
    border-radius: 999px;
    padding: 7px 10px;
    font-size: 0.66rem;
    font-weight: 800;
    letter-spacing: 0.1em;
}

.plan-name {
    display: inline-block;
    color: #6c4df6;
    font-weight: 800;
    letter-spacing: 0.14em;
    margin-bottom: 12px;
}

.price-card h3 {
    font-size: 3rem;
    line-height: 1;
    letter-spacing: -0.06em;
    margin-bottom: 8px;
}

.price-card h3 small {
    font-size: 1rem;
    color: #6b7280;
    font-weight: 600;
}

.price-card p {
    color: #586274;
    margin-bottom: 20px;
}

.price-btn {
    width: 100%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    padding: 12px 18px;
    border-radius: 12px;
    margin-bottom: 18px;
    font-weight: 800;
}

.price-btn.secondary {
    background: #f4f3ff;
    color: #6c4df6;
}

.price-card ul {
    list-style: none;
    color: #374151;
    display: grid;
    gap: 10px;
}

.price-card li {
    display: flex;
    align-items: center;
    gap: 8px;
}

.final-cta {
    position: relative;
    margin-top: 86px;
    padding: 48px 28px 52px;
    border-radius: 26px;
    text-align: center;
    background: linear-gradient(135deg, rgba(108,77,246,0.12), rgba(254,255,255,0.9));
    border: 1px solid rgba(108,77,246,0.12);
    overflow: hidden;
}

.cta-glow {
    position: absolute;
    inset: auto 20% -75px 20%;
    height: 180px;
    background: radial-gradient(circle, rgba(108,77,246,0.18), rgba(108,77,246,0) 66%);
}

.final-cta * {
    position: relative;
    z-index: 1;
}

footer {
    max-width: 1240px;
    margin: 0 auto;
    padding: 24px 32px 50px;
}

.footer-main {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 24px;
    padding-top: 18px;
    border-top: 1px solid rgba(17,24,39,0.08);
}

.footer-brand p {
    margin-top: 14px;
    max-width: 290px;
    color: #5d6678;
    line-height: 1.7;
}

.footer-column {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-column h4 {
    margin-bottom: 10px;
    font-size: 0.96rem;
}

.footer-column a {
    color: #374151;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    padding-top: 24px;
    margin-top: 18px;
    border-top: 1px solid rgba(17,24,39,0.08);
    color: #697385;
    font-size: 0.9rem;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 18px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, visibility 0.2s ease;
    z-index: 1000;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    width: min(100%, 438px);
    background: white;
    border-radius: 22px;
    border: 1px solid rgba(17,24,39,0.08);
    padding: 24px 22px 18px;
    position: relative;
    box-shadow: 0 32px 80px rgba(17,24,39,0.18);
}

.close-modal {
    position: absolute;
    top: 14px;
    right: 14px;
    width: 34px;
    height: 34px;
    border: none;
    background: #f3f4f6;
    border-radius: 10px;
    font-size: 1.5rem;
    cursor: pointer;
}

.modal-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #7d5cff, #6443ef);
    color: white;
    font-size: 1.6rem;
    margin: 0 auto 16px;
}

.modal h2 {
    text-align: center;
    margin-bottom: 8px;
    font-size: 2rem;
    letter-spacing: -0.05em;
}

.modal p {
    color: #5f6b7a;
    text-align: center;
    margin-bottom: 20px;
}

#authForm {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

#authForm input {
    width: 100%;
    padding: 14px 12px;
    border-radius: 12px;
    border: 1px solid rgba(17,24,39,0.12);
    background: #f9fafb;
    outline: none;
    color: #171925;
}

#authForm input:focus {
    border-color: rgba(108,77,246,0.6);
    box-shadow: 0 0 0 4px rgba(108,77,246,0.08);
}

.modal .primary-btn {
    margin-top: 4px;
    width: 100%;
}

.modal-note {
    display: block;
    margin-top: 14px;
    color: #6b7280;
    text-align: center;
    font-size: 0.8rem;
}

body.modal-open {
    overflow: hidden;
}

@media (max-width: 980px) {
    .hero {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .large-feature {
        grid-column: auto;
        grid-template-columns: 1fr;
    }

    .subjects-showcase {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .footer-main {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 760px) {
    .desktop-nav,
    .nav-actions {
        display: none;
    }

    .menu-btn {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .hero {
        padding-top: 10px;
    }

    .announcement {
        font-size: 0.9rem;
        padding: 8px 12px;
    }

    .hero h1 {
        font-size: 3rem;
    }

    .hero-text {
        font-size: 1.1rem;
    }

    .steps,
    .subjects-showcase,
    .pricing-grid,
    .footer-main {
        grid-template-columns: 1fr;
    }

    .step-line {
        display: none;
    }

    .testimonial-section blockquote {
        font-size: 2.15rem;
    }

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

    .navbar,
    main,
    footer {
        padding-left: 18px;
        padding-right: 18px;
    }
}

@media (max-width: 480px) {
    .brand {
        font-size: 1.7rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .secondary-btn {
        justify-content: center;
    }

    .modal {
        padding-left: 16px;
        padding-right: 16px;
    }
}