:root {
    --ink: #1f2933;
    --muted: #64748b;
    --paper: #fbfaf7;
    --surface: #ffffff;
    --surface-soft: #f3f7f5;
    --line: #d8e0dd;
    --line-strong: #b8c6c0;
    --teal: #0f766e;
    --teal-dark: #115e59;
    --coral: #d75a4a;
    --gold: #b7791f;
    --green: #2f855a;
    --shadow: 0 18px 45px rgba(31, 41, 51, 0.08);
    --shadow-soft: 0 8px 24px rgba(31, 41, 51, 0.06);
}

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

html {
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    background:
        linear-gradient(90deg, rgba(15, 118, 110, 0.045) 1px, transparent 1px),
        linear-gradient(180deg, rgba(15, 118, 110, 0.04) 1px, transparent 1px),
        var(--paper);
    background-size: 34px 34px;
    color: var(--ink);
    font-family: Inter, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.65;
}

a {
    color: var(--teal-dark);
    font-weight: 650;
    text-decoration: none;
    text-underline-offset: 4px;
}

a:hover {
    color: var(--coral);
    text-decoration: underline;
}

button,
input,
select {
    font: inherit;
}

.container {
    width: min(100% - 40px, 1320px);
    margin: 0 auto;
}

header {
    position: sticky;
    top: 0;
    z-index: 100;
    margin-bottom: 28px;
    border-bottom: 1px solid rgba(31, 41, 51, 0.12);
    background:
        linear-gradient(120deg, rgba(17, 94, 89, 0.96), rgba(31, 41, 51, 0.94)),
        repeating-linear-gradient(135deg, rgba(255, 255, 255, 0.12) 0 1px, transparent 1px 14px);
    color: #fff;
    box-shadow: 0 10px 28px rgba(31, 41, 51, 0.16);
}

header .container {
    position: relative;
}

header .container::after {
    content: "";
    position: absolute;
    right: 4px;
    top: 18px;
    width: 210px;
    height: 70px;
    opacity: 0.28;
    background:
        linear-gradient(90deg, transparent 0 11px, rgba(255, 255, 255, 0.7) 11px 12px, transparent 12px 24px),
        linear-gradient(0deg, transparent 0 11px, rgba(255, 255, 255, 0.7) 11px 12px, transparent 12px 24px);
    background-size: 24px 24px;
    pointer-events: none;
}

.header-content {
    min-height: 116px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 24px 0 22px;
}

h1 {
    max-width: 900px;
    font-size: clamp(1.8rem, 3vw, 3rem);
    line-height: 1.08;
    letter-spacing: 0;
    font-weight: 780;
}

.subtitle {
    margin-top: 10px;
    color: rgba(255, 255, 255, 0.84);
    font-size: 0.98rem;
    font-weight: 600;
    text-transform: uppercase;
}

.main-content {
    display: grid;
    grid-template-columns: minmax(280px, 0.85fr) minmax(0, 2.15fr);
    gap: 24px;
    align-items: start;
    margin-bottom: 34px;
}

.sidebar,
.content-area {
    border: 1px solid var(--line);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.92);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(10px);
}

.sidebar {
    position: sticky;
    top: 146px;
    padding: 24px;
}

.content-area {
    padding: 28px;
    overflow: hidden;
}

.section-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--line);
    color: var(--ink);
    font-size: 1.18rem;
    line-height: 1.3;
    font-weight: 780;
}

.section-title::before {
    content: "";
    width: 9px;
    height: 28px;
    flex: 0 0 auto;
    border-radius: 2px;
    background: linear-gradient(180deg, var(--teal), var(--coral));
}

.section-title>span,
.section-title>div {
    margin-left: auto;
}

.about-section .section-title {
    justify-content: flex-start;
    text-align: left;
}

#next-date {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 5px 10px;
    border: 1px solid rgba(15, 118, 110, 0.18);
    border-radius: 999px;
    background: #e8f4f1;
    color: var(--teal-dark);
    font-size: 0.86rem;
    font-weight: 750;
}

.motto-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 20px;
    padding: 14px 16px;
    border: 1px solid rgba(15, 118, 110, 0.18);
    border-radius: 10px;
    background: linear-gradient(135deg, rgba(15, 118, 110, 0.08), rgba(183, 121, 31, 0.08));
    box-shadow: var(--shadow-soft);
}

.motto-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: #e8f4f1;
    color: var(--teal-dark);
    font-size: 0.9rem;
}

.motto-banner p {
    color: var(--teal-dark);
    font-size: 1.05rem;
    font-weight: 750;
    letter-spacing: 0.02em;
    text-align: center;
}

