/* ==========================================================
   IH4 - Design System & Stylesheet
   Modern, Clean, High-Fidelity UI with Glassmorphism & Animations
   ========================================================== */

:root {
    --bg-main: #0b0f19;
    --bg-card: rgba(17, 24, 39, 0.85);
    --bg-card-border: rgba(255, 255, 255, 0.08);
    --bg-input: rgba(15, 23, 42, 0.7);
    --bg-input-hover: rgba(30, 41, 59, 0.8);
    --bg-dropzone: rgba(15, 23, 42, 0.4);
    --bg-dropzone-hover: rgba(56, 189, 248, 0.06);

    --primary: #38bdf8;
    --primary-hover: #0ea5e9;
    --primary-glow: rgba(56, 189, 248, 0.35);
    --secondary: #818cf8;
    
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --text-dim: #64748b;
    
    --danger: #f43f5e;
    --danger-bg: rgba(244, 63, 94, 0.12);
    --danger-border: rgba(244, 63, 94, 0.4);

    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.12);
    --success-border: rgba(16, 185, 129, 0.4);

    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-pill: 9999px;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', monospace, Consolas, sans-serif;

    --shadow-card: 0 25px 50px -12px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.06);
    --shadow-glow: 0 0 30px rgba(56, 189, 248, 0.15);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html, body {
    min-height: 100%;
    width: 100%;
    font-family: var(--font-sans);
    background-color: var(--bg-main);
    color: var(--text-main);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Ambient Background Mesh */
.app-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.grid-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(rgba(255, 255, 255, 0.08) 1px, transparent 1px);
    background-size: 32px 32px;
    opacity: 0.6;
    mask-image: radial-gradient(circle at 50% 30%, black 40%, transparent 80%);
    -webkit-mask-image: radial-gradient(circle at 50% 30%, black 40%, transparent 80%);
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(110px);
    opacity: 0.28;
    animation: pulseGlow 12s infinite alternate ease-in-out;
}

.glow-orb-1 {
    width: 550px;
    height: 550px;
    background: radial-gradient(circle, #38bdf8 0%, transparent 70%);
    top: -120px;
    left: 50%;
    transform: translateX(-65%);
}

.glow-orb-2 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, #6366f1 0%, transparent 70%);
    top: 200px;
    left: 50%;
    transform: translateX(-35%);
    animation-delay: -5s;
}

.glow-orb-3 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #0284c7 0%, transparent 70%);
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    animation-delay: -9s;
}

@keyframes pulseGlow {
    0% { transform: translate(-50%, -20px) scale(0.9); opacity: 0.2; }
    100% { transform: translate(-45%, 30px) scale(1.15); opacity: 0.32; }
}

/* Main Container & Centered Layout */
.app-container {
    position: relative;
    z-index: 1;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 56px 16px 88px 16px;
    gap: 44px;
}

/* Hero Section */
.hero-header {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    max-width: 680px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    color: #bae6fd;
    background: rgba(56, 189, 248, 0.1);
    border: 1px solid rgba(56, 189, 248, 0.3);
    padding: 6px 16px;
    border-radius: var(--radius-pill);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.15);
    backdrop-filter: blur(8px);
}

.pulse-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--success);
    box-shadow: 0 0 10px var(--success);
    animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.3); opacity: 0.6; }
}

.hero-headline {
    font-size: 2.75rem;
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.035em;
    color: #ffffff;
}

.gradient-text {
    background: linear-gradient(135deg, #38bdf8 0%, #818cf8 50%, #c084fc 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subheadline {
    font-size: 1.05rem;
    color: var(--text-muted);
    line-height: 1.6;
    max-width: 580px;
}

.card {
    width: 100%;
    max-width: 500px;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-radius: var(--radius-lg);
    box-shadow: 0 30px 60px -15px rgba(0, 0, 0, 0.8), 0 0 50px rgba(56, 189, 248, 0.12);
    padding: 36px 32px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    transition: var(--transition);
    position: relative;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 10%;
    right: 10%;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.6), transparent);
}

