static/css/style.css

/* ═══════════════════════════════════════════════════════════════
   BRATS — Brain Tumor Segmentation Interface
   Minimalistic · Sharp Edges · Dark Theme
   ═══════════════════════════════════════════════════════════════ */

/* ── Reset & Base ──────────────────────────────────────────────── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Palette */
    --bg:           #0a0a0f;
    --surface:      #111118;
    --surface-2:    #18181f;
    --border:       #222230;
    --border-hover: #33334a;
    --text:         #e4e4ef;
    --text-dim:     #6e6e82;
    --text-muted:   #3c3c50;
    --accent:       #6c5ce7;
    --accent-glow:  rgba(108, 92, 231, .25);
    --danger:       #e74c3c;
    --danger-bg:    rgba(231, 76, 60, .08);
    --success:      #00d2a0;
    --success-bg:   rgba(0, 210, 160, .08);

    /* Type */
    --font:       'Inter', system-ui, -apple-system, sans-serif;
    --font-mono:  'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --gap: 20px;
}

html {
    font-size: 15px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* ── Ambient Background ────────────────────────────────────────── */
.ambient-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.ambient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(140px);
    opacity: .25;
}

.ambient-orb--1 {
    width: 700px;
    height: 700px;
    background: #6c5ce7;
    top: -250px;
    left: -150px;
    animation: drift 25s ease-in-out infinite alternate;
}

.ambient-orb--2 {
    width: 600px;
    height: 600px;
    background: #00d2a0;
    bottom: -200px;
    right: -150px;
    animation: drift 30s ease-in-out infinite alternate-reverse;
}

.ambient-orb--3 {
    width: 500px;
    height: 500px;
    background: #e74c8b;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: pulse-orb 20s ease-in-out infinite alternate;
}

@keyframes pulse-orb {
    0%   { filter: blur(140px); opacity: .1; }
    100% { filter: blur(160px); opacity: .25; }
}

.ambient-orb--1 {
    width: 600px;
    height: 600px;
    background: var(--accent);
    top: -200px;
    left: -100px;
    animation: drift 20s ease-in-out infinite alternate;
}

.ambient-orb--2 {
    width: 500px;
    height: 500px;
    background: #e74c8b;
    bottom: -150px;
    right: -150px;
    animation: drift 25s ease-in-out infinite alternate-reverse;
}

@keyframes drift {
    0%   { transform: translate(0, 0); }
    100% { transform: translate(60px, 40px); }
}

/* ── Header ────────────────────────────────────────────────────── */
#main-header {
    position: relative;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 32px;
    border-bottom: 1px solid var(--border);
    background: rgba(10, 10, 15, .85);
    backdrop-filter: blur(20px);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-mark {
    width: 28px;
    height: 28px;
    background: var(--accent);
    position: relative;
}

.logo-mark::after {
    content: '';
    position: absolute;
    inset: 5px;
    background: var(--bg);
}

#main-header h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
}

.header-tag {
    font-size: .72rem;
    color: var(--text-dim);
    letter-spacing: .06em;
    text-transform: uppercase;
    padding-left: 12px;
    border-left: 1px solid var(--border);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.status-dot {
    width: 8px;
    height: 8px;
    background: var(--success);
    animation: pulse-dot 2s ease-in-out infinite;
}

.status-dot.processing {
    background: var(--accent);
}

.status-dot.error {
    background: var(--danger);
    animation: none;
}

.status-label {
    font-size: .75rem;
    font-family: var(--font-mono);
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: .05em;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50%      { opacity: .4; }
}

/* ── Main ──────────────────────────────────────────────────────── */
#app-main {
    position: relative;
    z-index: 10;
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 48px 24px 64px;
    gap: 32px;
    width: 100%;
}

/* 🧪 Experimental: Expanded mode when comparing */
#app-main:has(.panel--compare:not(.hidden)) {
    padding-left: 5%;
    padding-right: 5%;
}

/* ── Panel ─────────────────────────────────────────────────────── */
.panel {
    width: 100%;
    max-width: 600px;
    background: rgba(17, 17, 24, 0.65);
    backdrop-filter: blur(28px);
    -webkit-backdrop-filter: blur(28px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4), inset 0 1px 1px rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 36px;
    display: flex;
    flex-direction: column;
    gap: 28px;
    transition: opacity .4s, transform .4s, box-shadow .4s, max-width .6s cubic-bezier(0.4, 0, 0.2, 1);
}

