/**
 * Selection Studio — Studio Hub V1
 * Location: /studio/css/studio-hub.css
 *
 * Responsibility:
 * - Cold Boot Hub presentation
 * - Create / Open / Library mode navigation
 * - Experience / Page dual-context layout
 * - Responsive Hub foundation
 */

#studio-shell.is-hidden,
#studio-hub.is-hidden {
    display: none !important;
}

.studio-hub {
    width: 100%;
    height: 100vh;
    min-height: 0;
    overflow-x: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;

    padding:
        clamp(var(--space-5), 5vw, var(--space-8)) var(--space-5);

    background:
        radial-gradient(circle at 50% 0%,
            rgba(37, 57, 76, 0.78) 0,
            rgba(15, 23, 30, 0.92) 38%,
            var(--color-bg-canvas) 76%);

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

.hub-frame {
    width: min(1120px, 100%);
    min-height: calc(100vh - 128px);
    margin: 0 auto;
    padding-bottom: var(--space-8);

    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

/* =========================================================
   HEADER
   ========================================================= */

.hub-header {
    display: flex;
    flex-direction: column;
    align-items: center;

    margin-block:
        clamp(var(--space-5), 5vh, var(--space-8));

    text-align: center;
}

.hub-mark {
    display: block;
    width: 36px;
    height: 36px;
    margin-bottom: var(--space-4);

    object-fit: contain;
}

.hub-heading {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hub-brand {
    margin-bottom: var(--space-4);

    color: var(--color-accent);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.hub-title {
    max-width: 760px;
    margin: 0;

    color: var(--color-text-primary);
    font-size: clamp(34px, 5vw, 52px);
    font-weight: 520;
    line-height: 1.08;
    letter-spacing: -0.045em;
}

.hub-subtitle {
    max-width: 620px;
    margin: var(--space-4) auto 0;

    color: var(--color-text-secondary);
    font-size: 15px;
    line-height: var(--line-height-relaxed, 1.65);
}

/* =========================================================
   PRIMARY MODE CARDS
   ========================================================= */

.hub-mode-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-4);

    margin-bottom: var(--space-6);
}

.hub-mode-card {
    appearance: none;

    position: relative;
    display: flex;
    flex-direction: column;
    align-items: flex-start;

    min-width: 0;
    min-height: 190px;
    padding: var(--space-5);

    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-large);

    background:
        linear-gradient(145deg,
            rgba(255, 255, 255, 0.045),
            rgba(255, 255, 255, 0.018));

    color: var(--color-text-primary);
    font: inherit;
    text-align: left;

    cursor: pointer;

    transition:
        transform var(--motion-normal) var(--ease-standard),
        border-color var(--motion-normal) var(--ease-standard),
        background-color var(--motion-normal) var(--ease-standard),
        box-shadow var(--motion-normal) var(--ease-standard);
}

.hub-mode-card:hover {
    transform: translateY(-2px);

    border-color: var(--color-border-strong);

    background-color: rgba(255, 255, 255, .04);

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

.hub-mode-card:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 3px;
}

.hub-mode-card.is-active {
    border-color: var(--color-accent-border);

    background:
        linear-gradient(145deg,
            rgba(212, 180, 131, 0.11),
            rgba(212, 180, 131, 0.035));

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

.hub-mode-label {
    margin-bottom: auto;

    color: var(--color-accent);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.11em;
    text-transform: uppercase;
}

.hub-mode-card strong {
    display: block;
    margin-top: var(--space-6);

    color: var(--color-text-primary);
    font-size: 20px;
    font-weight: 590;
    line-height: 1.25;
    letter-spacing: -0.025em;
}

.hub-mode-card small {
    display: block;
    margin-top: var(--space-3);

    color: var(--color-text-secondary);
    font-size: 13px;
    line-height: 1.55;
}

/* =========================================================
   MODE WORKSPACE
   ========================================================= */

.hub-workspace {
    min-width: 0;
}

.hub-mode-panel[hidden] {
    display: none !important;
}

.hub-mode-panel {
    padding: var(--space-6);

    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-large);

    background: rgba(15, 23, 30, 0.78);
    box-shadow: var(--shadow-medium);

    animation:
        hub-panel-enter var(--motion-slow) var(--ease-standard);
}

@keyframes hub-panel-enter {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hub-panel-header {
    max-width: 680px;
    margin-bottom: var(--space-6);
}

.hub-panel-header h2 {
    margin: 0;

    color: var(--color-text-primary);
    font-size: clamp(24px, 3vw, 32px);
    font-weight: 550;
    line-height: 1.2;
    letter-spacing: -0.035em;
}

.hub-panel-header p {
    margin: var(--space-3) 0 0;

    color: var(--color-text-secondary);
    font-size: 14px;
    line-height: 1.65;
}

/* =========================================================
   EXPERIENCE / PAGE CONTEXT
   ========================================================= */

.hub-context-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-5);
}

.hub-context-column {
    min-width: 0;
}

.hub-context-label {
    display: block;
    margin-bottom: var(--space-3);

    color: var(--color-text-muted);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.hub-action-card {
    padding: var(--space-5);

    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-medium);

    background:
        linear-gradient(180deg,
            rgba(255, 255, 255, .03),
            rgba(255, 255, 255, .015));
}

.hub-action-card+.hub-action-card {
    margin-top: var(--space-3);
}

.hub-action-card h3 {
    margin: 0;

    color: var(--color-text-primary);
    font-size: 17px;
    font-weight: 590;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

