/* Modern CSS Reset and Base Styles */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Color Palette */
  --primary-blue: #2563eb;
  --primary-blue-light: #3b82f6;
  --primary-blue-dark: #1d4ed8;
  --secondary-blue: #60a5fa;
  --accent-blue: #93c5fd;

  --white: #ffffff;
  --white-90: rgba(255, 255, 255, 0.9);
  --white-80: rgba(255, 255, 255, 0.8);
  --white-60: rgba(255, 255, 255, 0.6);
  --white-40: rgba(255, 255, 255, 0.4);
  --white-20: rgba(255, 255, 255, 0.2);
  --white-15: rgba(255, 255, 255, 0.15);
  --white-10: rgba(255, 255, 255, 0.1);
  --white-5: rgba(255, 255, 255, 0.05);

  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;

  --red-500: #ef4444;
  --red-600: #dc2626;

  /* Typography */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-family-mono: "JetBrains Mono", "Fira Code", "Cascadia Code",
    "Courier New", monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;

  /* Viewport units with Safari fallbacks */
  --vh: 1vh;
  --vw: 1vw;
}

/* Import Google Fonts */
@import url("https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap");

/* Safari viewport height fix */
@supports (-webkit-appearance: none) {
  :root {
    --vh: 1svh;
  }
}

body {
  font-family: var(--font-family);
  background: linear-gradient(
    135deg,
    var(--gray-900) 0%,
    var(--gray-800) 50%,
    var(--gray-700) 100%
  );
  color: var(--white-90);
  min-height: calc(100 * var(--vh));
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  /* Safari-specific fixes */
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-lg);
  min-height: calc(100 * var(--vh));
  display: flex;
  flex-direction: column;
}

/* Header Styles */
header {
  text-align: center;
  margin-bottom: var(--space-2xl);
  padding: var(--space-lg) 0;
  flex-shrink: 0;
}

header h1 {
  font-size: clamp(2rem, 8vw, 4rem);
  font-weight: 800;
  background: linear-gradient(
    135deg,
    var(--primary-blue) 0%,
    var(--secondary-blue) 50%,
    var(--accent-blue) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.025em;
  line-height: 1.1;
  /* Prevent text selection issues on iOS */
  -webkit-user-select: none;
  user-select: none;
}

.subtitle {
  font-size: clamp(0.875rem, 3vw, 1.25rem);
  color: var(--white-60);
  font-weight: 400;
  letter-spacing: 0.025em;
}

/* Main content area */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* Card Components */
.card {
  background: var(--white-10);
  backdrop-filter: blur(20px);
  border: 1px solid var(--white-20);
  border-radius: var(--radius-2xl);
  padding: var(--space-xl);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-xl);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
  /* Ensure proper stacking on mobile */
  transform: translateZ(0);
  will-change: transform;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--primary-blue),
    transparent
  );
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.card:hover {
  transform: translateY(-2px) translateZ(0);
  box-shadow: var(--shadow-2xl);
  border-color: var(--white-30);
}

.card:hover::before {
  opacity: 1;
}

.card h2 {
  color: var(--primary-blue);
  margin-bottom: var(--space-lg);
  font-size: clamp(1.25rem, 4vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.025em;
}

/* Form Styles */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--space-sm);
  color: var(--white-90);
  font-weight: 600;
  font-size: clamp(0.875rem, 2.5vw, 0.95rem);
  letter-spacing: 0.025em;
}

.form-group input {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: var(--white-10);
  border: 2px solid var(--white-20);
  border-radius: var(--radius-lg);
  color: var(--white-90);
  font-size: clamp(0.875rem, 3vw, 1rem);
  font-family: var(--font-family);
  transition: all var(--transition-normal);
  font-weight: 500;
  /* iOS specific fixes */
  -webkit-appearance: none;
  appearance: none;
  -webkit-border-radius: var(--radius-lg);
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary-blue);
  background: var(--white-15);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
  transform: translateY(-1px);
  /* Prevent zoom on iOS */
  font-size: max(clamp(0.875rem, 3vw, 1rem), 16px);
}

.form-group input::placeholder {
  color: var(--white-40);
  font-weight: 400;
}

.form-group small {
  display: block;
  margin-top: var(--space-sm);
  color: var(--white-50);
  font-size: clamp(0.75rem, 2vw, 0.875rem);
  font-weight: 400;
}

/* Button Styles */
.btn {
  padding: var(--space-md) var(--space-xl);
  border: none;
  border-radius: var(--radius-lg);
  font-size: clamp(0.875rem, 3vw, 1rem);
  font-weight: 600;
  font-family: var(--font-family);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  letter-spacing: 0.025em;
  position: relative;
  overflow: hidden;
  min-height: 48px;
  /* iOS touch target optimization */
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  touch-action: manipulation;
}

.btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left var(--transition-slow);
}