.about-content p {
    margin-bottom: 13px;
    color: #3f4b56;
    font-size: 0.96rem;
}

.about-subtitle {
    margin: 24px 0 9px;
    color: var(--teal-dark);
    font-size: 0.95rem;
    font-weight: 780;
    text-transform: uppercase;
}

.research-areas,
.tutorial-section ul {
    list-style: none;
}

.research-areas {
    display: grid;
    gap: 8px;
    margin-bottom: 16px;
}

.research-areas li {
    position: relative;
    padding-left: 18px;
    color: #465462;
    font-size: 0.93rem;
}

.research-areas li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.68em;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--coral);
}

.tutorial-section {
    margin-top: 22px;
    padding: 18px;
    border: 1px solid rgba(183, 121, 31, 0.24);
    border-radius: 8px;
    background:
        linear-gradient(135deg, rgba(183, 121, 31, 0.1), rgba(15, 118, 110, 0.08)),
        #fffdf7;
}

.tutorial-section h3 {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    color: #734c12;
    font-size: 0.98rem;
}

.tutorial-section h3 i {
    color: var(--gold);
}

.tutorial-section li {
    position: relative;
    padding-left: 17px;
    margin-bottom: 7px;
    color: #4d5560;
    font-size: 0.92rem;
}

.tutorial-section li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.72em;
    width: 8px;
    height: 2px;
    background: var(--gold);
}

.next-meeting-card {
    position: relative;
    margin-bottom: 28px;
    padding: 22px 24px;
    border: 1px solid rgba(15, 118, 110, 0.24);
    border-radius: 8px;
    background:
        linear-gradient(135deg, rgba(15, 118, 110, 0.1), rgba(215, 90, 74, 0.06)),
        #fbfffd;
    box-shadow: var(--shadow-soft);
    overflow: hidden;
}

.next-meeting-card::before {
    content: "";
    position: absolute;
    inset: 0 auto 0 0;
    width: 5px;
    background: linear-gradient(180deg, var(--teal), var(--coral));
}

.next-meeting-card p {
    margin-bottom: 11px;
    color: #334155;
}

.next-meeting-card p:last-child {
    margin-bottom: 0;
}

.next-meeting-card strong {
    color: var(--ink);
}

.next-meeting-card span,
.next-meeting-card a {
    overflow-wrap: anywhere;
}

.filter-options {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-options select,
.filter-options input,
.items-per-page select {
    min-height: 40px;
    border: 1px solid var(--line-strong);
    border-radius: 6px;
    background: #fff;
    color: var(--ink);
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.filter-options select,
.filter-options input {
    min-width: 210px;
    padding: 8px 11px;
    font-size: 0.88rem;
}

.filter-options input {
    min-width: min(330px, 100%);
}

.filter-options select:focus,
.filter-options input:focus,
.items-per-page select:focus {
    border-color: var(--teal);
    box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.15);
}

.refresh-button,
.pagination-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    min-height: 40px;
    border: 1px solid var(--line-strong);
    border-radius: 6px;
    background: var(--surface);
    color: var(--teal-dark);
    cursor: pointer;
    transition: transform 0.18s ease, border-color 0.18s ease, color 0.18s ease, background-color 0.18s ease;
}

.refresh-button {
    padding: 0 12px;
}

.refresh-button:hover,
.pagination-btn:hover:not(:disabled) {
    border-color: var(--teal);
    background: #e8f4f1;
    color: var(--teal-dark);
    transform: translateY(-1px);
}



.archive-cards {
    display: grid;
    gap: 18px;
    margin-top: 12px;
}

.archive-card {
    display: flex;
    flex-direction: column;
    gap: 14px;
    padding: 20px 22px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--surface);
    box-shadow: var(--shadow-soft);
    transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.archive-card:hover {
    border-color: var(--line-strong);
    box-shadow: var(--shadow);
}

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

.card-heading {
    display: flex;
    align-items: baseline;
    gap: 12px;
    flex-wrap: wrap;
    min-width: 0;
}

.card-presenter {
    color: var(--ink);
    font-size: 1.08rem;
    font-weight: 780;
}

.card-date {
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 600;
    white-space: nowrap;
}

.card-topic-row {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    min-width: 0;
}

.card-topic {
    flex: 1 1 auto;
    min-width: 0;
    color: var(--teal-dark);
    font-size: 0.96rem;
    font-weight: 650;
    line-height: 1.5;
}

