:root {
    --bg: #f4f6fb;
    --surface: #ffffff;
    --surface-soft: #f8f9fd;
    --text: #172033;
    --muted: #687386;
    --line: #dfe4ed;
    --primary: #6558e8;
    --primary-dark: #5145c8;
    --danger: #c33c54;
    --success-bg: #e7f8ef;
    --success-text: #176a42;
    --warning-bg: #fff4d7;
    --warning-text: #7b5510;
    --error-bg: #fde9ed;
    --error-text: #8c2639;
    --shadow: 0 14px 40px rgba(25, 34, 56, .08);
    --radius: 18px;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { min-height: 100%; background: var(--bg); }
body {
    margin: 0;
    min-height: 100%;
    color: var(--text);
    background:
        radial-gradient(circle at 15% -10%, rgba(101, 88, 232, .14), transparent 32rem),
        var(--bg);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.5;
}

a { color: var(--primary-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255,255,255,.88);
    border-bottom: 1px solid rgba(223,228,237,.9);
    backdrop-filter: blur(14px);
}
.nav-wrap { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { color: var(--text); font-size: 1.15rem; font-weight: 850; letter-spacing: -.03em; }
.brand:hover { text-decoration: none; }
.nav { display: flex; align-items: center; gap: 18px; font-size: .94rem; }
.nav a { color: var(--text); }
.profile-menu { position: relative; }
.profile-menu summary {
    display: flex;
    align-items: center;
    gap: 8px;
    min-height: 42px;
    padding: 4px 8px 4px 5px;
    border: 1px solid transparent;
    border-radius: 12px;
    color: var(--text);
    font-weight: 760;
    list-style: none;
    cursor: pointer;
}
.profile-menu summary::-webkit-details-marker { display: none; }
.profile-menu summary:hover, .profile-menu[open] summary { border-color: var(--line); background: #fff; }
.profile-avatar {
    display: grid;
    width: 31px;
    height: 31px;
    place-items: center;
    border-radius: 10px;
    background: #eeecff;
    color: var(--primary-dark);
    font-size: .82rem;
    font-weight: 850;
}
.profile-name { max-width: 140px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.profile-chevron { color: var(--muted); font-size: .85rem; transition: transform .18s; }
.profile-menu[open] .profile-chevron { transform: rotate(180deg); }
.profile-menu-popover {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    z-index: 30;
    display: grid;
    width: 170px;
    padding: 7px;
    border: 1px solid var(--line);
    border-radius: 13px;
    background: #fff;
    box-shadow: var(--shadow);
}
.profile-menu-popover a { padding: 9px 10px; border-radius: 8px; }
.profile-menu-popover a:hover { background: var(--surface-soft); text-decoration: none; }
.page { padding: 38px 0 70px; }

h1, h2, h3 { margin-top: 0; line-height: 1.16; letter-spacing: -.035em; }
h1 { font-size: clamp(2rem, 5vw, 3.2rem); margin-bottom: 10px; }
h2 { font-size: 1.28rem; margin-bottom: 10px; }
h3 { margin-bottom: 8px; }
p { margin-top: 0; }
.muted { color: var(--muted); }
.eyebrow { margin-bottom: 9px; color: var(--primary); font-weight: 800; font-size: .78rem; letter-spacing: .12em; text-transform: uppercase; }
.optional { color: var(--muted); font-size: .82rem; font-weight: 500; }

