/* Modern flat UI (responsive base) */

:root {
    /* Theme tokens (default: dark) */
    --bg: #0b1220;
    --bg-grad-1: rgba(96, 165, 250, 0.18);
    --bg-grad-2: rgba(167, 139, 250, 0.18);
    --surface: rgba(255, 255, 255, 0.06);
    --panel: rgba(255, 255, 255, 0.08);
    --panel-solid: #0f172a;
    --text: rgba(255, 255, 255, 0.92);
    --muted: rgba(255, 255, 255, 0.68);
    --border: rgba(255, 255, 255, 0.12);
    --border-strong: rgba(255, 255, 255, 0.16);
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    --radius: 16px;
    --radius-sm: 12px;
    --gap: 16px;
    --accent: #60a5fa;
    --accent-2: #a78bfa;
    --danger: #fb7185;
    --focus: 0 0 0 3px rgba(96, 165, 250, 0.35);
    --header-bg: rgba(11, 18, 32, 0.72);
    --control-bg: rgba(255, 255, 255, 0.06);
    --control-bg-hover: rgba(255, 255, 255, 0.09);
    --card-border: rgba(255, 255, 255, 0.12);
    --card-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.05));
    --frame-bg: rgba(0, 0, 0, 0.12);
    --link-underline: rgba(255, 255, 255, 0.18);
    color-scheme: dark;
}

/* Auto theme (light system) */
@media (prefers-color-scheme: light) {
    :root {
        --bg: #f6f7fb;
        --bg-grad-1: rgba(59, 130, 246, 0.12);
        --bg-grad-2: rgba(124, 58, 237, 0.10);
        --surface: rgba(15, 23, 42, 0.04);
        --panel: rgba(15, 23, 42, 0.05);
        --panel-solid: #ffffff;
        --text: rgba(15, 23, 42, 0.92);
        --muted: rgba(15, 23, 42, 0.64);
        --border: rgba(15, 23, 42, 0.12);
        --border-strong: rgba(15, 23, 42, 0.18);
        --shadow: 0 10px 30px rgba(2, 6, 23, 0.10);
        --focus: 0 0 0 3px rgba(59, 130, 246, 0.25);
        --header-bg: rgba(246, 247, 251, 0.78);
        --control-bg: rgba(15, 23, 42, 0.04);
        --control-bg-hover: rgba(15, 23, 42, 0.06);
        --card-border: rgba(15, 23, 42, 0.12);
        --card-bg: linear-gradient(180deg, rgba(15, 23, 42, 0.02), rgba(15, 23, 42, 0.04));
        --frame-bg: rgba(15, 23, 42, 0.04);
        --link-underline: rgba(15, 23, 42, 0.20);
        color-scheme: light;
    }
}

/* Manual override */
html[data-theme="dark"] {
    --bg: #0b1220;
    --bg-grad-1: rgba(96, 165, 250, 0.18);
    --bg-grad-2: rgba(167, 139, 250, 0.18);
    --surface: rgba(255, 255, 255, 0.06);
    --panel: rgba(255, 255, 255, 0.08);
    --panel-solid: #0f172a;
    --text: rgba(255, 255, 255, 0.92);
    --muted: rgba(255, 255, 255, 0.68);
    --border: rgba(255, 255, 255, 0.12);
    --border-strong: rgba(255, 255, 255, 0.16);
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    --focus: 0 0 0 3px rgba(96, 165, 250, 0.35);
    --header-bg: rgba(11, 18, 32, 0.72);
    --control-bg: rgba(255, 255, 255, 0.06);
    --control-bg-hover: rgba(255, 255, 255, 0.09);
    --card-border: rgba(255, 255, 255, 0.12);
    --card-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.05));
    --frame-bg: rgba(0, 0, 0, 0.12);
    --link-underline: rgba(255, 255, 255, 0.18);
    color-scheme: dark;
}

html[data-theme="light"] {
    --bg: #f6f7fb;
    --bg-grad-1: rgba(59, 130, 246, 0.12);
    --bg-grad-2: rgba(124, 58, 237, 0.10);
    --surface: rgba(15, 23, 42, 0.04);
    --panel: rgba(15, 23, 42, 0.05);
    --panel-solid: #ffffff;
    --text: rgba(15, 23, 42, 0.92);
    --muted: rgba(15, 23, 42, 0.64);
    --border: rgba(15, 23, 42, 0.12);
    --border-strong: rgba(15, 23, 42, 0.18);
    --shadow: 0 10px 30px rgba(2, 6, 23, 0.10);
    --focus: 0 0 0 3px rgba(59, 130, 246, 0.25);
    --header-bg: rgba(246, 247, 251, 0.78);
    --control-bg: rgba(15, 23, 42, 0.04);
    --control-bg-hover: rgba(15, 23, 42, 0.06);
    --card-border: rgba(15, 23, 42, 0.12);
    --card-bg: linear-gradient(180deg, rgba(15, 23, 42, 0.02), rgba(15, 23, 42, 0.04));
    --frame-bg: rgba(15, 23, 42, 0.04);
    --link-underline: rgba(15, 23, 42, 0.20);
    color-scheme: light;
}