.card-topic-row .material-link {
    flex: 0 0 auto;
    margin-left: auto;
}

.card-papers {
    display: grid;
    gap: 10px;
}

.paper-item {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 14px;
    padding: 12px 14px;
    border-radius: 8px;
    background: var(--surface-soft);
    border: 1px solid rgba(216, 224, 221, 0.6);
}

.paper-info {
    min-width: 0;
}

.paper-title {
    display: block;
    font-weight: 700;
    color: var(--ink);
    line-height: 1.5;
    overflow-wrap: anywhere;
}

.conf-tag {
    display: inline-flex;
    align-items: center;
    margin-top: 7px;
    padding: 3px 10px;
    border-radius: 999px;
    background: #e8f4f1;
    border: 1px solid rgba(15, 118, 110, 0.16);
    color: var(--teal-dark);
    font-size: 0.78rem;
    font-weight: 650;
    line-height: 1.4;
}

.paper-download-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    flex: 0 0 auto;
    margin-top: 2px;
    color: var(--muted);
    font-size: 0.82rem;
    font-weight: 650;
    white-space: nowrap;
}

.paper-download-link:hover {
    color: var(--coral);
    text-decoration: none;
}

.material-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 30px;
    padding: 5px 12px;
    border: 1px solid rgba(15, 118, 110, 0.22);
    border-radius: 999px;
    background: #e8f4f1;
    color: var(--teal-dark);
    font-size: 0.8rem;
    font-weight: 760;
}

.material-link:hover {
    border-color: var(--coral);
    background: #fff1ee;
    color: var(--coral);
    text-decoration: none;
}

.pagination-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-top: 20px;
    padding-top: 18px;
    border-top: 1px solid var(--line);
}

.pagination-buttons {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.pagination-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.page-info {
    min-width: 94px;
    color: var(--muted);
    font-size: 0.9rem;
    text-align: center;
}

.items-per-page {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--muted);
    font-size: 0.9rem;
}

.items-per-page select {
    min-height: 38px;
    padding: 6px 10px;
}

.loading-indicator,
.error-message,
.warning-message {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin: 12px 0;
    padding: 18px;
    border-radius: 8px;
    font-size: 0.92rem;
}

.loading-indicator {
    border: 1px solid rgba(15, 118, 110, 0.2);
    background: #eef9f6;
    color: var(--teal-dark);
}

.loading-indicator i {
    color: var(--teal);
    animation: spin 1.1s linear infinite;
}

.error-message {
    border: 1px solid rgba(215, 90, 74, 0.28);
    background: #fff1ee;
    color: #b43f32;
}

.warning-message {
    justify-content: flex-start;
    border: 1px solid rgba(183, 121, 31, 0.28);
    background: #fff8e8;
    color: #7a4d0b;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

footer {
    margin-top: 32px;
    padding: 24px 0 30px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    text-align: center;
    font-size: 0.86rem;
}

.footer-link {
    color: var(--teal-dark);
}

.data-info,
.stats-container,
.stat-card,
.next-meeting-container,
.view-display-btn,
.material-links {
    display: none;
}

@media (max-width: 1020px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }
}

@media (max-width: 820px) {
    .container {
        width: min(100% - 28px, 1320px);
    }

    header {
        position: relative;
    }

    header .container::after {
        display: none;
    }

    .header-content {
        min-height: auto;
        padding: 22px 0;
    }

    .content-area,
    .sidebar {
        padding: 18px;
    }

    .section-title {
        align-items: flex-start;
        flex-wrap: wrap;
    }

    .section-title::before {
        height: 24px;
    }

    .section-title>div,
    .section-title>span {
        width: 100%;
        margin-left: 0;
    }

    .filter-options {
        justify-content: stretch;
    }

    .filter-options select,
    .filter-options input,
    .refresh-button {
        width: 100%;
        min-width: 100%;
    }

    .archive-card {
        padding: 16px 16px;
    }

    .paper-item {
        flex-direction: column;
        gap: 8px;
    }

    .pagination-controls {
        align-items: stretch;
        flex-direction: column;
    }

    .pagination-buttons,
    .items-per-page {
        justify-content: center;
    }
}

@media (max-width: 520px) {
    body {
        font-size: 15px;
    }

    .container {
        width: min(100% - 20px, 1320px);
    }

    h1 {
        font-size: 1.72rem;
    }

    .subtitle {
        font-size: 0.82rem;
    }

    .main-content {
        gap: 16px;
    }

    .pagination-buttons {
        display: grid;
        grid-template-columns: repeat(4, minmax(40px, 1fr));
    }

    .page-info {
        grid-column: 1 / -1;
        order: -1;
        width: 100%;
    }
}