.panel--compare {
    max-width: 1600px !important;
}

.panel:hover {
    box-shadow: 0 20px 56px rgba(0, 0, 0, 0.5), inset 0 1px 1px rgba(255, 255, 255, 0.08);
}

.panel.hidden {
    display: none;
}

.panel-header {
    display: flex;
    align-items: baseline;
    gap: 14px;
}

.panel-number {
    font-family: var(--font-mono);
    font-size: .7rem;
    color: var(--accent);
    letter-spacing: .1em;
}

.panel-header h2 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: .02em;
}

/* ── Field / Select ────────────────────────────────────────────── */
.field label {
    display: block;
    font-size: .7rem;
    text-transform: uppercase;
    letter-spacing: .08em;
    color: var(--text-dim);
    margin-bottom: 8px;
}

.select-wrapper {
    position: relative;
}

.select-wrapper select {
    width: 100%;
    appearance: none;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 0;
    color: var(--text);
    font-family: var(--font-mono);
    font-size: .82rem;
    padding: 10px 14px;
    cursor: pointer;
    transition: border-color .2s;
}

.select-wrapper select:focus {
    outline: none;
    border-color: var(--accent);
}

.select-arrow {
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-dim);
    font-size: .65rem;
    pointer-events: none;
}

/* ── Dropzone ──────────────────────────────────────────────────── */
.dropzone {
    border: 2px dashed var(--border);
    background: var(--surface-2);
    min-height: 220px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    position: relative;
    transition: border-color .2s, background .2s;
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--accent);
    background: rgba(108, 92, 231, .04);
}

.dropzone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 24px;
}

.dropzone-icon {
    color: var(--text-muted);
    transition: color .2s;
}

.dropzone:hover .dropzone-icon {
    color: var(--accent);
}

.dropzone-text {
    font-size: .88rem;
    font-weight: 500;
    color: var(--text-dim);
}

.dropzone-sub {
    font-size: .7rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    letter-spacing: .03em;
}

/* Preview inside dropzone */
.dropzone-preview {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-2);
}

.dropzone-preview img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.btn-clear {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 28px;
    height: 28px;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-dim);
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background .2s, color .2s;
}

.btn-clear:hover {
    background: var(--danger);
    color: #fff;
    border-color: var(--danger);
}

/* ── Buttons ───────────────────────────────────────────────────── */
.btn-primary {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #6c5ce7, #8e44ad);
    border: none;
    border-radius: 8px;
    color: #fff;
    font-family: var(--font);
    font-size: .88rem;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.4);
    transition: all .3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.btn-primary:hover:not(:disabled) {
    background: linear-gradient(135deg, #7d6cf0, #9b59b6);
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.6);
    transform: translateY(-2px);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0px);
}

.btn-primary:disabled {
    opacity: .35;
    cursor: not-allowed;
}

.btn-primary .btn-label {
    transition: opacity .2s;
}

.btn-primary.loading .btn-label {
    opacity: 0;
}

.btn-primary.loading .btn-loader {
    display: block !important;
}

.btn-loader {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255,255,255,.3);
    border-top-color: #fff;
    animation: spin .6s linear infinite;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.btn-secondary {
    width: 100%;
    padding: 12px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-dim);
    font-family: var(--font);
    font-size: .78rem;
    font-weight: 500;
    letter-spacing: .06em;
    text-transform: uppercase;
    cursor: pointer;
    transition: border-color .2s, color .2s;
}

.btn-secondary:hover {
    border-color: var(--text-dim);
    color: var(--text);
}

/* ── Verdict Banner ────────────────────────────────────────────── */
.verdict {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(24, 24, 31, 0.7);
    backdrop-filter: blur(10px);
    transition: all .4s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.verdict.detected {
    border-color: rgba(231, 76, 60, 0.4);
    background: rgba(231, 76, 60, 0.05);
    box-shadow: 0 0 20px rgba(231, 76, 60, 0.15), inset 0 0 10px rgba(231, 76, 60, 0.05);
}