* {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Noto Sans SC", "PingFang SC",
        "Microsoft YaHei", Arial, sans-serif;
    background: radial-gradient(circle at 20% 10%, var(--bg-grad-1) 0%, transparent 55%),
        radial-gradient(circle at 90% 20%, var(--bg-grad-2) 0%, transparent 60%), var(--bg);
    background-repeat: no-repeat;
    color: var(--text);
}

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

iframe {
    border: 0;
}

.site {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 80;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 16px clamp(14px, 4vw, 48px);
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.header-right {
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.logo-wrap {
    display: inline-flex;
    align-items: center;
    gap: 12px;
}

.logo {
    width: 44px;
    height: 44px;
    border-radius: 999px;
    border: 1px solid var(--border);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.25);
}

.nav-toggle {
    appearance: none;
    border: 1px solid var(--border);
    background: var(--control-bg);
    color: var(--text);
    border-radius: 999px;
    padding: 10px 12px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.nav-toggle:focus {
    outline: none;
    box-shadow: var(--focus);
}

.nav-toggle-bar {
    width: 18px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    display: block;
}

.nav-toggle-text {
    font-size: 14px;
    color: var(--muted);
}

.theme-toggle {
    appearance: none;
    border: 1px solid var(--border);
    background: var(--control-bg);
    color: var(--text);
    border-radius: 999px;
    padding: 10px 12px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.theme-toggle:focus {
    outline: none;
    box-shadow: var(--focus);
}

.theme-toggle-text {
    font-size: 14px;
    color: var(--muted);
    white-space: nowrap;
}

.nav {
    display: none; /* mobile drawer in mobile.css */
}

.nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 10px;
}

.nav-item a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 14px;
    border-radius: 999px;
    border: 1px solid transparent;
    color: var(--text);
    background: var(--control-bg);
    transition: transform 0.12s ease, background-color 0.12s ease, border-color 0.12s ease;
}

.nav-item a:hover {
    transform: translateY(-1px);
    border-color: var(--border-strong);
    background: var(--control-bg-hover);
}

.nav-item a:focus {
    outline: none;
    box-shadow: var(--focus);
}

/* Layout */
.layout {
    width: 100%;
    max-width: 1240px;
    margin: 0 auto;
    padding: 18px clamp(14px, 4vw, 48px) 28px;
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--gap);
    flex: 1;
}

.panel {
    border-radius: var(--radius);
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    overflow: hidden;
}

/* Content panel */
#content {
    padding: 18px;
    min-height: 360px;
}

.content-header {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 14px;
}

#appcenter {
    margin: 0;
    font-size: 26px;
    letter-spacing: 0.2px;
}

.content-subtitle {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.app-grid {
    display: grid;
    gap: 12px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.app-card {
    border-radius: var(--radius-sm);
    border: 1px solid var(--card-border);
    background: var(--card-bg);
    padding: 14px;
    min-height: 88px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 8px;
    transition: transform 0.12s ease, border-color 0.12s ease, background-color 0.12s ease;
}

.app-card:hover {
    transform: translateY(-2px);
    border-color: rgba(96, 165, 250, 0.35);
}

.app-title {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.2;
}

.app-title::after {
    content: "→";
    opacity: 0.7;
    font-weight: 700;
}

.app-tag {
    margin: 0;
    font-size: 12px;
    color: var(--muted);
}

.content-frame {
    width: 100%;
    height: 100%;
    min-height: 520px;
    border-radius: var(--radius-sm);
    background: var(--frame-bg);
}

/* Sidebar */
#sidebar {
    padding: 18px;
}

.sidebar-box {
    display: grid;
    gap: 14px;
}

.sidebar-top p {
    margin: 0;
    font-size: 18px;
    font-weight: 650;
}

.sidebar-top span {
    color: var(--muted);
    line-height: 1.7;
}

#easteregg a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    border: 1px solid var(--border);
    padding: 8px 12px;
    background: var(--control-bg);
}

/* Banner */
#main {
    min-height: 300px;
}

/* Footer */
.footer {
    padding: 18px clamp(14px, 4vw, 48px);
    border-top: 1px solid var(--border);
    background: var(--header-bg);
    backdrop-filter: blur(12px);
}

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

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
    justify-content: flex-end;
}

.footer-item {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
}

.footer-item a {
    color: var(--text);
    border-bottom: 1px solid var(--link-underline);
}

.footer-row-muted {
    margin-top: 8px;
}

/* Desktop layout */
@media (min-width: 1080px) {
    .nav-toggle {
        display: none;
    }

    .nav {
        display: block;
    }

    .layout {
        grid-template-columns: 300px 1fr 360px;
        grid-template-areas: "sidebar content banner";
        align-items: start;
    }

    #sidebar {
        grid-area: sidebar;
    }

    #content {
        grid-area: content;
    }

    #main {
        grid-area: banner;
    }

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

@media (min-width: 1320px) {
    .app-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (max-height: 460px) {
    .content-subtitle {
        display: none;
    }
}