.btn:hover::before,
.btn:focus::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--primary-blue) 0%,
    var(--primary-blue-light) 100%
  );
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover,
.btn-primary:focus {
  background: linear-gradient(
    135deg,
    var(--primary-blue-dark) 0%,
    var(--primary-blue) 100%
  );
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--white-10);
  color: var(--white-90);
  border: 2px solid var(--white-20);
}

.btn-secondary:hover,
.btn-secondary:focus {
  background: var(--white-20);
  border-color: var(--white-30);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-danger {
  background: linear-gradient(135deg, var(--red-500) 0%, var(--red-600) 100%);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-danger:hover,
.btn-danger:focus {
  background: linear-gradient(135deg, var(--red-600) 0%, #b91c1c 100%);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-small {
  padding: var(--space-sm) var(--space-lg);
  font-size: clamp(0.75rem, 2.5vw, 0.875rem);
  min-height: 40px;
}

/* Title Editing */
.title-edit-container {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
  justify-content: center;
  flex-wrap: wrap;
  width: 100%;
}

.title-input {
  background: var(--white-10);
  border: 2px solid var(--white-20);
  border-radius: var(--radius-lg);
  color: var(--white);
  font-size: clamp(1.125rem, 4vw, 1.5rem);
  font-weight: 700;
  font-family: var(--font-family);
  padding: var(--space-md) var(--space-lg);
  text-align: center;
  transition: all var(--transition-normal);
  min-width: min(250px, 100%);
  max-width: min(400px, 100%);
  width: 100%;
  letter-spacing: -0.025em;
  box-sizing: border-box;
  /* iOS specific fixes */
  -webkit-appearance: none;
  appearance: none;
  -webkit-border-radius: var(--radius-lg);
}

.title-input:focus {
  outline: none;
  border-color: var(--primary-blue);
  background: var(--white-15);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
  transform: translateY(-1px);
  /* Prevent zoom on iOS */
  font-size: max(clamp(1.125rem, 4vw, 1.5rem), 16px);
}

.title-input::placeholder {
  color: var(--white-40);
  font-weight: 400;
}

/* Timer Display */
.timer-container {
  text-align: center;
  margin: var(--space-xl) 0;
}

.time-display {
  margin-bottom: var(--space-xl);
  padding: clamp(var(--space-md), 4vw, var(--space-lg));
  background: var(--white-5);
  border-radius: var(--radius-2xl);
  border: 1px solid var(--white-10);
  /* Ensure good performance on mobile */
  will-change: contents;
}

.time-display span {
  font-size: clamp(2rem, 10vw, 4.5rem);
  font-weight: 300;
  font-family: var(--font-family-mono);
  color: var(--primary-blue);
  text-shadow: 0 0 30px rgba(37, 99, 235, 0.3);
  letter-spacing: 0.1em;
  line-height: 1;
  display: block;
  /* Prevent text selection on mobile */
  -webkit-user-select: none;
  user-select: none;
}

.timer-controls {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--space-lg);
}

.timer-info {
  background: var(--white-15);
  border-radius: var(--radius-xl);
  padding: var(--space-lg);
  margin-top: var(--space-lg);
  border: 1px solid var(--white-20);
}

.timer-info p {
  margin-bottom: var(--space-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 500;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--white-15);
  color: var(--white-90);
  font-size: clamp(0.875rem, 2.5vw, 1rem);
  gap: var(--space-md);
}

.timer-info p:last-child {
  margin-bottom: 0;
  border-bottom: none;
}

.timer-info span {
  color: var(--white);
  font-weight: 700;
  font-family: var(--font-family-mono);
  font-size: clamp(0.75rem, 2.5vw, 0.95rem);
  background: var(--primary-blue);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  min-width: 60px;
  text-align: center;
  flex-shrink: 0;
}

/* Loading Spinner */
.loading-spinner {
  width: clamp(40px, 8vw, 48px);
  height: clamp(40px, 8vw, 48px);
  border: 3px solid var(--white-10);
  border-top: 3px solid var(--primary-blue);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--space-lg);
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* Modal Styles */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* Safari-specific viewport fixes */
  width: 100vw;
  height: calc(100 * var(--vh));
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(10px);
  padding: var(--space-lg);
  overflow-y: auto;
  /* iOS scroll behavior fixes */
  -webkit-overflow-scrolling: touch;
}

.modal-content {
  background: var(--white-10);
  backdrop-filter: blur(20px);
  border: 1px solid var(--white-20);
  border-radius: var(--radius-2xl);
  padding: clamp(var(--space-lg), 4vw, var(--space-2xl));
  max-width: min(550px, 90vw);
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  text-align: center;
  box-shadow: var(--shadow-2xl);
  animation: modalSlideIn 0.3s ease-out;
  /* Ensure proper positioning on iOS */
  position: relative;
  margin: auto;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: translateY(-20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.modal-content h2 {
  color: var(--primary-blue);
  margin-bottom: var(--space-2xl);
  font-size: clamp(1.5rem, 5vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.025em;
}