.card {
    background: rgba(255,255,255,.94);
    border: 1px solid rgba(223,228,237,.95);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.page-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: 28px; }
.page-heading p { margin-bottom: 0; }
.session-heading { align-items: center; }
.session-heading-main { min-width: 0; flex: 1; }
.session-title-form { display: flex; align-items: center; gap: 9px; margin-bottom: 10px; }
.session-title-input {
    width: min(700px, 70vw);
    padding: 0;
    border-color: transparent;
    background: transparent;
    box-shadow: none;
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 800;
    line-height: 1.16;
    letter-spacing: -.035em;
}
.session-title-input[readonly] { cursor: default; }
.session-title-form.is-editing .session-title-input {
    padding: 7px 11px;
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 4px rgba(101,88,232,.12);
}
.icon-button {
    display: inline-grid;
    flex: 0 0 36px;
    width: 36px;
    height: 36px;
    place-items: center;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: #fff;
    color: var(--primary-dark);
    font: inherit;
    font-size: 1.05rem;
    font-weight: 800;
    cursor: pointer;
}
.icon-button:hover { border-color: var(--primary); background: #f4f2ff; }
.title-edit-controls { display: flex; align-items: center; gap: 9px; }
.title-edit-controls input { min-width: min(340px, 60vw); }
.narrow { width: min(650px, 100%); margin: 0 auto; }
.auth-shell { min-height: calc(100vh - 160px); display: grid; place-items: center; }
.auth-card { width: min(450px, 100%); padding: 36px; }
.form-card { padding: 28px; }
.back-link { display: inline-block; margin-bottom: 16px; color: var(--muted); font-weight: 650; }

.stack { display: grid; gap: 18px; }
.stack-lg { display: grid; gap: 24px; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
label { display: grid; gap: 7px; font-weight: 720; font-size: .93rem; }
input, textarea, select {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: #fff;
    color: var(--text);
    padding: 12px 14px;
    font: inherit;
    outline: none;
    transition: border-color .18s, box-shadow .18s;
}
textarea { resize: vertical; min-height: 130px; }
input:focus, textarea:focus, select:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(101,88,232,.12); }

.button {
    appearance: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 42px;
    border: 1px solid var(--line);
    border-radius: 11px;
    padding: 9px 15px;
    background: #fff;
    color: var(--text);
    font: inherit;
    font-weight: 760;
    cursor: pointer;
    text-decoration: none;
    transition: transform .15s, box-shadow .15s, border-color .15s, background .15s;
}
.button:hover { text-decoration: none; transform: translateY(-1px); border-color: #c6ccda; box-shadow: 0 8px 18px rgba(22,32,52,.08); }
.button-primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.button-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); }
.button-danger { color: var(--danger); border-color: rgba(195,60,84,.25); }
.button-ghost { background: transparent; }
.button-small { min-height: 36px; padding: 7px 11px; font-size: .85rem; }
.button:disabled { opacity: .7; cursor: wait; transform: none; }
.button.copy-success { border-color: rgba(23,106,66,.3); background: var(--success-bg); color: var(--success-text); }
.text-button { border: 0; padding: 0; background: none; font: inherit; cursor: pointer; font-weight: 700; }
.danger-text { color: var(--danger); }
.actions { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }
.actions form { margin: 0; }

.alert { margin-bottom: 20px; padding: 13px 15px; border-radius: 12px; font-weight: 650; }
.alert-success { background: var(--success-bg); color: var(--success-text); }
.alert-warning { background: var(--warning-bg); color: var(--warning-text); }
.alert-error { background: var(--error-bg); color: var(--error-text); }
.alert-info { background: #eaf1ff; color: #25508b; }

.session-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.session-card { padding: 24px; display: grid; gap: 18px; }
.session-card h2 { margin-bottom: 6px; }
.session-card-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
.session-meta { display: flex; flex-wrap: wrap; gap: 10px 18px; color: var(--muted); font-size: .9rem; }
.pill { display: inline-flex; white-space: nowrap; align-items: center; border-radius: 999px; padding: 5px 10px; background: #eeecff; color: #5447c8; font-weight: 800; font-size: .78rem; }
.pill-warning { background: var(--warning-bg); color: var(--warning-text); }
.empty-state { padding: 50px 28px; text-align: center; }
.empty-state.compact { padding: 28px; }
.empty-icon { font-size: 2.5rem; color: var(--primary); margin-bottom: 10px; }