.verdict.clear {
    border-color: rgba(0, 210, 160, 0.4);
    background: rgba(0, 210, 160, 0.05);
    box-shadow: 0 0 20px rgba(0, 210, 160, 0.15), inset 0 0 10px rgba(0, 210, 160, 0.05);
}

.verdict.clear {
    border-color: var(--success);
    background: var(--success-bg);
}

.verdict-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1.3rem;
}

.verdict-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.verdict-title {
    font-weight: 700;
    font-size: .92rem;
    letter-spacing: .02em;
}

.verdict.detected .verdict-title { color: var(--danger); }
.verdict.clear .verdict-title    { color: var(--success); }

.verdict-confidence {
    font-size: .72rem;
    color: var(--text-dim);
    font-family: var(--font-mono);
}

/* ── Image Comparison ──────────────────────────────────────────── */
.comparison {
    display: flex;
    gap: 2px;
    align-items: stretch;
}

.comparison-card {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    transition: transform .3s, box-shadow .3s;
}

.comparison-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.comparison-label {
    display: block;
    font-size: .65rem;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-dim);
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    font-family: var(--font-mono);
}

.comparison-card img {
    width: 100%;
    aspect-ratio: 1 / 1;
    object-fit: contain;
    background: #000;
    display: block;
}

.comparison-divider {
    width: 2px;
    background: var(--border);
    flex-shrink: 0;
}

/* ── Toast ─────────────────────────────────────────────────────── */
.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--danger);
    color: #fff;
    font-size: .78rem;
    padding: 12px 24px;
    z-index: 1000;
    opacity: 0;
    transition: opacity .3s, transform .3s;
    max-width: 460px;
    text-align: center;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ── Footer ────────────────────────────────────────────────────── */
#main-footer {
    position: relative;
    z-index: 10;
    text-align: center;
    padding: 18px;
    border-top: 1px solid var(--border);
    font-size: .68rem;
    color: var(--text-muted);
    letter-spacing: .04em;
    background: rgba(10, 10, 15, .85);
    backdrop-filter: blur(20px);
}

/* ── Utilities ─────────────────────────────────────────────────── */
.hidden {
    display: none !important;
}

/* ── Responsive ────────────────────────────────────────────────── */
@media (max-width: 600px) {
    #main-header {
        padding: 16px 18px;
    }
    .header-tag {
        display: none;
    }
    #app-main {
        padding: 28px 12px 48px;
    }
    .panel {
        padding: 20px 16px;
    }
    .comparison {
        flex-direction: column;
    }
    .comparison-divider {
        width: 100%;
        height: 2px;
    }
}

/* ── Animations ────────────────────────────────────────────────── */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

.panel--results:not(.hidden) {
    animation: fadeIn .45s ease-out;
}

.panel--compare:not(.hidden) {
    animation: fadeIn .45s ease-out;
}

/* ── Compare Button ────────────────────────────────────────────── */
.btn-compare {
    width: 100%;
    padding: 14px 24px;
    margin-top: 8px;
    font-family: var(--font);
    font-size: .92rem;
    font-weight: 600;
    letter-spacing: .03em;
    border: 2px solid var(--accent);
    border-radius: 0;
    background: transparent;
    color: var(--accent);
    cursor: pointer;
    transition: all .2s ease;
    position: relative;
    overflow: hidden;
}

.btn-compare:hover:not(:disabled) {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 0 24px var(--accent-glow);
}

.btn-compare:disabled {
    opacity: .35;
    cursor: not-allowed;
}

.btn-compare.loading .btn-label {
    opacity: 0;
}

.btn-compare.loading .btn-loader {
    display: inline-block;
}

/* ── Compare Panel ─────────────────────────────────────────────── */
.compare-subtitle {
    color: var(--text-dim);
    font-size: .88rem;
    margin-bottom: 20px;
    font-weight: 500;
}

.compare-grid {
    display: flex;
    overflow-x: auto;
    gap: 16px;
    padding-bottom: 20px;
    margin-bottom: 24px;
    /* Custom scrollbar for premium feel */
    scrollbar-width: thin;
    scrollbar-color: var(--border-hover) transparent;
}

.compare-grid::-webkit-scrollbar {
    height: 6px;
}
.compare-grid::-webkit-scrollbar-track {
    background: transparent;
}
.compare-grid::-webkit-scrollbar-thumb {
    background: var(--border-hover);
    border-radius: 10px;
}