.hub-action-card p {
    margin: var(--space-2) 0 0;

    color: var(--color-text-secondary);
    font-size: 13px;
    line-height: 1.55;
}

.hub-action-card.is-future {
    opacity: 0.62;
}

/* =========================================================
   CREATE FORM
   ========================================================= */

.hub-form {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: var(--space-2);

    margin-top: var(--space-5);
}

.hub-form input {
    width: 100%;
    min-width: 0;
    height: 44px;
    padding: 0 var(--space-4);

    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-medium);

    background: var(--color-bg-input);
    color: var(--color-text-primary);

    font: inherit;
    font-size: 13px;
    outline: none;

    transition:
        border-color var(--motion-fast) var(--ease-standard),
        box-shadow var(--motion-fast) var(--ease-standard);
}

.hub-form input::placeholder {
    color: var(--color-text-muted);
}

.hub-form input:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.hub-button {
    appearance: none;

    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);

    min-height: 44px;
    padding: 0 var(--space-5);

    border: 0;
    border-radius: var(--radius-medium);

    background: var(--color-accent);
    color: var(--color-bg-canvas);

    font: inherit;
    font-size: 13px;
    font-weight: 700;
    white-space: nowrap;

    cursor: pointer;

    transition:
        filter var(--motion-fast) var(--ease-standard),
        transform var(--motion-fast) var(--ease-standard),
        opacity var(--motion-fast) var(--ease-standard);
}

.hub-button:hover {
    filter: brightness(1.08);
}

.hub-button:active {
    transform: translateY(1px);
}

.hub-button:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 3px;
}

.hub-button:disabled {
    opacity: 0.52;
    cursor: wait;
}

/* =========================================================
   EXPERIENCE LIST
   ========================================================= */

.hub-experience-list {
    display: grid;
    gap: var(--space-2);

    max-height: 360px;
    overflow-y: auto;
    padding-right: var(--space-1);
}

.hub-experience-row {
    appearance: none;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);

    width: 100%;
    min-height: 52px;
    padding: var(--space-3) var(--space-4);

    border: 1px solid transparent;
    border-radius: var(--radius-medium);

    background: rgba(255, 255, 255, 0.03);
    color: var(--color-text-primary);

    font: inherit;
    text-align: left;

    cursor: pointer;

    transition:
        background-color var(--motion-fast) var(--ease-standard),
        border-color var(--motion-fast) var(--ease-standard),
        transform var(--motion-fast) var(--ease-standard);
}

.hub-experience-row:hover {
    border-color: var(--color-accent-border);
    background: var(--color-accent-soft);
}

.hub-experience-row:active {
    transform: translateY(1px);
}

.hub-experience-row:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 2px;
}

.hub-experience-row:disabled {
    opacity: 0.52;
    cursor: wait;
}

.hub-experience-row>span {
    min-width: 0;
    overflow: hidden;

    color: var(--color-text-primary);
    font-size: 13px;
    font-weight: 540;

    text-overflow: ellipsis;
    white-space: nowrap;
}

.hub-experience-row small {
    flex: 0 0 auto;

    color: var(--color-text-secondary);
    font-size: 11px;
}

/* =========================================================
   STATUS / EMPTY / ERROR
   ========================================================= */

.hub-status,
.hub-empty,
.hub-error {
    display: flex;
    align-items: center;
    justify-content: center;

    min-height: 120px;
    padding: var(--space-5);

    border: 1px dashed var(--color-border-default);
    border-radius: var(--radius-medium);

    background: rgba(255, 255, 255, 0.018);

    color: var(--color-text-muted);
    font-size: 13px;
    line-height: 1.55;
    text-align: center;
}

.hub-error {
    border-color: rgba(255, 105, 97, 0.28);
    color: var(--color-danger);
}

/* =========================================================
   SCROLLBAR
   ========================================================= */

.studio-hub::-webkit-scrollbar,
.hub-experience-list::-webkit-scrollbar {
    width: 6px;
}

.studio-hub::-webkit-scrollbar-track,
.hub-experience-list::-webkit-scrollbar-track {
    background: transparent;
}

.studio-hub::-webkit-scrollbar-thumb,
.hub-experience-list::-webkit-scrollbar-thumb {
    border-radius: var(--radius-pill);
    background: rgba(255, 255, 255, 0.1);
}

/* =========================================================
   RESPONSIVE
   ========================================================= */

@media (max-width: 900px) {
    .hub-mode-grid {
        grid-template-columns: 1fr;
    }

    .hub-mode-card {
        min-height: 0;
    }

    .hub-mode-card strong {
        margin-top: var(--space-5);
    }

    .hub-context-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .studio-hub {
        padding: var(--space-5) var(--space-4);
    }

    .hub-frame {
        min-height: auto;
        justify-content: flex-start;
    }

    .hub-header {
        margin-bottom: var(--space-6);
    }

    .hub-title {
        font-size: 34px;
    }

    .hub-subtitle {
        font-size: 14px;
    }

    .hub-mode-card {
        padding: var(--space-5);
    }

    .hub-mode-panel {
        padding: var(--space-5);
    }

    .hub-form {
        grid-template-columns: 1fr;
    }

    .hub-button {
        width: 100%;
    }
}

@media (prefers-reduced-motion: reduce) {
    .hub-mode-panel {
        animation: none;
    }

    .hub-mode-card,
    .hub-button,
    .hub-experience-row,
    .hub-form input {
        transition-duration: 1ms;
    }
}