/* App Header inside Card */
.app-header {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

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

.brand-logo {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: linear-gradient(135deg, #0284c7 0%, #6366f1 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
}

.brand-title {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: #ffffff;
}

.brand-tagline {
    font-size: 0.82rem;
    color: var(--text-dim);
    font-weight: 500;
}

/* Navigation Pill Switch */
.mode-toggle-wrapper {
    display: flex;
    justify-content: center;
}

.mode-toggle {
    position: relative;
    display: flex;
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid var(--bg-card-border);
    border-radius: var(--radius-pill);
    padding: 4px;
    width: 100%;
    max-width: 320px;
    user-select: none;
}

.pill-slider {
    position: absolute;
    top: 4px;
    left: 4px;
    height: calc(100% - 8px);
    width: calc(50% - 4px);
    background: linear-gradient(135deg, rgba(56, 189, 248, 0.15) 0%, rgba(99, 102, 241, 0.2) 100%);
    border: 1px solid rgba(56, 189, 248, 0.4);
    border-radius: var(--radius-pill);
    box-shadow: 0 2px 10px rgba(56, 189, 248, 0.2);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1;
    pointer-events: none;
}

.mode-toggle[data-active="receive"] .pill-slider {
    transform: translateX(100%);
}

.tab-button {
    flex: 1;
    position: relative;
    z-index: 2;
    background: none;
    border: none;
    padding: 10px 16px;
    font-family: var(--font-sans);
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--text-muted);
    border-radius: var(--radius-pill);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: color 0.2s ease;
}

.tab-button:hover {
    color: var(--text-main);
}

.tab-button.active {
    color: #ffffff;
}

.tab-button:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Panels */
.panels-container {
    position: relative;
    min-height: 250px;
}

.tab-panel {
    display: none;
    opacity: 0;
    transform: translateY(6px);
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.tab-panel.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* ================= SEND PANEL ================= */
.dropzone {
    border: 2px dashed rgba(255, 255, 255, 0.16);
    border-radius: var(--radius-md);
    background: var(--bg-dropzone);
    padding: 40px 24px;
    text-align: center;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    transition: var(--transition);
    outline: none;
}

.dropzone:hover, .dropzone:focus-visible {
    border-color: var(--primary);
    background: var(--bg-dropzone-hover);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.1);
}

.dropzone.drag-over {
    border-color: var(--primary);
    background: rgba(56, 189, 248, 0.12);
    transform: scale(1.015);
    box-shadow: 0 0 30px rgba(56, 189, 248, 0.25);
}

.dropzone.dropzone-error {
    border-color: var(--danger) !important;
    background: var(--danger-bg) !important;
    box-shadow: 0 0 20px rgba(244, 63, 94, 0.2) !important;
}

.dropzone-icon-wrapper {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.dropzone:hover .dropzone-icon-wrapper, .dropzone.drag-over .dropzone-icon-wrapper {
    transform: translateY(-4px);
    color: #ffffff;
    background: var(--primary);
}

.dropzone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.dropzone-primary-text {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.5;
}

.dropzone-highlight {
    color: var(--text-main);
    font-weight: 600;
}

.browse-link {
    color: var(--primary);
    text-decoration: underline;
    text-underline-offset: 3px;
    font-weight: 600;
}

.file-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px;
    margin-top: 4px;
}

.file-badge {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    letter-spacing: 0.02em;
    transition: var(--transition);
}

.dropzone:hover .file-badge, .dropzone.drag-over .file-badge {
    color: var(--text-muted);
    border-color: rgba(56, 189, 248, 0.2);
    background: rgba(56, 189, 248, 0.05);
}

/* Constraint Notice (Crucial) */
.constraint-text {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 14px;
    font-size: 0.82rem;
    color: var(--text-dim);
    text-align: center;
}

.constraint-text svg {
    flex-shrink: 0;
    color: var(--primary);
}

/* Progress View */
.progress-card {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--bg-card-border);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
}