.two-column { display: grid; grid-template-columns: minmax(310px, .75fr) minmax(0, 1.25fr); gap: 26px; align-items: start; }
.content-heading { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.content-heading h2 { margin: 0; }
.item-list { display: grid; gap: 14px; }
.item-card { padding: 18px; }
.item-header { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 14px; margin-bottom: 13px; font-size: .84rem; }
.item-type { color: var(--primary-dark); font-weight: 850; }
.note-card pre {
    margin: 0 0 14px;
    padding: 15px;
    border-radius: 12px;
    background: var(--surface-soft);
    border: 1px solid var(--line);
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    font: inherit;
}
.file-card { display: flex; align-items: center; gap: 14px; }
.file-icon { width: 42px; height: 42px; flex: 0 0 42px; display: grid; place-items: center; border-radius: 12px; background: #eeecff; color: var(--primary-dark); font-size: 1.25rem; font-weight: 900; }
.file-thumbnail { width: 68px; height: 68px; flex: 0 0 68px; overflow: hidden; border: 1px solid var(--line); border-radius: 12px; background: var(--surface-soft); }
.file-thumbnail img { display: block; width: 100%; height: 100%; object-fit: cover; }
.file-thumbnail:hover { border-color: var(--primary); }
.file-info { min-width: 0; flex: 1; display: grid; gap: 4px; }
.file-info strong { overflow-wrap: anywhere; }
.file-info span { font-size: .83rem; }
.dropzone { min-height: 142px; place-items: center; align-content: center; text-align: center; padding: 20px; border: 2px dashed #cfd5e2; border-radius: 14px; background: var(--surface-soft); cursor: pointer; transition: border-color .18s, background .18s; }
.dropzone:hover, .dropzone.is-dragging { border-color: var(--primary); background: #f1efff; }
.dropzone input { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.dropzone-title { font-weight: 850; }
.file-queue { display: grid; gap: 10px; }
.file-queue[hidden] { display: none; }
.file-queue-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.selected-files { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; }
.selected-files li { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 11px; background: var(--surface-soft); }
.selected-files li div { min-width: 0; display: grid; gap: 2px; }
.selected-files li strong { overflow-wrap: anywhere; }
.selected-files li span { font-size: .82rem; }
.admin-grid { grid-template-columns: minmax(280px, .7fr) minmax(0, 1.3fr); }
.admin-create-stack { display: grid; gap: 16px; }
.manual-user-create { overflow: hidden; }
.manual-user-create > summary {
    padding: 16px 18px;
    color: var(--primary-dark);
    font-weight: 780;
    cursor: pointer;
}
.manual-user-create-body { padding: 4px 18px 20px; border-top: 1px solid var(--line); }
.manual-user-create-body > p { margin: 16px 0; }
.user-card { display: grid; gap: 14px; padding: 18px; }
.user-summary { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; }
.user-summary p { margin: 3px 0 0; font-size: .86rem; }
.password-reset summary { width: fit-content; color: var(--primary-dark); font-weight: 750; cursor: pointer; }
.password-reset form { margin-top: 14px; }
.invitation-expiry { flex-basis: 100%; font-size: .84rem; }
.profile-sections { display: grid; gap: 24px; }
.settings-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 24px; align-items: start; }
.settings-menu {
    position: sticky;
    top: 92px;
    display: grid;
    gap: 6px;
    padding: 10px;
}
.settings-menu-button {
    width: 100%;
    min-height: 44px;
    padding: 10px 12px;
    border: 1px solid transparent;
    border-radius: 10px;
    background: transparent;
    color: var(--text);
    font: inherit;
    font-weight: 760;
    text-align: left;
    cursor: pointer;
}
.settings-menu-button:hover { border-color: var(--line); background: var(--surface-soft); }
.settings-menu-button.is-active { border-color: #d9d4ff; background: #eeecff; color: var(--primary-dark); }
.settings-panels, .settings-panel { min-width: 0; }
.section-heading.settings-panel-heading { margin-top: 0; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 18px; margin: 34px 0 16px; }
.section-heading h2 { margin-bottom: 0; }
.share-card { margin-bottom: 26px; }
.share-card-compact { margin-bottom: 0; padding: 20px; box-shadow: 0 9px 26px rgba(25,34,56,.06); }
.share-card .content-heading { align-items: flex-start; }
.share-intro { margin-bottom: 0; font-size: .88rem; }
.generated-link { margin: 20px 0; padding: 16px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface-soft); }
.generated-link label { margin-bottom: 8px; }
.generated-link-compact { display: flex; gap: 8px; margin: 10px 0 0; padding: 10px; }
.generated-link-compact input { min-width: 0; padding: 9px 11px; font-size: .82rem; }
.share-empty { margin: 18px 0 0; }
.share-link-list { display: grid; gap: 10px; margin-top: 14px; }
.share-link-row { overflow: hidden; border: 1px solid var(--line); border-radius: 13px; background: var(--surface-soft); }
.share-link-summary { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px; cursor: pointer; list-style: none; }
.share-link-summary::-webkit-details-marker { display: none; }
.share-link-summary > div:first-child { display: grid; gap: 2px; }
.share-link-row span { font-size: .84rem; }
.share-link-toggle { display: inline-flex; flex: 0 0 auto; align-items: center; gap: 6px; color: var(--primary-dark); font-weight: 800; }
.share-link-chevron { display: inline-block; font-size: 1.05rem !important; transition: transform .18s; }
.share-link-row[open] .share-link-chevron { transform: rotate(180deg); }
.share-link-details { padding: 12px; border-top: 1px solid var(--line); background: #fff; }
.share-link-details .generated-link-compact { margin-top: 0; }
.share-link-actions { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }
.share-link-settings { display: grid; grid-template-columns: minmax(0, 1fr); gap: 12px; padding-top: 12px; }
.share-link-settings label { font-size: .82rem; }
.share-link-settings select { padding: 9px 11px; font-size: .85rem; }
.share-link-settings .button { justify-self: start; }
.checkbox-label { display: flex; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 8px; }
.checkbox-label input { width: auto; }
.shared-once-warning { display: grid; gap: 3px; border: 1px solid #f0ad4e; background: #fff1db; color: #844805; }
.shared-readonly-layout { display: block; }