.completion-stats {
  margin-bottom: var(--space-2xl);
  background: var(--white-5);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  border: 1px solid var(--white-10);
}

.stat {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--white-10);
  font-weight: 500;
  gap: var(--space-md);
  font-size: clamp(0.875rem, 2.5vw, 1rem);
}

.stat:last-child {
  border-bottom: none;
}

.stat label {
  color: var(--white-70);
  font-weight: 600;
  flex-shrink: 0;
}

.stat span {
  color: var(--primary-blue);
  font-weight: 700;
  font-family: var(--font-family-mono);
  font-size: clamp(0.875rem, 2.5vw, 1.1rem);
  text-align: right;
}

/* Error Modal */
.error-modal {
  text-align: center;
  max-width: min(450px, 90vw);
}

.error-icon {
  font-size: clamp(2.5rem, 8vw, 4rem);
  margin-bottom: var(--space-lg);
  animation: pulse 2s infinite;
  filter: drop-shadow(0 0 20px rgba(239, 68, 68, 0.3));
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

.error-modal h2 {
  color: var(--red-500);
  margin-bottom: var(--space-lg);
  font-weight: 700;
  font-size: clamp(1.25rem, 4vw, 1.5rem);
}

.error-modal p {
  color: var(--white-80);
  margin-bottom: var(--space-2xl);
  line-height: 1.6;
  font-size: clamp(0.875rem, 3vw, 1.1rem);
  font-weight: 500;
}

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

/* Enhanced Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: var(--space-lg);
  }

  .card {
    padding: var(--space-xl);
    margin-bottom: var(--space-lg);
  }

  .timer-controls {
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .title-edit-container {
    flex-direction: column;
    gap: var(--space-md);
    align-items: stretch;
  }

  .title-input {
    min-width: 100%;
    max-width: none;
    width: 100%;
  }

  .modal {
    padding: var(--space-md);
  }

  .modal-content {
    padding: var(--space-xl);
  }

  .stat {
    flex-wrap: wrap;
    justify-content: flex-start;
  }

  .stat span {
    margin-left: auto;
  }
}

@media (max-width: 480px) {
  .container {
    padding: var(--space-md);
  }

  .card {
    padding: var(--space-lg);
    border-radius: var(--radius-xl);
  }

  .time-display {
    padding: var(--space-md);
  }

  .timer-info {
    padding: var(--space-lg);
  }

  .completion-stats {
    padding: var(--space-lg);
  }

  .stat {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
    text-align: left;
  }

  .stat span {
    margin-left: 0;
    text-align: left;
  }

  .title-input {
    padding: var(--space-sm) var(--space-md);
  }

  .title-edit-container {
    gap: var(--space-sm);
  }

  .timer-info p {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
  }

  .timer-info span {
    align-self: flex-end;
  }
}

/* Focus Management */
.btn:focus-visible,
.form-group input:focus-visible,
.title-input:focus-visible {
  outline: 2px solid var(--primary-blue);
  outline-offset: 2px;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .btn::before {
    display: none;
  }

  .card:hover {
    transform: none;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  .card {
    border: 2px solid var(--white-60);
  }

  .btn {
    border: 2px solid currentColor;
  }

  .form-group input,
  .title-input {
    border: 2px solid var(--white-60);
  }
}

/* Safari-specific optimizations */
@supports (-webkit-appearance: none) {
  /* Fix for Safari's aggressive input styling */
  input[type="text"] {
    -webkit-appearance: none;
    -webkit-border-radius: 0;
  }

  /* Ensure proper backdrop-filter support */
  .card,
  .modal-content {
    -webkit-backdrop-filter: blur(20px);
  }

  /* iOS safe area handling for newer devices */
  .container {
    padding-left: max(var(--space-lg), env(safe-area-inset-left));
    padding-right: max(var(--space-lg), env(safe-area-inset-right));
    padding-bottom: max(var(--space-lg), env(safe-area-inset-bottom));
  }

  .modal {
    padding-left: max(var(--space-lg), env(safe-area-inset-left));
    padding-right: max(var(--space-lg), env(safe-area-inset-right));
    padding-bottom: max(var(--space-lg), env(safe-area-inset-bottom));
  }
}

/* Landscape orientation fixes for mobile */
@media (max-height: 500px) and (orientation: landscape) {
  header {
    margin-bottom: var(--space-lg);
    padding: var(--space-md) 0;
  }

  .card {
    margin-bottom: var(--space-md);
    padding: var(--space-lg);
  }

  .modal-content {
    max-height: 85vh;
    padding: var(--space-lg);
  }

  .time-display {
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
  }
}