.progress-filename {
    font-weight: 600;
    color: var(--text-main);
    max-width: 260px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.progress-percentage {
    font-family: var(--font-mono);
    color: var(--primary);
    font-weight: 700;
}

.progress-bar-track {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-pill);
    overflow: hidden;
    position: relative;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #38bdf8 0%, #6366f1 100%);
    border-radius: var(--radius-pill);
    transition: width 0.15s ease;
}

.progress-status {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
}

/* Success View */
.success-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 16px;
    animation: fadeIn 0.3s ease;
}

.success-badge {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--success-bg);
    border: 1px solid var(--success-border);
    color: var(--success);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 25px rgba(16, 185, 129, 0.25);
}

.success-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
}

.success-filename {
    font-size: 0.88rem;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
    padding: 4px 12px;
    border-radius: var(--radius-pill);
    max-width: 100%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Massive 4-digit code display */
.code-display-box {
    width: 100%;
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(56, 189, 248, 0.3);
    border-radius: var(--radius-md);
    padding: 20px;
    margin: 6px 0;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.4), 0 0 25px rgba(56, 189, 248, 0.1);
}

.code-digits {
    font-family: var(--font-mono);
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: 0.3em;
    padding-left: 0.3em;
    color: #ffffff;
    text-shadow: 0 0 20px rgba(56, 189, 248, 0.6);
}

.success-subtext {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--text-dim);
}

.success-subtext svg {
    color: var(--primary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 600;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    cursor: pointer;
    border: none;
    transition: var(--transition);
    text-decoration: none;
}

.btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.btn-primary {
    background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #0369a1 0%, #1d4ed8 100%);
    box-shadow: 0 6px 20px rgba(2, 132, 199, 0.5);
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-copy.copied {
    background: linear-gradient(135deg, #059669 0%, #10b981 100%) !important;
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4) !important;
    color: #ffffff !important;
    border-color: transparent !important;
}

.code-actions-wrapper {
    display: flex;
    gap: 12px;
    width: 100%;
    align-items: stretch;
}

.code-actions-wrapper .btn {
    flex: 1 1 0;
    min-width: 0;
    padding: 12px 14px;
    font-size: 0.92rem;
    white-space: nowrap;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-main);
    border: 1px solid var(--bg-card-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.14);
    transform: translateY(-1px);
}

.btn-text {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 0.88rem;
    font-family: var(--font-sans);
    cursor: pointer;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    transition: color 0.2s ease;
}

.btn-text:hover {
    color: var(--text-main);
    text-decoration: underline;
}

/* ================= RECEIVE PANEL ================= */
.receive-view {
    display: flex;
    flex-direction: column;
    gap: 20px;
    align-items: center;
}

.otp-instruction {
    text-align: center;
}

.otp-headline {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 4px;
}

.otp-subtext {
    font-size: 0.88rem;
    color: var(--text-muted);
}

/* 4 OTP Input Boxes */
.otp-container {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin: 8px 0;
}

.otp-box {
    width: 64px;
    height: 68px;
    background: var(--bg-input);
    border: 1.5px solid var(--bg-card-border);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    color: #ffffff;
    transition: var(--transition);
    outline: none;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.otp-box:hover {
    background: var(--bg-input-hover);
    border-color: rgba(255, 255, 255, 0.2);
}

.otp-box:focus {
    border-color: var(--primary);
    background: rgba(15, 23, 42, 0.95);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.25), inset 0 2px 4px rgba(0, 0, 0, 0.4);
    transform: translateY(-2px);
}

.otp-box.error-state {
    border-color: var(--danger) !important;
    background: var(--danger-bg) !important;
    color: #fecdd3 !important;
    box-shadow: 0 0 0 3px rgba(244, 63, 94, 0.3) !important;
}

/* Shake Error Animation */
.shake-error {
    animation: shakeAnim 0.5s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

@keyframes shakeAnim {
    0%, 100% { transform: translateX(0); }
    15%, 45%, 75% { transform: translateX(-8px); }
    30%, 60%, 90% { transform: translateX(8px); }
}