@media (max-width: 840px) {
    .session-grid, .two-column, .admin-grid, .form-grid { grid-template-columns: 1fr; }
    .settings-layout { grid-template-columns: 1fr; }
    .settings-menu { position: static; grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .page-heading { align-items: flex-start; flex-direction: column; }
    .session-heading .actions { width: 100%; }
    .session-title-input { width: min(620px, 75vw); }
}

@media (max-width: 600px) {
    .container { width: min(100% - 22px, 1180px); }
    .page { padding-top: 24px; }
    .nav { gap: 11px; font-size: .86rem; }
    .profile-name { max-width: 90px; }
    .auth-card, .form-card, .session-card { padding: 21px; }
    .session-title-form { align-items: flex-start; flex-wrap: wrap; }
    .session-title-input { width: 100%; font-size: 2rem; }
    .session-title-form.is-editing .session-title-input { width: 100%; }
    .title-edit-controls { align-items: stretch; flex-direction: column; }
    .title-edit-controls input { min-width: 0; }
    .settings-menu-button { text-align: center; }
    .share-link-settings { grid-template-columns: 1fr; align-items: stretch; }
    .checkbox-label { padding-bottom: 0; }
    .generated-link-compact { align-items: stretch; flex-direction: column; }
    .file-card { align-items: flex-start; flex-wrap: wrap; }
    .file-card .actions { width: 100%; padding-left: 0; }
}