.compare-card {
    flex: 0 0 420px; /* Fixed width for horizontal scrolling cards */
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 0;
    overflow: hidden;
    transition: border-color .2s, box-shadow .2s;
}

.compare-card:hover {
    border-color: var(--border-hover);
    box-shadow: 0 4px 24px rgba(0,0,0,.3);
}

.compare-card--detected {
    border-color: rgba(231, 76, 60, .4);
}

.compare-card--detected:hover {
    border-color: var(--danger);
    box-shadow: 0 4px 24px rgba(231, 76, 60, .15);
}

.compare-card--clear {
    border-color: rgba(0, 210, 160, .3);
}

.compare-card--clear:hover {
    border-color: var(--success);
    box-shadow: 0 4px 24px rgba(0, 210, 160, .1);
}

.compare-card--error {
    border-color: rgba(255, 165, 0, .3);
    opacity: .7;
}

.compare-card-header {
    padding: 10px 14px;
    font-family: var(--font-mono);
    font-size: .78rem;
    font-weight: 500;
    color: var(--text-dim);
    text-transform: capitalize;
    background: rgba(0,0,0,.2);
    border-bottom: 1px solid var(--border);
    letter-spacing: .02em;
}

.compare-card-body {
    padding: 12px;
    display: flex; /* Horizontal Card Content */
    gap: 16px;
    align-items: flex-start;
}

.compare-card-img {
    width: 160px; /* Square fixed size for comparison */
    height: 160px;
    flex-shrink: 0;
    border-radius: 0;
    border: 1px solid var(--border);
    object-fit: cover;
}

.compare-card-stats {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.compare-badge {
    display: inline-block;
    padding: 3px 10px;
    font-size: .75rem;
    font-weight: 700;
    letter-spacing: .05em;
    text-transform: uppercase;
    border-radius: 0;
    margin-bottom: 4px;
    width: fit-content;
}

.compare-badge--tumor {
    background: var(--danger-bg);
    color: var(--danger);
    border: 1px solid rgba(231,76,60,.25);
}

.compare-badge--clear {
    background: var(--success-bg);
    color: var(--success);
    border: 1px solid rgba(0,210,160,.25);
}

.compare-badge--error {
    background: rgba(255,165,0,.1);
    color: #ffa500;
    border: 1px solid rgba(255,165,0,.25);
}

.compare-stat {
    font-size: .8rem;
    color: var(--text-dim);
}

.compare-stat strong {
    color: var(--text);
}

.compare-error-msg {
    font-size: .75rem;
    color: var(--text-muted);
    margin-top: 6px;
    word-break: break-word;
}

.compare-card-error-body {
    min-height: 60px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

@media (max-width: 600px) {
    .compare-grid {
        grid-template-columns: 1fr;
    }
}

/* ── Invalid MRI Notice ────────────────────────────────────── */
.invalid-mri-notice {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 48px 32px;
    width: 100%;
    animation: fadeIn .5s ease-out;
}

.invalid-mri-icon {
    font-size: 4rem;
    margin-bottom: 16px;
    filter: grayscale(40%);
    animation: pulse-orb 3s ease-in-out infinite alternate;
}

.invalid-mri-title {
    font-family: var(--font);
    font-size: 1.6rem;
    font-weight: 700;
    color: #ff6b6b;
    margin: 0 0 12px 0;
    letter-spacing: -.01em;
}

.invalid-mri-desc {
    font-size: .95rem;
    color: var(--text-dim);
    max-width: 500px;
    line-height: 1.6;
    margin: 0 0 20px 0;
}

.invalid-mri-hint {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-left: 3px solid var(--accent);
    padding: 14px 20px;
    font-size: .82rem;
    color: var(--text-dim);
    line-height: 1.7;
    text-align: left;
    max-width: 460px;
    margin-bottom: 24px;
    border-radius: 0 8px 8px 0;
}

.invalid-mri-hint strong {
    color: var(--text);
}

.invalid-mri-preview {
    max-width: 180px;
    max-height: 180px;
    border-radius: 8px;
    border: 1px solid var(--border);
    opacity: .35;
    filter: grayscale(80%);
    transition: opacity .3s, filter .3s;
}

.invalid-mri-preview:hover {
    opacity: .7;
    filter: grayscale(30%);
}