/* Error Banner */
.error-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    background: var(--danger-bg);
    border: 1px solid var(--danger-border);
    color: #fecdd3;
    padding: 10px 16px;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 500;
    text-align: center;
    width: 100%;
    animation: fadeIn 0.2s ease;
}

.error-icon {
    flex-shrink: 0;
    color: var(--danger);
}

/* Loader */
.loader-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 0.88rem;
    color: var(--primary);
    padding: 8px;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2.5px solid rgba(56, 189, 248, 0.2);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Card Footer */
.app-card-footer {
    display: flex;
    justify-content: center;
    margin-top: 8px;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

/* Destruction Notice */
.destruct-notice {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--success-bg);
    border: 1px solid var(--success-border);
    color: #a7f3d0;
    padding: 12px 18px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
}

.destruct-notice svg {
    flex-shrink: 0;
    color: var(--success);
}

.security-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.76rem;
    color: var(--text-dim);
    letter-spacing: 0.02em;
}

.security-tag svg {
    color: var(--success);
}

/* ================= INFORMATIVE SECTIONS ================= */
.info-wrapper {
    width: 100%;
    max-width: 860px;
    display: flex;
    flex-direction: column;
    gap: 64px;
}

.info-section {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.section-header {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.section-tag {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 4px 12px;
    border-radius: var(--radius-pill);
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    border: 1px solid rgba(56, 189, 248, 0.25);
}

.section-tag-security {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.25);
}

.section-title {
    font-size: 1.65rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

.section-subtitle {
    font-size: 0.95rem;
    color: var(--text-muted);
    max-width: 540px;
    line-height: 1.5;
}

/* Steps Grid */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.step-card {
    position: relative;
    background: rgba(17, 24, 39, 0.6);
    border: 1px solid var(--bg-card-border);
    backdrop-filter: blur(12px);
    border-radius: var(--radius-md);
    padding: 28px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: var(--transition);
}

.step-card:hover {
    border-color: rgba(56, 189, 248, 0.3);
    transform: translateY(-2px);
    box-shadow: 0 12px 30px -10px rgba(0, 0, 0, 0.5);
}

.step-badge {
    position: absolute;
    top: 14px;
    right: 16px;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.2);
}

.step-icon-box {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.step-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-main);
}

.step-desc {
    font-size: 0.86rem;
    color: var(--text-muted);
    line-height: 1.55;
}

/* FAQ List */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.faq-item {
    background: rgba(17, 24, 39, 0.5);
    border: 1px solid var(--bg-card-border);
    border-radius: var(--radius-md);
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: rgba(255, 255, 255, 0.15);
}

.faq-question {
    font-size: 0.96rem;
    font-weight: 600;
    color: var(--text-main);
}

.faq-answer {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.55;
}

/* Global Footer */
.global-footer {
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    display: flex;
    justify-content: center;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-main);
}

.footer-logo-text {
    font-weight: 700;
    color: var(--primary);
}

.footer-sep {
    color: var(--text-dim);
}

.footer-desc {
    color: var(--text-muted);
    font-weight: 400;
}

.footer-copy {
    font-size: 0.78rem;
    color: var(--text-dim);
}

/* Utility Helpers */
.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .app-container {
        padding: 32px 16px 64px 16px;
        gap: 40px;
    }

    .steps-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-headline {
        font-size: 2rem;
    }

    .hero-subheadline {
        font-size: 0.95rem;
    }

    .card {
        padding: 28px 20px;
        gap: 20px;
    }

    .brand-title {
        font-size: 1.25rem;
    }

    .section-title {
        font-size: 1.35rem;
    }

    .otp-container {
        gap: 8px;
    }

    .otp-box {
        width: 54px;
        height: 60px;
        font-size: 1.75rem;
    }

    .code-digits {
        font-size: 2.8rem;
        letter-spacing: 0.2em;
    }

    .code-actions-wrapper {
        gap: 8px;
    }

    .code-actions-wrapper .btn {
        padding: 10px 8px;
        font-size: 0.84rem;
        gap: 6px;
    }
}